I use WRF simulations to investigate the record-breaking 2022 East Asian heatwave, placing the event in a historical storyline framework through comparison with a major historical heatwave analogue. We aim to understand the physical processes that pushed the 2022 event to such an extreme state and whether its intensity approached the upper limit attainable under the present-day climate.

I also develop a hybrid statistical–physical temperature model to investigate how and why heatwave behavior changes in a warming climate.

This project is ongoing.

We examine how the seasonal evolution of the Asian monsoon circulation regulates climate variability, remote teleconnections, and extreme events over East Asia. We show that an internally generated mode of atmospheric variability can link Pakistan flooding to persistent East Asian heatwaves through perturbations to the upper-tropospheric westerly jet and the resulting downstream circulation response. This pathway is strongly conditioned by the monthly mean state, operates most effectively during July–August, and has relatively low seasonal predictability.

In contrast, we identify the September–October shoulder season as a distinct and highly predictable regime over monsoon Asia. Its dominant interannual variability features a large-scale cyclone–anticyclone circulation pattern accompanied by a poleward shift of the subtropical westerly jet. This variability is largely driven by combined sea-surface temperature forcing across the tropical Pacific, Indo–western Pacific, and North Atlantic. These circulation anomalies exert coherent impacts on regional tropical cyclone activity, making the shoulder season a key window of predictability over monsoon Asia.

We investigate how Antarctic meltwater forcing reshapes the climate system through coupled atmosphere–ocean dynamics. Our work shows that Antarctic meltwater can alter the seasonal evolution of tropical rainfall through SST-induced changes in large-scale atmospheric circulation and the associated energy adjustments. By comparing coupled and ocean-only simulations, we further examine how air–sea coupling modulates global sea surface salinity responses through atmospheric pathways and ocean dynamics.

This project is ongoing.

Our work investigates the physical mechanisms, future changes, and probabilistic modeling of multiple tropical cyclone events (MTCEs), focusing on how tropical cyclones cluster in space and time and why these events vary across ocean basins.

Over the western North Pacific, we identify distinct spatial regimes of MTCEs arising from different large-scale circulation configurations, while enhanced midlevel ascent and barotropic energy conversion provide common dynamical support. Variability on quasi-biweekly, intraseasonal, and lower-frequency timescales further regulates their occurrence.

Using high-resolution climate-model simulations, we further examine how MTCEs may evolve in a warming climate. Projections reveal contrasting basin-scale responses, with increasing frequency and persistence over the North Atlantic, declining activity over the western North Pacific, and greater uncertainty over the eastern North Pacific. These changes are linked to shifts in the large-scale environments supporting tropical cyclone genesis, particularly vertical motion and vertical wind shear.

We also develop a probabilistic framework to distinguish dynamically organized clusters from tropical cyclones that simply occur together by chance. Applied to observations and climate simulations, the framework reveals a pronounced shift in MTCE hotspots from the western North Pacific toward the North Atlantic, driven by changes in tropical cyclone frequency and synoptic-scale wave activity, with a tenfold increase in cluster likelihood over the North Atlantic during the past several decades.

Using two years of hourly PM2.5 composition measurements in central Shanghai, we found that effective SO₂ emission control substantially reduced sulfate pollution, while nitrate remained substantial and increased rapidly during haze events. Thermodynamic simulations further showed that aerosols remained moderately acidic, with clear seasonal and diurnal variations. Our results suggest that nitrate has become an increasingly important driver of haze in Shanghai and highlight vehicle-emission control as a priority for further reducing PM2.5 and acid-rain pollution in the Yangtze River Delta.