Qi Zhuang

Extreme rainfall is projected to intensify with climate warming, yet changes in the spatiotemporal structure of extreme‐producing storms remain poorly understood in the tropics, as the most convectively active regions of the world are also the most data‐scarce. We here leverage the first long‐term, sub‐kilometer, sub‐hourly observational network in equatorial Singapore (730 ), with 122 rain gauges reporting 5 min intensities for 2020–2024 and 82 stations with hourly accumulations for 1980–2024, combined with X‐band radar (5 min, 100 m) to produce a high‐resolution gridded rainfall reanalysis. Our findings indicate that extreme rainfall in Singapore is becoming larger and more persistent, with intensification resulting in higher storm rainfall volumes while rainfall peak intensities remain largely unchanged. Furthermore, extreme rainfall storms are strikingly compact, with spatial and temporal correlations halving over just 2 km and 4 min, decaying faster than previously recognized and observed elsewhere. This suggests that analyses based on coarse data sets or single stations may have misrepresented rainfall intensification under warming.

Transpiration (T) connects water, energy, and carbon cycles within ecosystems. While T has often been reported to increase with soil warming, underlying reasons remain poorly understood. Here, using a mechanistic ecohydrological model, T&C‐BG, we simulated T responses to soil warming at 30 sites spanning various biomes and climates. Consistent with observations, the numerical model reproduces negative, insignificant, and predominantly positive T responses under soil warming. Numerical results show that soil warming generally increases T for sites with a small Bowen ratio. The main mechanisms leading to positive T responses to soil warming are complex changes in energy partitioning with modifications of canopy surface temperature and aerodynamic, stomatal, and leaf boundary layer conductance. However, soil warming can also affect phenology, which might result in either increased or decreased T. Our findings shed light on how T changes with warmer soil and help interpret outcomes of warming experiments.

Urban hydrological systems are highly sensitive to precipitation variability at fine spatial and temporal scales, yet such variability remains poorly characterized due to limited high-resolution observations. Here, we analyze extreme rainfall in equatorial Singapore using a uniquely dense observational network, including 122 rain gauges at 5-min resolution (2020–2024), and long-term hourly gauge records (1980–2024), which are then combined with X-band radar data at 100-m and 5-min resolution to produce a high-resolution gridded rainfall reanalysis. We use this new dataset to quantify the changing space–time organization of extreme convective rainfall over 45 years. Results show that extreme convective rainfall in this tropical urban environment is more highly localized and short-lived than previously thought, with spatial and temporal correlations halving over just 1.6 km and 4 min. In response to climate warming, the total rainfall amount, spatial extent, and temporal persistence of extreme events have increased, while peak rainfall intensities remained largely stable, likely due to limitations in local humidity supply. Such compact storm structures challenge the representativeness of sparse rain gauge networks and underscore the need for high-resolution analysis in tropical regions.

Tropical cyclones (TC) in the western North Pacific, known as typhoons, cause significant socioeconomic damage in East and Southeast Asian countries. The city of Shanghai in China is highly vulnerable to TC damages. For example, Typhoons Bebinca and Pulasan recently (September 2024) struck the city, resulting in widespread flooding, power outages, and the evacuation of more than half a million residents, while also breaking local rainfall records. Despite these threats, there is limited knowledge about the variability and mechanisms of TC activities in this region under climate change and urbanization. Here, we use the Weather Research and Forecasting (WRF) convection-permitting model to simulate five TC events that made landfall along the southeastern coast of China and severely impacted Shanghai between 2018 and 2022. Different scenarios are conducted, including considering a future expansion of Shanghai's urban area and increases in sea surface temperature (SST) by 1, 2, and 3 °C. The results indicate that while SST warming significantly shifts TC tracks away from the city, the local risk continues to increase due to substantial enhancement of rainfall intensity and wind velocity. Warmer SST increases air temperature and decreases sea level pressure, thereby facilitating the formation and development of TC sizes and intensities. Furthermore, we find a consistent southward shift of the TC tracks that can be linked to the Fujiwhara effect, a phenomenon that occurs when two typhoons interact, causing a mutual counterclockwise rotation. Compared to SST changes, urbanization has a limited influence on TC tracks and structures. The increase in surface roughness due to urban expansion reduces wind velocity but enhances the rainfall intensity within Shanghai, further exacerbating local risk. These findings could improve our understanding of typhoon variability under the combined effects of urbanization and climate change, as well as the risks they pose to Shanghai and other megacities in TC-prone regions.

Tropical cyclones (TC) in the western North Pacific, known as typhoons, cause significant socioeconomic damage in East and Southeast Asian countries. The city of Shanghai in China is highly vulnerable to TC damages. For example, Typhoons Bebinca and Pulasan recently (September 2024) struck the city, resulting in widespread flooding, power outages, and the evacuation of more than half a million residents, while also breaking local rainfall records. Despite these threats, there is limited knowledge about the variability and mechanism of TC activities in this region under climate change and urbanization. Here, we use the Weather Research and Forecasting (WRF) convection-permitting model to simulate five TC events that made landfall along the southeastern coast of China and severely impacted Shanghai between 2018 and 2022. Different scenarios are conducted, including considering a future expansion of Shanghai's urban area and increases in sea surface temperature (SST) by 1, 2, and 3 °C. The results indicate that while SST warming significantly shifts TC tracks away from the city, the local risk continues to increase due to substantial enhancement of rainfall intensity and wind velocity. Warmer SST increases air temperature and decreases sea level pressure, thereby facilitating the formation and development of TC sizes and their dynamic systems. Furthermore, we find a consistent southward shift of the TC tracks that can be linked to the Fujiwhara effect, a phenomenon that occurs when two typhoons interact, causing a mutual counterclockwise rotation. Compared to SST changes, urbanization has limited influence on TC tracks and structures. The increase in surface roughness due to urban expansion reduces wind velocity but enhances the rainfall intensity within Shanghai, further exacerbating local risk. These findings could improve our understanding of typhoon variability under the combined effects of urbanization and climate change, as well as the risks they pose to Shanghai and other megacities in TC-prone regions.

Tropical cyclones (TC) in the western North Pacific, known as typhoons, cause significant socioeconomic damage in East and Southeast Asian countries. The city of Shanghai in China is highly vulnerable to TC damages. For example, Typhoons Bebinca and Pulasan recently (September 2024) struck the city, resulting in widespread flooding, power outages, and the evacuation of more than half a million residents, while also breaking local rainfall records. Despite these threats, there is limited knowledge about the variability and mechanism of TC activities in this region under climate change and urbanization. Here, we use the Weather Research and Forecasting (WRF) convection-permitting model to simulate five TC events that made landfall along the southeastern coast of China and severely impacted Shanghai between 2018 and 2022. Different scenarios are conducted, including considering a future expansion of Shanghai's urban area and increases in sea surface temperature (SST) by 1, 2, and 3 °C. The results indicate that while SST warming significantly shifts TC tracks away from the city, the local risk continues to increase due to substantial enhancement of rainfall intensity and wind velocity. Warmer SST increases air temperature and decreases sea level pressure, thereby facilitating the formation and development of TC sizes and their dynamic systems. Furthermore, we find a consistent southward shift of the TC tracks that can be linked to the Fujiwhara effect, a phenomenon that occurs when two typhoons interact, causing a mutual counterclockwise rotation. Compared to SST changes, urbanization has limited influence on TC tracks and structures. The increase in surface roughness due to urban expansion reduces wind velocity but enhances the rainfall intensity within Shanghai, further exacerbating local risk. These findings could improve our understanding of typhoon variability under the combined effects of urbanization and climate change, as well as the risks they pose to Shanghai and other megacities in TC-prone regions.

Tropical cyclones (TC) in the western North Pacific, known as typhoons, cause significant socioeconomic damage in East and Southeast Asian countries. The city of Shanghai in China is highly vulnerable to TC damages. For example, Typhoons Bebinca and Pulasan recently (September 2024) struck the city, resulting in widespread flooding, power outages, and the evacuation of more than half a million residents, while also breaking local rainfall records. Despite these threats, there is limited knowledge about the variability and mechanism of TC activities in this region under climate change and urbanization. Here, we use the Weather Research and Forecasting (WRF) convection-permitting model to simulate five TC events that made landfall along the southeastern coast of China and severely impacted Shanghai between 2018 and 2022. Different scenarios are conducted, including considering a future expansion of Shanghai's urban area and increases in sea surface temperature (SST) by 1, 2, and 3 °C. The results indicate that while SST warming significantly shifts TC tracks away from the city, the local risk continues to increase due to substantial enhancement of rainfall intensity and wind velocity. Warmer SST increases air temperature and decreases sea level pressure, thereby facilitating the formation and development of TC sizes and their dynamic systems. Furthermore, we find a consistent southward shift of the TC tracks that can be linked to the Fujiwhara effect, a phenomenon that occurs when two typhoons interact, causing a mutual counterclockwise rotation. Compared to SST changes, urbanization has limited influence on TC tracks and structures. The increase in surface roughness due to urban expansion reduces wind velocity but enhances the rainfall intensity within Shanghai, further exacerbating local risk. These findings could improve our understanding of typhoon variability under the combined effects of urbanization and climate change, as well as the risks they pose to Shanghai and other megacities in TC-prone regions.

Tropical cyclones (TC) in the western North Pacific, known as typhoons, cause significant socioeconomic damage in East and Southeast Asian countries. The city of Shanghai in China is highly vulnerable to TC damages. For example, Typhoons Bebinca and Pulasan recently (September 2024) struck the city, resulting in widespread flooding, power outages, and the evacuation of more than half a million residents, while also breaking local rainfall records. Despite these threats, there is limited knowledge about the variability and mechanism of TC activities in this region under climate change and urbanization. Here, we use the Weather Research and Forecasting (WRF) convection-permitting model to simulate five TC events that made landfall along the southeastern coast of China and severely impacted Shanghai between 2018 and 2022. Different scenarios are conducted, including considering a future expansion of Shanghai's urban area and increases in sea surface temperature (SST) by 1, 2, and 3 °C. The results indicate that while SST warming significantly shifts TC tracks away from the city, the local risk continues to increase due to substantial enhancement of rainfall intensity and wind velocity. Warmer SST increases air temperature and decreases sea level pressure, thereby facilitating the formation and development of TC sizes and their dynamic systems. Furthermore, we find a consistent southward shift of the TC tracks that can be linked to the Fujiwhara effect, a phenomenon that occurs when two typhoons interact, causing a mutual counterclockwise rotation. Compared to SST changes, urbanization has limited influence on TC tracks and structures. The increase in surface roughness due to urban expansion reduces wind velocity but enhances the rainfall intensity within Shanghai, further exacerbating local risk. These findings could improve our understanding of typhoon variability under the combined effects of urbanization and climate change, as well as the risks they pose to Shanghai and other megacities in TC-prone regions.

Tropical cyclones (TC) in the western North Pacific, known as typhoons, cause significant socioeconomic damage in East and Southeast Asian countries. The city of Shanghai in China is highly vulnerable to TC damages. For example, Typhoons Bebinca and Pulasan recently (September 2024) struck the city, resulting in widespread flooding, power outages, and the evacuation of more than half a million residents, while also breaking local rainfall records. Despite these threats, there is limited knowledge about the variability and mechanism of TC activities in this region under climate change and urbanization. Here, we use the Weather Research and Forecasting (WRF) convection-permitting model to simulate five TC events that made landfall along the southeastern coast of China and severely impacted Shanghai between 2018 and 2022. Different scenarios are conducted, including considering a future expansion of Shanghai's urban area and increases in sea surface temperature (SST) by 1, 2, and 3 °C. The results indicate that while SST warming significantly shifts TC tracks away from the city, the local risk continues to increase due to substantial enhancement of rainfall intensity and wind velocity. Warmer SST increases air temperature and decreases sea level pressure, thereby facilitating the formation and development of TC sizes and their dynamic systems. Furthermore, we find a consistent southward shift of the TC tracks that can be linked to the Fujiwhara effect, a phenomenon that occurs when two typhoons interact, causing a mutual counterclockwise rotation. Compared to SST changes, urbanization has limited influence on TC tracks and structures. The increase in surface roughness due to urban expansion reduces wind velocity but enhances the rainfall intensity within Shanghai, further exacerbating local risk. These findings could improve our understanding of typhoon variability under the combined effects of urbanization and climate change, as well as the risks they pose to Shanghai and other megacities in TC-prone regions.