A5030090604- Climate variability and models
- Meteorological Phenomena and Simulations
- Atmospheric Ozone and Climate
- Atmospheric and Environmental Gas Dynamics
- Geology and Paleoclimatology Research
- Aeolian processes and effects
- Geological formations and processes
- Tropical and Extratropical Cyclones Research
- Precipitation Measurement and Analysis
- Geological and Geophysical Studies
- Forest, Soil, and Plant Ecology in China
- Environmental Changes in China
- Pleistocene-Era Hominins and Archaeology
- Ionosphere and magnetosphere dynamics
- Remote Sensing and Land Use
- Geological Studies and Exploration
- Hydrocarbon exploration and reservoir analysis
- Plant Ecology and Soil Science
- Hydraulic Fracturing and Reservoir Analysis
- Environmental and Agricultural Sciences
- Spectroscopy and Laser Applications
- Geophysics and Gravity Measurements
- Air Quality and Health Impacts
- Ocean Acidification Effects and Responses
- Arctic and Antarctic ice dynamics
ETH Zurich
2020-2024
University at Albany, State University of New York
2024
Jiangsu Institute of Meteorological Sciences
2020-2022
University of Utah
2017-2020
Research Institute of Petroleum Exploration and Development
2020
South China Normal University
1998-2010
Tung Fang Design Institute
2002
Abstract Projected changes in the Northern Hemisphere stratospheric polar vortex are analyzed using Climate Model Intercomparison Project Phase 6 experiments. Previous studies showed that projections of wintertime zonally averaged strength diverge widely between climate models with no agreement on sign change, and this uncertainty contributes to regional change uncertainty. Here, we show there remains large projected experiments global warming levels ranging from moderate (SSP245 runs)...
Abstract We analyze the sources for spread in response of Northern Hemisphere wintertime stratospheric polar vortex (SPV) to global warming Climate Model Intercomparison Project Phase 5 (CMIP5) and 6 (CMIP6) model projections. About half intermodel SPV projections by CMIP6 models, but less than a third CMIP5 can be attributed stationary planetary wave driving. In CMIP6, weakening is mostly driven increased upward flux from troposphere, while strengthening associated with equatorward...
Stratospheric sudden warmings and other polar vortex events have well-documented impacts on winter surface weather climate over middle to high latitudes. However, the scientific understanding of influence stratosphere tropics remains in its early stages. There are two primary pathways through which these influences can occur. In first pathway, modulate strength Brewer-Dobson circulation, affecting both tropical troposphere. second dynamical downward coupling from into extratropical...
Abstract. The MJO-Teleconnections diagnostics package is an open-source Python software that provides process-level evaluation of predicted by subseasonal-to-seasonal (S2S) forecast systems. in-depth both tropospheric and stratospheric pathways defining the atmospheric teleconnections from tropics to extratropics on S2S times scale. analyses include comparison a model with default verification data set or user-provided data. consists user-friendly graphic user interface (GUI), which allows...
Abstract Atmospheric rivers (ARs), narrow intense moisture transport, account for much of the poleward transport in midlatitudes. While studies have characterized AR features and associated hydrological impacts a warming climate observations comprehensive models, fundamental dynamics changes statistics (e.g., frequency, length, width) are not well understood. Here we investigate response to global with combination idealized models. To that end, developed an atmospheric GCM Earth-like...
Abstract The climatological frequency of stratospheric sudden warming events (SSWs) is an important dynamical characteristic the extratropical stratosphere. However, modern climate models have difficulties in simulating this frequency, with many either considerably under- or overestimating observational estimates. Past research has found that a higher upper lid tend to simulate and more realistic number SSWs. present study revisits issue investigates causes for biases simulated SSW from...
Based on the Weather Research and Forecasting (WRF) Model three-dimensional variational (3DVAR) data assimilation system, this study investigates effects of radar reflectivity radial velocity under different momentum control variables forecast Southwest China Vortex precipitation. It is shown that U−V variable strengthens wind speed vorticity to be better matching observation, while using ψ−χ as will produce too large increments which are unphysical. The root mean square errors (RMSE) around...
Abstract. Extreme stratospheric events such as sudden warming (SSW) and strong vortex can have downward impacts on surface weather that last for several weeks to months. Hence, successful predictions of these be beneficial extended-range prediction. However, the predictability extreme is most often limited around 2 or less. The strongly differs within same type also between event types. reasons observed differences in predictability, however, are not resolved. We extend analysis include wind...
Abstract Idealized models are useful for the investigation of dynamical phenomena in which physical processes play a secondary role. Typically, such employ highly idealized topography and zonally symmetric equilibrium temperatures as forcings. However, these simplifications somewhat unrealistic make unfit investigations similarity with real atmosphere is crucial. In this study, we present new model stratosphere‐troposphere system has more Earth‐like circulation than previous models. We...
Abstract. Recent work has shown that variability in the subtropical jet's (STJ) latitude, ϕSTJ, is not coupled to of Hadley cell (HC) edge, ϕHC, but robustness this disconnect been examined detail. Here, we use meteorological reanalysis products, comprehensive climate models, and an idealized atmospheric model determine necessary processes for a between ϕHC ϕSTJ Northern Hemisphere's December–January–February season. We find decoupling can occur dry general circulation model, indicating...
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...
Sudden stratospheric warmings (SSWs) are the most dramatic wintertime phenomena. They preceded by a sustained wave dissipation in stratosphere that leads to deceleration of polar vortex. The signal from SSWs then typically propagates downward reaching troposphere and inducing negative phase Annular Mode may persist several weeks up two months. Incorporating information subseasonal seasonal (S2S) forecast systems has been shown improve skill S2S predictions for surface climate. However, on...
<title>Abstract</title> The value of Madden-Julian oscillation (MJO) prediction for extratropical subseasonal forecasts hinges on the assumption that reliable MJO simulation translates to its teleconnections. This study discusses and teleconnections in two recently developed NOAA Unified Forecast System (UFS) coupled model prototypes: Prototype 7 (UFS7) 8 (UFS8). is skillfully predicted at a lead time 27 days UFS8, which considerable improvement (~ one-week skill increase) compared UFS7....
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...