Researcher Information
researchmap URL
Research activity information
Papers
- J.V. Ratnam; Swadhin K. Behera; Masami Nonaka; Kalpesh R. Patil
Skillful prediction of Indian Ocean Dipole index using machine learning models
Applied Computing and Geosciences, Feb. 2025
25, 100228, 100228
[Reviewed]
Lead - Swadhin K. Behera; Roma Varghese; J. V. Ratnam; Takeshi Doi; Mukunda Dev Behera
Role of ocean and climate in terrestrial ecosystems
Sustainable Development Perspectives in Earth Observation, 01 Jan. 2025
419, 435 - J. V. Ratnam; Swadhin K. Behera; Ibrahim Hoteit; Takeshi Doi; Masami Nonaka
Predicting monthly precipitation in the wet season over Saudi Arabia using a seasonal prediction system
Weather and Forecasting, 19 Dec. 2024
[Reviewed]
Lead - J. V. Ratnam; Swadhin K. Behera; Takeshi Doi; Masami Nonaka
Skillful prediction of the maximum air temperature over India using a seasonal prediction system
Climate Dynamics, 13 Sep. 2024
62, 10, 9861, 9879
[Reviewed]
Lead - Ingo Richter; Jayanthi V. Ratnam; Patrick Martineau; Pascal Oettli; Takeshi Doi; Tomomichi Ogata; Takahito Kataoka; François Counillon
A Simple Statistical Postprocessing Scheme for Enhancing the Skill of Seasonal SST Predictions in the Tropics
Monthly Weather Review, Apr. 2024
152, 4, 1039, 1056 - Micheal T Pillay; Noboru Minakawa; Yoonhee Kim; Nyakallo Kgalane; Jayanthi V Ratnam; Swadhin K Behera; Masahiro Hashizume; Neville Sweijd
Utilizing a novel high-resolution malaria dataset for climate-informed predictions with a deep learning transformer model.
Scientific reports, 28 Dec. 2023
13, 1, 23091, 23091 - J. V. Ratnam; Swadhin K. Behera; Masami Nonaka; Patrick Martineau; Kalpesh R. Patil
Predicting maximum temperatures over India 10-days ahead using machine learning models
Scientific Reports, 11 Oct. 2023
13, 1
[Reviewed]
Lead - Patrick Martineau; Swadhin K. K. Behera; Masami Nonaka; Ratnam Jayanthi; Takayoshi Ikeda; Noboru Minakawa; Philip Kruger; Qavanisi E. E. Mabunda
Predicting malaria outbreaks from sea surface temperature variability up to 9 months ahead in Limpopo, South Africa, using machine learning
FRONTIERS IN PUBLIC HEALTH, Aug. 2022
10 - J. V. Ratnam; Takeshi Doi; Ingo Richter; Pascal Oettli; Masami Nonaka; Swadhin K. Behera
Using Selected Members of a Large Ensemble to Improve Prediction of Surface Air Temperature Anomalies Over Japan in the Winter Months From Mid-Autumn
Frontiers in Climate, 16 Jun. 2022
4
Lead - J. V. Ratnam; Masami Nonaka; Swadhin K. Behera
Winter surface air temperature prediction over Japan using artificial neural networks
Weather and Forecasting, 17 May 2021
36, 4, 1343, 1356
[Reviewed]
Lead - J. V. Ratnam; Takeshi Doi; Yushi Morioka; Pascal Oettli; Masami Nonaka; Swadhin K. Behera
Improving Predictions of Surface Air Temperature Anomalies over Japan by the Selective Ensemble Mean Technique
Weather and Forecasting, Feb. 2021
36, 1, 207, 217
[Reviewed]
Lead - Yoonhee Kim; J. V. Ratnam; Takeshi Doi; Yushi Morioka; Swadhin Behera; Ataru Tsuzuki; Noboru Minakawa; Neville Sweijd; Philip Kruger; Rajendra Maharaj; Chisato Chrissy Imai; Chris Fook Sheng Ng; Yeonseung Chung; Masahiro Hashizume
Publisher Correction: Malaria predictions based on seasonal climate forecasts in South Africa: A time series distributed lag nonlinear model (Scientific Reports, (2019), 9, 1, (17882), 10.1038/s41598-019-53838-3)
Scientific Reports, 01 Dec. 2020
10, 1 - Swadhin Kumar Behera; Takeshi Doi; J. Venkata Ratnam
Air-sea interactions in tropical Indian Ocean: The Indian Ocean Dipole
Tropical and Extratropical Air-Sea Interactions: Modes of Climate Variations, 01 Jan. 2020
115, 139 - J.V. Ratnam; H. A. Dijkstra; Swadhin K. Behera
A machine learning based prediction system for the Indian Ocean Dipole
Scientific Reports, Jan. 2020
[Reviewed] - Manali Pal; Rajib Maity; J. V. Ratnam; Masami Nonaka; Swadhin K. Behera
Long-lead Prediction of ENSO Modoki Index using Machine Learning algorithms
Scientific Reports, Jan. 2020
10, 1
[Reviewed] - Rajib Maity; Kironmala Chanda; Riya Dutta; J. V. Ratnam; Masami Nonaka; Swadhin Behera
Contrasting features of hydroclimatic teleconnections and the predictability of seasonal rainfall over east and west Japan
Meteorological Applications, Jan. 2020
27, 1
[Reviewed] - Kim, Yoonhee; Ratnam, J. V.; Doi, Takeshi; Morioka, Yushi; Behera, Swadhin; Tsuzuki, Ataru; Minakawa, Noboru; Sweijd, Neville; Kruger, Philip; Maharaj, Rajendra; Imai, Chisato C. Hrissy; Ng, Chris Fook Sheng; Chung, Yeonseung; Hashizume, Masahiro
Malaria predictions based on seasonal climate forecasts in South Africa: A time series distributed lag nonlinear model
SCIENTIFIC REPORTS, Nov. 2019
9
[Reviewed] - J. V. Ratnam; H. A. Dijkstra; Takeshi Doi; Yushi Morioka; Masami Nonaka; Swadhin K. Behera
Improving seasonal forecasts of air temperature using a genetic algorithm
Scientific Reports, Sep. 2019
9
[Reviewed] - Ratnam, J. V.; Doi, Takeshi; Behera, Swadhin K.
Improving austral summer precipitation forecasts of SINTEX-F2 coupled ocean-atmosphere general circulation model over southern Africa by simple bias correction techniques
ATMOSPHERIC SCIENCE LETTERS, Mar. 2019
20, 3
[Reviewed] - Swadhin K. Behera; J. V. Ratnam
Quasi-asymmetric response of the Indian summer monsoon rainfall to opposite phases of the IOD
Scientific Reports, 01 Dec. 2018
8, 1
[Reviewed] - Ratnam, J. V.; Doi, Takeshi; Landman, Willem A.; Behera, Swadhin K.
Seasonal Forecasting of Onset of Summer Rains over South Africa
JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY, Dec. 2018
57, 12, 2697, 2711
[Reviewed] - Behera, Swadhin K.; Morioka, Yushi; Ikeda, Takayoshi; Doi, Takeshi; Ratnam, Jayanthi V.; Nonaka, Masami; Tsuzuki, Ataru; Imai, Chisato; Kim, Yoonhee; Hashizume, Masahiro; Iwami, Shingo; Kruger, Philip; Maharaj, Rajendra; Sweijd, Neville; Minakawa, Noboru
Malaria incidences in South Africa linked to a climate mode in southwestern Indian Ocean
ENVIRONMENTAL DEVELOPMENT, Sep. 2018
27, 47, 57
[Reviewed] - Ratnam J. V; Behera Swadhin K; Krishnan R; Doi Takeshi; Ratnam J. V.
Sensitivity of Indian summer monsoon simulation to physical parameterization schemes in the WRF model
Climate Research, 2018
74, 1, 43, 66
[Reviewed] - Satyaban B. Ratna; J. V. Ratnam; Swadhin K. Behera; Annalisa Cherchi; Wanqiu Wang; Toshio Yamagata
The unusual wet summer (July) of 2014 in Southern Europe
ATMOSPHERIC RESEARCH, Jun. 2017
189, 61, 68
[Reviewed] - Ratnam J. V; Doi Takeshi; Behera Swadhin K
Dynamical Downscaling of SINTEX-F2v CGCM Seasonal Retrospective Austral Summer Forecasts over Australia
Journal of Climate, May 2017
30, 9, 3219, 3235
[Reviewed] - Satyaban B. Ratna; J. V. Ratnam; S. K. Behera; Fredolin T. Tangang; T. Yamagata
Validation of the WRF regional climate model over the subregions of Southeast Asia: climatology and interannual variability
CLIMATE RESEARCH, 2017
71, 3, 263, 280
[Reviewed] - J. V. Ratnam; Swadhin K. Behera; H. Annamalai; Satyaban B. Ratna; M. Rajeevan; Toshio Yamagata
ENSO's far reaching connection to Indian cold waves
SCIENTIFIC REPORTS, Nov. 2016
6
[Reviewed] - J. V. Ratnam; Swadhin K. Behera; Satyaban B. Ratna; M. Rajeevan; Toshio Yamagata
Anatomy of Indian heatwaves
SCIENTIFIC REPORTS, Apr. 2016
6
[Reviewed] - Ratnam J. V; Behera Swadhin K; Doi Takeshi; Ratnam J. V.; Landman Willem A
Improvements to the WRF Seasonal Hindcasts over South Africa by Bias Correcting the Driving SINTEX-F2v CGCM Fields
Journal of Climate, Apr. 2016
29, 8, 2815, 2829
[Reviewed] - J. Venkata Ratnam; Satyaban B. Ratna; Swadhin K. Behera; C. J. Dew. Rautenbach; Keiko Takakashi; Toshio Yamagata
Dynamical downscaling of seasonal climate in southern Africa
World Scientific Series on Asia-Pacific Weather and Climate, 2016
7, 265, 279
[Reviewed] - Satyaban B. Ratna; J. V. Ratnam; Swadhin. K. Behera; Takeshi Doi; Toshio Yamagata
Downscaled prediction of extreme seasonal climate over Southeast Asia using a regional climate model
TECHNO-OCEAN 2016: RETURN TO THE OCEANS, 2016
375, 380
[Reviewed] - J. V. Ratnam; Yushi Morioka; Swadhin K. Behera; Toshio Yamagata
A model study of regional air-sea interaction in the austral summer precipitation over southern Africa
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, Mar. 2015
120, 6, 2342, 2357
[Reviewed] - J. V. Ratnam; Yushi Morioka; Swadhin K. Behera; Toshio Yamagata
A model study of regional air-sea interaction in the austral summer precipitation over southern Africa
Journal of Geophysical Research, 2015
120, 6, 2342, 2357
[Reviewed] - J. V. Ratnam; S. K. Behera; T. Yamagata
Role of Cross-Equatorial Waves in Maintaining Long Periods of Low Convective Activity over Southern Africa
Journal of the Atmospheric Sciences, 2015
72, 2, 682, 692
[Reviewed] - Satyaban B. Ratna; J. V. Ratnam; S. K. Behera; C. J. deW. Rautenbach; T. Ndarana; K. Takahashi; T. Yamagata
Performance assessment of three convective parameterization schemes in WRF for downscaling summer rainfall over South Africa
CLIMATE DYNAMICS, Jun. 2014
42, 11-12, 2931, 2953
[Reviewed] - J. V. Ratnam; S. K. Behera; Y. Masumoto; T. Yamagata
Remote Effects of El Nino and Modoki Events on the Austral Summer Precipitation of Southern Africa
JOURNAL OF CLIMATE, May 2014
27, 10, 3802, 3815
[Reviewed] - Netrananda Sahu; Swadhin K. Behera; J. V. Ratnam; Roberto Valmir Da Silva; Pradipta Parhi; Weili Duan; Kaoru Takara; R. B. Singh; Toshio Yamagata
El Nino Modoki connection to extremely-low streamflow of the Paranaiba River in Brazil
CLIMATE DYNAMICS, Mar. 2014
42, 5-6, 1509, 1516
[Reviewed] - Swadhin Behera; Jayanthi V. Ratnam; Yukio Masumoto; Toshio Yamagata
Origin of extreme summers in Europe: the Indo-Pacific connection
CLIMATE DYNAMICS, Aug. 2013
41, 3-4, 663, 676
[Reviewed] - Yushi Morioka; J. V. Ratnam; Wataru Sasaki; Yukio Masumoto
Generation Mechanism of the South Pacific Subtropical Dipole
JOURNAL OF CLIMATE, Aug. 2013
26, 16, 6033, 6045
[Reviewed] - J. V. Ratnam; S. K. Behera; S. B. Ratna; C. J. de W. Rautenbach; C. Lennard; J. -J. Luo; Y. Masumoto; K. Takahashi; T. Yamagata
Dynamical Downscaling of Austral Summer Climate Forecasts over Southern Africa Using a Regional Coupled Model
JOURNAL OF CLIMATE, Aug. 2013
26, 16, 6015, 6032
[Reviewed] - Satyaban B. Ratna; Swadhin Behera; J. Venkata Ratnam; Keiko Takahashi; Toshio Yamagata
An index for tropical temperate troughs over southern Africa
CLIMATE DYNAMICS, Jul. 2013
41, 2, 421, 441
[Reviewed] - J. V. Ratnam; S. K. Behera; Y. Masumoto; T. Yamagata
Role of Rossby Waves in the Remote Effects of the North Indian Ocean Tropical Disturbances
MONTHLY WEATHER REVIEW, Nov. 2012
140, 11, 3620, 3633
[Reviewed] - J. V. Ratnam; S. K. Behera; Y. Masumoto; K. Takahashi; T. Yamagata
A simple regional coupled model experiment for summer-time climate simulation over southern Africa
CLIMATE DYNAMICS, Nov. 2012
39, 9-10, 2207, 2217
[Reviewed] - J. V. Ratnam; S. K. Behera; Y. Masumoto; K. Takahashi; T. Yamagata
Anomalous climatic conditions associated with the El Nio Modoki during boreal winter of 2009
CLIMATE DYNAMICS, Jul. 2012
39, 1-2, 227, 238
[Reviewed] - Satyaban Bishoyi Ratna; D. R. Sikka; Mohit Dalvi; J. Venkata Ratnam
Dynamical simulation of Indian summer monsoon circulation, rainfall and its interannual variability using a high resolution atmospheric general circulation model
INTERNATIONAL JOURNAL OF CLIMATOLOGY, Nov. 2011
31, 13, 1927, 1942
[Reviewed] - J. Venkata Ratnam; Swadhin K. Behera; Y. Masumoto; K. Takahashi; T. Yamagata
Pacific Ocean origin for the 2009 Indian summer monsoon failure
GEOPHYSICAL RESEARCH LETTERS, Apr. 2010
37
[Reviewed] - J. Venkata Ratnam; Filippo Giorgi; Akshara Kaginalkar; Stefano Cozzini
Simulation of the Indian monsoon using the RegCM3-ROMS regional coupled model
CLIMATE DYNAMICS, Jul. 2009
33, 1, 119, 139
[Reviewed] - J. Venkata Ratnam; D. R. Sikka; Sudipta Banerjee
Simulation of 2006 monsoon using T170L42 AGCM: sensitivity to convective parameterization schemes
INTERNATIONAL JOURNAL OF CLIMATOLOGY, Feb. 2009
29, 2, 289, 303
[Reviewed] - J. Venkata Ratnam; D. R. Sikka; Akshara Kaginalkar; Amit Kesarkar; N. Jyothi; Sudipta Banerjee
Experimental seasonal forecast of monsoon 2005 using T170L42 AGCM on PARAM padma
PURE AND APPLIED GEOPHYSICS, Sep. 2007
164, 8-9, 1641, 1665
[Reviewed] - JV Ratnam; EA Cox
Simulation of monsoon depressions using MM5: sensitivity to cumulus parameterization schemes
METEOROLOGY AND ATMOSPHERIC PHYSICS, Jun. 2006
93, 1-2, 53, 78
[Reviewed] - JV Ratnam; KK Kumar
Sensitivity of the simulated monsoons of 1987 and 1988 to convective parameterization schemes in MM5
JOURNAL OF CLIMATE, Jul. 2005
18, 14, 2724, 2743
[Reviewed]
