Article
Geography, Physical
Yiping Yang, Rong Xiang, Yun Huang, Shengfa Liu, Jianguo Liu, Somkiat Khokiattiwong, Narumol Kornkanitnan
Summary: By reconstructing high-resolution local δO-18(sw) and sea surface temperature (SST) values in the southern Andaman Sea, this study reveals that the maximum Indian Ocean Monsoon (IOM) precipitation during the early Holocene migrated meridionally from the tropics to the subtropics before moving southward again after 5.0 ka. This shift is likely in response to the northward migration of the Intertropical Convergence Zone (ITCZ) and changes in El Nino Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) activities.
QUATERNARY SCIENCE REVIEWS
(2021)
Article
Environmental Sciences
Jingru Sun, Gabriel Vecchi, Brian Soden
Summary: Satellite remote sensing data spanning multiple years have been used in this study to investigate the climatological characteristics of sea surface salinity (SSS) response to tropical cyclones (TCs). The study found that TCs initially lead to a decrease in SSS due to precipitation, followed by a salinification largely driven by vertical ocean processes. Factors such as TC intensity, translation speed, and vertical stratification in different basins also significantly impact the salinity response during and after TC passage.
Article
Geosciences, Multidisciplinary
Jiangbo Jin, Run Guo, Minghua Zhang, Guangqing Zhou, Qingcun Zeng
Summary: This study proposes a new explicit tidal scheme and evaluates its performance in a global ocean model. The new scheme improves the simulation of tidal characteristics and reduces errors, leading to better dynamic sea level (DSL) simulation in the North Atlantic.
GEOSCIENTIFIC MODEL DEVELOPMENT
(2022)
Article
Geosciences, Multidisciplinary
Nicolas Reul, Bertrand Chapron, Semyon A. Grodsky, Sebastien Guimbard, Vladimir Kudryavtsev, Gregory R. Foltz, Karthik Balaguru
Summary: Decade-long satellite observations show that different intensities and moving speeds of tropical cyclones result in varying sea surface salinity changes on their left and right sides, with the most intense storms causing salinification and being influenced by the vertical salinity gradient in the upper ocean and barrier layers.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Meteorology & Atmospheric Sciences
Xiao Dong, Jiangbo Jin, Hailong Liu, He Zhang, Minghua Zhang, Pengfei Lin, Qingcun Zeng, Guangqing Zhou, Yongqiang Yu, Mirong Song, Zhaohui Lin, Ruxu Lian, Xin Gao, Juanxiong He, Dongling Zhang, Kangjun Chen
Summary: The Chinese Academy of Sciences' Earth System Model, version 2.0 (CAS-ESM2.0), is participating in the Ocean Model Intercomparison Project Phase 1 (OMIP1) experiment of phase 6 of the Coupled Model Intercomparison Project (CMIP6). The preliminary evaluation shows that the model's performance in simulating global ocean characteristics is reasonable compared with observations, and the dataset is available for use in related research.
ADVANCES IN ATMOSPHERIC SCIENCES
(2021)
Article
Oceanography
Qiwei Sun, Yuhong Zhang, Yan Du, Xingwei Jiang
Summary: This study investigates the asymmetric response of sea surface salinity (SSS) to positive and negative Indian Ocean Dipole (IOD) events in the southern tropical Indian Ocean. The findings show that positive IOD events lead to a decrease in SSS, while negative IOD events result in an increase in SSS. The study also highlights that SSS response is more sensitive to thermocline shoaling and that the response to precipitation is greater at shallower mixed layer.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Oceanography
Zhengbei Zhang, Jing Wang, Dongliang Yuan
Summary: The balance of mixed layer salinity (MLS) in the eastern tropical Indian Ocean has been investigated using observations and model output. The study finds that the annual mean MLS is determined by the balance between surface freshwater forcing and ocean advection. The seasonal variation of MLS in the eastern equatorial Indian Ocean is influenced by salt advection associated with the Wyrtki Jet. MLS is lowest in summer due to freshwater advection, while it reaches its maximum in fall due to strong evaporation. During the negative Indian Ocean Dipole (IOD), eastward currents transport high-salinity water, leading to positive MLS anomalies. The MLS balance during positive IOD is nearly the opposite of that during negative IOD.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Engineering, Marine
Chaoli Tang, Dewei Hao, Yuanyuan Wei, Fengmei Zhao, Han Lin, Xin Wu
Summary: The time-frequency domain analysis of sea surface temperature (SST) in the tropical western Indian Ocean was conducted using various methods and COBE-SST data from 1974 to 2020. The results showed that the SST has short, medium, and long periods, as well as resonance periods with precipitation, sea surface heat flux, total cloud cover, and long-wave radiation. It was also found that SST is negatively or positively correlated with precipitation, total cloud cover, and long-wave radiation, and plays a significant role in seasonal migration activities.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Article
Meteorology & Atmospheric Sciences
Brandon W. Kerns, Shuyi S. Chen
Summary: This study investigates the impact of precipitation, evaporation, and salinity (P-E-S) coupling on the upper ocean and finds that heavy precipitation and strong winds associated with MJO events result in a locally fresher, warmer western Pacific warm pool with shallower mixed layer and thicker barrier layer. The fresh, warm water mass extends into the central-eastern Pacific, accompanied by a well-defined salinity/density front propagating eastward. The P-E-S coupling plays an important role in the eastward extension of the warm pool prior to the onset of El Nino in July 2018.
Article
Oceanography
Aurpita Saha, Nuno Serra, Detlef Stammer
Summary: In the northwestern tropical Atlantic, the growth and decay mechanisms of barrier layers are influenced by factors such as horizontal temperature advection, stretching of isotherms, and tilting of temperature fronts. Near the North Equatorial Current, thick barrier layers may form in winter and completely erode in spring due to changes in the constant-density and constant-temperature layers.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2021)
Article
Meteorology & Atmospheric Sciences
Ying Lu, Yuanlong Li, Jing Duan, Pengfei Lin, Fan Wang
Summary: This study investigates the mechanisms of sea level rise in the southeast Indian Ocean and highlights the importance of ocean salinity. The analysis of observational datasets and model results reveals that both subsurface freshening trend and temperature effect contribute to the sea level rise in the region.
JOURNAL OF CLIMATE
(2022)
Article
Meteorology & Atmospheric Sciences
Chiyu Zhao, Xin Geng, Wenjun Zhang, Li Qi
Summary: This study finds that the Atlantic multidecadal oscillation (AMO) can affect the El Nino-Southern Oscillation (ENSO). It shows that during a negative AMO phase, the atmospheric anomaly amplitudes in the tropical Pacific for El Nino events are more pronounced and for La Nina events are weaker, compared to a positive AMO phase. This discrepancy may be largely attributed to the decadal modulation of AMO.
JOURNAL OF CLIMATE
(2022)
Article
Meteorology & Atmospheric Sciences
Ping Zhang, Anmin Duan, Jun Hu
Summary: This study reveals the individual and combined effects of the Indian Ocean basin mode (IOBM) and tropical North Atlantic (TNA) sea surface temperature anomalies (SSTAs) on the interannual variability of Tibetan Plateau precipitation. The warm SSTAs in the Indian Ocean induce an anomalous anticyclone over the Bay of Bengal and trigger a positive precipitation anomaly over the southeastern Tibetan Plateau. The TNA SSTAs further strengthen this effect by inducing easterly winds and a suppressed convection over the central Pacific, resulting in a significant positive precipitation anomaly over the southeastern Tibetan Plateau.
JOURNAL OF CLIMATE
(2022)
Article
Oceanography
Ke Huang, Ming Feng, Ying Wu, Dongxiao Wang, Wen Zhou, Tingting Zu, Weiqiang Wang, Qiang Xie, Lei Yang, Jinglong Yao, Wei Zhou
Summary: This study examines the interannual variability of upper-ocean salinity in the tropical Indian Ocean (TIO). The results indicate the presence of a coherent near-biennial band driven by wind-induced horizontal advections and evaporation-minus-precipitation anomalies. The displacement of sea surface temperature anomalies plays a significant role in modulating the structures of salinity anomalies and inducing dynamical connections.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2022)
Article
Meteorology & Atmospheric Sciences
Ze Meng, Lei Zhou, Raghu Murtugudde, Qingxuan Yang, Kandaga Pujiana, Jingyuan Xi
Summary: The study analyzed the dynamics of tropical oceanic intraseasonal variabilities associated with the Central Indian Ocean (CIO) mode, attributing intraseasonal sea surface temperature anomalies during the CIO mode mainly to zonal thermal advection and surface heat flux.
Article
Oceanography
Smitha Ratheesh, Neeraj Agarwal, Aditya Chaudhary, J. Lijin, J. Sree Lekha, Manikandan Mathur, Rashmi Sharma, Raj Kumar
DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY
(2020)
Article
Environmental Sciences
Aditya Chaudhary, Neeraj Agarwal, Rashmi Sharma, Satya P. Ojha, Raj Kumar
Summary: This study evaluates the advantages of SWOT measurements over nadir looking altimeters using sensitivity experiments in the Bay of Bengal region. Results show that SWOT-generated gridded SLA fields have less errors in regions of high variability compared to nadir altimeters, which perform better in regions of low variability. Additionally, SWOT is able to resolve the position and strength of mesoscale eddies better than nadir altimeter.
REMOTE SENSING OF ENVIRONMENT
(2021)
Article
Geochemistry & Geophysics
Anup Kumar Mandal, Aditya Chaudhary, Neeraj Agarwal, Rashmi Sharma
Summary: The study utilized the isQG methodology to reconstruct subsurface density anomaly in the Arabian Sea and Bay of Bengal, revealing the impact of errors on the density anomalies. Seasonal dependency and the stability profile N-2 were found to affect the performance of the isQG method significantly.
Article
Meteorology & Atmospheric Sciences
Neeraj Agarwal, Rashmi Sharma, Raj Kumar
Summary: In this study, altimeter based sea surface height anomaly (SSHA) observations are assimilated in a high resolution Indian Ocean model to analyze their impact on the Bay of Bengal region. The assimilation of SSHA improves the simulation of ocean currents, particularly the strength and position of mesoscale eddies. The assimilated model exhibits observed variability in sub-surface currents, which was absent in the non-assimilated model. The statistics show a significant improvement in ocean current simulations at all depths after assimilation. Particle trajectory analysis confirms that the assimilated model accurately simulates observed tracer trajectories.
Article
Engineering, Aerospace
Rashmi Sharma, Aditya Chaudhary, M. Seemanth, Suchandra Aich Bhowmick, Neeraj Agarwal, Jacques Verron, Pascal Bonnefond, Honey Gupta, J. V. Thomas
Summary: The Y AltiKa altimeter on board SARAL satellite has gone through different operational phases, and a detailed assessment of the data quality and its usefulness in studying mesoscale dynamics has been conducted. The results show high quality data during the Exact Repeat Mission and Drifting phase, while the Mispointing phase has larger differences. Assimilation of along-track data improves wave height simulation, but has no significant impact on circulation modeling.
ADVANCES IN SPACE RESEARCH
(2022)
Article
Environmental Sciences
M. Jishad, Neeraj Agarwal
Summary: This study evaluates two different methods for detecting oceanic thermal fronts using satellite-derived high-resolution sea surface temperature data. The results show that the histogram-based edge detection technique is more accurate in detecting thermal fronts compared to the gradient-based method. The application of these techniques on SST images during a cyclone confirms the success of the histogram-based method in detecting cooling-related thermal fronts.
JOURNAL OF THE INDIAN SOCIETY OF REMOTE SENSING
(2022)
Article
Environmental Sciences
Rashmi Sharma, Neeraj Agarwal, R. Ratheesh, Surisetty V. V. Arun Kumar, A. D. Rao, K. V. S. R. Prasad, Jaya Kumar Seelam, R. Mani Murali, V Suneel, Surendra K. Singh, R. K. Sarangi, Soba J. Kizhakudan, A. Saravana Kumar, R. N. Samal, Ansuman Das, Aditya Chaudhary, M. Seemanth, M. Jishad, Anup K. Mandal, Shivani Shah, Abhisek Chakraborty, Suchandra A. Bhowmick, Smitha Ratheesh, Subrat K. Mallick, V. Trinadha Rao, Rimjhim B. Singh, Vibha S. Jain, Chandra Prakash, Rakeshkumar N. Luhar, G. Nagababu, Ravi Patel, Ghanshyam J. Doshi, YagneshKumar R. Patel, Nishkam Jain, Saurabh Bhalla, Kumar Ravi Prakash, Vimlesh Pant, Ch Venkateswarlu, B. Gireesh, B. Sivaiah, Syed Moosa Ali, Kiran Mali, Vinod Kumar Mudumala, Mourani Sinha, K. N. Babu, Mini Raman, J. G. Patel, Nitant Dube, Raj Kumar, I. M. Bahuguna, Nilesh M. Desai
Summary: SAMUDRA is a satellite-based marine research and application program aimed at supporting the development of the nation's blue economy. It has achieved significant milestones by developing value-added products, improving existing methods, and providing information and tools to end users.
JOURNAL OF THE INDIAN SOCIETY OF REMOTE SENSING
(2022)
Article
Environmental Sciences
Jai Kumar, Ravi Kamal Choudhary, Manikandan Mathur, Neeraj Agarwal, Rashmi Sharma
Summary: This study investigates the horizontal mixing properties in the North Indian Ocean using FSLE analysis. The optimal resolution for FSLE features is found to be at a distance of 110 km. The study identifies the relationship between surface horizontal stirring and chlorophyll standing stocks, as well as analyzes seasonal and interannual variations of the mixing characteristics. The co-variability between FSLE field structure and chlorophyll-field structure is also studied.
JOURNAL OF THE INDIAN SOCIETY OF REMOTE SENSING
(2022)
Article
Geosciences, Multidisciplinary
Atul Kumar Varma, Neeru Jaiswal, Ayan Das, Mukesh Kumar, Nikhil V. V. Lele, Rojalin Tripathy, Saroj Maity, Mehul Pandya, Bimal Bhattacharya, Anup Kumar Mandal, M. Jishad, M. Seemanth, Arvind Sahay, Debojyoti Ganguly, Suchandra Aich Bhowmick, R. K. Sarangi, Neeraj Agarwal, Mini Raman, Rashmi Sharma, Vibhuti Bhushan Jha, Nimisha Singh, Rohit Pradhan, Amit K. K. Dubey, Shard Chander, R. P. Singh, Neerja Sharma, Shivani Shah, Ishmohan Bahuguna, Nilesh M. M. Desai
Summary: A Very Severe Cyclonic Storm 'Yaas' formed in the Bay of Bengal on 23 May and made landfall in Odisha on 26 May with maximum wind speed of 75 kts. Forecast and tracking models were used to predict its path accurately. The storm caused changes in sea surface temperature, salinity, and density, as well as increased Ekman suction velocity and chlorophyll concentration. Storm surge, wave height, and coastal inundation were also forecasted. Satellite imagery and data analysis were used to assess the impact of the storm on crops, fisheries, and forest areas.
Article
Environmental Sciences
Suchandra Aich Bhowmick, Maneesha Gupta, Abhisek Chakraborty, Neeraj Agarwal, Rashmi Sharma, Meer Mohammed Ali
Summary: This study combines observations from SCATSAT-1 satellite and a numerical weather prediction model to generate a 6-hourly gridded hybrid wind product. The novel technique fills the spatio-temporal data gaps of scatterometer winds and shows promising results in terms of noise reduction and bias correction. Compared with existing daily products, the generated hybrid winds demonstrate higher quality.
Article
Geosciences, Multidisciplinary
Neeru Jaiswal, M. Jishad, Sanjib K. Deb, Atul K. Varma, Neeraj Agarwal, Rashmi Sharma
Summary: In September 2021, a tropical cyclone named Gulab formed in the Bay of Bengal and crossed the Indian subcontinent to re-emerge as TC Shaheen in the Arabian Sea, making landfall in Oman. This was unusual as it occurred during the active southwest monsoon period and the formation and re-emergence of cyclones in these regions is uncommon. The analysis of atmospheric and oceanic parameters indicates that the low vertical wind shear and high middle level relative humidity contributed to the development and survival of these cyclones. The favorable sea surface temperature and oceanic heat content further intensified TC Shaheen.
JOURNAL OF EARTH SYSTEM SCIENCE
(2023)
Article
Geochemistry & Geophysics
Smitha Ratheesh, Aditya Chaudhary, Suchandra Aich Bhowmick, Neeraj Agarwal
Summary: Satellite observations over the Arabian Sea have shown strong air-sea interaction during the Indian Ocean monsoon. This study focuses on the mesoscale variability in wind and SST coupling over the Arabian Sea using satellite observations from 2017 to 2019. Results indicate that a strong background wind field and SST gradient are necessary for the generation of strong coupling between wind speed and sea surface temperature.
PURE AND APPLIED GEOPHYSICS
(2022)
Article
Multidisciplinary Sciences
Suchandra A. Bhowmick, Neeraj Agarwal, Rashmi Sharma, R. Sundar, R. Venkatesan, C. Anoopa Prasad, K. N. Navaneeth
Article
Geochemistry & Geophysics
Subrat Kumar Mallick, Neeraj Agarwal, Rashmi Sharma, K. V. S. R. Prasad, S. S. V. S. Ramakrishna
PURE AND APPLIED GEOPHYSICS
(2020)
Article
Multidisciplinary Sciences
Smitha Ratheesh, Aditya Chaudhary, Neeraj Agarwal, Rashmi Sharma
