Increase in Compound Drought and Heatwaves in a Warming World

Mukherjee, Sourav; Mishra, Ashok K.

doi:10.1029/2020gl090617

Cited by 177 publications

(152 citation statements)

References 63 publications

(94 reference statements)

Supporting

Mentioning

132

Contrasting

Order By: Relevance

“…Concurrent hot and dry events (CHDs) can result in significant socio-economic damages, compared to individual events (Leonard et al, 2014). The observed increase in CHDs, which severally impacted the society, economy, and the environment over the past decades, has brought the scientific community to make an extensive analysis of the variability, trends, and future projection of these events, either at global scale (Feng et al, 2020;Ridder et al, 2020;Mukherjee and Mishra, 2021) or at regional scale (Kattsov et al, 2005;Von Buttlar et al, 2018;Hao et al, 2019;Russo et al, 2019;Vogel et al, 2019;Bezak and Mikoš, 2020;Kong et al, 2020). In this respect, we explored the spatio-temporal variability of CHDs at European level and we quantified the relationship between the occurrence of CHDs and the large-scale atmospheric circulation.…”

Section: Discussionmentioning

confidence: 99%

Compound Hot and Dry Events in Europe: Variability and Large-Scale Drivers

2021

View full text Add to dashboard Cite

An important aspect of inevitable surprises, for the climate system, is the potential of occurrence of compound extreme events. These can be events that occur at the same time over the same geographic location or at multiple locations within a given country or around the world. In this study, we investigate the spatio-temporal variability of summer compound hot and dry (CHD) events at European level and we quantify the relationship between the occurrence of CHDs and the large-scale atmospheric circulation. Here we show that summer 1955 stands out as the year with the largest spatial extent characterized by hot and dry conditions (~21.2% at European level), followed by 2015 (~20.3%), 1959 (~19.4%), and 1950 (~16.9%). By employing an Empirical Orthogonal Function (EOF) analysis we show that there are three preferred centers of action of CHDs over Europe: Fennoscandia, the central part of Europe, and the south-eastern part of Europe. Overall, hot and dry summers are, in general, associated with persistent high-pressure systems over the regions affected by CHDs, which in turn reduces the zonal flow and diverts the storm tracks southward. The high-pressure systems associated with each mode of variability largely suppresses ascending motions, reduces water vapor condensation and precipitation formation, leading to drought conditions below this atmospheric system. This study may help improve our understanding of the spatio-temporal variability of hot and dry summers, at European level, as well as their driving mechanisms.

show abstract

Section: Discussionmentioning

confidence: 99%

Compound Hot and Dry Events in Europe: Variability and Large-Scale Drivers

2021

View full text Add to dashboard Cite

show abstract

“…Similarly, the global analysis using in situ observations and earth system models showed that the co‐occurrence of increased VPD and low SM is projected to be more frequent and severe under the warming climate (Zhou et al., 2019). However, a majority of the previous studies (Mukherjee & Mishra, 2020; Sharma & Mujumdar, 2017; Zhou et al., 2019; Zscheischler et al., 2018; Zscheischler & Seneviratne, 2017) on compound extremes are based on the future projections that do not account for the role of irrigation. Therefore, the risk of compound extremes in heavily irrigated regions may be under or overestimated.…”

Section: Discussionmentioning

confidence: 99%

“…Despite the profound implications, the role of irrigation on compound extremes of low soil moisture and high VPD has not been examined in India. Previous studies reported the mechanisms for concurrent soil moisture – VPD, heatwave – temperature, and heatwave – drought events at the global and regional scales (AghaKouchak et al., 2014; Ambika & Mishra, 2020; Mishra, Ambika, et al., 2020; Mishra, Thirumalai, et al., 2020; Mukherjee & Mishra, 2020; Sharma & Mujumdar, 2017; Zhou et al., 2019), however, the role of irrigation was not considered. For instance, compound extremes of drought and heatwaves at short and long time‐scales are attributable to anticyclone, atmospheric blocking, and advection of air masses (Zhou et al., 2019; Zscheischler et al., 2018, 2020), which can be significantly modulated by irrigation.…”

Section: Introductionmentioning

confidence: 99%

Modulation of Compound Extremes of Low Soil Moisture and High Vapor Pressure Deficit by Irrigation in India

Ambika

Mishra

2021

JGR Atmospheres

View full text Add to dashboard Cite

Compound extremes of low soil moisture and high vapor pressure deficit (VPD) have implications on terrestrial carbon sequestration, vegetation growth, and net primary productivity (NPP). Yet, the role of irrigation on the occurrence of compound extremes remains unexplored in India. Here, we use satellite observations, reanalysis data sets, and high‐resolution simulations from the Weather Research and Forecasting (WRF) model to show that irrigation significantly reduces the frequency of compound extremes of low soil moisture and high VPD in India. The Indo‐Gangetic plain witnessed a significant (p < 0.05) increase in mean annual soil moisture while a substantial reduction in VPD during 1979–2018. Moreover, irrigation caused considerable cooling over the Indo‐Gangetic plain during 1982–2018. The increase in soil moisture and the decline in VPD partly contributed to a substantial rise in Normalized Difference Vegetation Index (NDVI) and NPP. We conducted high‐resolution simulations using the WRF model to examine the role of irrigation in modulating the frequency of compound extremes during 1979–2018. The WRF simulations under the irrigation‐on show a considerably reduced frequency of the compound extremes compared to the irrigation‐off (control) simulations. Irrigation modulates compound extremes by changing the land surface energy budget and planetary boundary layer height. Therefore, there is a need to consider irrigation for reliable projections of compound extremes under a warming climate in intensively irrigated regions.

show abstract

“…Heatwaves are predicted to increase in frequency, duration and intensity as a result of climate change [ 1 ]. The formation of heatwaves can vary based on location, yet is fundamentally a result of high pressure in the upper atmosphere trapping hot, low-pressure air close to the Earth’s surface for extended periods [ 2 ].…”

Section: Introductionmentioning

confidence: 99%

Social Sensing of Heatwaves

Young

Arthur

Spruce

et al. 2021

Sensors

View full text Add to dashboard Cite

Heatwaves cause thousands of deaths every year, yet the social impacts of heat are poorly measured. Temperature alone is not sufficient to measure impacts and “heatwaves” are defined differently in different cities/countries. This study used data from the microblogging platform Twitter to detect different scales of response and varying attitudes to heatwaves within the United Kingdom (UK), the United States of America (US) and Australia. At the country scale, the volume of heat-related Twitter activity increased exponentially as temperature increased. The initial social reaction differed between countries, with a larger response to heatwaves elicited from the UK than from Australia, despite the comparatively milder conditions in the UK. Language analysis reveals that the UK user population typically responds with concern for individual wellbeing and discomfort, whereas Australian and US users typically focus on the environmental consequences. At the city scale, differing responses are seen in London, Sydney and New York on governmentally defined heatwave days; sentiment changes predictably in London and New York over a 24-h period, while sentiment is more constant in Sydney. This study shows that social media data can provide robust observations of public response to heat, suggesting that social sensing of heatwaves might be useful for preparedness and mitigation.

show abstract

Increase in Compound Drought and Heatwaves in a Warming World

Abstract: The evolution of drought and heatwaves are controlled by a variety of land surface fluxes (Mishra & Singh, 2010), and their spatial patterns are heterogeneous due to the regional differences in precipitation, temperature anomalies, and other hydrological changes (

Cited by 177 publications

References 63 publications

Compound Hot and Dry Events in Europe: Variability and Large-Scale Drivers

Compound Hot and Dry Events in Europe: Variability and Large-Scale Drivers

Modulation of Compound Extremes of Low Soil Moisture and High Vapor Pressure Deficit by Irrigation in India

Social Sensing of Heatwaves

Contact Info

Product

Resources

About