Diverse Dynamical Response to Orographic Gravity Wave Drag Hotspots-A Zonal Mean Perspective

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F21%3A10440685" target="_blank" >RIV/00216208:11320/21:10440685 - isvavai.cz</a>

Result on the web

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=IzwTCFwUuU" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=IzwTCFwUuU</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1029/2021GL093305" target="_blank" >10.1029/2021GL093305</a>

Result language

angličtina

Original language name

Diverse Dynamical Response to Orographic Gravity Wave Drag Hotspots-A Zonal Mean Perspective

Original language description

In the extratropical atmosphere, Rossby waves (RWs) and internal gravity waves (GWs) propagating from the troposphere mediate a coupling with the middle atmosphere by influencing the dynamics therein. In state-of-the-art chemistry-climate models (CCMs), RW effects are well resolved while the majority of GW effects have to be parameterized. Here, we analyze orographic GW (OGW) interaction with resolved dynamics in a comprehensive CCM on daily time scales. For this, we apply a recently developed method of strong OGW drag event composites for three pronounced northern hemisphere OGW hotspots. We show that strong OGW drag events are associated with anomalous resolved wave propagation in the stratosphere. Causal links are inferred from previously published work and are supported by the anomalies in zonal circulation and wave activity tendencies. The nature of these anomalies varies depending on the hotspot region, which underlines the parameterized OGW-resolved dynamics interaction being a two-way process. Plain Language Summary The majority of atmospheric waves are generated near the surface and propagate subsequently upward in the atmosphere. This includes Rossby waves that are resolved in climate models and small-scale gravity waves (GWs) that commonly have to be parameterized. In the middle atmosphere, the waves eventually break, thereby dissipating their momentum and energy, which influences atmospheric dynamics. The interaction of GWs with the large-scale circulation is to date poorly understood. In this study, we associate regionally enhanced GW drag with anomalies in resolved wave propagation in the stratosphere in a comprehensive chemistry-climate model on the time scale of days. For this, we identify strong orographic GW (OGW) events for the three most pronounced northern hemisphere OGW hotspots and construct composites of anomalies of selected variables with respect to the climatological mean. We find that the response of the resolved wavefield strongly depends on the hotspot region, leading to diverse consequences on the large-scale stratospheric circulation. Strong OGW events in the hotspots are in turn determined by the resolved fields from the surface to the level of OGW dissipation, which highlights the two-way coupling between OGWs and resolved flow.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10509 - Meteorology and atmospheric sciences

Project

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Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2021

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Geophysical Research Letters

ISSN

0094-8276

e-ISSN

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Volume of the periodical

48

Issue of the periodical within the volume

13

Country of publishing house

US - UNITED STATES

Number of pages

11

Pages from-to

e2021GL093305

UT code for WoS article

000694024100040

EID of the result in the Scopus database

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