A5029640818- Climate variability and models
- Meteorological Phenomena and Simulations
- Oceanographic and Atmospheric Processes
- Tropical and Extratropical Cyclones Research
- Geology and Paleoclimatology Research
- Underwater Acoustics Research
- Ocean Waves and Remote Sensing
- Tree-ring climate responses
- Underwater Vehicles and Communication Systems
- Plant Water Relations and Carbon Dynamics
- Methane Hydrates and Related Phenomena
- Atmospheric Ozone and Climate
Indian Institute of Science Education and Research Pune
2017-2023
University of California, Los Angeles
2014-2020
University of California System
2015
Indian Institute of Tropical Meteorology
2010-2012
Abstract The Madden–Julian oscillation (MJO) represents a primary source of predictability on the intraseasonal time scales and its influence extends from seasonal variations to weather extreme events. While last decade has witnessed marked improvement in dynamical MJO prediction, an updated estimate contemporary suite dynamic models, conjunction with their corresponding prediction skill, is crucial for guiding future research development priorities. In this study, boreal winter revisited...
Boreal summer intraseasonal oscillation (BSISO) is one of the dominant modes variability tropical climate system, which has fundamental impacts on regional monsoons, storms, and extra-tropical variations. Due to its distinctive characteristics, a specific metric for characterizing observed BSISO evolution assessing numerical models’ simulations previously been proposed (Lee et al. in Clim Dyn 40:493–509, 2013). However, current dynamical model’s prediction skill predictability have not...
[1] Understanding the underlying dynamics of Indian summer monsoon (ISM) extremes such as severe droughts is key to improving seasonal prediction ISM rainfall. A large number over past century occurred unrelated external forcing like El Nino–Southern Oscillation (ENSO). In this study, we challenge perception that 2009 drought was driven by ENSO and show it caused internally processes. The result two very long breaks, one in month June other July–August (JA). While some studies provide strong...
The east Pacific, dominated by synoptic scale convective activity, presents a unique environment to explore the question of how disturbances can modulate strength mean meridional circulation. role mixed Rossby-Gravity (MRG) waves in modulating Pacific Hadley circulation (EPHC) is explored during boreal summer season using ERA5 reanalysis data. Composite analysis MRG activity for five strong and weak EPHC seasons identified based on mass stream function metric reveal that are associated with...
Abstract A significant fraction of interannual variability (IAV) the Indian summer monsoon (ISM) is known to be governed by “internal” dynamics arising from interactions between high-frequency fluctuations and annual cycle. While several studies indicate that intraseasonal oscillations (MISOs) are at heart such internal IAV monsoon, exact mechanism through which MISOs influence seasonal mean has remained elusive so far. Here it proposed exchange kinetic energy (KE) provides a conceptual...
Abstract An understanding of the limit on potential predictability is crucial for developing appropriate tools extended‐range prediction active/break spells Indian summer monsoon (ISM). The global low‐frequency changes in climate modulate annual cycle ISM and can influence intrinsic intraseasonal oscillations (ISOs). Using 104‐year (1901–2004) long daily rainfall data, change active break are estimated by an empirical method. It found that both have undergone a rapid increase during recent...
Abstract The eastern Pacific (EPAC) warm pool is a region of strong intraseasonal variability (ISV) during boreal summer. While the EPAC ISV known to have large-scale impacts that shape weather and climate in (e.g., tropical cyclones local monsoon), simulating still great challenge for present-day global models. In present study, predictive skill predictability are explored eight coupled model hindcasts from Intraseasonal Variability Hindcast Experiment (ISVHE). Relative prediction winter...
Abstract The three-dimensional structure, horizontal and vertical propagation characteristics, convection–circulation coupling of the convectively coupled westward-propagating mixed Rossby–gravity (MRG) waves are examined by classifying based on their amplitude. Convective signals MRG were identified isolated using empirical orthogonal function analysis wavenumber–frequency-filtered outgoing longwave radiation (OLR) data. It was found that about 50% occur during August–November months, this...
Abstract In this study we have examined the modulation of convectively coupled Kelvin waves (CCKWs) by different Madden-Julian oscillation (MJO) states over Indian, Pacific and Atlantic Ocean domains. Convectively active CCKW events associated with MJO convection, suppressed quiescent were derived using wavenumber-frequency filtered outgoing long-wave radiation (OLR) indices three Composite analysis during indicate that amplitude phase speed are modulated state. is stronger (weaker), it...
The Northern hemispheric circum global teleconnection (CGT) pattern is thought to be maintained by two main forcings—viz-diabatic heating associated with the Indian summer monsoon (ISM) and barotropic instability generation over jet exit region North Atlantic. CGT ISM impacts one another through circulation responses West central Asia (WCA). In this study we revisit CGT-ISM interactions focusing on WCA try understand whether downstream impact of dominates feedback CGT. Analysis indicates...
Abstract A lesser known relationship between boreal spring El Niño state and the Indian summer monsoon (ISM) is explored, considering differences in evolution of sea surface temperature convection over Pacific. Rossby wave tracing analysis reveals that convective permits two distinct eastward waveguides from central Pacific to ISM domain. The first waveguide reaches northern region roughly along African‐Asian jet, second crosses Southern Hemisphere eastern extends up south Ocean region. net...
Earth and Space Science Open Archive This preprint has been submitted to is under consideration at Journal of Climate. ESSOAr a venue for early communication or feedback before peer review. Data may be preliminary.Learn more about preprints preprintOpen AccessYou are viewing the latest version by default [v1]Modulation Convectively Coupled Kelvin Waves MJO over different domainsAuthorsJ.M.NeenaiDE.SuhasiDXiananJiangSee all authors J.M. NeenaiDCorresponding Author• Submitting AuthorIndian...
Earth and Space Science Open Archive This preprint has been submitted to is under consideration at Journal of Geophysical Research - Atmospheres. ESSOAr a venue for early communication or feedback before peer review. Data may be preliminary.Learn more about preprints preprintOpen AccessYou are viewing the latest version by default [v1]Understanding Subseasonal Modulation Moisture Transport over Indian Monsoon DomainAuthors J.M. Neena iD V Dilip Aneesh Subramanian See all authors...
Earth and Space Science Open Archive This preprint has been submitted to is under consideration at Journal of Geophysical Research - Atmospheres. ESSOAr a venue for early communication or feedback before peer review. Data may be preliminary.Learn more about preprints preprintOpen AccessYou are viewing the latest version by default [v1]Understanding Subseasonal Modulation Moisture Transport over Indian Monsoon DomainAuthors J.M. Neena iD V Dilip Aneesh Subramanian See all authors...
Abstract The Atlantic multidecadal oscillation (AMO) is considered as one of the major drivers Indian Summer monsoon (ISM) variability, but exact mechanism teleconnection remains elusive. AMO can impact ISM dominantly by two pathways – generating upperlevel circulation and heating responses across Eurasia via Pacific through atmospheric bridge associated modulations Hadley-Walker circulations in Indo-Pacific. Using PMIP3 Last millennium (LM) simulations, current study investigates AMO-ISM...