Mutual Interference of Local Gravity Wave Forcings in the Stratosphere

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F20%3A10421921" target="_blank" >RIV/00216208:11320/20:10421921 - isvavai.cz</a>

Result on the web

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=vJfeRKYyD6" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=vJfeRKYyD6</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3390/atmos11111249" target="_blank" >10.3390/atmos11111249</a>

Result language

angličtina

Original language name

Mutual Interference of Local Gravity Wave Forcings in the Stratosphere

Original language description

Gravity wave (GW) breaking and associated GW drag is not uniformly distributed among latitudes and longitudes. In particular, regions of enhanced GW breaking, so-called GW hotspots, have been identified, major Northern Hemisphere examples being located above the Rocky Mountains, the Himalayas and the East Asian region. These hotspots influence the middle atmosphere circulation both individually and in combination. Their interference is here examined by performing simulations including (i) the respective single GW hotspots, (ii) two GW hotspots, and (iii) all three GW hotspots with a simplified global circulation model. The combined GW hotspots lead to a modification of the polar vortex in connection with a zonal mean flow decrease and an increase of the temperature at higher latitudes. The different combinations of GW hotspots mainly prevent the stationary planetary wave (SPW) 1 from propagating upward at midlatitudes leading to a decrease in energy and momentum transfer in the middle atmosphere caused by breaking SPW 1, and in turn to an acceleration of the zonal mean flow at lower latitudes. In contrast, the GW hotspot above the Rocky Mountains alone causes an increase in SPW 1 amplitude and Eliassen-Palm flux (EP flux), inducing enhanced negative EP divergence, decelerating the zonal mean flow at higher latitudes. Consequently, none of the combinations of different GW hotspots is comparable to the impact of the Rocky Mountains GW hotspot alone. The reason is that the GW hotspots mostly interfere nonlinearly. Depending on the longitudinal distance between two GW hotspots, the interference between the combined Rocky Mountains and East Asian GW hotspots is more additive than the interference between the combined Rocky Mountains and Himalaya GW hotspots. While the Rocky Mountains and the East Asian GW hotspots are longitudinally displaced by 105 degrees, the Rocky Mountains are shifted by 170 degrees to the Himalayas. Moreover, while the East Asian and the Himalayas are located side by side, the interference between these GW hotspots is the most nonlinear because they are latitudinally displaced by 20 degrees. In general, the SPW activity, e.g., represented in SPW amplitudes, EP flux or Plumb flux, is strongly reduced, when the GW hotspots are interacting with each other. Thus, the interfering GW hotspots mostly have a destructive effect on SPW propagation and generation.

Czech name

—

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

—

OECD FORD branch

10509 - Meteorology and atmospheric sciences

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2020

Confidentiality

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

Name of the periodical

Atmosphere

ISSN

2073-4433

e-ISSN

—

Volume of the periodical

11

Issue of the periodical within the volume

11

Country of publishing house

CH - SWITZERLAND

Number of pages

26

Pages from-to

1249

UT code for WoS article

000593582900001

EID of the result in the Scopus database

2-s2.0-85097584860