Description of task
A grid of complex-instrumented ice-tethered buoys based on new technology (link to core theme 1 and 3) and a grid of simple-instrumented ice buoys embedded within that grid will be installed over the Arctic Ocean for better cyclone detection and analyses.
Satellite observations of the following quantities will be made both over sea ice and the open ocean: cloud liquid water path, total water vapour, as well as surface and air temperature. Various data (SSM/I, AMSU, AMSR, and SSM/IS) and new inversion techniques will be applied, and the existing processing algorithms will be improved. The new sensors SSM/IS and AMSR-E will allow an integrated retrieval of both surface and atmospheric parameters and thus also provide potential for the detection of cyclones.
The quality of liquid water path and precipitable water path retrievals will be assessed, as well as the systematic weaknesses of NWP models in temperature and moisture in the Arctic.
The Arctic cyclone activity will be analysed on the basis of existing as well as new in-situ data (buoy grid, a Swedish ice-breaker, Polarstern, Russian drift stations) and remote sensing data.
The contribution of the cyclones to the transport of heat and moisture over the Arctic sea ice will be analysed on the basis of operational model fields, which are produced in WP4 utilizing the new in-situ data and remote sensing products in data assimilation.
The interaction of atmosphere and sea ice during strong winds and severe storms will be studied on the basis of meteorological and ice drift data from the new buoy array as well as coupled mesoscale modelling. This will be done in co-operation with WP1, and the specific contribution of WP2 is to validate and improve the atmospheric forcing on sea ice drift.
The effect of cyclones and local weather conditions on the Atlantic water transport and the West Spitsbergen Current variability will be analyzed (in co-operation with WP3).
As a result of this work, improvements are expected in the detection and statistical description of (a) the Arctic cyclones, (b) their contribution to the transport of heat and moisture, and (c) their effect on sea ice dynamics (applicable in core themes 1 and 4). The result of interpretation of microwave satellite data and atmospheric model data will be supplied to the data assimilation core theme 4. Improvements in NWP and coupled air-ice-ocean modelling will be assessed on the basis of new buoy and satellite data. Recommendation will be given on future regular deployments of grids of ice buoys operated, e.g., by pan-Arctic weather services (applicable in the overarching activity 3 on short timesscales).
