Details
| Originalsprache | Englisch |
|---|---|
| Seiten (von - bis) | 12,513-12,532 |
| Fachzeitschrift | Journal of Geophysical Research Atmospheres |
| Jahrgang | 119 |
| Ausgabenummer | 22 |
| Frühes Online-Datum | 20 Nov. 2014 |
| Publikationsstatus | Veröffentlicht - 27 Nov. 2014 |
Abstract
We investigated the impact of roll convection on the convective boundary layer and vertical transports in different cold air outbreak (CAO) scenarios using large eddy simulations (LES). The organization of convection into rolls was triggered by upstream heterogeneities in the surface temperature, representing ice and water. By changing the sea ice distribution in our LES, we were able to simulate a roll and a nonroll case for each scenario. Furthermore, the roll wavelength was varied by changing the scale of the heterogeneity. The characteristics of the simulated rolls and cloud streets, such as aspect ratios, orientation of the roll axes, and downstream extensions of single rolls agreed closely with observations in CAO situations. The vertical turbulent fluxes, calculated for each simulation, were decomposed into contributions from rolls and from unorganized turbulence. Even though our results confirmed that rolls triggered by upstream heterogeneities can substantially contribute to vertical turbulent fluxes, the total fluxes were not affected by the rolls.
ASJC Scopus Sachgebiete
- Erdkunde und Planetologie (insg.)
- Atmosphärenwissenschaften
- Erdkunde und Planetologie (insg.)
- Geophysik
- Erdkunde und Planetologie (insg.)
- Erdkunde und Planetologie (sonstige)
- Erdkunde und Planetologie (insg.)
- Astronomie und Planetologie
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in: Journal of Geophysical Research Atmospheres, Jahrgang 119, Nr. 22, 27.11.2014, S. 12,513-12,532.
Publikation: Beitrag in Fachzeitschrift › Artikel › Forschung › Peer-Review
}
TY - JOUR
T1 - On the impact of forced roll convection on vertical turbulent transport in cold air outbreaks
AU - Gryschka, Micha
AU - Fricke, Jens
AU - Raasch, Siegfried
PY - 2014/11/27
Y1 - 2014/11/27
N2 - We investigated the impact of roll convection on the convective boundary layer and vertical transports in different cold air outbreak (CAO) scenarios using large eddy simulations (LES). The organization of convection into rolls was triggered by upstream heterogeneities in the surface temperature, representing ice and water. By changing the sea ice distribution in our LES, we were able to simulate a roll and a nonroll case for each scenario. Furthermore, the roll wavelength was varied by changing the scale of the heterogeneity. The characteristics of the simulated rolls and cloud streets, such as aspect ratios, orientation of the roll axes, and downstream extensions of single rolls agreed closely with observations in CAO situations. The vertical turbulent fluxes, calculated for each simulation, were decomposed into contributions from rolls and from unorganized turbulence. Even though our results confirmed that rolls triggered by upstream heterogeneities can substantially contribute to vertical turbulent fluxes, the total fluxes were not affected by the rolls.
AB - We investigated the impact of roll convection on the convective boundary layer and vertical transports in different cold air outbreak (CAO) scenarios using large eddy simulations (LES). The organization of convection into rolls was triggered by upstream heterogeneities in the surface temperature, representing ice and water. By changing the sea ice distribution in our LES, we were able to simulate a roll and a nonroll case for each scenario. Furthermore, the roll wavelength was varied by changing the scale of the heterogeneity. The characteristics of the simulated rolls and cloud streets, such as aspect ratios, orientation of the roll axes, and downstream extensions of single rolls agreed closely with observations in CAO situations. The vertical turbulent fluxes, calculated for each simulation, were decomposed into contributions from rolls and from unorganized turbulence. Even though our results confirmed that rolls triggered by upstream heterogeneities can substantially contribute to vertical turbulent fluxes, the total fluxes were not affected by the rolls.
KW - cold air outbreak
KW - large eddy simulation
KW - roll convection
KW - turbulent fluxes
UR - http://www.scopus.com/inward/record.url?scp=84918571025&partnerID=8YFLogxK
U2 - 10.1002/2014JD022160
DO - 10.1002/2014JD022160
M3 - Article
AN - SCOPUS:84918571025
VL - 119
SP - 12,513-12,532
JO - Journal of Geophysical Research Atmospheres
JF - Journal of Geophysical Research Atmospheres
SN - 2169-897X
IS - 22
ER -