Article
Meteorology & Atmospheric Sciences
Ari Kurniadi, Evan Weller, Seung-Ki Min, Min-Gyu Seong
Summary: This study uses Generalized Extreme Value analysis to investigate the independent seasonal impacts of El Nino-Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) on rainfall extremes in Indonesia. The study finds that the impacts are strongest during dry seasons and weaker during wet seasons. ENSO and IOD can make extreme climate conditions drier or wetter in Indonesia.
INTERNATIONAL JOURNAL OF CLIMATOLOGY
(2021)
Article
Meteorology & Atmospheric Sciences
Biqi Liu, Guixing Chen, Wenxin Zeng, Lanqiang Bai, Huiling Qin
Summary: Monsoon southerlies play an important role in rainfall over East Asia, with multiday variations and distinct diurnal cycles. This study categorizes southerly monsoon surges into two types based on their wind diurnal variations, which have different influences on rainfall patterns in East Asia. The differences between the two types highlight the interaction between multiday large-scale conditions and subdaily regional forcings, which greatly regulate the detailed evolution of the summer rainband over East Asia.
JOURNAL OF CLIMATE
(2022)
Article
Meteorology & Atmospheric Sciences
Yeon-Woo Choi, Elfatih A. B. Eltahir
Summary: Crop production in East Africa is facing challenges due to climate change, population growth, and slow adoption of agricultural technology. The impacts of climate change on food crop productivity are uncertain, but our projections suggest increased temperature and precipitation during 2021-2050. However, the effects will vary across the region, with negative impacts in Sudan and mixed impacts in Ethiopia. Proactive adaptation measures, including technological adoption and expansion of croplands, are needed to mitigate the projected challenges.
THEORETICAL AND APPLIED CLIMATOLOGY
(2023)
Article
Geochemistry & Geophysics
Moses A. Ojara, Lou Yunsheng, Md. Jalal Uddin, Hassen Babaousmail, Brian Ayugi
Summary: This study investigates the variability and trends of rainfall in East African countries using rainfall datasets and atmospheric indices. Results show periodicity and trend changes in rainfall, with significant correlations between rainfall and El Nino-Southern Oscillation (ENSO) as well as Indian Ocean Dipole (IOD). The findings have implications for drought and flood early warning systems and economic programs in the region.
PURE AND APPLIED GEOPHYSICS
(2022)
Article
Meteorology & Atmospheric Sciences
Foupouapegnigni Moihamette, Wilfried Mba Pokam, Ismaila Diallo, Richard Washington
Summary: This study examines the influence of extreme Indian Ocean Dipole (IOD) events on Central Africa rainfall using both observational and reanalysis datasets. The results show that during extreme positive IOD events, rainfall in Central Africa increases, while during extreme negative IOD events, rainfall decreases. The study also finds that the intensification of the African Easterly Jet and the non-El Nino effect are important factors in driving this rainfall variability.
INTERNATIONAL JOURNAL OF CLIMATOLOGY
(2022)
Article
Meteorology & Atmospheric Sciences
Peter G. G. Hill, Thorwald H. M. Stein, Carlo Cafaro
Summary: East Africa is highly susceptible to severe weather events, resulting in numerous deaths each year. Accurate forecasts of convective events in this region are urgently needed. Through a six-year study, this research aims to enhance understanding of convective events in East Africa and their impact on surface precipitation. By tracking convective systems and analyzing their life cycles and associated precipitation, it is found that most heavy precipitation events are caused by convective systems, while light rainfall events are not. The study also links the Madden-Julian oscillation to rainfall amount due to convective systems.
QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY
(2023)
Article
Meteorology & Atmospheric Sciences
Chanil Park, Seok-Woo Son, Hyemi Kim
Summary: The study investigates the atmospheric river (AR) and its impact on monsoon rainfall in East Asia. It found that the characteristics of AR vary from the early to late period of the East Asian summer monsoon, with different influencing factors during each period. Early- and late-EASM ARs both contribute substantially to monsoon rainfall, especially to heavy rainfall events.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2021)
Article
Meteorology & Atmospheric Sciences
Athanase Nkunzimana, Bi Shuoben, Wang Guojie, Mohamed Abdallah Ahmed Alriah, Isaac Sarfo, Xu Zhihui, Floribert Vuguziga, Brian Odhiambo Ayugi
Summary: This study used SPI and trend analysis to find that the northern part of Burundi experienced high frequency of extreme drought events during the 1990s, leading to consecutive dry periods and significant differences compared to the South and mountainous regions. Additionally, teleconnection factors showed a link between dry events and sea surface temperature anomalies over the Indian Ocean during negative phases of the Indian Ocean Dipole and La Nina years.
THEORETICAL AND APPLIED CLIMATOLOGY
(2021)
Article
Geochemistry & Geophysics
Kumarjit Saha, Anirban Guha, Trisanu Banik
Summary: The study shows that the different phases and amplitudes of IOD and ENSO have an impact on the interannual variability of Indian summer monsoon rainfall in Northeast India, with different precipitation trends observed in different event years.
JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS
(2021)
Article
Meteorology & Atmospheric Sciences
Qian Liu, Guixing Chen, Lin Wang, Yuki Kanno, Toshiki Iwasaki
Summary: The winter monsoon in East Asia is significantly influenced by cold air outbreaks (CAOs) with different types such as H-L, H-M, and M-L events, each displaying different patterns of cold air flux over Eurasia and northeastern Asia. H-L events lead to widespread and long-lasting low temperatures in East Asia, while M-L events mainly cause sharp temperature drops in low latitude regions. The occurrences of H-L and M-L events have decreased since the 1980s, resulting in a stronger warming trend in cold extremes than in winter mean temperature at mid-low latitudes in East Asia.
JOURNAL OF CLIMATE
(2021)
Article
Meteorology & Atmospheric Sciences
Winifred A. Atiah, Leonard K. Amekudzi, Robert A. Akum, Emmanuel Quansah, Philip Antwi-Agyei, Sylvester K. Danuor
Summary: Rain-fed agriculture is crucial for livelihoods in sub-Saharan Africa, with Ghana heavily reliant on it for employment and GDP contribution. However, limited research on the impacts of climate variability on crop yield in the region hinders policy planning to address threats to crop production. This particular study in Ghana highlights the vulnerability of maize yield to climatic factors and underscores the need for investment in climate-smart agricultural technologies to maximize productivity.
QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY
(2022)
Article
Ecology
Jingkang Liao, Mingzhen Lu, Huijie Gu, Binyu Luo, Xin Jing, Jin-Sheng He
Summary: This perspective piece aims to establish a baseline understanding of the spatial distribution of ants on the Tibetan Plateau, evaluate their response to climate change, and identify future research avenues to elucidate the impacts of warming-induced ant expansion.
Article
Geosciences, Multidisciplinary
Xiaolin Zhang, Takashi Mochizuki
Summary: This study examines the decadal modulations in impacts of El Nino and Southern Ocean (ENSO) and Indian Ocean Dipole (IOD) on the tropical Indian Ocean upwelling. By combining observational data and statistical model simulations, the study identifies important contributors to these decadal modulations. The results show that a Bayesian Dynamic Linear Model (BDLM) can better reproduce the time series of the eastern and western Indian Ocean upwellings compared to a conventional Static Linear regression Model. The study also reveals that the observed shift in the IOD impact on the eastern Indian Ocean upwelling is mainly due to changes in alongshore wind stress forcing and the sensitivity of the upper ocean temperature in the eastern Indian Ocean.
FRONTIERS IN EARTH SCIENCE
(2023)
Article
Meteorology & Atmospheric Sciences
Armenia Franco-Diaz, Nicholas P. Klingaman, Andrew G. Turner, Buwen Dong, Liang Guo
Summary: This study evaluates the simulation of the East Asian summer monsoon (EASM) by the Met Office Unified Model (GA7 and GC3 configurations) and identifies systematic model biases. The results show overestimated rainfall over southern China and underestimated rainfall over northern China, indicating a monsoon that does not penetrate northward enough. The study also investigates the effects of regional errors in sea-surface temperature (SST) conditions on the EASM, and finds that global SST biases significantly alter the EASM seasonal cycle and weaken the teleconnection pathways related to ENSO and IOD.
Article
Meteorology & Atmospheric Sciences
Xu Xue, Wen Chen, Shangfeng Chen, Sisi Sun, Shuangshuang Hou
Summary: This paper analyzes the different relationships between the two types of South Asian highs (SAH) and variations in summer rainfall over East Asia. The ESAH is closely related to summer rainfall over northeastern China, whereas the SSAH is linked to summer rainfall over the Yangtze River valley, northern China, and Japan. Shifts in the westerly jet and the western Pacific subtropical high play a role in the variations of ESAH and SSAH.
INTERNATIONAL JOURNAL OF CLIMATOLOGY
(2021)
Article
Geosciences, Multidisciplinary
Takeshi Doi, Swadhin K. Behera, Toshio Yamagata
GEOPHYSICAL RESEARCH LETTERS
(2020)
Article
Environmental Sciences
Netrananda Sahu, Arpita Panda, Sridhara Nayak, Atul Saini, Manoranjan Mishra, Takahiro Sayama, Limonlisa Sahu, Weili Duan, Ram Avtar, Swadhin Behera
Article
Geosciences, Multidisciplinary
Takeshi Doi, Swadhin K. Behera, Toshio Yamagata
GEOPHYSICAL RESEARCH LETTERS
(2020)
Article
Green & Sustainable Science & Technology
Netrananda Sahu, Atul Saini, Swadhin Behera, Takahiro Sayama, Sridhara Nayak, Limonlisa Sahu, Weili Duan, Ram Avtar, Masafumi Yamada, R. B. Singh, Kaoru Takara
Article
Oceanography
Yushi Morioka, Swadhin K. Behera
Summary: Sea ice in the Weddell Sea does not show significant trend in the four-decade satellite observation period, but does experience large interannual-to-decadal variability. Weakening westerly winds and strengthening of the Weddell Gyre can lead to an increase in sea ice extent. Both remote atmospheric forcing and local ice-ocean interaction play crucial roles in generating decadal sea ice variability in the Weddell Sea.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2021)
Article
Meteorology & Atmospheric Sciences
Balaji Senapati, Pranab Deb, Mihir K. Dash, Swadhin K. Behera
Summary: Through empirical orthogonal function analysis, a stationary atmospheric wavenumber-4 (AW4) pattern is identified in the Southern mid-latitudes during austral summer, forced by a Rossby wave source in the upstream region. This pattern influences rainfall in different parts of South America and Australia by modulating upper-level divergence.
Article
Environmental Sciences
Tomomichi Ogata, Marie-Fanny Racault, Masami Nonaka, Swadhin Behera
Summary: Cholera is a water-borne infectious disease that affects millions of people globally each year, with high fatality rates. Understanding the mechanistic link between climate variability and cholera outbreaks can help predict and prepare for outbreaks. Factors such as the summer monsoon and climate patterns like La Nina play a significant role in driving cholera outbreaks, highlighting the importance of considering multi-decadal variations in climate interactions for better public health responses.
INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH
(2021)
Article
Geosciences, Multidisciplinary
Balaji Senapati, Mihir K. Dash, Swadhin K. Behera
Summary: A decadal variability is observed in the sea surface temperature wavenumber-4 pattern of the southern subtropics. This variability is influenced by the South Pacific Meridional Mode. Changes in SST residuals affect the frequency of occurrence of the SST wavenumber-4 pattern and impact rainfall variability over the Southern continents through modulation of local atmospheric circulation.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Environmental Sciences
Atul Saini, Netrananda Sahu, Saroj K. Mishra, Shipra Jain, Swadhin Behera, Sushil K. Dash
Summary: This study analyzed the regional variations of monsoon onset dates in India under different climate variations and flood/drought years. The results showed that the northern, northeastern, and southern parts of India were highly susceptible to early onset of La Nina, while the northern and northwest parts were highly susceptible to early onset of El Nino. Monsoon onset dates were early in flood years and later in drought years.
Article
Meteorology & Atmospheric Sciences
Le Chang, Yushi Morioka, Swadhin Behera, Jing-Jia Luo, Haiming Xu, Bing Zhou
Summary: This study investigates the interannual variations of air temperature and sea ice concentration in the Barents-Kara Seas region. The Arctic Dipole is found to be a leading factor in the variability, affecting atmospheric circulations and local feedbacks. Positive temperature advection anomalies during negative Arctic Dipole phase promote sea ice melting, while negative Arctic Dipole phase results in increased sea ice. Additionally, sea surface temperature variability in the midlatitudes of the North Atlantic also plays a role in sea ice concentration variability in the Barents-Kara Seas.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2022)
Article
Geosciences, Multidisciplinary
P. Martineau, S. K. Behera, M. Nonaka, H. Nakamura, Y. Kosaka
Summary: The dominant mode of interannual variability in summertime high-frequency tropospheric temperature fluctuations over Southern Africa is associated with tropical Pacific sea surface temperature variability. El Nino is typically accompanied by enhanced high-frequency variability. This relationship is established via El Nino's teleconnection that contributes to shifting the midlatitude jetstream and associated baroclinic zone equatorward into the vicinity of Southern Africa, which enhances the baroclinic conversion of energy from the seasonal-mean flow to high-frequency eddies. The enhanced temperature variance, combined with the overall warmer summertime-mean temperatures induced by El Nino, results in more frequent warm extremes over Southern Africa.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Meteorology & Atmospheric Sciences
Kalpesh Ravindra Patil, Takeshi Doi, Swadhin K. Behera
Summary: The East African region is prone to severe floods and persistent droughts, greatly impacting millions of people's livelihoods. Most prediction systems using dynamical models perform poorly at long lead times. In this study, a statistical deep learning approach based on a convolutional neural network (CNN) is proposed to predict extreme floods and droughts during the short rains season (October-December). The CNN model can capture the occurrence of extreme floods and droughts two to three seasons ahead, except for a few cases. By diagnosing the model's skills using heatmaps, it is found that predicted extreme floods and droughts are linked with sea surface temperature anomalies of the Indian Ocean Dipole at shorter leads and with other oceanic factors at longer leads. The superior skill of the CNN-based predictions at longer leads provides significant advantages in developing mitigation measures.
NPJ CLIMATE AND ATMOSPHERIC SCIENCE
(2023)
Article
Environmental Sciences
Yushi Morioka, Doroteaciro Iovino, Andrea Cipollone, Simona Masina, Swadhin K. Behera
Summary: Decadal sea ice variability in the west Antarctic seas can be skillfully predicted by initializing sea surface temperature, sea ice concentration, and subsurface ocean temperature and salinity from observations. Skillful prediction of decadal sea ice variability benefits from combined ocean and sea ice initializations.
COMMUNICATIONS EARTH & ENVIRONMENT
(2022)
Editorial Material
Multidisciplinary Sciences
Benjamin F. Zaitchik, Neville Sweijd, Joy Shumake-Guillemot, Andy Morse, Chris Gordon, Aileen Marty, Juli Trtanj, Juerg Luterbacher, Joel Botai, Swadhin Behera, Yonglong Lu, Jane Olwoch, Ken Takahashi, Jennifer D. Stowell, Xavier Rodo
NATURE COMMUNICATIONS
(2020)
Article
Environmental Sciences
Atul Saini, Netrananda Sahu, Pankaj Kumar, Sridhara Nayak, Weili Duan, Ram Avtar, Swadhin Behera