• Sumanta Dandapath added an answer:
    What is your opinion about Impact of the Evolution of Continents and Oceans on Climate of the Past?

    The continental drift is a reality now, supported by the dynamics of plate tectonics and seafloor spreading. Continuous convergence (collision) and divergence (separation) of continental and oceanic plates from each other has been reshaping our Earth since the initiation of the process. Therefore, the absolute location (latitudinal and longitudinal) of places has been changing with the change of associated biotic and abiotic environments (tropics shift to equator, or polar regions being shifted to mid latitudes for example). 

    Then, how the shape of the earth arises due to the continuous movement of the continents and oceans is impacting the global climate? Does it also impact the paleoclimatic records which are being considered to understand the climate of the past?

    Sumanta Dandapath


    Thanks for the overwhelming response and your expert opinion.

    @ Kenneth sir, I think each and every response/opinion are unique with regard to the their objectives. I can see lot of differences in opinion here over the subject. Some of them seems to be more or less related, but mostly are not. For example, if you see last 10 messages you will find the three set of opinion here:

    (a) Based on geological evidences about past earth experiences (links between paleoclimate and past environment of earth)

    (b) Also there are logical conclusion of past and future possible events and the expected outcomes (modeling of earth system) 

    (c) And, justification of expanding earth concept for the anomaly being documented/observed now.

    @ Chris Scotese Sir,

    Thanks for your valuable input and the details given in PALEOMAP webpage. Regarding Hothouse or Icehouse concept: I have a different question: ( (see the responses too)  ...I would like to have your opinion there.

    @ James Maxlow, thanks for your reference webpage and argument in support of expanding earth hypothesis.

    I am also thankful for the valuable addition by Ashkan Vafadar, Keith Robert Oliver, Habib Alimohammadian, John Burgener, Julian Osuji, Max Semenovich Barash and Anicet Beauvais sir besides others mentioned earlier.

    Some of the inputs are really interesting.



  • Tomeu Rigo added an answer:
    How to perform altitude filtering for raster dataset in R?

    I have a raster stack (with binary values:0,1) and DEM. Both DEM and stack have same resolution and extent. I want to reclassify the values of stack using information from DEM. I want to reclassify stack values below 5000m to zero. How can i do this in R?

    Tomeu Rigo



  • Kenneth M Towe added an answer:
    How can I get total ozone column data over Bihar, India?

    I want to use to TOC data to study how meteorological parameters affect the concentration of tropospheric ozone in Bihar. 

  • Chris Jurewicz added an answer:
    Can anyone point me to research separating the influences of the weather and economic indicators on crashes in a European country?
    For long term trend of the number of crashes in a country, the weather conditions (long hard winter, warm spring and/or autumn) definitely are relevant.

    Besides this, I have read about the relevance of the state of the economy as a further determinant of a rise or decrease of crashes several times. But the evidence always was from the US. I am curious if there is European evidence available, also.

    I anybody aware of research from Europe, dealing with the influence of the weather and economic indicators on road crashes?
    Chris Jurewicz

    BRSI link to weather and road safety research appears to have been fixed:

  • Muhammad Usman Saleem added an answer:
    30 years investigation of Geopotential Height investigation

    I want to do my master thesis on geopotential height investigation over different pressure levels. I have 30 years historic data set, Please guide me what can i do for my master thesis with this geopotential height. My study area is south asia

    Thanks Always!

    Muhammad Usman Saleem

    Ali-Akbar Sabziparvar my study area consist on flat platue, including fertile land with desert also, some portion is in coastal toughing the occean. What levels u suggest and what will the technology?

  • Neeraj Kumar added an answer:
    What is the importance of reanalysis in climate studies?
    I want to know about the quality of reanalysis data.
  • Michael Issigonis added an answer:
    What are the reasons of the unique extremes of air temperature in July 2016 ?

    In Ukraine, scientists of Central Geophysical Observatory (Kiev) have found a unique air temperature extremes, the maximum of which was registered on 17 July + 35,4 ° C. And in four days, this record has dropped to its lowest level in 136 years of observations +18,2 ° C.

    Scientists  also point out that the cold snap at the beginning of the third decade of July was interrupted by a unique series of 90 temperature records, which began December 20, 2014.

    The average monthly temperature in July was 22,4 ° C, which exceeded the climate norm by 3,1°C. Coldest was on July 8, when the temperature in the morning dropped to + 12,7 ° C. What are the reasons of the unique extremes of air temperature in July 2016

    Michael Issigonis

    What you are describing in Ukraine are almost identical to the events in Canada.

    Since I came to this country, everything in relation to the weather has changed, but more dramatically since early 2000's. On top of just measuring temperature, the felt-temperature has changed in the last few years, because the increase in humidity (entirely new phenomenon here) has introduced the "heat-index" which can bring a temperature of 34 degrees to over 40. Then, it gets serious and one needs to do something to survive.

  • Matthew S Landis added an answer:
    Biomass burning emissions?


    I'm wading through Jacobson (2014), learning that the net radiative forcing from biomass burning emissions is a complex story. Does anyone know of any work that's been done to characterize the suite of products (trace gases, black/brown carbon etc.) emitted from wildland biomass burning according to fire intensity, flaming/smoldering phase, fuel component, moisture content, fuelbed/ecosystem type?

    I'm imagining that while chemical soup(s) have been measured in plumes (via, say, instrumented aircraft) from wildland fires and reported in literature, there's not much to relate the chemical profiles back to fuel bed/combustion conditions etc.

    thanks for any pointers

    K. Scott

    *Jacobson, M. Z. (2014), Effects of biomass burning on climate, accounting for heat and moisture fluxes, black and brown carbon, and cloud absorption effects, J. Geophys. Res. Atmos., 119, 8980–9002, doi:10.1002/2014JD021861.

    Matthew S Landis

    There are numerous papers in the literature on emissions from specific fuel types and burning conditions.  I suggest you start your search with Shawn Urbanski from the USFS Missoula Fire Lab.  The Second International Smoke Symposium is being held in your back yard November 14-17, 2016 in Long Beach, CA.  Check out:

    This will be an excellent meeting with all the latest research from the field being presented and discussed, including a special session on FASMEE.

  • Kenneth M Towe added an answer:
    How does ever-changing Global Climate maintain its Dynamic Equilibrium with Global Water Cycle? Which one is the initiator of Change? Any evidence?

    Global warming = Ice melting = Sea level rise = More water availability for evaporation and (possible) decrease of salinity = More evaporation = More clouds = Less solar radiation to earth = Global cooling = Fresh ice formation = Sea level fall = Less water availability for evaporation and (possible) increase of salinity = Less evaporation = Less atmospheric clouds = More incoming solar radiation = Global warming again.

    (1) Are these consequences always true?

    (2) If not, then what are the alternative circumstances?

    (3) How does ever-changing Global Climate maintain its Dynamic Equilibrium with Global Water Cycle? Which one is the initiator of Change? Any evidence?


    (4) Is there any long term record of salinity of oceanic water?

    **Note: Above are the physical factors (components) for global change and associated consequences... excluding biological factors such as changes of concentration of Oxygen/Carbon-dioxide/Methane etc. and their inter-relation which also influence the global cycle.


    UPDATE: Few Related & Interesting References (referred by the experts with their answers)

    (IPCC Working Group Reports, referred by Harry ten Brink and Commenter) (referred by Alastair Bain McDonald) (referred by Yuri Yegorov) (referred by Yuri Yegorov) (referred by Yuri Yegorov)   (referred by Yuri Yegorov) (referred by Steingrimur Stefansson)  (referred by Henrik Rasmus Andersen) (Commenter) (referred by Alastair Bain McDonald)  (Commenter)  (Commenter)  (Commenter) [Click Introduction to Paleoclimatology] (Commenter) (Commenter) [For Global and Regional Analysis of (1) Climate, (2) Hazards, (3) Snow & Ice, (4) Upper Air, and (5) ENSO events .....during late 1990s to till date] (Commenter)

    ...for refence see the Global Major Climate Events (originally source & compiled map credit NOAA-NCDC and WMO) during year 2012, 2013, 2014, 2015 and some images related to historical trend of global temperature (Images collected from various webpages referred here)...

    + 19 more attachments

  • Marcos de Oliveira Valin Jr added an answer:
    How can you go about monitoring atmospheric heat and humidity at the micro level within an on station study site?
    I intend to research on how incorporation of trees into farming systems can influence the micro climate of a place.How can I go about monitoring the micro climatic aspects of the site over the study period?
    Marcos de Oliveira Valin Jr

    Research of urban systems are developed mostly by universities and educational centers, where resources are limited and dependent on notices or even own research resources.

    It is possible to build alternative systems for measurement.

    The sensors may be constructed with Arduino system for example.
    Protective shelters with pvc pipe, plastic plates, among others.

    In this work I detail a little more about these alternative shelters.

    • Source
      [Show abstract] [Hide abstract] ABSTRACT: A padronização dos instrumentos de coleta de dados é fundamental para a qualidade dos estudos microclimáticos. Devido a limitações financeiras e necessidades especificas, muitos sensores, abrigos e sistemas alternativos aos padrões são desenvolvidos, baseados na experiência e criatividade dos pesquisadores. O objetivo geral deste trabalho é analisar o desempenho termo-higrométrico de abrigos micrometeorológicos de diferentes materiais alternativos em coletas de dados em pontos fixos. Para tanto, a metodologia consistiu em construir cinco tipos de abrigos, instalados em campo aberto para garantir o mesmo ambiente para o estudo, e avaliados quanto ao desempenho das variáveis termo-higrométricas, a facilidade de execução, os materiais e ferramentas utilizados, e os custos envolvidos. Os resultados apontaram que os abrigos do tipo vertical e o com pote de sorvete não se demonstram eficientes para a coleta de dados em pontos fixos, principalmente se utilizados durante o dia. Quanto aos demais tipos, com pratos plásticos, tubo de pvc na horizontal e casa de madeira, se mostraram alternativas viáveis quanto ao desempenho, cabendo analisar o local onde será utilizado para definir qual deles melhor se adapta, pois o horizontal depende de já conhecer o sentido da direção do vento, o de madeira do espaço disponível devido ao seu tamanho e peso e o de pratos depende da disponibilidade de pratos plásticos na cor branca. É possível também concluir que o desempenho termo-higrométrico não está associado apenas ao material empregado, mas também à sua forma.
      Full-text Article · Jul 2016
  • Kenneth M Towe added an answer:
    What is the origin of Atlantic Multidecadal Oscillation (AMO)?

    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.

  • Dhanya Praveen added an answer:
    How do I convert rainfall rates from "mm day-1 50 yrs-1" to mm/year?

    I have estimated a decreasing trend in wet-season precipitation for a tropical-forest site in eastern Guatemala using real climate data (and regression), as -59.9 mm/year (between 1992 and 2009), and want to compare this value to other tropical sites. In an IPCC report, a decrease for Central America is estimated as “-1 mm day-1 50 yrs-1” (I copied it literally), and in a recent paper in PNAS, it is stated that “The model median amplitude of this trend is between 0.5 and 1 mm day-1 per 100 yr over most of the (Central American-Caribbean) region”. My question is, how do I transform these values to mm/year? I don´t understand the units of the cited data to make the calculation myself. Thank you climatologists!!

    Dhanya Praveen

     For directly calculating the linear trends and the slopes, You can use Kendal's tau and Sen's slope estimators

  • Hasan Tatli added an answer:
    How can I fill the missing climatological data?
    I have just worked on the dissertation thesis: "Bioclimatic characteristics of of Focsani city." I get climate data (temperature, atmospheric pressure, cloudiness and wind speed to calculate the bioclimatic indexes) for the period 2000-2012, but I am missing some values of all climatic parameters. For example, I am missing data on temperature and atmospheric pressure in a few months (in 2005 and 2006 - January and February) but data about wind speed.
    Could you offer me more details about the your method work to fill the missing climatological data?
    Hasan Tatli

    Ms. Ana, "filling missing data" is a very important research area. Data assimilation method is not only a interpolation process it is also to resolve how representing the real world. For example, "multiple imputation" has stochastic characteristics should be applied when there is no available spatial data. The other unbiased method "kriging" has advantages over other methods like IDW, Shepherd etc. I have just applied for daily wind data that the "least square directional kriging" has better performance over the other methods (with correction altitude).  I suggest you firstly read the book of Kalnay on this topic...   

  • Neeraj Kumar added an answer:
    Why does el_nino occur?
    I'm interested to know more about the phenomena el_nino
  • Vikram Kumar added an answer:
    What are the uncertainties that could arise from distribution of precipitation and temperature at Himalayan Basins?

    What are the issues that could arise by distribution of point observation of precipitation and temperature in Himalayan catchment using lapse rates and precipitation gradient ?

    Vikram Kumar

    Dear Amrit

    Temperature causes fluctuation in the discharge value which could cause major uncertainty in discharge estimation. 

    Please find literature showing these

    Hope you find something.

  • Sabyasachi Swain added an answer:
    Suggestion about 30 years monthly dataset

    I have grided data sets of monthly average upper air temperature, geopotential height, relative humidity, wind speeds(on 1000-200hPa levels) and i wish to investigate trends, normals high,low, thickness, atmospheric stability, long shortwaves etc.

    What i can do:

    (1) Use monthly average climatic variables but how can i predict my requirements from past 30 years data set?

    (2) Other option is to convert my data set into annul average datasets? and then do these analysis

    Problem in option 1 is dealing with monthly avergae data set on 8 different pressure levels of 30 years it  will be trouble some for me as there will be a lot of maps will form for each month of 30 year, difficult to place them in research

    Problem in option 2 , there are different definitions of annual average , some  authors nerate it is just average of each month in a year( jan+feb...dec/12) while others write yearly average climatic variable is average of high and low value of variable appear in a year?

    My grid consist on 64 locations, i am confuse which strategy will be fine for my research? Guide me with literature

    Sabyasachi Swain

    Dear Muhammad,

    I completely agree with Naveen Kalra. You can do multiple things with the data you have.

    I would suggest to use monthly averages (the first case). You can do trend analysis or regression analysis so that you can estimate your requirements for present. The modelling is also used for simulating data based on past conditions, which can be used for your present work. Indices are used for classifying areas at regional/global scales or to assess the impacts.

    For your second question, I would suggest that it varies for different parameters. Say for rainfall, when annual trend analysis is performed, they consider the rainfall of whole year. But for streamflows, annually averaged daily flows are considered. Adding monthly data and dividing by 12 is not a good idea as it may be misleading for most of the meteorological data.

    I hope it helps.

    All the best !

  • Laszlo Komaromi added an answer:
    Where can I find mothly average weather data history from Hveravellir weather station, Iceland?

    There is detailed historical data on the Met Office website between 1965 and 2004. However, I would need the same data covering the period between 2004 and 2015 as well.

    Laszlo Komaromi

    Thanks Kenneth. I am conducting research in Iceland that involves climatic data trends. I am not planning to go back earlier than the 1980's and I have data from the local met office too which I also find more reliable.

  • Claire Harnett added an answer:
    How can I read GHCN precipitation daily files (format .dly) with MATLAB or R?

    I have downloaded daily climatological data from the Global Historical Climatology Network (GHCN), but it is provided in a not very common format such as .dly. I have found some R packages related to this, but apparently they are aimed at retrieving temperature measures. Any suggestions?

    Claire Harnett

    For any future confused people who stumble across this thread, I also found a toolbox here:

    It is open access and runs in matlab, letting you import your variables without actually writing any of your own script. Good user interface and would highly recommend!

  • Jitendra Kumar Meher added an answer:
    How could I rearrrange or tidy data downloaded from DAILY GLOBAL HISTORICAL CLIMATOLOGY NETWORK (GHCN-DAILY) in R?

    I have downloaded data from DAILY GLOBAL HISTORICAL CLIMATOLOGY NETWORK (GHCN-DAILY). I have managed to upload it into R but I am having problems to rearrange the dataframe. I am attaching how the data is displayed in my console. I would like to reshape it in order to have the date in one column, and the value of each variable in the following ones. 

    I am a beginner in R so I'm familiarized with the basics. I tried the melt function but with no positive outcomes. 

    Thank you in advance


    Jitendra Kumar Meher

    #first make separate file for each variable: Its very easy, just use filter option from the excel
    #here I am writing a code for the prcp variable, 
    #I read prcp variable data (only data, no alphabet) in a text file with .txt extension and named that precip_ghcn_daily.txt (See attachment)
    #very imp point to remember is, in ur file the variables date range is not same, there are jumps in between year. So first make them all of same dimension in excel, if you have no data for different years just put -999 or NA, but dimension (rows*column) of all the variable data frame should be same. don't leave gap in between years while preprocessing of data in excel
    a<-read.delim('J:/precip_ghcn_daily.txt',sep='',header=F) #see attachment  and first download it


    #you can copy and paste the output of R in excel and give them date. or just follow #the following code if you want it in R only. 
    e<-data.frame(d) # one variable done
    #in this way you can do for other variables.
    #save them in different objects inside r, for example here I stored the prcp variable into e with date and data in two separate column
    #you save other 3 variables in f,g and h and follow the final step

    #cbind can only be done if your years common say 1964-01-01 to 2014-01-31 for all variables. 

  • Rajat Kr Sharma added an answer:
    What are different Evapotranspiration datasets available over india region??

     what are their temporal and spatial resolution?

    I have to calibrate and validate the model.

    Thanks to all..

    Rajat Kr Sharma

    Thanks Swain..

  • Nivaldo Fernandes Teixeira added an answer:
    How much drought events are related with ENSO oscillation?

    In South America, there is a high connection between seasonal rainfall and El Niño/La Niña teleconnection, but not every drought event is high correlated with changing sea surface temperatures at the Pacific ocean. 

    Nivaldo Fernandes Teixeira

    I would suggest to those interested in the subject, the readings of published works:

    • Source
      [Show abstract] [Hide abstract] ABSTRACT: This study aims to perform the analysis of the daily rainfall events by calculating the rainfall anomalies and values of the Concentration Index (CI) of daily precipitation. The database consists of 22 points from observations of the Agência Nacional de Águas (ANA), a sufficiently long series for the period 1953 to 2012. The R software (Climatol and Precintcon packages) was used for verification of consistency and standardization, also for the calculation of CI, and subsequent preparation of maps using the Surfer program 10. Generally, in the semi-arid drought years correspond to El Niño years and La Niña with abundant rainfall, although other factors, such as the Atlantic, can distort this relationship. Previous analyzes showing that the stronger are the El Niño (La Niña), the greater the rainfall anomalies, namely, intense El Niño – Southern Oscillation (ENSO) events cause heavy rains (La Niña), or severe drought (El Niño) are confirmed contributing to the daily concentration.
      Full-text Conference Paper · Oct 2014

    + 1 more attachment

  • R. Perdomo added an answer:
    A Database of beach sand temperatures exists?

    I found data in some papers (mostly concerning marine turtles sexual determination), but I can't find a monitoring of that for a extended period of time (a year, e. g.).

    R. Perdomo

    Good morning Gabriela,

    In general the reanalysis data bases, haved data of temperatures of soil is necessary determinate your interest area.

    the names of possible data bases for utility are CFS NCEP-NCAR, ERA 40 and ERA Interim

  • Pallavi Kulkarni added an answer:
    How to calculate "Air temperature" from "land surface temperature"?
    Air temperature from LST (day and night).
    Pallavi Kulkarni

    @Richard Daniel Smith-Unna. I tried to download data from the Worldclim but I did not get the year wise data instead I got the average data for 12 months. How can I download year wise data from Worldclim?

  • Alex Edstrom added an answer:
    What do these error messages concerning gridded Green and Ampt infiltration in HEC-HMS mean?

    I am trying to set up a model in HEC-HMS using gidded Green and Ampt Infiltration as the loss method and ModClark for transformation but when I try to run it I get the following error messages: 

    ERROR 44850: Loss method "Gridded Green Ampt" is invalid for grid cells.
    ERROR 40501: An error occurred while initializing grid cell data for subbasin "W90". Parameter grid is missing or incomplete.
    ERROR 40441: Subbasin "W90" could not be initialized because the grid cells were missing or parameter data was invalid.

     I created a grid cell file using HecGeoHMS and I followed the instructions of the GeoHMS User Manual in order to create an ascii- file in the same coordinate system (SHG100) and then used this file as a mask to create all the gridded parameter information I need (Impervious area, initial water content, etc.) I also used this file to get my gridded precipitation data in the same resolution and the same extent as the grid cell file... 

    Then I transformed all these ascii-grids to dss files using the asc2dssGrid utility. 

    In case it is of importance: Before the error messages I also got those warnings:

    NOTE 40552: Grid cell file contained 4 invalid cells for subbasin "W140". Lost area equals 0.00008
    NOTE 40552: Grid cell file contained 3 invalid cells for subbasin "W90". Lost area equals 0.00003
    NOTE 40552: Grid cell file contained 2 invalid cells for subbasin "W80". Lost area equals 0.00006

    Alex Edstrom

    Follow up:

    Regarding gridded approaches and HEC-HMS, the current versions (3.5, 4.0, and 4.1) do not support gridded Green& Ampt losses. Gridded Curve Number, Gridded Deficit Loss, and Gridded SMA should all work, although I haven't evaluated (Gridded SMA at this time).

    Additionally, gridded deficit constant loss was only working if I initially used version 3.5. I experienced some bugs in going from HEC-GeoHMS to HEC-HMS version 4.0 and 4.1. Hopefully this helps. 

  • Muhammad Usman Saleem added an answer:
    How to get Radar Reflectivity(dbz and mdbz ) from WRF_Chem Model..?

    Dear All,

                  dbz and mdbz are diagnostic varibles which we can get from ARW post. It is working fine for WRF runs but when i am trying to get dbz and mdbz from WRF_Chem output ARW post is not giving these values. I am using same physics in both WRF and WRF_Chem runs. can any one please help me to solve this problem.

    Muhammad Usman Saleem

    For modify calculation, please try to read these documentations

    Use ITU recommendations for constant define values for ice and water

  • Nouar Boulghobra added an answer:
    Hello; Is a wind series of 1 measurement per day (at 12:00h) sufficient for obtaining reliable values of Sand Drift Potential ?

    Using the Fryberger's and Dean (1979) formulae.

    Nouar Boulghobra

    Dear professor Yasseri, a good question could contribute on well understanding, and consequently on producing accurate and reliable knowledge, herein manifestes the impact of beneficial assistance of high level experts as you are professor. My gratutude and respect.


  • Virendra Yadav added an answer:
    Is there anyone who can discuss about sporadic-E occurrence over equatorial region?

    I currently analyzing diurnal and seasonal pattern of sporadic-E occurrence over Indonesia (equatorial or low-latitude region) and found that the occurrence drop at 12:00 local time during which solar irradiation is maximum. It is hard for me to find specific reference related to this subject. Is there anyone who can discuss about this matter?

    Virendra Yadav

    Even though Blanketing Sporadic E (Esb) is a stronger form of Sporadic E (Es) at mid-latitudes, at dip equatorial region, the characteristics of Es and Esb are different, the processes involved in their formation are different. Hence it is better to look at Es and Esb as two different phenomena close to equator.

    My paper "Occurrence of blanketing Es-layer..." mentioned in the 1st answer only covers the occurrence of Esb. You can also use the references mentioned in that paper.

    For Es, you can look at the below reference. They have studied Es in the Brazilian sector.

    Please keep this in mind that Es and Esb are more of localized phenomena. Hence the characteristics seen in one longitude sector are different from the characteristics seen in some other longitude sector.

About Climatology

Climatology is the study of climate, scientifically defined as weather conditions averaged over a period of time, and is a branch of the atmospheric sciences.

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