A5006482254- Climate variability and models
- Meteorological Phenomena and Simulations
- Tropical and Extratropical Cyclones Research
- Atmospheric aerosols and clouds
- Atmospheric chemistry and aerosols
- Distributed and Parallel Computing Systems
- Oceanographic and Atmospheric Processes
- Hydrological Forecasting Using AI
- Precipitation Measurement and Analysis
- Atmospheric Ozone and Climate
- Air Quality Monitoring and Forecasting
- Air Quality and Health Impacts
- Parallel Computing and Optimization Techniques
- Advanced Data Storage Technologies
- Atmospheric and Environmental Gas Dynamics
- Hydrology and Watershed Management Studies
- Computational Physics and Python Applications
- Cryospheric studies and observations
- Arctic and Antarctic ice dynamics
- Scientific Computing and Data Management
- Climate change impacts on agriculture
- Cloud Computing and Resource Management
- Wind and Air Flow Studies
- Flood Risk Assessment and Management
- Ocean Waves and Remote Sensing
Indian Institute of Science Bangalore
2015-2024
Indian Institute of Tropical Meteorology
2017-2023
Ministry of Earth Sciences
2020-2023
NOAA Oceanic and Atmospheric Research
2016-2020
Indian Academy of Sciences
2004
Argonne National Laboratory
1994
This paper presents a methodology to downscale monthly precipitation river basin scale in Indian context for special report of emission scenarios (SRES) using Support Vector Machine (SVM). In the presented, probable predictor variables are extracted from (1) National Center Environmental Prediction (NCEP) reanalysis data set period 1971–2000 and (2) simulations third generation Canadian general circulation model (CGCM3) SRES A1B, A2, B1 COMMIT 1971–2100. These include both thermodynamic...
Abstract In spite of the summer monsoon’s importance in determining life and economy an agriculture-dependent country like India, committed efforts toward improving its prediction simulation have been limited. Hence, a focused mission mode program Monsoon Mission (MM) was founded 2012 to spur progress this direction. This article explains made by Earth System Science Organization (ESSO), Ministry Sciences (MoES), Government implementing MM develop dynamical framework improve monsoon...
Abstract This study reports a very high-resolution (400 m grid-spacing) operational air quality forecasting system developed to alert residents of Delhi and the National Capital Region (NCR) about forthcoming acute pollution episodes. Such has been for first time is evaluated during October 2019-February 2020. The assimilates near real-time aerosol observations from in situ space-borne platform Weather Research Forecasting model coupled with Chemistry (WRF-Chem) produce 72-h forecast daily...
Abstract The presence of persistent heavy fog in northern India during winter creates hazardous situations for transportation systems and disrupts the lives about 400 million people. meteorological factors responsible its genesis predictability are not yet completely understood this region. Given high potential socioeconomic impact, there is a pressing need extensive research that understands inherently complex nature phenomena through field observations modeling exercises. WiFEX...
Abstract In this paper, downscaling models are developed using a support vector machine (SVM) for obtaining projections of monthly mean maximum and minimum temperatures ( T max min ) to river‐basin scale. The effectiveness the model is demonstrated through application downscale predictands catchment Malaprabha reservoir in India, which considered be climatically sensitive region. probable predictor variables extracted from (1) National Centers Environmental Prediction (NCEP) reanalysis...
Abstract Synergizing satellite remote sensing data with vertical profiles of atmospheric thermodynamics and regional climate model simulations, we investigate the relative importance, transport pathways, seasonality contribution dust from (Thar Desert adjoining arid regions) (southwest Asia northeast Africa) sources over Indian Ocean [i.e., Bay Bengal (BOB)]. We show that while northern BOB contribute more than 50% to total load during southwest monsoon period (June–September),...
Abstract This paper examines the accuracy of Weather Research and Forecasting model coupled with Chemistry (WRF‐Chem) generated 72 hr fine particulate matter (PM 2.5 ) forecasts in Delhi during crop residue burning season October‐November 2017 respect to assimilation Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol optical depth (AOD) retrievals, persistent fire emission assumption, aerosol‐radiation interactions. The significantly pushes AOD PM toward observations largest...
One of the most important modes summer season precipitation variability over Indian region, diurnal cycle, is studied using Tropical Rainfall Measuring Mission 3‐hourly, 0.25° × 3B42 rainfall product for nine years (1999–2007). Most previous studies have provided an analysis a single year or few satellite‐ station‐based data. Our study aims to systematically analyze statistical characteristics diurnal‐scale signature and surrounding regions. Using harmonic analysis, we extract signal...
Abstract Amazon discharges a large volume of freshwater into the ocean, yet its impact on climate is largely unknown. Climate projections show that warmer northern tropical Atlantic Ocean together with equatorial Pacific lead to extreme droughts in Amazonia, considerably reducing runoff. Here we present results from coupled model simulations and observations climatic response significant reduction runoff Ocean. simulation without resulted cooler Atlantic, weakening Hadley cell thereby...
Air quality has become one of the most important environmental concerns for Delhi, India.In this perspective, we have developed a high-resolution air prediction system Delhi based on chemical data assimilation in transport model -Weather Research and Forecasting with Chemistry (WRF-Chem).The was applied to improve PM2.5 forecast via MODIS aerosol optical depth retrievals using threedimensional variational analysis scheme.Near real-time fire count were simultaneously adjust fire-emission...
Abstract. This paper discusses the newly developed Decision Support System version 1.0 (DSS v1.0) for air quality management activities in Delhi, India. In addition to standard forecasts, DSS provides contribution of its surrounding districts, and stubble-burning fires neighboring states Punjab Haryana PM2.5 load Delhi. also quantifies effects local neighborhood emission-source-level interventions on pollution The DSS-simulated Air Quality Index post-monsoon winter seasons 2021–2022 shows...
In recent years, medium-range AI weather forecasting models have improved significantly, now offering accuracy comparable to classical numerical prediction (NWP) models, while also being faster and (once trained) less computationally demanding. Due inherent assumptions limitations, all exhibit some degree of persistent systematic errors, called biases, in their forecast output, with certain performing better than others for specific variables regions. To address these we introduce a machine...
The Indian summer monsoon displays intraseasonal variability with alternating "active" (intense rainfall) and "break" (deficient phases. Analysis of Meteorological Department (IMD) daily rainfall data (1979–2020, June–September) over Central India (CI) shows that active spells are more frequent during flood years (4.6 events/year) than drought (2.3 events/year), similar durations (3–4 days). In contrast, break prolonged in (3.9 events/year, 6–7 days,...
Role of Asian and African orography in the Indian summer monsoon has been investigated using a general circulation model. Orography region west 80°E appears to have more impact on rainfall than east 80°E. It found that removal increases seasonal precipitation over sub‐continent by 28%, whereas entire globe reduces it 25%. Moreover, there was substantial delay all‐India onset experiment which mountains were removed globally, mainly due intrusion midlatitude dry air The increase Africa...
Abstract. A theory is proposed to determine the onset of Indian Summer Monsoon (ISM) in an Atmospheric General Circulation Model (AGCM). The ISM delayed substantially absence global orography. impact orography over different parts Earth on has also been investigated using five additional perturbed simulations. large difference date these simulations explained by a new based Surface Moist Static Energy (SMSE) and vertical velocity at mid-troposphere. It found that occurs only after SMSE...
Abstract The low‐level jet (LLJ) over the Indian region, which is most prominent during monsoon (June–September) season, has been studied with a general circulation model (GCM). role of African orography in modulating this focus article. presence intensifies cross‐equatorial flow. Contrary to previous modelling studies we find that flow occurs even absence orography, though much weaker when rainfall high. However, location meridional near equator Somali region linked rather than land–sea...
Abstract In this study, rainfall estimates by the Tropical Rainfall Measuring Mission are used to understand spatiotemporal structures of convection in intraseasonal time scale and their intensity during boreal summer over South Asia. A quantitative analysis on how these modes modulate central Indian is also provided. Two dominant variability with periodicities 10–20 20–60 days found, latter strongly modulated sea surface temperature. The 20–60-day mode shows northward propagation from...
Abstract The Indian summer monsoon (ISM) shows quasi-rhythmic intraseasonal oscillations (ISO) manifested as alternate ‘active’ phases of copious rainfall and quiescent ‘break’. Within these periodic phases, the daily large variability exhibits spatiotemporally sporadic extreme events. recent decades have witnessed a significant increase in number events, especially phases. This is accompanied by decreasing trend mean weakening variance its low-frequency ISO (LF-ISO) cycle. However, any...