Responses of compound daytime and nighttime warm-dry and warm-humid events to individual anthropogenic forcings

Bibliographic Data

ID15547890
AuthorsFelicia Chiang (0000-0003-4191-6157, Goddard Institute for Space Studies, corresponding author), Benjamin I Cook (0000-0002-4501-9229, Lamont-Doherty Earth Observatory), Sonali McDermid (0000-0002-4244-772X, New York University), Kate Marvel (0000-0002-9771-6720, Goddard Institute for Space Studies), Gavin A Schmidt (0000-0002-2258-0486, Goddard Institute for Space Studies), Larissa Nazarenko (0000-0003-3172-9358, Goddard Institute for Space Studies), Larissa S Nazarenko, Maxwell Kelley (Goddard Institute for Space Studies)
Year2022
Volume17
Issue8
Pages084015-084015
Publication date2022-07-13
Open AccessYes
TypeARTICLE
VenueEnvironmental Research Letters (JOURNAL)
Journal identifiersISSN: 1748-9326 • E-ISSN: 1748-9326
PublisherIOP Publishing (PUBLISHER • GB)
DOI10.1088/1748-9326/ac80ce
OpenAlexW4285395005
LanguageEN
Citations received1
References cited55

Daytime heat is often associated with reduced soil moisture and cloud cover, while nighttime heat is connected to high humidity and increased cloud cover. Due to these differing mechanisms, compound daytime and nighttime heat events may respond differently to major anthropogenic forcings (greenhouse gases, anthropogenic aerosols, land-use and land-cover change). Here, we use GISS ModelE2.1-G historical single-forcing runs from 1955 to 2014 to examine how individual anthropogenic forcings affect compound heat events—specifically warm daytime and nighttime temperatures compounded with dry precipitation or high humidity conditions. We show that greenhouse gases alone amplify the natural frequency of warm-dry events by 1.5–5 times and warm-humid events by 2–9 times in tropical and extratropical latitudes. Conversely, aerosols and land-use/land-cover change reduce the frequency of these events, resulting in more modest increases and in some regions, declines, in the historical ‘all-forcings’ scenario. Individually, aerosol effects are stronger and more widespread compared to land-use, oftentimes reducing the natural frequency of these events by 60%–100%. The responses of these compound events are primarily driven by changes in daytime and nighttime temperatures through large-scale warming via greenhouse gases and cooling from aerosols and land-use/land-cover change. However, changes in warm-dry events are amplified in regions with concurrent precipitation declines (e.g. Central America, Mediterranean regions) and warm-humid events are amplified by global concurrent humidity increases. Additionally, we find differences between daytime and nighttime compound responses in the historical experiment that can be traced back to the individual forcings. In particular, aerosols produce a greater cooling effect on daytime relative to nighttime temperatures, which notably results in a historical reduction of Northern Hemisphere daytime warm-dry events relative to natural conditions. Our analysis provides a more comprehensive understanding of the significant impacts of different anthropogenic climate forcings on daytime and nighttime warm-dry and warm-humid events, informing future risk and impact assessments

Aerosol · Atmospheric sciences · Climate change · Climatology · Cloud cover · Daytime · Forcing (mathematics · Geography · Greenhouse gas · Humidity · Land cover · Land use · Meteorology · Precipitation · Radiative forcing · Sensible heat · Atmospheric and Environmental Gas Dynamics · Climate variability and models · Environmental Science · Meteorological Phenomena and Simulations · Ecology

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