BALTEX Phase II 2003 – 2012. Science Framework and ...

BALTEX Phase II Science Framework and Implementation Strategy 61
7.2.3. Grid Pilot Project
One of the major objectives of BALTEX Phase I was the development of coupled atmosphere-landocean-models
for the Baltic Sea basin. This aim has been achieved, and two coupled systems have
been developed: the Regional Coupled Atmosphere-Ocean Model (RCAO) at the Rossby Centre
(Sweden), and the coupled model system in the Baltic Region of the German research project
“BALTIMOS” at the MPI-M (Germany). For BALTEX Phase II, these models will be further
developed and applied for BALTEX research, and will produce large amounts of data. These data are
of very high scientific potential, and the analysis, validation and improvement of the models need
international collaborations of different scientists, not only modellers. These models produce
consistent data sets which are and will be unique for the Baltic Sea catchment.
The Pilot Grid Project will concentrate on the period from 1999-2004. This period includes the
BRIDGE period and recent extreme inflows to the Baltic Sea as well as extreme summers and
flooding. Thus this period is extraordinarily well suited to study extreme events in the Baltic Sea
basin.
A synthesis of BALTEX BRIDGE is missing up to now. With the modelled
data and corresponding observations, a synthesis would now be possible
providing for a detailed quantification of the energy and water cycle of the
Baltic Sea basin. It should be stressed that the pilot grid project is
interdisciplinary and comprises analyses from observations including satellite
data and model data. It thus requires the combined expertise from observers
and modellers.
The grid idea within the pilot study is mainly to share resources (model data, observations and
expertise) within the existing BALTEX communication network which have to be further explored.
Within international collaborations, which have to be defined, a free information and data exchange
with respect to the BALTEX data policy is expected. In addition to the planned simulations, reinitialisations
(nudging) and data assimilation will be performed. Thus, data from the BALTEX Data
Centres as well as additional observations (hydrographical and satellite data) will be needed.
Furthermore, these data are important for process studies and model validation. The following
objectives are planned to be dealt with in the Pilot Grid Project:
• Quantification of the energy and water cycle for the period 1999-2004, including precipitation
and evaporation;
• Quantification of corresponding uncertainties;
• Detailed investigation of coastal regions of the Baltic area (coastal ocean and atmospheric
boundary layer);
• Analysis of extreme events and “Großwetterlagen” (forcing and response);
• Analysis of sea ice evolution, comparison with new satellite data and observations;
• Detailed investigation of atmosphere-ocean and atmosphere-sea ice-ocean fluxes;
• Detailed analysis of water mass exchange between the deep basins of the Baltic Sea.