A5023286145- Climate variability and models
- Atmospheric Ozone and Climate
- Atmospheric and Environmental Gas Dynamics
- Meteorological Phenomena and Simulations
- Oceanographic and Atmospheric Processes
- Hydrology and Watershed Management Studies
- Atmospheric chemistry and aerosols
- Hydrology and Drought Analysis
- Tropical and Extratropical Cyclones Research
- Marine and coastal ecosystems
- Earthquake Detection and Analysis
- Plant Water Relations and Carbon Dynamics
- Geology and Paleoclimatology Research
- Arctic and Russian Policy Studies
- Big Data and Business Intelligence
- Climate change impacts on agriculture
- Methane Hydrates and Related Phenomena
- Flood Risk Assessment and Management
- Computational Physics and Python Applications
- Cryospheric studies and observations
- Geophysics and Gravity Measurements
- Complex Systems and Time Series Analysis
- Scientific Research and Discoveries
- Scientific Computing and Data Management
- Groundwater and Watershed Analysis
Institute of Atmospheric Sciences and Climate
2024
ETH Zurich
2021-2024
Earth System Science Interdisciplinary Center
2023-2024
University of Maryland, College Park
2023-2024
Goddard Space Flight Center
2023
University of Delaware
2019-2021
George Mason University
2014-2017
Indian Institute of Science Bangalore
2011
Abstract This study evaluates the ability of state-of-the-art subseasonal-to-seasonal (S2S) forecasting systems to represent and predict teleconnections Madden–Julian oscillation their effects on weather in terms midlatitude patterns North Atlantic tropical cyclones. evaluation forecast applies novel diagnostics developed track along preferred pathways troposphere stratosphere, measure global regional responses induced by across both Northern Southern Hemispheres. Results this will help...
Abstract The Madden‐Julian Oscillation (MJO) can influence the extratropical circulation on timescales up to several weeks, with a dependence MJO characteristics: episodes that propagate slowly across Maritime Continent have stronger impact Euro‐Atlantic weather than fast episodes. While tropospheric pathway for teleconnections varying phase speeds is well understood, in this study, we investigate contribution of Northern Hemisphere stratospheric versus slow During episodes, Phases 5–6 lead...
Abstract Fast and slow Madden–Julian oscillation (MJO) episodes have been identified from 850- 200-hPa zonal wind outgoing longwave radiation (OLR) for 32 winters (16 October–17 March) 1980/81–2011/12. For 26 fast cases the OLR took no more than 10 days to propagate phase 3 (convection over Indian Ocean) 6 western Pacific). 8 propagation at least 20 days. episode composite anomalies of 500-hPa height (Z500) show a developing Rossby wave in mid-Pacific with downstream through MJO phases 2–4....
Abstract Flash droughts are noted by their unusually rapid rate of onset or intensification, which makes it difficult to anticipate and prepare for them, thus resulting in severe impacts. Although the development flash drought can be associated with certain atmospheric conditions, vegetation also plays a role propagating drought. This study examines climatology warm season (March–September) occurrence United States between 1979 2014, quantifies possible impacts on based set sensitivity...
© 2018 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).CORRESPONDING AUTHOR: Ayrton Zadra, ayrton.zadra@canada.ca
Abstract. The simulated Northern Hemisphere winter stationary wave (SW) field is investigated in 11 Subseasonal-to-Seasonal (S2S) prediction project models. It shown that while most models considered can well simulate the wavenumbers 1 and 2 during first weeks of integration, they diverge from observations following week 3. Those with a poor resolution stratosphere struggle to waves, both troposphere stratosphere, even weeks. Focusing on tropospheric regions where SWs peak amplitude reveals...
Abstract. Since the Madden–Julian oscillation (MJO) is a major source for tropical and extratropical variability on weekly to monthly timescales, intrinsic predictability of its global teleconnections great interest. As diabatic heating associated with MJO ultimately drives these teleconnections, in among ensemble forecasts initialized from same episode will limit this predictability. In order assess limitation, suite 60 d reforecasts has been carried out ECMWF forecast model, spanning 13...
Abstract. Results from 10 global climate change models are synthesized to investigate changes in extremes, defined as wettest and driest deciles precipitation, soil moisture runoff based on each model's historical 20th century simulated climatology. Under a moderate warming scenario, regional increases drought frequency found with little increase floods. For more severe warming, both flood become much prevalent, nearly the entire globe significantly affected. Soil tend toward drying, while...
Intervention experiments using the Coupled Forecast System model, version 2 (CFSv2), have been performed in which various Madden-Julian Oscillation (MJO) evolutions were added to model’s internally generated heating: Slow Repeated Cycles, Single Cycle, Fast and Cycle. In each experiment, one of these specified MJO tropical diabatic heating was multiple ensemble reforecasts boreal winter (1 November 31 March for winters: 1980–2010). Since re-forecasts made with identical evolution added,...
Abstract This study continues the evaluation of prediction MJO teleconnections in two versions NOAA Unified Forecast System (UFS): prototype 5 (UFS5) and 6 (UFS6). The key difference between prototypes is number vertical layers (127 UFS6 vs. 64 UFS5) model top (80 km 54 UFS5), role this increased resolution for stratospheric pathway explored. higher (UFS6) suffers from larger biases its representation tropospheric stationary waves, though both simulate a reasonable flux wave activity...
The Sarayan River is a groundwater fed meandering river, originating near Gola Gokaran Nath Town in Lakhimpur Kheri District of Uttar Pradesh the Ganga Plain. It flows around 170 km before joining Gomti at Kaintain hamlet, Sidhauli Tehsil, Sitapur District, Pradesh. morphometric analysis Basin explained present paper by using Geographical Information System (GIS) technique and Survey India topographical sheets to integrate basic, shape derived characteristics. shows dendritic drainage...
Abstract This study continues the evaluation of prediction MJO teleconnections in two versions NOAA Unified Forecast System (UFS): prototype 5 (UFS5) and 6 (UFS6). The key difference between prototypes is number vertical layers (127 UFS6 vs. 64 UFS5) model top (80 km 54 UFS5), role this increased resolution for stratospheric pathway explored. higher (UFS6) displays larger biases its representation tropospheric stationary waves, though both simulate a reasonable flux wave activity entering...
Abstract. Results from ten global climate change models are synthesized to investigate changes in extremes, defined as wettest and driest deciles precipitation, soil moisture runoff based on each model's historical twentieth century simulated climatology. Under a moderate warming scenario, regional increases drought frequency found with little increase floods. For more severe warming, both flood become much prevalent, nearly the entire globe significantly affected. Soil tend toward drying...
Abstract. Since the Madden-Julian Oscillation (MJO) is a major source for tropical and extratropical variability on weekly to monthly timescales, intrinsic predictability of its global teleconnections great interest. As diabatic heating associated with MJO ultimately drives these teleconnections, effect among various episodes same phase will limit this predictability. In order assess limitation, suite 60-day ensemble reforecasts has been carried out ECMWF forecast model, spanning 13 starting...
Based on the experiments with Coupled Forecast System version 2 (CFSv2), mechanism by which Madden-Julian Oscillation (MJO) modulates North Atlantic (NAO) is investigated. To isolate cyclic MJO heating an eastward propagation over Indian Ocean and western Pacific, three sets of are conducted spatio-temporal varying added to model’s internally generated heating. The results suggest that anomalous Ocean, rather than dominates formation NAO anomaly in following 10-20 days. triggers a westward...
Abstract. The simulated Northern Hemisphere stationary wave (SW) field is investigated in 11 subseasonal-to-seasonal (S2S) models. It shown that while most models considered can well-simulate the wavenumbers 1 and 2 during first two weeks of integration, they diverge from observations following week 3. Those with a poor resolution stratosphere struggle to simulate waves, both troposphere stratosphere, even weeks, biases extend all way up stratosphere. Focusing on tropospheric regions where...
In early 2022, several extreme weather events occurred in the Southern Hemisphere. Devastating floods killed more than 500 people South Africa (11-12 April) and about 26 eastern Australia (24-28 February 25-31 March), while an unprecedented heatwave broke temperature records Antarctica (16-22 March). This study presents a multiscale perspective of atmospheric processes associated with these from synoptic to planetary scales. Equatorward Rossby wave breaking facilitated transport moist air...
Teleconnection patterns associated with the Madden–Julian oscillation (MJO) and El Niño–Southern Oscillation (ENSO) impact weather climate phenomena in Pacific–North American region beyond, therefore accurately simulating these teleconnections is of importance for seasonal subseasonal forecasts. Systematic biases boreal midwinter ENSO MJO are found eight to (S2S) forecast models over America region. All simulate an anomalous 500-hPa geopotential height...
<p>For early career researchers (ECRs), it is of utmost importance to acquire various skills including the application different methods under umbrella data science. However, curricula scientific degrees do not necessarily always include all relevant in field, and there are also new methodologies emerging. Besides organized training schools, self-organized learning groups common universities  for collaboratively acquiring skills. Here, we present a concept that...
<p>The simulated Northern Hemisphere stationary wave (SW) field is investigated in 11 subseasonal-to-seasonal (S2S) models. It shown that while most models considered can well-simulate the wavenumbers 1 and 2 during first two weeks of integration, they diverge from observations following week 3. Those with a poor resolution stratosphere struggle to simulate waves, both troposphere stratosphere, even weeks, biases extend all way up stratosphere. Focusing on tropospheric regions...