Wei Zhang

Utah State University | USU · Department of Plants, Soils and Climate

The western United States (U.S.) has been experiencing more severe wildfires, in part due to climate change, but the underlying synoptic patterns and their modulation in driving fire weather is unclear. Here we investigated the relationship between weather regimes (WRs) and fire weather indices, specifically vapor pressure deficit (VPD) and the Can...

The effectiveness of frequent compost application in improving soil health is well‐documented. Less is known on the long‐term effects of infrequent compost application to semiarid soils. Compost made of dairy manure and straw bedding was applied once in a dryland organic hard red winter wheat (Triticum aestivum L. emend. Thell.)–fallow system at 50...

Robust projections and predictions of climate variability and change, particularly at regional scales, rely on the driving processes being represented with fidelity in model simulations. Consequently, the role of enhanced horizontal resolution in improved process representation in all components of the climate system continues to be of great intere...

Probable maximum precipitation (PMP) has been an important criterion for designing hydrological infrastructure and it is likely to change with respect to global warming. To assess the potential risk that hydrological infrastructure in the U.S. state of Utah may encounter under the least mitigated emission scenario of Representative Concentration Pa...

In this study, we present the first nationwide assessment of the uneven rainfall effects on economic growth at the county scale in China. Our results demonstrate that while sufficient annual rainfall amount is advantageous for county economy, the increases in the number of rainy days or extreme rainfall amount are adverse for economic growth, parti...

The Asian monsoon (AM) region is a well-known region with prevailing stratosphere–troposphere exchange (STE). However, how the STE across this region changes with the weakening AM remains unclear. Here, we particularly diagnose the air mass transport between the planetary boundary layer (PBL) and the stratosphere over the AM region during 1992–2017...

The Three-Rivers Headwater (TRH) region has experienced notable dry-to-wet shift in summer precipitation in recent decades. Despite the widespread efforts of scientific community, the causes of such climate shift remain not well-understood. Building upon an ensemble of high-resolution Lagrangian simulations and moisture source diagnostic, this stud...

Plain Language Summary Historically, the Contiguous United States (CONUS) was parched in the West and soaked in the East. Despite the importance of this distinct spatial pattern of precipitation variability, the drivers of this hydroclimatic phenomenon remain elusive. Therefore, there is big knowledge gap in understanding the zonal precipitation pa...

The Great Salt Lake (GSL) is a shallow terminal lake located in Northern Utah, the United States. Over the years the water extent of the GSL has undergone substantial reduction due to water diversions and a changing climate – in particular rising temperatures. However, the potential impacts of the shrinking GSL water body on the local hydroclimate...

Plain Language Summary Precipitation displays pronounced seasonal cycle, and its phase and amplitude are closely associated with ecosystems and our society by redistributing water resources. The phase of precipitation cycle has been well understood in previous studies, but how its magnitude changes remain largely unknown. In this study, we use mult...

The eastern periphery of the Tibetan Plateau (EPTP) is prone to frequent and severe Persistent Extreme precipitation (PEP) events in summer. Given the complexity of weather systems and the intricate nature of terrain over this region, the generation and development mechanisms of the PEP in the EPTP remain to be determined. In this study, the format...

Heatwaves are consecutive hot days with devastating impacts on human health and the environment. These events may evolve across both space and time, characterizing a spatiotemporally contiguous propagation pattern that has not been fully understood. Here, we track the spatiotemporally contiguous heatwaves in both reanalysis datasets and model simul...

The Three-Rivers Headwater (TRH) region has experienced notable dry-to-wet shift in summer precipitation in recent decades. Despite the widespread efforts of scientific community, the causes of such climate shift remain not well-understood. Building upon an ensemble of high-resolution Lagrangian simulations and moisture source diagnostic, this stud...

The eastern European (EE) region has experienced record-breaking heatwave events in recent years, and such events are expected to increase in future with global warming. Early warning systems are an important step towards mitigating their impacts. Here we seek to further clarify the effect of Atlantic Meridional Mode (AMM) on the EE region temperat...

Interannual relationship between the Pacific Meridional Mode (PMM) and landfalling tropical cyclone (TC) frequency in China (LTCFC) exhibits an interdecadal enhancement since the late-1980s, Epochs I (E1, 1951–1985) and II (E2, 1987–2019) are therefore defined to unravel possible mechanisms. Strengthened low-level vorticity and weakened vertical wi...

Extreme heat is among the deadliest of weather-related hazards, exerting far-reaching impacts on the natural environment and human society globally. Its risk has been rising worldwide over the past decades, particularly in densely populated urban settlements that more than half the world’s population live in. This rise is primarily attributed to an...

Heatwaves are among the deadliest weather-related disasters. They are not only seen in summer but also may appear in spring and autumn, especially under climate warming. Although the mechanisms of summertime heatwaves have been extensively studied, how they differ from spring and autumn seasons and possibly season-dependent mechanisms of heatwaves...

Background: Studies exploring the racial/ethnicity disparity of the impact of heat on hospital admission are notably limited, especially in Texas, a state with a diverse population and consistently ranking among the top ten U.S. states for heat-related deaths per capita from 2018 to 2020. Objective: Our objective is to determine the correlation...

While seasonal climate forecasts have major socio-economic impacts, current forecast products, especially those for precipitation, are not yet reliable for forecasters and decision makers. Here we developed a novel statistical-dynamical hybrid model for precipitation by applying Weather Regimes (WRs) and Gaussian Mixture Models (WR-GMM) to the Nati...

The Flood‐Drought condition over the Three‐River Headwater region (TRHR) of the Tibetan Plateau (TP) exerts vital impacts on regional climate and downstream livelihoods. However, the reasons behind precipitation variability over this region remain elusive. In this study, the multi‐year moisture sources of water vapour reaching the TRHR were identif...

Summertime air quality is a growing public health concern in the populated region of Northern Utah. Whereas winter air pollution is highly linked with local atmospheric temperature inversions associated with upper atmospheric high- pressure and radiational cooling in valleys, the relationship between climate factors and the frequency of poor air qu...

Understanding the drivers of the major 2021 drought conditions across the Western U.S. (WUS) is important to develop future resilience and adaptation measures. While evapotranspiration (ET) tends to increase in a warming climate when water is available, areas with low precipitation would evaporate less water than expected, as seen in the 2021 droug...

Among the many impacts of COVID-19, the pandemic led to improved air quality conditions in the countries under quarantine due to the shutdown of industries, drastically reduced traffic, and lockdowns. Meanwhile, the western United States, particularly the coastal areas from Washington to California, received much less precipitation than normal duri...

The changes in stream discharge extremes due to temperature and seasonality are key metrics in assessing the effects of climate change on the hydrological cycle. While scaling is commonly applied to temperature and precipitation due to the physical connections between temperature and moisture (i.e., Clausius-Clapeyron), the scaling rate of stream d...

Tropical cyclones (TCs) regularly form in association with the intertropical convergence zone (ITCZ), and thus, its positioning has implications for global TC activity. While the poleward extent of the ITCZ has varied markedly over past centuries, the sensitivity with which TCs responded remains poorly understood from the proxy record, particularly...

Weather types (WTs) are common atmospheric patterns that shape weather and climate characteristics. While an improved understanding of WTs can provide insights into seasonal predictions, few studies have investigated WT transitions and their impacts on temperature and precipitation across the continental United States (U.S.). This study focuses on...

During 19-21 July 2021, Henan located in central-eastern China experienced torrential rainfall that caused devastating floods and claimed more than 300 casualties. It remains unclear whether and to what extent this extreme precipitation event is contributed by Typhoon In-Fa (TIF). Here we quantify the contribution of TIF to this record-breaking “21...

Plain Language Summary The western U.S. is a hotspot for studying climate change impacts on the hydrological cycle. Despite lower‐than‐average total precipitation in 2021, the contrasting dryness and wetness in the western U.S. has been widely reported as a “precipitation roller coaster.” In this paper we quantified the “precipitation roller coaste...

Heatwaves detrimentally affect human health and ecosystems. While previous studies focused on either temporal changes or spatial extents of heatwaves, their spatiotemporal contiguity and propagation patterns are unclear. Here, we investigate the climatology, long-term trends, and interannual variations of spatiotemporally contiguous heatwaves acros...

Floods claim a high toll in fatalities and economic impacts. Despite their societal relevance, there is much more to learn about the projected changes in discharge and flooding. Here we force an operational hydrologic model over the state of Iowa with high‐resolution convection‐permitting climate‐model precipitation to evaluate the response of 140...

Increased occurrence of heatwaves across different parts of the world is one of the characteristic signatures of anthropogenic warming. With a 1.3 billion population, India is one of the hot spots that experience deadly heatwaves during May-June – yet the large-scale physical mechanism and teleconnection patterns driving such events remain poorly u...

Landfalling tropical cyclones (LTCs) are the most devastating disaster to affect the U.S., while the demonstration of skillful subseasonal (between 10 days and one season) prediction of LTCs is less promising. Understanding the mechanisms governing the subseasonal variation of TC activity is fundamental to improving its forecast, which is of critic...

Floods claim a high toll in fatalities and economic impacts. Despite their societal relevance, there is much more to learn about the projected changes in discharge and flooding. Here we force an operational hydrologic model over the state of Iowa with high-resolution convection-permitting climate-model precipitation to evaluate the response of 140...

Our study focuses on the hydrologic implications of resolving and modeling atmospheric processes at different spatial scales. Here we use heavy precipitation events from an atmospheric model that was run at different horizontal grid spacings (i.e., 250 m, 500 m, 1 km, 2 km 4 km, and 12 km) and able to resolve different processes. Within an idealize...

While the changes of extreme weather and climate events have been well investigated, the change of compound events (i.e., combinations of multiple weather/climate extremes and/or hazards), which severely affect the biophysical and human systems, remains poorly understood. Here, we examine the decadal trends of subsequently (or “preconditioned”) com...

High-amplitude ridges can enforce heat-trapping systems that persist through an entire season, contributing to drought events. However, the impact of day-to-day weather system changes at the meso- and synoptic-scale are also important, albeit less well studied. We identify five weather types (WTs) from 500-hPa geopotential height anomalies. These c...

Compound extremes pose immense challenges and hazards to communities, and this is particularly true for compound hydrometeorological extremes associated with deadly floods, surges, droughts, and heat waves. To mitigate and better adapt to compound hydrometeorological extremes, we need to better understand the state of knowledge of such extremes. He...

This study focuses on the development of a probabilistic rainfall generator for tropical cyclones (TCs) affecting Louisiana. We consider 12 storms making landfall along the Louisiana coast during 2002–2017 and generate ensembles of high‐resolution (~5 km and 20 min) TC‐rainfall fields for each storm. We develop a data‐driven multiplicative model, r...

Our study focuses on the hydrologic implications of resolving and modeling atmospheric processes at different spatial scales. Here we use heavy precipitation events from an atmospheric model that was run at different horizontal grid spacings (i.e., 250 m, 500 m, 1 km, 2 km 4 km, and 12 km) and able to resolve different processes. Within an idealize...

Changes in the translational speed of tropical cyclones (e.g., sluggish tropical cyclones) are associated with extreme precipitation and flash flooding. However, it is still unclear regarding the spatial and temporal variability of extreme tropical cyclone translation events in the North Atlantic and underlying large-scale drivers. This work finds...

Atlantic hurricanes are a major hazard to life and property, and a topic of intense scientific interest. Historical changes in observing practices limit the utility of century-scale records of Atlantic major hurricane frequency. To evaluate past changes in frequency, we have here developed a homogenization method for Atlantic hurricane and major hu...

This study examines the climatology and structure of rainfall associated with tropical cyclones (TCs) based on the atmosphere-only Coupled Model Intercomparison Project Phase 6 (CMIP6) HighResMIP runs of the PRocess-based climate sIMulation: AdVances in high resolution modelling and European climate Risk Assessment (PRIMAVERA) Project during 1979–2...

This study examines the association between the Pacific meridional mode (PMM) and summer precipitation extremes over China using observational and reanalysis datasets. Results suggest that positive PMM phases are accompanied by suppressed extreme precipitation over the mid-lower reaches of the Yangtze River basin (MLYRB) and strengthened rainfall e...

Compared with individual events, compound weather and climate extremes may impose more serious influences on natural systems and human society, especially in populated areas. In this study, we examine the changes in the compound precipitation events that follow extremely hot weather within several days during 1961–2017 in South China by taking the...

The compound heat wave and extreme precipitation events are responsible for severe damages to the environment and human societies. Although major advances have been made in understanding the compound extremes (e.g., drought and heat wave), little is known about two types of extremes synchronized/connected in different regions in China. Here we iden...

Although slower translation speed can induce a larger amount of local rainfall for an individual tropical cyclone (TC), whether change in total TC precipitation (TCP) affecting China is related to TC translation speed in the satellite era remains unclear. Based on multiple TC best-track datasets and a reanalysis dataset, we find a significant incre...

The central USA experienced major flooding during spring 2019, with both the Missouri and Mississippi Rivers at major flood stage at several locations, causing levees to breach and widespread flooding. Here, we examine the total precipitation responsible for the spring 2019 flooding across the central USA from the perspective of weather types. We f...

This study examines the potential improvement in seasonal predictability of monthly precipitation and temperature using a novel machine learning approach, the convolutional Gaussian process (CGP). This approach allows us to take into account multiple quantities and their interdependencies simultaneously. We use one global climate model (FLORb01) pa...

Atlantic hurricanes are a major hazard to life and property 1,2,3 , and a topic of intense scientific interest 4,5,6 . Historical changes in observing practices limit the utility of century-scale records of Atlantic major hurricane frequency ⁷⁻¹³ . To evaluate past changes in frequency, we have here developed a homogenization method for Atlantic hu...

The City of Cedar Rapids was significantly affected by the June 2008 flood. However, little is known about the role anthropogenic warming during this event, not only in terms of hydrologic response but also of impacts. Here we use a continuous distributed hydrologic model forced with precipitation with and without external forcing and show that the...

Floods represent a major natural hazard in Africa, causing over 27000 fatalities during the period 1950-2019. Despite its relevance, little is known about changes in flood hazard across this continent due to the lack of long-term high-quality streamflow records. Here we use a newly assembled discharge dataset of African rivers, and provide a long-t...

While major advances have been made toward understanding flooding across the central United States, little is known about the linkage between heat stress, characterized by high temperature and humidity, and flooding during the summer in this area. Here, we focus on a compound event that relates these two hazards; we find that a high percentage of f...

There are two key modes of the South Asia high (SAH) during the boreal summer: the Iranian Plateau (IP) and Tibetan Plateau (TP) modes. The anomalies of chemical constituents in the upper troposphere and lower stratosphere (UTLS) region within the SAH area largely depend on this bimodality. To better understand the underlying mechanisms of this dep...

Atlantic tropical cyclones (TCs) can cause significant societal and economic impacts, as 2019's Dorian serves to remind us of these storms' destructiveness. Decades of effort to understand and predict Atlantic TC activity have improved seasonal forecast skill, but large uncertainties still remain, in part due to an incomplete understanding of the d...

This study identifies a significant positive association between tropical North Atlantic (TNA) sea surface temperature (SST) during preceding spring and the frequency of intense tropical cyclones (TCs) making landfall over mainland China during autumn on interannual time scales. Observational analyses show that a warm SST anomaly in TNA during spri...

Extreme weather and climate events, including hurricanes [...]

Medicanes, hurricane‐like cyclonic systems in the Mediterranean Sea, are becoming an increasingly severe problem for many Mediterranean countries because climate projections suggest a higher risk under anthropogenic forcing even under an intermediate scenario. Due to the small size of these weather systems, high‐resolution data are required to bett...

Our study focuses on the projected changes in annual and seasonal maximum daily runoff (used as a proxy for flooding) across the continental United States based on outputs from eight global climate models (GCMs) from the Sixth Coupled Model Intercomparison Project (CMIP6). Analyses performed at the regional scale indicate that the GCMs are generall...