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Questions related to Climate Dynamics
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I came across a lot of peer-reviewed journal articles and most of the authors have concluded there is a climate change phenomena happening by applying Mann-Kendall Trend test on Hydro-Metrological variables (rainfall, temperature). It has to noted that Mann-Kendall is a statistical technique which on applied to dataset (including time series) shows whether there is a monotonic increasing or decreasing trend & whether that trend so arrived is statistically significant or not ?
My question is that how we can conclude the trend detected is due to climate change only without citing any physical process/phenomena (like Teleconnections) drives this change ?, that too based on Statistical test (Mann-Kendall) at a particular Level of significance (LOS).
The LOS applied is also statistically subjective and the value can vary from person to person?
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Climate change is a reality, but we must found a reference to be sur about the tendency of change. No one can explain which is the next step for climate change.
The statistical test can not respond to a dynamique change.
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What kind of scientific research dominate in the field of Global warming?
Please, provide your suggestions for a question, problem or research thesis in the issues: Global warming.
Please reply.
I invite you to the discussion
Best wishes
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The cost and benefits of global warming will vary greatly from area to area. For moderate climate change, the balance can be difficult to assess. But the larger the change in climate, the more negative the consequences will become. Global warming will probably make life harder, not easier, for most people. This is mainly because we have already built enormous infrastructure based on the climate we now have.
Climate Q&A - Why is global warming a problem? (nasa.gov)
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If we take the Mediterranean, its not one distinct climate it varies greatly from east to west and north to south. The north is more temperate-like with rainfall more dispersed throughout the year while the south drier with more heavy rainy spells. This surely would have an impact on the way green roofs perform .
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The performance of substrates are extensively analyzed in the following paper:
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Global warming affects many processes in biological ecosystems.
Different species of flora and fauna change their habitats and geographical areas according to climate change and specific geographical environments.
Areas of occurrence of specific species, for example insects in terrestrial areas and fish and arthropods in the seas and oceans, change.
For example bird habitats change, so migrations of some bird species may also be subject to modification. In the situation when forest areas dry out and turn into steppes and deserts, changes in natural habitats and areas of occurrence of species change and concern simultaneously many species of flora and fauna.
Do you agree with me on the above matter?
In the context of the above issues, I am asking you the following question:
What changes in natural ecosystems are caused by the ongoing global warming process?
Please reply
I invite you to the discussion
Thank you very much
Best wishes
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Dariusz Prokopowicz still learning from your questions...thanks
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Many observations and calculations of the atmospheric absorption can be found, but it would appear very few studies on climate had explicitly applied the basic radiative transfer equation in different forms, including scattering and atmospheric radiation. If you know any relevent references or your own papers to share, that would be wonderful.
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Y.C. Zhong thank you so much for your valuable comments.
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In connection with the warming of the Earth's climate, progressive global warming, some areas located in the sub-tropical zone in the future will not be fit for existence, and the migration processes of the population will be intensified.
Do you agree with my opinion?
Please reply
Best wishes
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El calentamiento global es un fenómeno físico q puede ocurrir al deterioro de la capa de ozono. Los científicos y expertos buscaran una solución para conservar la vida en el planeta Tierra. Por ahora debemos protegernos de los rayos solares y el cuidado del medio ambiente.
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Although determining the origin of sand storms on the Earth as well as possible, But it is difficult for dust storms.  Because this storm covers a large surface area and the specific days, and also dust storms do not always originate from sand dunes.
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The good choice is by screening the weather satellite images.
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According to a theoretical Greenhouse Gas Effect of 0 with 0ppm CO-equivalents the global temperature were 0°F or -18°C.
Due to the fact, all natural systems tend to show a maximum threshold value instead of infinite growth I wonder if there is a value of CO-equivalents that causes the maximum Greenhouse Gas Effect related to the current Energy output of the sun.
If there is an investigation or estimation on this value, how high is it and how high is the resulting rise in temperature?
Assuming a theoretical scenario with:
Energy Output of Sun = constant
Circulation System of Earth = constant
time = infinite
CO-equivalents = infinite
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Yes i assumed my result also to be a very low estimation. my numbers are widely used for surface radiation and downwelling radiation, also in the first fig in the paper you cited.
My approach was to calculate the ratio of both of them and then assume, that a ratio of 1 was equal to a "100%" GHG-Effect where all the radiation is absorbed and reflected downwards. But I assume I lack alot of understanding where these numbers come from.
You mentioned Venus. Are there similar estimations for W/m² for our neighbour planet? If we have a GHGE of +33°C, then how strong is it on Venus? How much of the 450°C does the GHGE contribute.
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Decades of rising emissions continued to do what scientists have long warned they would: make the world hotter.
Indeed, the 2010s mark the decade when the impacts from climate change became unmistakable, at least for any objective-minded observer.
Carbon dioxide from fossil fuels, which makes up about 90% of total emissions from human activities, was relatively flat from 2013 through 2016.
However, Fossil-fuel emissions rose an estimated 0.6% to a record 37 billion metric tons in 2019, capping three straight years of growth.
Sea-level rise is accelerating!!
The planet got a lot hotter this decade!!
Most countries have done very little so far to displace the power plants, cars, factories, and buildings polluting the atmosphere with more emissions each year.
In your view, is the world doing enough on climate change?
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I do not believe it is. Many people and companies are seeing the signs and disregarding them.
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(specifically into the mountain area)
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Interesting insights on the matter may be provided by the ESPON SUPER project (Sustainable Urbanisation and Land Use in European Regions).
The inception report is published already, and the interim report should follow in a month or so.
Hope this helps!
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Nafiseh Pegahfar Thank you very much.
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Currently (end of January, beginning of February 2019) in Australia the heat of the centuries has been recorded reaching in some places to almost 50 ° C, and in the USA, in some places now winter has appeared with frosts reaching around minus 50 degrees C.
In recent years, various weather anomalies have appeared more and more.
The recorded increase in weather anomalies and climatic cataclysms may be a derivative of the progressing greenhouse effect, ie the warming of the Earth's climate. This is also confirmed by the numerous climatic cataclysms and weather anomalies that also occurred in the last year of 2018 appear in numerous places on the Earth. In the autumn of 2018, fires of huge forest areas appeared in some areas of the Earth, such as in Scandinavia, California in the USA, Australia, the Iberian Peninsula, Africa, etc. In addition, weather anomalies, e.g. snow and floods in October and November 2018 occurred in the south of Europe. In addition, numerous tornadoes in 2018 in many places on Earth and so on.
Perhaps these problems will get worse. It is necessary to improve security systems and anti-crisis services, improve the prediction of these anomalies and climatic cataclysms so that people can, have managed to get shelter or cope with an imminent cataclysm. One of the technologies that can help in more precise forecasting of these cataclysms is the processing of large collections of historical and current information on this subject in the cloud computing technology in Big Data database systems.
In view of the above, in connection with the increasingly frequent cataclysms and climatic anomalies, perhaps in the future we will be forced to change our assessment of particular seasons, and for example favorite in some climatic zones, summer will no longer be universally recognized as a positive season, if at this time will often appear increasingly higher temperatures, droughts, fires, tornadoes, etc.
In connection with the above, I would like to ask you:
Are the current weather anomalies the effect of global warming?
Please reply
Best wishes
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There is a clear distinction between weather and climate. To define a climate, it is necessary thirty years or more of methodological observations of meteorological variables.
With respect to Climate, see the Figures of pages 14 and 15 in the link below, relative to the annual precipitation in Praia, Cape Verde, between the period 1886 to 2006.
According to World Meteorological Organization (2009): “Guidelines on
Analysis of extremes in a changing climate in support of informed decisions for adaptation”, it is written in Page 37, https://www.ecad.eu/documents/WCDMP_72_TD_1500_en_1.pdf
“The detection of changes in extremes is difficult because they are rare, and thus the amount of information available for analysis is limited. Nevertheless, failure to detect changes in extremes at a given location does not mean that the frequency or intensity of extremes is not changing.
(…)
It is important to note that large uncertainties and gaps in our knowledge of climate change
remain, particularly concerning extremes on regional and local scales.”
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Do you think that the desert environments considered as a lab for future cities?
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Not just because of climate change but with the increased deforestation that it's occurring at Brazil, for exemple, the desert environments can take place with serious negative impacts at the hydrologic others biogeochemical cycles. The deforestation has impact at water, fauna and flora, regional weather, climate change, soil quality, etc.
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I'm trying to calculate rainfall anomaly from monthly rainfall measurements taken between 1997 and 2017 at a single location in Panama (subjected to highly seasonal rainfall as well as El Niño-derived fluctuations in rainfall). My data is one measurement per month per year; 20 values for January (1997-2017), 20 for February, and so on. I have attached a screen shot of the first few rows of data if further clarification is needed.
I am aware of the common anomaly technique of subtracting the long term mean from the actual value and dividing by the standard deviation [(x-xbar)/stdev], but as I understand it this should only be used on normally distributed data.
My issue is that while SOME of my months have normally distributed (gaussian) rainfall over the sampling period, others do not - some are uniformly distributed, some are lognormal. I'm not clear on whether I can use the same anomaly calculation for these different distributions, or if it's appropriate to transform the data. It seems inappropriate to use different anomaly calculations on different months, since I want to eventually compare anomalies from different months together.
I am new to this type of data so I am feeling a bit out of my depth. Any advice would be appreciated - thank you!
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Dear Emma Young,
In the attached pdf, there is a lot of useful information I believe can help you.
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The climate is changing for sure. However, the question is how much CO2 contributing to the phenomenon. Do we know enough about other possible drivers? Is there any research which focused on all possible drivers of climate change and their proportion of contribution?
Looking for your kind suggestions and discussions
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Can you please help me understand the relationships?
1. Concentration of CO2 is increasing in atmosphere (well-mixed greenhouse gas)
2. Well-mixed means newly added CO2 has spread in the atmosphere homogeneously
3. Newly added CO2 has additional capacity to contribute in atmospheric warming
CO2 is a GHG, concentration of CO2 in atmosphere is continuously increasing, and we are calculating their impact after they got well-mixed in the atmosphere. If so, why the world experiencing extreme hot in New Zealand and extreme cold in USA.
As I can understand, In presence of additional CO2 in the atmosphere, temperature in any part of the world must not fall below average.
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Isn't temperature fall and down related to geological and astronomical dynamics rather than anthropogenic!
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Main drivers for Change in temperature are deterministics.
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When polar jet stream has southward shift mandering happens, it leads to polar vortex.
It is also true that the magnitude of polar vortex depends on the temperature difference between poles and mid-latitudes.
Moreover, the southward shift of jet stream is related to the southward shift of ITCZ (Intertropical Convergence Zone)
Then, Why polar vortex is not a regular phenomenon?
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Totally agreed with Matthew Mabey . It is a regular phenomenon but complicated and a broad field of study. Just let's add a comment about its dynamics. One fundamental feature of polar vortex is its nonlinear evolution of its instability in diabatic and adiabatic environments. The growth of instability and the most unstable mode of a polar vortex in gamma plane can define the crudest features of the vortex. The stationary state of zonal velocity in 'geostrophic balance' can specify the most unstable mode based on the linear stability analysis that is not universal and varies for each planet.
For more information and having a big picture about underlying dynamics of polar vortex and polar jets on Earth and other planets like Mars or Saturn and vortex in general, I propose to read some relevant articles like:
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The report of the International Panel on Climate Change (IPCC) shows that greenhouse gas levels on the globe are the highest in 800,000 years. Further emission, which arises according to the authors of the report mainly due to the combustion of fossil fuels, will lead to climate changes, which will be the greater, the more intensive will be the release of gases into the atmosphere. The report is a synthesis of earlier findings of the IPCC.
The conducted prognostic analyzes show that if the industrial development proceeds in the same way as before, i.e. without the implementation of eco-innovations, without reducing greenhouse gas emissions, etc. there is a risk that by 2050 the average temperature on the Earth's surface may increase by another one degrees ° C. It would have been an increase in the average temperature on the surface of the Earth from the end of the first industrial revolution, from the beginning of the 20th century by two degrees ° C. Then the pace of climate change will increase so much that the global warming process can escape any control and then the person will not be able to stop or significantly slow down this process. In such a dark scenario, the average temperature on the surface of the Earth until the end of the twenty-first century may increase by as much as four degrees ° C. Then it will be several times the increase of any negative external effects of climate change on the current state. Slak of emerging climatic cataclysms, including tornadoes, droughts, volcanic eruptions, melting of glaciers in chains of mountain peaks and in the arctic circle region at the Arctic will significantly accelerate. The melting of eternal decay in the Arctic region will release further millions of tons of methane and the greenhouse effect will accelerate even further and in the XXII century an increase in the average temperature on the Earth's surface can achieve a geometric pace. Then it will be a disaster not only for human civilization but also for a large part of life forms on Earth. Pradoxically, man as a rational, intelligent being who, evolutionarily gained an advantage over all other forms of life on Earth and subordinated the whole planet to itself, may lead to self-destruction. Or maybe it is not too late to implement a new eco-friendly economy to at least try to stop greenhouse gas emissions and reverse unfavorable global warming processes? It is therefore necessary to promote and implement the principles of sustainable development within the framework of the new green economy.
Please reply. I invite you to the discussion
Chart. Global Warming. CO2 emissions of greenhouse gases, a forecast of the increase in the average temperature on Earth. Source: NOAA, NASA.
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Hi,
the predictions above are for the near term (next 5 years). They are based on current levels of greenhouse gases and give current chances of temporarily exceeding 1.5degrees above preindustrial.
Thanks
Adam
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Since the beginning of the 20th century, the average temperature on the Earth has increased by 1 ° C
Therefore, the greenhouse effect of the Earth has already begun.
Greenhouse gas emissions have increased in recent decades.
As a result, the global warming process accelerates.
The climate is warming, and therefore more and more climatic cataclysms are emerging.
Droughts and declining areas of agricultural crops are a serious threat.
Will these adverse climate changes be deepened?
In connection with the above, it is particularly important to answer the question: How many degrees ° C the will increase the average temperature on the Earth by the end of the 21st century?
Please reply. I invite you to the discussion
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Following
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Dear Researchers,
I would like to ask that Please guide me by sharing your knowledge and expert opinion "Which is the good tool for Extreme Climate Indices Analysis".
Kind Regards
Naveed.
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RClimdex as suggested by Sania is useful for this work
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We would like to invite you to contribute with your original research articles, reviews, and technical notes to the Special Issue "Climate prediction of extreme events" in the journal Geosciences.
More information can be found at:
Deadline for manuscript submissions: 31 August 2019
We are looking forward to your valuable contribution,
Dr. Marco Turco
Dr. Sonia Jerez
Guest Editors
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Certainly climate predictions do not allow forecasting the specific location/day an extreme event will occur. However they can inform about the probability of occurrence of climatic anomalies for the next months and seasons based on dynamical or empirical models. For instance, climate predictions provide probabilistic information about whether next season will be more, equal or less warm and/or humid than usual.
Traditionally these forecast systems provide monthly anomalies. However, forecasting statistics of extreme events, such as the number of frost/hot days within a season, can be more useful for industries and end-users due to their potential for damaging. In spite of the increasing interest in estimating the ability of forecast systems to predict extreme events, little work has been performed so far on the topic.
We hope that this special issue will provide new insight into this strategic issue.
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Machine Learning as a tool for Meteorology.
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Hello Mukesh, in Ireland we used machine learning for removal of systematic errors (i.e., systematic bias removal) from windspeed forecasts for wind-farms. As forecasts are made and then validated, a history of forecast errors builds up over time, and the "machine" can "learn" from this history to identify and then correct what it finds to be systematic errors - leading to systematically more accurate forecasts. We used the R package implementation of Bayes Model Averaging (BMA) to do this. See our papers on this at and You may be able to think of other applications for this (or similar) methods.
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Can any one direct me on a trusted website about data of station based precipitation archive (monthly) between 1950-2010?
especially in Africa
thx
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Hi
You can find WMO observatory data for entire globe in this link https://www7.ncdc.noaa.gov/CDO/cdoselect.cmd?datasetabbv=GSOD
The data is up to date. But the range 1950-2010 you are looking may be available with some of the listed stations.
HTH!
Vijay
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Would the gradual melting of Earth's glaciers, due to the greenhouse effect, cause a further increase of the SLR?
If not, what happen to that water?
How ocean currents contribute to the phenomenon?
I offer my thanks in advance to all those who will answer for the attention.
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There is a lot of confusion in the answers to this question. Let us all recall the main question being asked: 
– Would the gradual melting of Earth's glaciers, due to the greenhouse effect, cause a further increase of the SLR?
There are 2 main causes of global sea level rise resulting from the greenhouse effect:
1. Melting of land-based ice (permafrost, valley glaciers, and ice sheets) flowing into the ocean
and
2. Volumetric thermal expansion of oceanic water due to increased global temperature
So, yes melting glaciers on land does increase the rate of SLR, however the amount of water stored in the greenland ice sheet and in the permafrost is much greater that the amount of water being stored in valley glaciers. Thermal expansion also plays an important role and will get worse as time goes on, even after all the land based cryosphere melts.
– How ocean currents contribute to the phenomenon?
Ocean currents drive local climate conditions (i.e. Europe being warmer than Canada at the same Latitude), and therefore with warming ocean currents, there is a positive feedback with the rate of cryospheric melt. There are other ways that the destabilization of the global thermohaline circulation can be effected by the addition of less dense freshwater to the currents, but this is a long subject to discuss.
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I am actually thinking about different variables linked to each others. When I assume temperature will increase hence the convection so the winds can be slower than the present. But at the same time the height of planetary boundary layer might increase from its normal value, which can compensate the whole changes and brings the atmosphere in normal condition. By the way it is not so easy to think as it involves important role of time and space. Discussion on it is valuable.
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Dear Annu Panwar,
Winds and planetary layer dynamics are best investigated using complex climate models of the atmosphere and oceans. In such models, all variables are related each with other on the physical and mathematical most correct way. Before that should set the initial conditions of the model in accordance with the purpose of research. For example, see the link:https://www.researchgate.net/publication/273139935_Modelling_of_the_Aral_and_Caspian_seas_drying_out_influence_to_climate_and_environmental_changes
Regards,
Milivoj B. Gavrilov
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What is the role of the predictability of the MOC on the N. European Climate
How much of the MOC predictability is atmosphere led ( see Roberts 2013)
How much is due to re-emergence of the atmospheric forced SST anomalies the following year ?  
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Dear Neil Christopher Wells,
The deterministic predictability of the atmosphere is limited to about 12 days (Thompson 1957; Lorenz 1969a, 1969b, 1973 - References in link below). This is practically demonstrated in the work Gavrilov, Jovanovic and Janjic (2011).
Regards,
Milivoj B. Gavrilov
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I would like to observe the mesoscopic characteristics of earth and rock contact interface in the earth-rock aggregate during the direct shear test. Is there any possibility?
Thank you all
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Hello,
I don't know if there is any specific measuring device for your problem. I think you have to build something by your own. One possibility is to "cut" the direct shear testing device and place a massive Plexiglass sheet on the open site. Then you can observe the shearing process with a digital camera.
Best regards
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Dear all,
I'd like to know how are defined on a surface map the position of fronts (cold and warm) that we find on meteorological surface pressure maps (see link). I want to plot those fronts at a specific time during a cyclone (low pressure), see the attached pdf file upper panel.
Is there a specific criterion to define those front positions?
I'm using ECMWF ERA-20C reanalysis data so I have access to many parameters. I've tried dew point temperature gradient (norm) to find the brutal change in temperature and moisture associated with warm front without great success. Maybe a specific isoline of dew point temperature? I'm using 1 degree gridded data, maybe my resolution is too coarse?
Thanks in advance,
Nicolas
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Dear Nicolas,
The position of atmospheric fronts on weather maps are determined with more surface meteorological parameters, such as: forms of sea level pressure, the tendency of pressure, temperature, types of clouds, precipitation, wind and humidity; and with more upper parameters, such as: pressure, temperature, wind and humidity. Also, these parameters are different for cold, warm and occluded fronts. In addition, the position of the front is determined the orographic obstacles. Products numerical weather prediction not contain explicitly positions of atmospheric fronts. On these products positions of fronts are drawn later with the help of the general criteria of recognizing fronts. This is usually done by specialists, synoptic meteorologist. He draws the position of the front with the help of synoptic experience. Thus, the position of atmospheric fronts is not completely objective atmospheric parameter. Determination of the position of the front is partly based on subjective experience synoptic meteorologist. The criteria for the position of fronts are best learned in the courses offered " Weather Analysis", and / or "Synoptic Meteorology", and then in practice. Also, the criteria for determining the front can be found in books of similar titles (e.g. Djuric, D., 1994: Weather Analysis. Prentice-Hall, New Jersey, p. 304.)
Best,
M.B.Gavrilov
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Hello 
I am preparing a manuscrit on farmer's perceptions about climate variability in Côte d'Ivoire and I need climate data in order to compare the perceptions to climate data!
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Ditto to what George said above. If you use R, follow this link for an easy way to work with the GSOD data.
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I have netcdf-files with daily precipitation values ("rr"), one file for every single day which means there would be 30-31 files for every month. I want to get site specific information about monthly precipitation, which mean I need to extract values at a specific latitude and longitude from every file (see attchment for information about data). Do someone have any suggestions on how to do this in an efficient way, so I don´t need to open one and one file?
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Dear Vikane Sir,
See the following steps.
Step-1: Concatenate all the files in CDO. Install CDO in Linux/Ubuntu. The command is- 
 cdo -r -f nc copy ifile1.nc  ifile2.nc ifile3.nc ....... ofile.nc
Alternatively, merge all files in R. Check this website. 
Step-2: Retrieve the data from a single location using regrid() function in R. For that you have to install 'esd' package available in github. See 
P.S.: If you know CDO and R both or only R, it's a matter of 15-minute job. I can help you if you will provide me 2 to 3 of your .nc files.
Happy to help. Cheers.  
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I am trying to quantify the performance of a decadal climate forecast compared to observations for a number of variables (e.g., temperature, precipitation, geopotential hight, and others).is there any good paper discussing completely around applicable metrics or measures on decadal scale?
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Hope it helps you :-)
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It is believed that clays can control the formation of red tides. Therefore, construction of dams that can reduce the discharge of clays into the marine bodies, may be considered as one of the reasons for the fomation of red tides. Does dust fall control the formation of red tides? In the recent years, due to the lower precipitations, many marshes in middle east region are fully or partially dried. These marshes are now the main source of atmospheric dusts in the region. Sometimes the concentration of such dust particles can reach to as high as 3000 mg/m3.
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Yes, it can be a significant source of nutrient supply during red tide
period. To gain more information, you can refer to the following publications:
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Dear all
I am doing seasonal simulation of monsoon (~5 months) with climate model. As per my knowledge spin up time of a model is very important for the reliability of the model output for further study. I have found that there is very little literature regarding the spin up time for seasonal scale simulation. Everybody taken some amount of time (10days - 1 month) model simulation as spin up  and excluded that from their analysis without proper justification or figures regarding that. Some literature can be found for long term simulation but I didn't found no literature for seasonal scale simulation. How to see/figure out that? I want to justify what is the amount of time I need to take as spin up and why? Any kind of clue in this regard will be highly appreciated.
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Dear Suman,
The spin up time is the time the model takes for the input/ouput values of an annual to reach a steady state. However, if you are doing a seasonal model then it will not reach a steady state because it is part of an annual cycle which is continually changing throughout the seasonal cycle.
You will have to incorporate your model within an annual model and run the annul model for several years until it reaches a steady state. Running a seasonal model, March through June, will always give the same results for every run since input values for March will always be the same. The output values form June are not suitable as input values for March. For March you need the output values for February which you do not have.
HTH,
Cheers, Alastair.
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The soil moisture changes are in West Jilin Province, China.
I calculate the mean soil moisture time series from the GLDAS four models(CLM, Mosaic, Noah and VIC). The West Jilin Province locates 43N-46N, 122E-126E. Thanks for your attention. 
This case also appear in Moiwo's paper.
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Wetting and drying are the two processes that keep this earth alive. At the end of rainy season: October, the earth is completely wet. From November onwards earth keeps on progressively drying and at end of May(before rainy season starts) earth is completely dried with visible cracks on soft soil. Hence moisture content in soil will go on diminishing as we pass from November to May(with October maximum and May minimum). This fact is applicable to NORTHERN hemisphere only.In SOUTHERN hemisphere minimum moisture in atmosphere and also in soil will be in month of October and maximum in month of May. This phenomenon is associated and accompanied with raining phase on earth's surface.
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3 out of 4 extinction events were caused by a build-up of methane hydrates in the atmosphere.  We are seeing an increase of methane with the melting of permafrost.  With the continued increase of warming and the admission by climate scientists that the warming event is accelerating this should be a huge concern.
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Karyl,
You say three out of four extinctions were caused by methane hydrates. Could you itemise them, please. As far as I know only the PETM event has been blamed on methane hydrates, and now the cause is thought to be the up welling during the opening of the Atlantic Ocean which cooked the fossil fuel deposits.
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For background information, see previous question from Susan Salafsky "What was the global extent of drought conditions during 2001-2003 and how did it affect the biota?"
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Dear Susan!
I do not agree with the "worldwide drought" in 2001-2003 too. However, the lack of precipitation was observed in some regions. Figures of 12-month SPI in additional files can answer to your question.
Regards, Elena
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there is a line of maximum wind speed with 115 degree measured from direction of tropical cyclone motion
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I agree with Mr Contreras and I would like to add that if a hurricane makes a landfall, the convective area near the eye decays faster than the rest of the system, at the outer radii of the cyclone and hence the maximum surface winds could be measured in different places. 
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Hello everyone,
I asked a previous question as to whether dense ash aggregates (or "acc-laps") have ever been made in any wind tunnel lab thus far in their fully formed sub-spherical or ellipsoïdal shape ?
The answer has been: "not yet", even though this would allow to more closely simulate mixed phase aggregation under more realistic in situ ashcloud conditions.
I am wondering if any accretionary lapilli greater than about 10mm across or so have ever been collected immediately upon reaching the ground and studied immediately, or preserved in a cold box (to prevent them from any melting) and studied in the lab (eg. on a cryogenic SEM stage, or to measure their in situ temperature, and recover inner fluids from the intergranular space....) ?
The reason is that there is the hypothesis that they form like hailstones by riming, once they grow above a size characteristic of the drop break-up limit (5-6mm across). If this "volcanogenic hailstone" hypothesis is correct, then my expectation is that a proportion of accretionary lapilli larger than about 6mm diameter should still be frozen upon reaching the ground (especially if above-ground températures are close to 0°C; if not partial melting takes place), so that somewhat larger ones (say 10mm diameter ones) may still be frozen (despite partial melting) and still contain inner ice upon landing on the ground.
Has anyone checked for this ?
Assuming for a moment that larger sub-concentric acclaps can be sampled immediately, preserved and analysed for oxygen isotopes of any trapped ice water, then this could provide valuable data as to the temperature environments through which the acc-laps have been recycled again and again in the volcanic cloud before ultimately falling out.
Analogous oxygen isotope ratio studies  of the subconcentric layers of hailstones from severe thunderstorms have provided such information in that case.
I am looking forward to hearing back.
Best wishes and kind regards,
Gerald
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Hello Gerald, Ulli, Volker,
There quite a few nice examples I'm aware of where accretionary lapilli were sampled soon after fallout. One is the 2002 study by Bonadonna et al. on the 1995-1999 eruption at Montserrat (Geol. Soc. London Memoirs). Another is the 2009 eruption of Redoubt, Alaska, described by Kristi Wallace et al. in JVGR, 2013. The latter samples provided the basis of my study of 'volcanic hail' using radar observations and plume modeling with ATHAM in Nature Communications. As suggested by Gerald, these samples were indeed frozen upon landing, though that's not too surprising for an Alaskan eruption. It is clear from lab experiments that neither ice nor salt precipitates are required to grow aggregates >1cm diameter. I do not think aggregates need to undergo freezing, however, it does seem to be very common and does affect their growth rates and internal structure. 
There are also some gorgeous, layered accretionary lapilli from the 18 May 1980 eruption of Mount St. Helens, which have been archived for the past 35 years. I've recently thin-sectioned these samples and am currently working on comparing their internal structures to the eruptive stratigraphy and photographic record of the eruption dynamics. Hopefully I'll be presenting this work at the Cities on Volcanoes meeting in Chile this year. Ulli and I were talking about organizing a workshop on ash aggregation there if there's enough interest. 
All the best
Alexa
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I am interested in the theories and evidence linking the AMO to Atlantic Meridional Overturning Circulation, solar forcing and possibly other causes in explaining this phenomenon.  Is there literature reviewing these mechanisms? Do you have links to relevant net sources.
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Here's a good link: "Forced and Internal Twentieth-Century SST Trends in the North Atlantic", by Mingfang Ting et al., 2008:  http://journals.ametsoc.org/doi/abs/10.1175/2008JCLI2561.1 .  Their conclusion is that the AMO is an internal mode of variability, not forced by global factors such as anthropogenic warming or solar variability. 
Otherwise, the wikipedia article (https://en.wikipedia.org/wiki/Atlantic_multidecadal_oscillation) is a good place to start and has plenty of further references.
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how to access their data or to get Atmospheric wind data from ground to altitudes of 150 km or more?
Generally atmospheric data including pressure,humidity, temp,wind velocity w.r.t altitude has been provided by radiosonde upto 35 km height. i want  to access this data from 35 km onwards. so, how can i get it?
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you could have start by looking at the available models (including HWM07) on http://spdf.gsfc.nasa.gov/pub/models/old_models_from_nssdc/atmospheric/
and/or
The NRL G2S model also uses MSISE and HWM models above 35 km.
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I am looking for information on advanced courses in English that would be open for graduate or post-graduate level foreign students. This would be interesting for students specializing on climate reconstruction, past climate dynamics, current issues of climatology, and so on. Is there any web-sites listing such activities? 
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The Urbino summer school in Italy has an extremely good reputation, and all of the details (including course content and logistics) are on their website: http://www.urbinossp.it/
I don't know of others, but I hope that is helpful.
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Thanks in advance for your replies.
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Here is a great paper (Nature) that details climate scenarios and some of the methodology behind the RCP scenarios... (Moss et al., 2010)
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Dear Researchers I am doing a study regarding effect of climate change on a very small catchment. I need future climate data for period 2050-2060s. I have few questions I will be thankful if you share your experience and give suggestions:
1:  How many Climate models exist in CMIP5? What are RCP4.5 and RCP8.5 ?How many models exist in RCP 4.5 and RCP 8.5?
2. I have read there are 40 models for RCP4.5 and RCP 8.5 am i right? Among RCP 4.5 and RCP8.5  if i want to select some suitable models for my catchment what will be the procedure?
3. Dose spatial resolution mater for small catchment having watershed 200km square? 
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Dear Muhammad, RCP4.5 and RCP8.5 are different representative concentration pathways corresponding to different  possible scenarios, all of which are considered possible depending on how much greenhouse gases will be emitted. Regarding the period you are interested in, the RCP8.5 project a  global warming of about 2deg compared to the 1.5deg in RCP4.5 (this is a CMIP5 models ensemble average). If you want to focus on small spatial  domains (you mentioned 200km)  you could decide to get the 10 models with the higher resolution providing both scenarios: 
CCSM4,  
CMCC-CMS
CMCC-CM
CNRM-CM5
HadGEM2-CC
HadGEM2-ES
INM-CM4
IPSL-CM5-MR
MIROC5
MRI-CGCM3
enrico
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I am using a Species Distribution model and want to use Climate gridded data for different scenarios from downloaded Climond. How can I extract the data only for my country of interest? Any suggestions please
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there are some workers in 'meteoroloji genel müdürülüğü/ANKARA, goverment office' for turkey. And prof. Murat türkeş as scientist interests in climate change in middle east technical  universty.
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What are all the Microphysical schemes available?
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Usually a one moment scheme is used with rain, snow (and graupel) (and hail). However, novadays 2-moment microphysics schemes are upcoming. See e.g. Beheng and Seifert. All of them are implemented in e.g. the COSMO model.
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In my study I am trying to verify whether there have been climate refugia for a species. Unfortunately, publicly available databases only have data for the Last Glacial Maximum (circa 21kya), the Holocene (circa 6kya) present and future. Considering that the Younger Dryas were a period of forest (vegetation) contraction and this could influence the distribution of my targeted species, I think it would be important to include it in my study. Unfortunately, I can't find climate variables for this period. Can anyone provide any suggestion?
Thanks in advance!
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I'm currently running a simulation for the Younger Dryas. There is an older simulation called "TraCE" with CCSM3. Data can be downloaded from
I'm however not sure to which extent the simulation is correct over Eurasia. In my high resolution simulation, the summers are not really colder but winters are. TraCE shows a very strong summer cooling.
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Different modelling centres have given the historical runs for their GCMs, in this respect I am looking for some studies which seems to Identify the models able to simulate the Indian Summer Monsoon and its features in a more comprehensive and realistic manner.
Any update will be appreciated.
Thanks in anticipation.
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No one study can be comprehensively concluding that a particular CMIP5 model or a set of these models are realistic in simulating Indian summer monsoon. Because ISM is not a single entity and it has so many associated features so it depends on what you are looking at-  from the recent CMIP5 studies it can be concluded that a set of models can be good in representing mean state and hence interannual changes but if you go further into the values, the same set is not that good in representing the daily values and hence the intraseasonal variability. similarly for annual cycle or monsoon-enso teleconnection. try to understand one of the reasons behind this. a model simulation is in essence,  merely one combination out of of a large number of possible combinations of existing physical parameterisation schemes and this combination of schemes play together for simulation to happen. one scheme's success (for a particular process like convection and hence real mean state) lies in compensating other scheme's failure (for say cloud formation and hence daily value) for one combination/simulation/model. it's philosophical and mathematical more than physics. so by science it is never possible for design a perfect model or simulation or combination to exist. what is only possible is to (through use of high computational facility) to find a perfect combination of output or ensemble. try reading this. very good article/report in nature's scientific report journal on CMIP5
see figure 3a
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I recently had  a look at the Mauna Loa dataset.
They are archived and distributed by the NOAA Administration of the US. An intruiging dataset indeed.
I detrended the full monthly dataset (april 1954 till now) and subsequently calculated the yearly rate of change (See figure enclosed). According to me the data suggest that - at least for the Mauna Loa dataset - the atmospheric CO2 mixing ratio has entered a runaway mode (as they say in systems analysis). This would suggest a strong feed-foward mechanism in the processes determining the rate of increase of Mauna Loa CO2 mixing ratio! Nw my questions.
1. Do you agree with my findings (see graph added here as well)?
2. Have other scientists found something comparable to what I find in the Mauna Loa data?
Eagerly waiting (also for the non-believers in climate change) to put your teeth in my hypothesis shortly outlined here and hack it to pieces.
Thanks for looking into the data and findings.
Frank
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Hi Alastair,
Are you sure about the magnitude of global emissions. Do you think that for example China, India, Bangla-Desh the majority of African countries, Russia or North-Korea and many other countries, produce reliable emission date? In some of these countries emissions of CO2 are even kept a secret if these countries even make inventories at all ! I have the  strongest doubts on that!
That's why I leave out global ermission estimates, because they are - according to me - utterly unreliable, at the global scale, I think even their magnitude is underestimated severely. A small minority of countries does a good job though, but we are dealing with a global phenomenon here. Hence?
in the interpretation of Mauna Loa data - because that's what we are dealing with here, how do you corroborate the one third  - one third rule for CO2 absorption in oceans and terrestrial vegetation. This would mean that 60%  of all CO2 emissions would be taken up again.Well the terrestrial science community  and remote sensers are still trying to accurately pin down the uptake of CO2 by vegetation. The same for the oceanographers and CO2 dissolution in oceans and the subsequent uptake by phtytoplankton, and that with oceans which acidify?  CO2 oceanography is a field of research which is even more complicated than the terrestrial one, especially to get a grasp on the CO2 uptake figures by those systems. I think you are strongly underestimating the complexity of these systems Alastair. Hence, Are you not speculating a little but too much collaegue and introducing some very crude assumptions and rules of thumb?
Figures and facts that's what we need, not the mumbo jumbo of rules of thumb. And what is the difference between a runaway process and a process with a strong positive feedback? Semantics or physics? Please man!
CHeers,
Frank
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I am aware of LAI as one of the most important factors in creating shades and providing cooling. But what else can be investigated?
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See, "Design with Microclimate" by Robert D. Brown (Island Press). You will learn that there are many factors including transmissability of different species' leaves (not just leaf area, but short-wave transmission and scatter).
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Warm or cold scenarios are predicted about Upper-Air?
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Raffaele is correct :- carbon dioxide warms the surface and the troposphere, and the warming increases with height in the tropics so that it maximizes in the upper tropical troposphere.  However, it simultaneously cools the stratosphere and mesosphere.  There is obviously then a point in between with no warming or cooling and this occurs near the tropopause.  This warming of the lower atmosphere and cooling of the stratosphere and mesosphere can be explained by radiative arguments, as carbon dioxide is a net emitter of long wave radiation at higher altitudes.  The cooling increases with height and is around a degree or so per decade at the stratopause - much faster then the warming rate below.
Note though that this is not true of all greenhouse gases and CFCs for example warm the whole depth of the atmosphere as they absorb/emit at different wavelengths. 
I would recommend the basic climate change book by John Houghton which contains an explanation of these effects.  You should also try working through the 2 layer model of the atmosphere, assuming blackbody radiation and ozone heating  in the upper layer to represent the stratosphere and this basic result can be derived analytically.
Best regards
Adam
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I am interested in comparing the learning process and adaptive cycle in the context of cities working together in transnational city networks for climate action. Lee and van de Meene (2012) conceptualized the learning process into three phases (information gathering, adoption, policy change) in their network analysis study. I would like to look further into urban policy change and whether TCNs are a necessary condition to catalyze cities building resilience against sea-level rise. I think a better understanding of the phases of the adaptive cycle would be useful. I would appreciate any assistance.
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Frankly, TCNs are fairly irrelevant, at least in the US.  We're lucky if we can get cities across a state boundary to work together!  I think you can find literature describing how they could work, I have seen very little on them actually working.  Perhaps more fruitful would be an investigation of barriers to them working:  $, language, culture, laws and regulatory regimes...one of the biggest barriers is actually our lack of knowledge about the translation of data to action.  I've tried to provide some thoughts in my recent blogs at www.resilientus.org but these are certainly not validated by experience and are simply my attempt to synthesize both my own experiences and what I've read in the literature. 
The crux of the problem is that we haven't adequately understood community action.  Academia has focused on some inchoate collaborative processes that are poor representations (IMO) of what actually happens.  They pay too much attention to the "horizontal" gathering of information and defining of goals and too little to how (and even if!) these goals are achieved through the "vertical" hierarchies that actually act.
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I am working on a project to use WRF-ARW as a regional climate model and  project potential impact of climate change for future periods. But the WRF model doesn't directly ingest the Climate Model out put dat (GCM) from CMIP5   available in ESGF portal directly. So I need some mechanism so as to make this GCM outputs  able to use in WPS the WRF prepossessing system before I run WRF
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Our group at NCAR does a significant amount of Regional Climate Downscaling with WRF. Here are two articles that might help:
Done J.M., G.J. Holland, C.L. Bruyère, L.R. Leung, and A. Suzuki-Parker, 2013: Modeling High-Impact Weather and Climate: Lessons from a Tropical Cyclone Perspective, Climatic Change. doi:10.1007/s10584-013-0954-6
Bruyère C.L., J.M. Done, G.J. Holland, and S. Fredrick, 2014: Bias Corrections of Global Models for Regional Climate Simulations of High-Impact Weather. Climate Dynamics, 43, 1847-1856. doi:10.1007/s00382-013-2011-6
We have also just completed a project to convert the CESM AR5 data to WRF Intermediate file format. We have also bias corrected this data. All the data are available here:
The source code used will be make public soon, on the above web site. We are also in the process of generating a technical document describing the methods and code. The document will also be on the above web site when completed.
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I only have field measured values of solar radiation, air temp, relative humidity, dew point, air pressure, wind speed and direction.  I do not have any information on ratio of clear/cloudy time and I'm having a difficult time arriving at the necessary emissivity values needed to calculate incoming longwave rad. 
Thank you for any help. 
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Dear  Jessica,
I think, with the three answers you have received so far, you have found a clue foryour question. If you have some data relevant to the surface net radiation, you might find another simple solution for your question. As you know, surface net radiation is the subtract of Net Shortwave (SWi-SWo) radiation from Net Longwave radiation (LWi-LWo). Rnet=(SWi-SWo)-(LWi-LWo). LWi can be determined from the relationship, if you access above radiation components.
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Maureen Raymo hypothesized that the Himalayas radically changed climate by affecting wind patterns by their uplift. I want to know how you can radically change climate by removing a miles-high ice sheet. Hypothetically what would happen to climate if the Greenland Ice Sheet were removed? How did the rapid removal of the Laurentide ice sheet affect wind patterns and climate for eastern North America in the recent past? Has anyone done any modeling of this? Thanks, Joanne
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Joanne, The articles cited above (various John Kutzbach publications; Schmittner et al 2011; and Oster et al 2015) are excellent suggestions. Another article that may be of interest to you, recently published in Climate Dynamics, is: doi:10.1007/s00382-015-2502-8; "Higher Laurentide and Greenland ice sheets strengthen the North Atlantic ocean circulation" by Xun Gong et al. 2015. Model simulations of various glacial and interglacial climates are conducted with the goal of identifying different [North Atlantic-based] surface-wind patterns (and associated ocean circulation patterns) that evolve under different profiles of ice-sheet topographies. Marcia
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I know there are no any rules. But I just want to know the community idea about how many will suffice for a study.
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One answer is that you cannot be sure. But as a rule of thump we tend to use at least 3 GCMs to make a meaningful assumption.
Regards, Levent
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Is it possible to relate lagoon water spread area with climate variables such as precipitation and temperature?
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Thank you so much Sir.... Thank you very much for your time and consideration
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Do you have any paper that clearly describes this technique ? 
thanks.
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If you just want to visualize your data, Panoply from Nasa is what you need:
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When I use ENVI-met v3.1 to compare between deep canyon H/W=5 and Shallow canyon H/W=1, I observed that the air temperature at daylight is similar with literature review about deep canyon has low temperature from shallow canyon as shown in attached file, because the effect of wall height which decrease of effect from direct short radiation. At night the air temperature in deep canyon is lower than shallow canyon, literature review which has studied street canyon ratio proved that air temperature in deep canyon in night is higher than shallow canyon, because SVF is low and low air velocity in deep canyon to release heat from walls.
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Here http://www.cnrm-game.fr/spip.php?rubrique134&lang=fr there's the link to download the TEB code
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The harmattan in west Africa has not been as strong as it is now, and the reports all over Europe, America and some part of Asia, Africa e.t.c have also recorded increased snow, hail storms, flooding and in some cases poor visibility. What is the scientific link of these events to climate change. Proof may be needed
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These extreme weather conditions are all linked to man's destruction of his own habitat, the earth., through his various activities driven by greed and selfishness
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There are several climate indices that can be used to show the state and the changes in local climate systems but which index is better and can show the effects of long term land-use change on local climate dynamics.
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This is an interesting question.
It may be good to differentiate the climatic effects from local (e.g. urbanization) and regional (e.g. farming) land use and land cover changes, however, though they are in most cases exhibiting similar characteristics for certain climatic variables such as temperature and relative moisture.
In view of urbanization, diurnal temperature range (DTR) should be one of the best measures for indicating the long-term change in local climate in mid- to high latitude zones, with it generally significantly being reduced. With regard of large-scale land use and land cover change, including the transformation from forests or grasslands to farm lands, the continentality index, and probably other indicators including DTR, would be useful.
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I am studying semivarigram for climatic data, and I would like to have a reference in order to analyse the available models and be able to choose the best one for my data.
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Just to add one more point................usually in most of the cases, half of the maximum inter-station distance is enough for active lag distance. In most of the variogram modelling packages such as GS+ use it by default, although you can use the full distance as well. But active lag distance equal to half of the maximum interstation distance is enough and it is mentioned in many materials such as GS+ manual. Alternatively, you can find it in "Practical Geostatistics" by Isobel Clark published in 1979.
Use this technique and do perform your cross validation, hopefully, you will see the variogram models are perform well with satisfying all cross-validation criteria such as MSE, RMSE, ASE, RMSS. You can find all details of these statistics in ArcGIS Geostatistical Analyst extension manual.
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We are studying the impact of water scarcity due to climate change and population growth on economic growth and development. We have all the data we need but still require precipitation projection estimates by country. Many of the climate models used in the latest IPCC give estimates of precipitation but the aggregate data at the country level is very hard to find. I have looked at downloading CMIP5 data from ESGF data facility but the system has many bugs and I cannot find the exact data I am looking for. Moreover it only provides data at very high spatial resolution. This is fine as I can aggregate this information to the level of the country but I don't know what dataset is most appropriate for doing this analysis. Has an emulator been developed for precipitation, or perhaps an average estimate of precipitation changes estimated by the different climate change models? We are interested in changes out to 2050 and 2100. Monthly estimates would also be helpful as this gives seasonal changes in water availability.  I know these estimates are highly uncertain, but we are taking this into consideration in our study. 
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CMIP5 projections are provided PER COUNTRY by the USGS here:
Click on a country (on the map) to see graphs displayed.
Where it says "Temperature" change it to "Precipitation" (it's a pull down menu).
Click on "Select Dataset" to choose the RCP and time horizon of interest.
You can display results for each of 26 individual GCMs, or for the average of them.
GCMs can differ hugely between them.  If in a given country you get fair agreement among most GCMs, then perhaps you can hope to attach some confidence to those projections.  But this topic of UNCERTAINTY is not what you asked about.
Mariza
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see above
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I sent   my answers by email.
See please our publication of the experimentally proved urban climate model CTTc
Limor Shashua- Bar and Milo E. Hoffman
The Green CTTC Model for predicting the Air Temperature in Small Urban Wooded Sites
Building and Environment 17 (2002) 1279-1288
Also previous publications of Hoffman and  Hanna Swaid, and with Nurit Sharlin. See in References of The above paper. Also in further  publications  see in Research Gate. with Shashua- Bar and Hoffman and other investigators.
For fuurther  questions about this theme you are wellcome to write directly to my email:
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A mesoscale convective system (MCS) is a complex of thunderstorms that becomes organized on a scale larger than the individual thunderstorms but smaller than extratropical cyclones, and normally persists for several hours or more. A mesoscale convective system's overall cloud and precipitation pattern may be round or linear in shape, and include weather systems such as tropical cyclones, squall lines, lake-effect snow events, polar lows, and Mesoscale Convective Complexes (MCCs), and generally form near weather fronts. The type that forms during the warm season over land has been noted across North America, Europe, and Asia, with a maximum in activity noted during the late afternoon and evening hours.
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Very nice radar image. It shows a classic supercell structure with hook echo (this is not an MCS). But there were several similar storms. If George could be more specific about the time of day and location also the answer can be more specific. Severe weather reports are collected in the European Severe Weather Database maintained by the European Severe Storms Laboratory: http://www.eswd.eu
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I am working on new research studying the impact of climate change on water resources. We want to develop future climate scenarios and test them against the current system to come up with different mitigations.
My knowledge of climate change modeling is very limited. I want to downscale different climate change scenarios to a spatial level in order to conduct the test on the targeted region (small county in CA state).
My question here is: Are there any recommended books/papers that help explain the different methods of downscaling (Statistical & Dynamic) in detail? Also, what is the best computer software to generate the scenarios? (I am here basically talking about daily precipitation, wind, humidity, and temperature.)
Thanks in advance!
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Hy, I have send you some link of some papers, documents, books.
1. Methods of Downscaling Future Climate Information and Applications by Linda O. Mearns - National Center for Atmospheric Research
2. Uncertainty of downscaling method in quantifying the impact of climate change
on hydrology
3. Statistical Downscaling Techniques for Global Climate Model Simulations of Temperature and Precipitation with Application to Water Resources Planning Studies
4. Climate downscaling: techniques and application
5. REGIONAL CLIMATE DOWNSCALING - ROBERT L. WILBY AND HAYLEY J. FOWLER
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We on the globe, notice that days and years have fixed periods due to earth's own rotation well defined 24 hour cycle and nearly but exactly 365 days yearly period around the sun. The question is whether, despite such absolutely repeatable motions, the effect on the earth faces uncertainties appearing as storms, floods and other natural calamities. These are randomized and unpredictable on long term basis, though models based on empirical data do account for such forecasts. In my opinion the positional fluctuations in temperature in air and water on the earth cause this randomness which results in such huge effects. Thus, is it safe to conclude that although the nature completes its essentially repeatable cycles when viewed from outside the universe, these local fluctuations are like uncertainties inherent because of man made disturbances in the atmosphere consisting of moveable stuff like air and water? Does it mean that inter planet effects are maintained uniformly without any variations year after year, but intra planet effects can be tremendous and this is generalized to all similar inter and intra systems?
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Hey Vijay,
You're becoming enthousiastic. Thanks.
I think there is a lot of analogy indeed between the dynamics of the Earth's systems, especially its atmosphere. The analogy is not so much with the bubble chamber, but more with the vapor chambers, though both type of chamers contain metastable states of a liquid (in the bubble chamber) or in the gas phase (in a vapor chamber).
Since the atmosphere can be more or less be considered as a gaseous mixture (with liquid, solid and electrically loaded particles in it), the analogy with the vapor chamber looks fruitfull to me as a concept to understand and predict the impact of small changes (like a small temperature increase of the atmosphere, typically due to an increased radiative forcing) on macro-scale atmospheric dynamics (like (increased) cloudiness). Actually cloudiness is quite comparable to the transition dynamics in a vapor chamber. When an (elementary) particle passes through a vapor chamber, the metastable state of the vapor degrades and the vapor phase is transformed into the liquid phase along the path of the particle traversing the vapor chamber.
Once can consider the increased loading of the atmosphere with aerosols from volcanic or anthropogenic origin in the same way. Increased aerosol loads in a water vapor saturated can quickly induce a decline in atmospheric horizontal visibility, which means that transitions from the vapor to the liquid phase have occured at the surface of the aerosols. Evidently an aerosol is not an elementary particle, but, the process of an atmosphere saturated with water vapor and aerosols inducing transitions of the water vapor to the liquid phase inducing a smog, occur on a daily basis now. Especially in densely urbanized areas, close to mountains, or during wintertime or in the tropics (in fact in each climate zone having a lot of water vapor satured conditions in the atmopshere). Intense rainfall or hail stroms can be the consequence of the vapor to liquid phase transition. These transitions from vapor to liquid (rain) or even the solid phase (hail) occur in very short time intervals (also typical for condensation in a vapor chamber along an elementary paricle track) and can be quite intense or even catastrophic (with big hail balls coming down).
I think it is worth considering to what extent the thermodynamics of a vapor chamber can be used as a model for the thermodynamics of the Earth's atmosphere. I guess it can be a fruitfull exercise, as far as this has not been done yet. Anyhow there is a large scale difference (elementary particle in the vapor chamber versus an aerosol particle in the atmosphere). If the impact of the scale difference on the systems thermodynamcis can be described, one can get close to a model explaining the thermodynamics of the Earth's atmosphere in more detail. With a bit of luck, predictions can be refined concerning the impact of increased radiation forcing on the characteristics of the Earth's atmospheric thermodynamics. Well worth investigating to what extent this has been investigated as we speak.
Cheers,
Frank
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I am working on snow cover and vegetation phenology in near real time from remote sensing methods. Some special patterns of these variables could be easily explained by temperature or precipitation parameters. But I can't find a synthesis comparing weather conditions of a month or of a season with past data at the European scale which would be very useful for me.
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yes, that is past weather data
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A warmer ocean can exclude significant amount of CO2 to the atmosphere. It indicates a positive forcing factor to the global warming scenarios.
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Anthropogenic CO2 is emitted to the atmosphere first, then a good part of it is absorbed by the ocean. An estimate of the oceanic anthropogenic sink for the period 1800-1994 shows that 48% of anthropogenic carbon emitted during this period is in the ocean (Sabine et al., 2004). In terms of warming, atmosphere warms first as an effect of the increased trapping of longwave radiation. Again, the ocean comes to the rescue absorbing part of the anthropogenic heat (I don't have a number for this, I'll look into it). After this initial atmosphere-to-ocean flux, both carbon and heat become part of complex and dynamic feedback cycles between atmosphere and ocean. One of them is what you mention, the effect of warming on the CO2 solubility in sea water.
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Teleconnection between global ocean SST and the rainfall variability over the Ethiopian Highland.
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Hello
There is a huge bibliography on the teleconnection between tropical rainfall anomaly at regional-scale and gllobal/zonal/regional SST patterns. Some previous works about Ethiopia have already analyzed the connections either for the spring and boreal summer season. Just try "Camberlin, Hulme, Conway, Jury & Ethiopian rainfall" in scholar.google.com. Or perhaps, your question should be precised ?
Vincent
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I want to know if there are any merits of climate extremes.
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I would imagine that extremes in climate present an excellent opportunity for disaster risk reduction, encouraging greater mitigation, legislation, planning and DRR technologies and allow for the opportunity for a proactive approach to disaster management in order to mitigate and reduce the potential risk, therefore I would hope that the threat or increased risk maybe a merit in itself encouraging new and holistic approaches to DRR