دورية أكاديمية

Resolving Weather Fronts Increases the Large‐Scale Circulation Response to Gulf Stream SST Anomalies in Variable‐Resolution CESM2 Simulations

التفاصيل البيبلوغرافية
العنوان: Resolving Weather Fronts Increases the Large‐Scale Circulation Response to Gulf Stream SST Anomalies in Variable‐Resolution CESM2 Simulations
المؤلفون: Robert C. J. Wills, Adam R. Herrington, Isla R. Simpson, David S. Battisti
المصدر: Journal of Advances in Modeling Earth Systems, Vol 16, Iss 7, Pp n/a-n/a (2024)
بيانات النشر: American Geophysical Union (AGU), 2024.
سنة النشر: 2024
المجموعة: LCC:Physical geography
LCC:Oceanography
مصطلحات موضوعية: high‐resolution climate modeling, North Atlantic, Gulf Stream, weather front, large‐scale circulation, climate prediction, Physical geography, GB3-5030, Oceanography, GC1-1581
الوصف: Abstract Canonical understanding based on general circulation models (GCMs) is that the atmospheric circulation response to midlatitude sea‐surface temperature (SST) anomalies is weak compared to the larger influence of tropical SST anomalies. However, the ∼100‐km horizontal resolution of modern GCMs is too coarse to resolve strong updrafts within weather fronts, which could provide a pathway for surface anomalies to be communicated aloft. Here, we investigate the large‐scale atmospheric circulation response to idealized Gulf Stream SST anomalies in Community Atmosphere Model (CAM6) simulations with 14‐km regional grid refinement over the North Atlantic, and compare it to the responses in simulations with 28‐km regional refinement and uniform 111‐km resolution. The highest resolution simulations show a large positive response of the wintertime North Atlantic Oscillation (NAO) to positive SST anomalies in the Gulf Stream, a 0.4‐standard‐deviation anomaly in the seasonal‐mean NAO for 2°C SST anomalies. The lower‐resolution simulations show a weaker response with a different spatial structure. The enhanced large‐scale circulation response results from an increase in resolved vertical motions with resolution and an associated increase in the influence of SST anomalies on transient‐eddy heat and momentum fluxes in the free troposphere. In response to positive SST anomalies, these processes lead to a stronger and less variable North Atlantic jet, as is characteristic of positive NAO anomalies. Our results suggest that the atmosphere responds differently to midlatitude SST anomalies in higher‐resolution models and that regional refinement in key regions offers a potential pathway to improve multi‐year regional climate predictions based on midlatitude SSTs.
نوع الوثيقة: article
وصف الملف: electronic resource
اللغة: English
تدمد: 1942-2466
Relation: https://doaj.org/toc/1942-2466
DOI: 10.1029/2023MS004123
URL الوصول: https://doaj.org/article/c2c662f12d53404caeb27f1eef303942
رقم الأكسشن: edsdoj.2c662f12d53404caeb27f1eef303942
قاعدة البيانات: Directory of Open Access Journals
الوصف
تدمد:19422466
DOI:10.1029/2023MS004123