dc.contributor.author
Steinfeld, Daniel
dc.contributor.author
Sprenger, Michael
dc.contributor.author
Beyerle, Urs
dc.contributor.author
Pfahl, Stephan
dc.date.accessioned
2022-09-01T11:51:09Z
dc.date.available
2022-09-01T11:51:09Z
dc.identifier.uri
https://refubium.fu-berlin.de/handle/fub188/36117
dc.identifier.uri
http://dx.doi.org/10.17169/refubium-35833
dc.description.abstract
Weather extremes are often associated with atmospheric blocking, but how the underlying physical processes leading to blocking respond to climate change is not yet fully understood. Here we track blocks as upper-level negative potential vorticity (PV) anomalies and apply a Lagrangian analysis to 100 years of present-day (∼2000) and future (∼2100, under the RCP8.5 scenario) climate simulations restarted from the Community Earth System Model–Large Ensemble Project runs (CESM-LENS) to identify different physical processes and quantify how their relative importance changes in a warmer and more humid climate. The trajectories reveal two contrasting airstreams that both contribute to the formation and maintenance of blocking: latent heating in strongly ascending airstreams (moist processes) and quasi-adiabatic flow near the tropopause with weak radiative cooling (dry processes). Both are reproduced remarkably well when compared against ERA-Interim reanalysis, and their relative importance varies regionally and seasonally. The response of blocks to climate change is complex and differs regionally, with a general increase in the importance of moist processes due to stronger latent heating (+1 K in the median over the Northern Hemisphere) and a larger fraction (+15%) of strongly heated warm conveyor belt air masses, most pronounced over the storm tracks. Future blocks become larger (+7%) and their negative PV anomaly slightly intensifies (+0.8%). Using a Theil–Sen regression model, we propose that the increase in size and intensity is related to the increase in latent heating, resulting in stronger cross-isentropic transport of air with low PV into the blocking anticyclones. Our findings provide evidence that moist processes become more important for the large-scale atmospheric circulation in the midlatitudes, with the potential for larger and more intense blocks.
en
dc.format.extent
12 Seiten
dc.rights.uri
https://creativecommons.org/licenses/by/4.0/
dc.subject
atmospheric blocking
en
dc.subject
latent heating
en
dc.subject
moist and dry processes
en
dc.subject
air parcel trajectories
en
dc.subject
climate change
en
dc.subject
extreme weather
en
dc.subject
ensemble climate simulations
en
dc.subject.ddc
500 Naturwissenschaften und Mathematik::550 Geowissenschaften, Geologie::550 Geowissenschaften
dc.title
Response of moist and dry processes in atmospheric blocking to climate change
dc.type
Wissenschaftlicher Artikel
dcterms.bibliographicCitation.articlenumber
084020
dcterms.bibliographicCitation.doi
10.1088/1748-9326/ac81af
dcterms.bibliographicCitation.journaltitle
Environmental Research Letters
dcterms.bibliographicCitation.number
8
dcterms.bibliographicCitation.volume
17
dcterms.bibliographicCitation.url
https://doi.org/10.1088/1748-9326/ac81af
refubium.affiliation
Geowissenschaften
refubium.affiliation.other
Institut für Meteorologie
refubium.resourceType.isindependentpub
no
dcterms.accessRights.openaire
open access
dcterms.isPartOf.eissn
1748-9326
refubium.resourceType.provider
WoS-Alert