Flash drought and heatwave compound events increased in strength and length from 1980 to 2022 in China

Weather and Climate Extremes, Journal Year: 2024, Volume and Issue: unknown, P. 100720 - 100720

Published: Sept. 1, 2024

Language: Английский

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Urbanization Intensifies Heavy Hourly Rainfall Preconditioned by Heatwaves

Journal of Geophysical Research Atmospheres, Journal Year: 2025, Volume and Issue: 130(2)

Published: Jan. 16, 2025

Abstract Heatwave preconditioned‐heavy rainfall (HW_HR), a preconditioned compound event, can cause more damage than single heatwave or rainstorm. Both heatwaves and rainstorms be exacerbated by the presence of cities, but response their compounding to urbanization remains unclear especially at hourly scale. Here, we investigate spatial temporal responses HW_HR typical urban agglomeration, Pearl River Delta, using observations scenario‐based numerical simulations. Compared rural areas, show that in areas has higher probability occurrence mean intensity, its diurnal cycle frequency is narrower, peaking afternoon. The intensity effects most significant, with urbanization‐induced increase being five times non‐heatwave (noHW_HR). Our simulations support suggest changes are intense spatially heterogeneous relatively weak continuous noHW_HR. also preconditioning not only amplifies key variables alter atmospheric conditions provides pre‐storm unstable environment for urban‐induced warm‐dry surface trigger enhance convection. sub‐daily suggests preconditioning‐induced thermodynamic gradually decrease, whereas dynamic as event approaches. study highlights importance understanding on events, providing new insights into role preconditions water cycle.

Language: Английский

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Evolution characteristics of extreme maximum temperature events in Central China and adaptation strategies under different future warming scenarios

Open Geosciences, Journal Year: 2025, Volume and Issue: 17(1)

Published: Jan. 1, 2025

Abstract This study examined the spatiotemporal characteristics of extreme maximum temperature events (EMTEs) in Central China using observational data from national meteorological stations and coupled model intercomparison project phase 6 models by focusing on variances between global warming thresholds 1.5, 2.0, 4°C. The threshold was determined based 99th percentile daily temperature, an improved intensity–area–duration method employed to determine EMTE characteristics. Results indicated that during reference period (1995–2014), intensity, coverage, duration, number hot days EMTEs increased 0.19°C/10a, 1.6 × 105 km 2 /10a, 0.2 days/10a, 3 respectively. Compared with period, under future scenarios shared socioeconomic pathways SSP1-2.6, SSP2-4.5, SSP3-7.0, SSP4-6.0, SSP5-8.5, 0.05–0.21°C/10a, 0.54–4.3 0.12–1.19 0.7–2.2 Regionally, projected high values were mainly concentrated eastern Henan, northeastern Hubei, Jiangxi, central regions. For 4.0°C, larger threshold, greater likelihood EMTEs. Considering increasing probability more severe EMTEs, it is recommended research monitoring, early warning, forecasting be strengthened, effective measures taken limit increase within 1.5°C mitigate impacts such events.

Language: Английский

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Characteristics and Driving Mechanisms of Heatwaves in China During July and August

Atmosphere, Journal Year: 2025, Volume and Issue: 16(4), P. 434 - 434

Published: April 8, 2025

Against the backdrop of global warming, heatwaves in China have become more frequent, posing serious risks to public health and socio-economic stability. However, existing identification methods lack precision, driving mechanisms remain unclear. This study applies Excess Heat Factor (EHF) characterize across from 2013 2023, analyzing their spatiotemporal patterns exploring key drivers such as atmospheric circulation soil moisture. Key findings reveal significant regional differences: (1) Frequency Duration—The southeastern coastal regions (e.g., Yangtze River Delta) experience higher annual heatwave frequencies (1.75–3.5 events) but shorter durations (6.5–8.5 days). In contrast, arid northwest has both frequent (1.5–3.5 events per year) prolonged (8.5–14.5 days) heatwaves, while Tibetan Plateau sees weaker events. (2) Driving Factors—Heatwaves Delta are primarily driven by an intensified subtropical high, leading subsidence clear-sky conditions. Fujian, anomalous low-level winds enhance heat accumulation, areas show strong moisture–temperature coupling, where drier soils intensify warming. Conversely, moisture a influence on Plateau, suggesting dominant control. It is important note that EHF index used this does not directly account for humidity, which may limit its applicability humid regions. Additionally, ERA5 ERA5-Land reanalysis data were systematically validated against ground observations, introducing potential uncertainties.

Language: Английский

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Relationships between Landscape Patterns and Hydrological Processes in the Subtropical Monsoon Climate Zone of Southeastern China

Remote Sensing, Journal Year: 2023, Volume and Issue: 15(9), P. 2290 - 2290

Published: April 26, 2023

With rapid economic development, extensive human activity has changed landscape patterns (LPs) dramatically, which further influenced hydrological processes. However, the effects of LPs changes on processes, especially for streamflow–sediment relationship in subtropical monsoon climate zone, have not been reported. In our study, 10 watersheds with different sizes zone southeastern China were chosen as study area, and effect 14 most commonly used metrics (LMs) 4 typical indices (water yields (WY), runoff coefficient (RC), soil erosion modulus (SEM), suspended sediment concentration (SSC)) analyzed based land use maps data from 1990 to 2019. The results reveal that LP characteristics within area significantly. number patches shape significantly positively correlated watershed size (p < 0.01). For watersheds, largest patch index was negatively WY, RC, SEM, perimeter fractal dimension SSC. several LMs had scale effects. WY/RC interspersion juxtaposition larger but smaller watersheds. Similar found Shannon’s diversity/evenness SEM. general, an increase a small diversity would fragmentation result more erosion, affect between streamflow yield. As result, proper decrease physical connectivity benefit prevention. These enhance knowledge about processes local water conservation efforts.

Language: Английский

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Amplification of Coupled Hot‐Dry Extremes Over Eastern Monsoon China

Earth s Future, Journal Year: 2023, Volume and Issue: 11(12)

Published: Dec. 1, 2023

Abstract High air temperatures and low atmospheric humidity can result in severe disasters such as flash droughts regions characterized by high (monsoon regions). However, it remains unclear whether responses of hot extremes to warming temperature are amplified on dry days well the response days. Here, taking eastern monsoon China (EMC) a typical region, we find faster increase drier summer days, decrease hotter indicating “hotter get drier” “drier hotter” (i.e., coupling extremes), especially southern EMC. The EMC is also hotspot where hot‐dry has become significantly stronger during past six decades. associated with anomalies large‐scale circulations, reduced total cloud cover, abnormal anticyclones upper atmosphere, intense descending motion, strong moisture divergence over this region. Land‐atmosphere feedback enhance increasing land surface dryness (seen evaporation fraction). decreasing fraction drying soil moisture, controlled decreases pre‐summer 1‐m summer‐mean precipitation. Given projected predicted future, very likely that will be witnessed regions, which should mitigated against adopting adaptive measures.

Language: Английский

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Summer long-lived heatwaves in Northeast Asia promote heavy precipitation in South China

Atmospheric Research, Journal Year: 2024, Volume and Issue: 300, P. 107244 - 107244

Published: Jan. 10, 2024

Heatwaves interact with various extreme weather events, amplifying their impacts beyond the risks associated high temperatures alone. However, previous research has often overlooked extent to which heatwaves influence regions origin. In this study, we introduce a classification of in Northeast Asia, distinguishing between long-lived (LHWs) lasting five days or more and short-lived (SHWs) less than days. The study highlights significant role LHWs triggering heavy precipitation South China. anticyclonic anomalies are influenced by slow-moving wave train, initiating sustaining cyclonic over China, resulting upward airflow anomalies. Additionally, easterly wind southern region facilitate moisture transport creating favorable conditions for precipitation. findings underscore that could account noticeable portion (17.6%) total summer LHWs-related circulations

Language: Английский

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An unprecedented high temperature event in southern China in autumn 2021 and the essential role of the mid-latitude trough

Advances in Climate Change Research, Journal Year: 2022, Volume and Issue: 13(6), P. 772 - 777

Published: Nov. 12, 2022

Studies about high temperatures in China rarely touched the period beyond summer. But September–early October 2021, a record-breaking temperature event occurred southern China, and affected agriculture many provinces. Both daily maximum number of days were highest September since 1951. To better understand different features possible causes extreme autumn from those summer, analysis atmospheric circulation patterns was conducted. The western Pacific subtropical (WPSH) quite stronger extended much more westward most 2021 than its climatology, which directly caused this unprecedented event. Besides, mid-latitude trough over east Japan may also play an essential role Due to southward extension trough, cyclonic anomaly appeared at 850 hPa, northerly wind component prevailed west blocked eastward retreat WPSH. As result, stably controlled by WPSH, led persistence conclusion is further confirmed statistical results multi-year data analogue analysis. Compared previous studies, study reveals highlights joint impacts WPSH causing

Language: Английский

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Preparation of a Novel Structure-Designed Porous Ceramsite for Water Retention

ACS Applied Materials & Interfaces, Journal Year: 2023, Volume and Issue: 15(36), P. 42753 - 42763

Published: Aug. 30, 2023

Ceramsites can be used as water storage materials, but the challenges of low absorption and short water-retention time are restricted to their application. In this paper, a novel multilayer powder coatings method was prepare structure-designed ceramsite. The results showed that ceramsite prepared by coating method. A with large internal small external pores has superior properties, rate 51.3% at 24 h 56 50 °C 55% RH. This work not only broadens new way solid waste resource utilization also great significance in promoting construction sponge cities overcoming urban heat island effect.

Language: Английский

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Response of surface energy components to urban heatwaves and its impact on human comfort in coastal city

Urban Climate, Journal Year: 2024, Volume and Issue: 54, P. 101836 - 101836

Published: March 1, 2024

Language: Английский

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