TY  - JOUR
A1  - Totz, Sonja Juliana
A1  - Eliseev, Alexey V.
A1  - Petri, Stefan
A1  - Flechsig, Michael
A1  - Caesar, Levke
A1  - Petoukhov, Vladimir
A1  - Coumou, Dim
T1  - The dynamical core of the Aeolus 1.0 statistical-dynamical atmosphere model
BT  - validation and parameter optimization
JF  - Geoscientific model development : an interactive open access journal of the European Geosciences Union
N2  - Here, we present novel equations for the large-scale zonal-mean wind as well as those for planetary waves. Together with synoptic parameterization (as presented by Coumou et al., 2011), these form the mathematical description of the dynamical core of Aeolus 1.0. The regions of high azonal wind velocities (planetary waves) are accurately captured for all validation experiments. The zonal-mean zonal wind and the integrated lower troposphere mass flux show good results in particular in the Northern Hemisphere. In the Southern Hemisphere, the model tends to produce too-weak zonal-mean zonal winds and a too-narrow Hadley circulation. We discuss possible reasons for these model biases as well as planned future model improvements and applications.
Y1  - 2018
U6  - https://doi.org/10.5194/gmd-11-665-2018
SN  - 1991-959X
SN  - 1991-9603
VL  - 11
IS  - 2
SP  - 665
EP  - 679
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Lehmann, Jascha
A1  - Coumou, Dim
A1  - Frieler, Katja
A1  - Eliseev, Alexey V.
A1  - Levermann, Anders
T1  - Future changes in extratropical storm tracks and baroclinicity under climate change
JF  - Environmental research letters
N2  - The weather in Eurasia, Australia, and North and South America is largely controlled by the strength and position of extratropical storm tracks. Future climate change will likely affect these storm tracks and the associated transport of energy, momentum, and water vapour. Many recent studies have analyzed how storm tracks will change under climate change, and how these changes are related to atmospheric dynamics. However, there are still discrepancies between different studies on how storm tracks will change under future climate scenarios. Here, we show that under global warming the CMIP5 ensemble of coupled climate models projects only little relative changes in vertically averaged mid-latitude mean storm track activity during the northern winter, but agree in projecting a substantial decrease during summer. Seasonal changes in the Southern Hemisphere show the opposite behaviour, with an intensification in winter and no change during summer. These distinct seasonal changes in northern summer and southern winter storm tracks lead to an amplified seasonal cycle in a future climate. Similar changes are seen in the mid-latitude mean Eady growth rate maximum, a measure that combines changes in vertical shear and static stability based on baroclinic instability theory. Regression analysis between changes in the storm tracks and changes in the maximum Eady growth rate reveal that most models agree in a positive association between the two quantities over mid-latitude regions.
KW  - storm tracks
KW  - baroclinicity
KW  - climate change
Y1  - 2014
U6  - https://doi.org/10.1088/1748-9326/9/8/084002
SN  - 1748-9326
VL  - 9
IS  - 8
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  -