Local and remote atmospheric responses to soil moisture anomalies in Australia

Martius, Olivia; Wehrli, Kathrin; Rohrer, Marco (2021). Local and remote atmospheric responses to soil moisture anomalies in Australia. Journal of Climate, 34(22), pp. 9115-9131. American Meteorological Society 10.1175/JCLI-D-21-0130.1

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Three sets of model experiments are performed with the Community Earth System Model to study the role of soil moisture anomalies as a boundary forcing for the formation of upper-level Rossby wave patterns during the Southern Hemisphere summer. In the experiments, soil moisture over Australia is set to ±1 standard deviation (STD) of an ERA-Interim-derived soil moisture reconstruction for the years 2009–16 and 50 ensemble members are run. The local response is a positive heating anomaly in the dry simulations that results in a thermal low–like circulation anomaly with an anomalous surface low and upper-level anticyclone. Significant differences in convective rainfall over Australia are related to differences in convective instability and associated with changes in near-surface moisture and moisture advection patterns. A circum-hemispheric flow response is identified both in the upper-level flow and in the surface storm tracks that overall resembles a positive southern annular mode–like flow anomaly in the dry simulations. The structure of this atmospheric response strongly depends on the background flow. The results point to a modulation of the hemispheric flow response to the forcing over Australia by El Niño–Southern Oscillation. Significant changes of precipitation over the Maritime Continent and South Africa are found and significant differences in the frequency of surface cyclones are present all along the storm tracks.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Institute of Geography > Physical Geography > Unit Impact
10 Strategic Research Centers > Oeschger Centre for Climate Change Research (OCCR)
08 Faculty of Science > Institute of Geography
08 Faculty of Science > Institute of Geography > Physical Geography

UniBE Contributor:

Romppainen-Martius, Olivia

Subjects:

900 History > 910 Geography & travel

ISSN:

0894-8755

Publisher:

American Meteorological Society

Funders:

[18] European Research Council

Language:

English

Submitter:

Yannick Barton

Date Deposited:

24 Feb 2022 15:49

Last Modified:

24 Feb 2022 15:49

Publisher DOI:

10.1175/JCLI-D-21-0130.1

BORIS DOI:

10.48350/165203

URI:

https://boris.unibe.ch/id/eprint/165203

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