Workshop "Variability of the Global Atmospheric Circulation During the Past 100 Years"
15 – 20 June 2008 at Monte Verità, Switzerland

Conference board: Stefan Brönnimann, Jürg Luterbacher, Henry Diaz, Urs Neu, Tracy Ewen

The Sessions

Atmospheric circulation modes

The aim of this session is to put together the latest research in our understanding of large-scale variability modes in the atmosphere, their variability during the 20th century and their representation in current climate models. Presentations are sought on the "classical" variability modes such as North Atlantic or Arctic Oscillation or the Pacific-North American pattern, but also on new concepts emphasising dynamical aspects.

Multidecadal modes in the climate system

In recent years, several multidecadal modes of the climate systems have been proposed such as the Pacific Decadal Oscillation or the Atlantic Multidecadal Oscillation, or the Arctic Low Frequency Oscillation. Multidecadal modes are of particular interest as they might lead to forecast skill on decadal scales. In this session, the latest research on multidecadal modes in the climate systems will be presented.

The tropical circulation

The tropical Hadley and Walker cells as well as the monsoon systems are arguably the most important drivers of the global atmospheric circulation. In this session the variability of these circulation systems over the past 100 years will be discussed, their mutual interaction, their interaction with the extratropical circulation as well as their response to specific forcings. Again, observations based studies as well as model analyses will be presented.

ENSO teleconnections

ENSO is the globally dominant mode of interannual climate variability. It affects climate not only in the tropical or Pacific North American regions, but also in more remote regions. In recent years, substantial progress has been made in the forecast of ENSO, which provokes the hope to also improve seasonal forecast in the extratropics due to ENSO's teleconnections. However, the some of the teleconnections seem to be non-linear and non-stationary. In this session, ENSO teleconnections will be discussed in the light of atmospheric circulation.

Large-scale circulation and droughts

Several models suggest that severe droughts will increase in frequency in a future climate. Understanding the large-scale circulation patterns behind droughts is therefore of particular importance. The presentations given in this section will address the relation between droughts in different regions and the large-scale circulations. The relation between droughts and the oceans will be discussed in data analysis and model simulations. Finally, the potential predictability of severe droughts will be addressed.

The polar circulation

This session deals with atmospheric circulation in the polar regions. The Arctic is a very sensitive part of the climate system, which has experienced large changes in the past and will experience even larger changes in the future. During the past 100 years the Arctic experienced two periods of pronounced warming which will be discussed in the light of atmospheric circulation. Another topic concerns recent changes in the circulation over Antarctica, including temperature trends in the free troposphere as well as the effect of the ozone hole on the circulation.

Invited speakers (not all confirmed)

M. Wallace, Univ. Washington, USA
H. Wanner, Univ. Bern, Switzerland
C. Raible, Univ. Bern, Switzerland
C. Appenzeller/M. Liniger, MeteoSwiss, Switzerland
D. Stephenson, Univ. Exeter, UK
K. Kodera, Nagoya Univ. Japan
U. Ulbrich, FU Berlin, Germany
H.C. Davies, ETH Zurich, Switzerland
M. Latif, Univ. Kiel, Germany
C. Folland, UK Met Office, UK
C. Deser, NCAR, USA
I. Polyakof, Univ. Fairbanks, USA
G.A. Vecchi, NASA-GFDL, USA
C. Wang, NOAA-AOML, USA
K. Krishna Kumar, Ind. Inst. Trop. Meteorol., Pune, India
K. Trenberth, NCAR, USA
Ch. Schär, ETH Zurich, Switzerland
R. Allan, Met Office, UK
G.J. van Oldenborgh, KNMI, The Netherlands
M. Hoerling, NOAA-ESRL, USA
A. Gershunov, UCSD, USA
A. Giannini, Columbia Univ., USA
J. Overland, NOAA-PMEL, USA
L. Bengtsson, MPI Meteorologie, Germany
M. Holland, NCAR, USA
M. Serreze, CIRES, USA
A. Grant, ETH Zürich, Switzerland
N. Gillett, Univ. East Anglia, UK
D. Dommenget, IFM Geomar, Kiel, Germany
G. Compo, NOAA-ESRL, USA
A. Mariotti, ENEA, S. Maria di Galeria, Italy
G. van der Schrier, KNMI, The Netherlands
E. Xoplaki, Univ. Bern, Switzerland
P. Sardeshmukh, NOAA-ESRL, USA
P. Stott, Met Office, UK
P. Calanca, ART, Reckenholz, Switzerland
B. Christiansen, DMI, Copenhagen, Denmark
P. Thejll, DMI, Copenhagen, Denmark

For additional information contact Stefan Brönnimann.