Saji Hameed

Saji Hameed
The University of Aizu · Division of Computer Sciences

PhD (Atmospheric Sciences)

About

43
Publications
27,000
Reads
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7,662
Citations
Introduction
I am working to understand the role of coupled ocean-atmosphere interaction in the tropical Indian and Pacific Oceans
Additional affiliations
January 2010 - present
August 2006 - December 2009
APEC Climate Center
Position
  • Research Director
February 2002 - July 2006
University of Hawaiʻi at Mānoa
Position
  • Research Assistant

Publications

Publications (43)
Article
Full-text available
Impacts of Indian Ocean Dipole mode (IOD) events on global climate are estimated by correlation/regression analysis. The analysis examined land rain and temperature and 3-dimensional atmospheric variables for a 42 yr period from January 1958 to December 1999. The correlation between IOD and the El Niño Southern Oscillation (ENSO) is accounted for u...
Article
Full-text available
1] Intense intraseasonal cooling events in the tropical south Indian Ocean are examined using eight years of TRMM observations. These events occur almost every year during austral summer when the intertropical convergence zone is displaced south of the equator and roughly collocated with a thermocline ridge. Composite maps of SST, OLR and surface w...
Article
Full-text available
For the tropical Pacific and Atlantic oceans, internal modes of variability that lead to climatic oscillations have been recognized, but in the Indian Ocean region a similar ocean-atmosphere interaction causing interannual climate variability has not yet been found. Here we report an analysis of observational data over the past 40 years, showing a...
Chapter
Full-text available
A review of the Indian Ocean Dipole. It is available online at http://climatescience.oxfordre.com/view/10.1093/acrefore/9780190228620.001.0001/acrefore-9780190228620-e-619 or DOI: 10.1093/acrefore/9780190228620.013.619
Experiment Findings
Following advise from Immanuel Kant, I started using my own coginitive and judgement machinery. 1. First, I looked around me and saw if people were gasping for breath and passing out, as I had seen on social media platforms. 2. I travelled to certain risky areas, sampled the fresh air into my lungs continuously, exchanged hand shakes and hugs....
Experiment Findings
Full-text available
Following advise from Immanuel Kant, I started using my own coginitive and judgement machinery. 1. First, I looked around me and saw if people were gasping for breath and passing out, as I had seen on social media platforms. 2. I travelled to certain risky areas, sampled the fresh air into my lungs continuously, exchanged hand shakes and hugs....
Article
Full-text available
The usefulness of dynamical downscaling of seasonal reforecasts of Indian Monsoon is explored to address the seasonal mean biases in the reforecasts. Almost all the current generation global coupled models, including the Climate Forecast System version 2 (CFSv2, T126 ~110 km), exhibit systematic mean dry bias over the central Indian region during t...
Article
Full-text available
A dry bias in climatological Central Indian rainfall plagues Indian summer monsoon (ISM) simulations in multiple generations of climate models. Here, using observations and regional climate modeling, we focus on a warm coastal Bay of Bengal sea surface temperature (SST) front and its impact on Central Indian rainfall. The SST front, featuring sharp...
Article
Full-text available
(The article can be accessed from https://www.nature.com/articles/s41467-018-04803-7; Open Access) // --------------------------------------------------------------------------------------------------------------------- // Super El Niños, the strongest and most powerful of El Niños, impact economies, societies, and ecosystems disproportionately. D...
Article
Full-text available
The eastern China Precipitation Dipole (ECPD) features an out-of-phase relationship between boreal summer precipitation over the middle and lower reaches of the Yangtze River and the Hetao Region to its northwest. The precipitation dipole is strongly influenced by ENSO teleconnections over the western tropical Pacific. Here it is shown that a prono...
Article
Full-text available
High Performance Computing (HPC) platforms allow scientists to model computationally intensive algorithms. HPC clusters increasingly use General-Purpose Graphics Processing Units (GPGPUs) as accelerators; FPGAs provide an attractive alternative to GPGPUs for use as co-processors, but they are still far from being mainstream due to a number of chall...
Article
The connection between north tropical Atlantic (NTA) sea surface temperature (SST) anomalies and tropical cyclone (TC) genesis over the western North Pacific (WNP) and associated physical mechanisms are investigated in this study. We demonstrate a remarkable negative correlation of WNP TC genesis frequency with the (preceding) boreal spring NTA SST...
Conference Paper
Full-text available
FLEXPART is a popular simulator that models the transport and diffusion of air pollutants, based on the Lagrangian approach. It is capable of regional and global simulation and supports both forward and backward runs. A complex model like this contains many calculations suitable for parallelisation. Recently, a GPU-accelerated version of the simula...
Conference Paper
Full-text available
FLEXPART is a popular simulator that models the transport and diffusion of air pollutants, based on the Lagrangian approach. It is capable of regional and global simulation and supports both forward and backward runs. A complex model like this contains many calculations suitable for parallelisation. Recently, a GPU-accelerated version of the simula...
Article
Full-text available
Cool and wet weather conditions hit northern Central Asia, East Asia and central North America during the 2009 summer in concert with a strong jet stream and a prominent meandering upper-level circulation in the Northern Hemisphere mid-latitudes despite the fact that the year 2009 is the fifth warmest year globally in the modern record. It is found...
Article
Full-text available
The hypothesis that regional characteristics of the East Asian summer monsoon (EASM) result from the presence of nonlinear coupled features that modulate the seasonal circulation and rainfall at the intraseasonal time scale is advanced in this study. To examine this hypothesis, the authors undertake the analysis of daily EASM variability using a no...
Article
Full-text available
We advance the hypothesis that regional characteristics of the East Asian Summer Monsoon (EASM) result from the presence of non-linear coupled features that modulate the seasonal circulation and rainfall at the intraseasonal timescale. To examine this hypothesis, we undertake the analysis of daily EASM variability using a non-linear multivariate da...
Article
The ability of the CLImate GENerator (CLIGEN) weather generator to reproduce daily precipitation characteristics for Korea was assessed on the basis of 55-year long historical daily precipitation records from eight weather stations (Seoul, Incheon, Daegu, Ulsan, Gwangju, Busan, Kangneung, and Jeonju) representing different parts of the Korean penin...
Article
Full-text available
This paper presents an assessment of the seasonal prediction skill of current global circulation models, with a focus on the two-meter air temperature and precipitation over the Southeast United States. The model seasonal hindcasts are analyzed using measures of potential predictability, anomaly correlation, Brier skill score, and Gerrity skill sco...
Article
Full-text available
A pattern projection downscaling method is applied to predict summer precipitation at 60 stations over Korea. 'Me predictors are multiple variables from the output of six operational dynamical models. The hindcast datasets span a period of 21 yr from 1983 to 2003. A downscaled prediction was made for each model separately within a leave-one-out cro...
Article
The sea surface temperature anomalies (SSTA) of tropical Pacific in the boreal summer of 2004 show a distinct tripolar pattern with warm SSTA in the central tropical Pacific, flanked on both sides by cold SSTA. The distinct conditions during the boreal summer of 2004 and the following winter were catalogued as a new coupled phenomenon named El Niño...
Article
Full-text available
Intense cooling of the sea surface at intraseasonal time scales takes place in the southern tropical Indian Ocean during austral summer. Mechanisms that cause intraseasonal cooling are investigated using in situ observations by Argo floats, remote sensing data sets and simulation using a high resolution ocean general circulation model of the Indian...
Article
Full-text available
The relative impacts of the ENSO and Indian Ocean dipole (IOD) events on Indian summer (June–September) monsoon rainfall at sub-regional scales have been examined in this study. GISST datasets from 1958 to 1998, along with Willmott and Matsuura gridded rainfall data, all India summer monsoon rainfall data, and homogeneous and sub-regional Indian ra...
Article
For coupled modelling studies, the atmospheric component is required to simulate the large-scale part of the observed surface winds accurately, as only this part is responsible for driving low-frequency interannual variability in the oceans. A simple linear model of the tropical atmosphere is developed in which surface winds are viewed as the respo...
Article
Full-text available
The twentieth-century simulations using by 17 coupled ocean–atmosphere general circulation models (CGCMs) submitted to the Intergovernmental Panel on Climate Change’s Fourth Assessment Report (IPCC AR4) are evaluated for their skill in reproducing the observed modes of Indian Ocean (IO) climate variability. Most models successfully capture the IO’s...
Article
Full-text available
The Asian summer monsoon is organized into distinct convection centers, but the mechanism for this organization is not well understood. Analysis of new satellite observations reveals that narrow mountain ranges are an important organizing agent anchoring monsoon convection centers on the windward side. The Bay of Bengal convection, in particular, f...
Article
Full-text available
The impact of Indian Ocean Dipole (IOD) mode events on austral surface air temperature (SAT) variability was studied both by statistical analysis of observed/assimilated data and experiments with a mechanistic baroclinic atmospheric model.During the period of analysis (January 1958–December 1999), IOD events had the strongest impact on SAT anomalie...
Article
Full-text available
The relative influences of the ENSO and Indian Ocean Dipole (IOD) events on the Indian summer rainfall were studied using observational data and an atmospheric general circulation model (AGCM). The composite analysis of rainfall anomalies demonstrates that the IOD, while significantly influencing the Indian summer monsoon rainfall, also significant...
Article
Full-text available
A study of the detailed spatiotemporal characteristics of the Indian Ocean dipole (IOD) mode in SST and surface winds using available observations from 1958 till 1997 is reported. The analysis is used to address several of the controversial issues regarding the IOD.One key finding of this study is that interdecadal fluctuations contribute strongly...
Article
Full-text available
The misleading aspect of the statistical analyses used in Dommenget and Latif, which raises concerns on some of the reported climate modes, is demonstrated. Adopting simple statistical techniques, the physical existence of the Indian Ocean dipole mode is shown and then the limitations of varimax and regression analyses in capturing the climate mode...
Article
Full-text available
Unusual westward wind anomalies were observed in the Indian Ocean during 1994. The response of the ocean to these anomalies is studied using an ocean general circulation model forced with interannual winds. Model results show that the eastward equatorial jets in the Indian Ocean were weak during 1994. Consequently, the sea level in the eastern Indi...
Article
Full-text available
The mean state of the tropical atmosphere is important as the nature of the coupling between the ocean and the atmosphere depends nonlinearly on the basic state of the coupled system. The simulation of the annual cycle of the tropical surface wind stress by 17 atmospheric general circulation models (AGCMs) is examined and intercompared. The models...
Article
Full-text available
The authors present the simulation of the tropical Pacific surface wind variability by a low-resolution (R15 horizontal resolution and 18 vertical levels) version of the Center for Ocean-Land-Atmosphere Interactions, Maryland, general circulation model (GCM) when forced by observed global sea surface temperature. The authors have examined the month...

Questions

Question (1)
Question
What do you think about this year's IOD development? Please check all the relevant fields (SST, SSH, OLR and surface wind anomalies) to analyze the situation. Are these different fields consistent with IOD development and among themselves? What kind of feedback is present among the different fields? Based on these, will the IOD further develop? How do the fields compare to 2006, the strongest IOD of the 21st century?

Projects

Projects (7)
Project
To provide an alternative, personal view of current and events to come (now that we have the Noble metal poured into climate change, it is hard not to see what might happen)
Project
Provide near real-time updates of ocean-atmosphere conditions over the tropical Indian Ocean. We seem to have the first strong IOD since 2006 Pls. visit http://enformtk.u-aizu.ac.jp
Project
ICAR is an exciting new climate center being set up at the Nanjing University of Information Science and Technology in Nanjing, China. In this space, I will post information related to ICAR, especially upcoming positions and projects