Divergent flash drought risks indicated by evaporative stress and soil moisture projections under warming scenarios

Offline drought indices have been utilizable for monitoring drought conditions, but their reliability in projecting future drought risks is uncertain due to non-meteorological influences on atmospheric water demand (Ep ). This study investigated the impact of surface resistance sensitivity (rs ) to elevated CO2 (eCO2) on projections of future flash droughts (FD). We evaluated FD risks across an East Asian region during a historical period (1981–2020) and a future period (2021–2060) using two evaporative stress index (ESI) series. One series employs the conventional Penman-Monteith (PM) equation for Ep , while the other incorporates a generic rs sensitivity to eCO2 derived from advanced Earth System Models (ESMs). We compared the FD risks identified by the two ESI series with assessments based on soil moisture data from atmospheric reanalysis and multiple ESM projections under two emission scenarios linked with the Shared Socioeconomic Pathways. Results showed that the response of rs to eCO2 has had minimal influences on temporal variations of ESI for the past decades, likely due to its low sensitivity and the masking effects of other environmental factors. However, for the future decades, the ESI projected by the conventional PM equation significantly diverged from soil moisture projections, overestimating future FD risks even under a low emission scenario. We found that incorporating the generic rs sensitivity into the PM equation did not simply resolve the disparity in FD frequencies between ESI and soil moisture projections. Many associated factors contributing to stomatal responses to eCO2 complicate the understanding of future flash drought risks. This study suggests that overreliance on the conventional Ep formula, which neglects non-meteorological effects, could decrease the ability of ESI to detect future FD events under eCO2.

[1]  J. Otkin,et al.  Global projections of flash drought show increased risk in a warming climate , 2023, Communications Earth & Environment.

[2]  J. Otkin,et al.  A global transition to flash droughts under climate change , 2023, Science.

[3]  S. Higgins,et al.  Shifts in vegetation activity of terrestrial ecosystems attributable to climate trends , 2023, Nature Geoscience.

[4]  D. Ellsworth,et al.  Optimal stomatal theory predicts CO2 responses of stomatal conductance in both gymnosperm and angiosperm trees. , 2022, The New phytologist.

[5]  R. Qualls,et al.  Power‐Function Expansion of the Polynomial Complementary Relationship of Evaporation , 2022, Water Resources Research.

[6]  Xing Yuan,et al.  Land-atmosphere coupling speeds up flash drought onset. , 2022, The Science of the total environment.

[7]  N. McDowell,et al.  The uncertain role of rising atmospheric CO2 on global plant transpiration , 2022, Earth-Science Reviews.

[8]  S. Vicente‐Serrano,et al.  The Rise of Atmospheric Evaporative Demand Is Increasing Flash Droughts in Spain During the Warm Season , 2022, Geophysical Research Letters.

[9]  A. P. Williams,et al.  Large Divergence in Tropical Hydrological Projections Caused by Model Spread in Vegetation Responses to Elevated CO2 , 2022, Earth's Future.

[10]  Robb M. Randall,et al.  Global distribution, trends, and drivers of flash drought occurrence , 2021, Nature Communications.

[11]  S. Seneviratne,et al.  Stronger temperature–moisture couplings exacerbate the impact of climate warming on global crop yields , 2021, Nature Food.

[12]  B. Medlyn,et al.  To what extent can rising [CO2 ] ameliorate plant drought stress? , 2021, The New phytologist.

[13]  Daeha Kim,et al.  New Drought Projections Over East Asia Using Evapotranspiration Deficits From the CMIP6 Warming Scenarios , 2021, Earth's Future.

[14]  M. Hobbins,et al.  Flash drought in Australia and its relationship to evaporative demand , 2021, Environmental Research Letters.

[15]  A. Berg,et al.  No projected global drylands expansion under greenhouse warming , 2021, Nature Climate Change.

[16]  R. Seager,et al.  Disentangling the Regional Climate Impacts of Competing Vegetation Responses to Elevated Atmospheric CO2 , 2021, Journal of geophysical research. Atmospheres : JGR.

[17]  S. Coats,et al.  CO2-plant effects do not account for the gap between dryness indices and projected dryness impacts in CMIP6 or CMIP5 , 2021 .

[18]  Shenglian Guo,et al.  A new framework for tracking flash drought events in space and time , 2020 .

[19]  Ximing Cai,et al.  Drought Propagation in Contiguous U.S. Watersheds: A Process‐Based Understanding of the Role of Climate and Watershed Properties , 2020, Water Resources Research.

[20]  Ke Zhang,et al.  Increased control of vegetation on global terrestrial energy fluxes , 2020, Nature Climate Change.

[21]  A. Timmermann,et al.  Future Changes of Summer Monsoon Characteristics and Evaporative Demand Over Asia in CMIP6 Simulations , 2020, Geophysical Research Letters.

[22]  J. Overpeck,et al.  Flash droughts present a new challenge for subseasonal-to-seasonal prediction , 2020, Nature Climate Change.

[23]  S. Vicente‐Serrano,et al.  Unraveling the influence of atmospheric evaporative demand on drought and its response to climate change , 2019, WIREs Climate Change.

[24]  J. Arblaster,et al.  Flash Drought in CMIP5 Models , 2019 .

[25]  F. Yuan,et al.  Flash droughts characterization over China: From a perspective of the rapid intensification rate. , 2019, The Science of the total environment.

[26]  Pierre Gentine,et al.  Land–atmosphere feedbacks exacerbate concurrent soil drought and atmospheric aridity , 2019, Proceedings of the National Academy of Sciences.

[27]  J. Otkin,et al.  The evolution, propagation, and spread of flash drought in the Central United States during 2012 , 2019, Environmental Research Letters.

[28]  J. Chun,et al.  Historical Drought Assessment Over the Contiguous United States Using the Generalized Complementary Principle of Evapotranspiration , 2019, Water Resources Research.

[29]  Xueming Li,et al.  The 2012 Flash Drought Threatened US Midwest Agroecosystems , 2019, Chinese Geographical Science.

[30]  J. Otkin,et al.  Using the evaporative stress index to monitor flash drought in Australia , 2019, Environmental Research Letters.

[31]  S. Schubert,et al.  Flash Drought as Captured by Reanalysis Data: Disentangling the Contributions of Precipitation Deficit and Excess Evapotranspiration , 2019, Journal of Hydrometeorology.

[32]  Martha C. Anderson,et al.  Exploring seasonal and regional relationships between the Evaporative Stress Index and surface weather and soil moisture anomalies across the United States , 2018, Hydrology and Earth System Sciences.

[33]  Sergio M. Vicente-Serrano,et al.  Global Assessment of the Standardized Evapotranspiration Deficit Index (SEDI) for Drought Analysis and Monitoring , 2018, Journal of Climate.

[34]  P. Gentine,et al.  When Does Vapor Pressure Deficit Drive or Reduce Evapotranspiration? , 2018, Journal of advances in modeling earth systems.

[35]  S. Seneviratne,et al.  Future climate risk from compound events , 2018, Nature Climate Change.

[36]  J. Sheffield,et al.  Drivers of Variability in Atmospheric Evaporative Demand: Multiscale Spectral Analysis Based on Observations and Physically Based Modeling , 2018 .

[37]  Christopher F. Labosier,et al.  Meteorological conditions associated with the onset of flash drought in the Eastern United States , 2017 .

[38]  R. Murtugudde,et al.  A threefold rise in widespread extreme rain events over central India , 2017, Nature Communications.

[39]  B. Santer,et al.  Competing influences of anthropogenic warming, ENSO, and plant physiology on future terrestrial aridity. , 2017, Journal of climate.

[40]  Zhuguo Ma,et al.  Production of a combined land surface data set and its use to assess land‐atmosphere coupling in China , 2017 .

[41]  P. Blanken,et al.  The increasing importance of atmospheric demand for ecosystem water and carbon fluxes , 2016 .

[42]  M. Melotto,et al.  Regulation of Stomatal Defense by Air Relative Humidity1[OPEN] , 2016, Plant Physiology.

[43]  P. Milly,et al.  Potential evapotranspiration and continental drying , 2016 .

[44]  R. Moss,et al.  The Scenario Model Intercomparison Project (ScenarioMIP) for CMIP6 , 2016 .

[45]  J. Randerson,et al.  From the Cover: Plant responses to increasing CO2 reduce estimates of climate impacts on drought severity , 2016 .

[46]  Xiaomang Liu,et al.  Assessment of the Influences of Different Potential Evapotranspiration Inputs on the Performance of Monthly Hydrological Models under Different Climatic Conditions , 2016 .

[47]  Justin L. Huntington,et al.  The Evaporative Demand Drought Index. Part I: Linking Drought Evolution to Variations in Evaporative Demand , 2016 .

[48]  Justin L. Huntington,et al.  The Evaporative Demand Drought Index. Part II: CONUS-Wide Assessment against Common Drought Indicators , 2016 .

[49]  D. Ellsworth,et al.  Conserved stomatal behaviour under elevated CO2 and varying water availability in a mature woodland , 2016 .

[50]  Dennis P. Lettenmaier,et al.  Precipitation Deficit Flash Droughts over the United States , 2016 .

[51]  Feng Gao,et al.  The Evaporative Stress Index as an indicator of agricultural drought in Brazil: An assessment based on crop yield impacts , 2016 .

[52]  Veronika Eyring,et al.  Overview of the Coupled Model Intercomparison Project Phase 6 (CMIP6) experimental design and organization , 2015 .

[53]  Xing Yuan,et al.  Microwave remote sensing of short‐term droughts during crop growing seasons , 2015 .

[54]  K. Mo,et al.  Heat wave flash droughts in decline , 2015 .

[55]  Martha C. Anderson,et al.  Examining the Relationship between Drought Development and Rapid Changes in the Evaporative Stress Index , 2014 .

[56]  R. Trigo,et al.  Evidence of increasing drought severity caused by temperature rise in southern Europe , 2014 .

[57]  J. Chiang,et al.  Increase in the range between wet and dry season precipitation , 2013 .

[58]  V. Singh,et al.  A review of drought concepts , 2010 .

[59]  S. Seneviratne,et al.  Investigating soil moisture-climate interactions in a changing climate: A review , 2010 .

[60]  A. Rogers,et al.  The response of photosynthesis and stomatal conductance to rising [CO2]: mechanisms and environmental interactions. , 2007, Plant, cell & environment.

[61]  A. Rogers,et al.  Rising atmospheric carbon dioxide: plants FACE the future. , 2004, Annual review of plant biology.

[62]  J. Valdes,et al.  Nonparametric Approach for Estimating Return Periods of Droughts in Arid Regions , 2003 .

[63]  George H. Hargreaves,et al.  Reference Crop Evapotranspiration from Temperature , 1985 .

[64]  C. Swift,et al.  Microwave remote sensing , 1980, IEEE Antennas and Propagation Society Newsletter.

[65]  C. Priestley,et al.  On the Assessment of Surface Heat Flux and Evaporation Using Large-Scale Parameters , 1972 .

[66]  C. W. Thornthwaite An Approach Toward a Rational Classification of Climate , 1948 .

[67]  Weather Roulette,et al.  Climate , 1858, The Sanitary Review and Journal of Public Health.

[68]  C. Hain,et al.  FLASH DROUGHTS A Review and Assessment of the Challenges Imposed by Rapid-Onset Droughts in the United States Want to make a valuable contribution to your local library or community college? , 2018 .

[69]  T. McVicar,et al.  Hydrologic implications of vegetation response to elevated CO2 in climate projections , 2018, Nature Climate Change.

[70]  William P. Kustas,et al.  Using a Diagnostic Soil-Plant-Atmosphere Model for Monitoring Drought at Field to Continental Scales , 2013 .

[71]  G. Meehl,et al.  OVERVIEW OF THE COUPLED MODEL INTERCOMPARISON PROJECT , 2005 .

[72]  D. Wilhite Drought as a natural hazard : Concepts and definitions , 2000 .

[73]  L. S. Pereira,et al.  Crop evapotranspiration : guidelines for computing crop water requirements , 1998 .