The role of atmospheric dynamics and large-scale topography in driving heatwaves.

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State: Public
Version: Final published version
License: CC BY 4.0
Serval ID
serval:BIB_C73868CC3CEA
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
The role of atmospheric dynamics and large-scale topography in driving heatwaves.
Journal
Quarterly journal of the Royal Meteorological Society. Royal Meteorological Society
Author(s)
Jiménez-Esteve B., Domeisen DIV
ISSN
0035-9009 (Print)
ISSN-L
0035-9009
Publication state
Published
Issued date
07/2022
Peer-reviewed
Oui
Volume
148
Number
746
Pages
2344-2367
Language
english
Notes
Publication types: Journal Article
Publication Status: ppublish
Abstract
Heatwaves are weather events characterized by extreme near-surface temperature anomalies that persist for several days, and therefore lead to catastrophic impacts on natural ecosystems, agriculture, human health, and economies. Different physical processes can contribute to the temperature anomaly associated with heatwaves. Previous studies have shown that increased solar radiation and adiabatic heating associated with blocking systems and local land-atmosphere coupling are important drivers of summer heatwaves. Less is known about the fundamental role of atmospheric large-scale dynamics and topography in generating heatwaves. Here, we perform idealized model simulations where all physical parameterisations are substituted by a simple zonally symmetric temperature relaxation scheme. This allows us to characterize the dynamical processes involved in the life cycle of heatwaves occurring at different latitudes. We find that blocking plays an active role in the life cycle of high- and midlatitude heatwaves, while blocking is less relevant for low-latitude heatwaves. Rossby-wave packets are the dominant drivers for midlatitude heatwaves, with horizontal advection being the main mechanism leading to heat extremes. Heatwaves exhibit a higher persistence and frequency near the pole and Equator compared with the midlatitudes, but a higher intensity in the midlatitudes compared with higher and lower latitudes. Topography located along the midlatitude jet has the largest impact on the heatwave distribution around the planet, resulting in increased heatwave frequency upstream for moderate topographic forcing and a circumglobal increase for topographic elevations above 6 km. Identifying the most relevant processes driving heatwaves can potentially benefit the prediction and representation of extreme events in operational weather and climate forecast systems.
Keywords
Atmospheric Science, atmospheric dynamics, blocking, heatwaves, idealized modeling, jet, latitude, topography
Pubmed
Web of science
Open Access
Yes
Funding(s)
Swiss National Science Foundation / PP00P2_170523
Swiss National Science Foundation / PP00P2_198896
Create date
07/10/2022 18:08
Last modification date
02/02/2023 7:52
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