Polar Lows: A Challenge for Experimental Studies and Numerical Weather Prediction
Abstract
Polar low research has been a matter of interest of the scientific community for more than 30 years, since polar lows are affecting e.g. fishery, oil and gas exploration and logistical operations in polar regions. The term "polar meso-scale cyclone" or "polar mesocyclone" is now generally accepted for all polar cyclones poleward of the main polar front having scales smaller than 2000 km. The classical 'polar low' (PL) is included as a subtype, which is restricted to maritime systems with near surface winds exceeding 15 m/s. While in its early years polar low research was mainly focussed to the areas of European polar seas, polar MCs are now investigated over almost all oceans affected by cold air outbreaks in the Northern Hemisphere (NH) and also in the Southern Hemisphere (SH). For the NH, research has been conducted e.g. for the Japan Sea, the Labrador Sea, Hudson Bay and the Davis Street, and also for the areas of the Greenland Sea, the Norwegian Sea and the Barents Sea. For the SH, MCs have been studied e.g. for the areas of the Ross, Bellingshausen Sea, and Weddell Sea. Polar MCs are a challenge for experimental studies because of their short lifetime, their fast development and the lack of good numerical forecasts with respect to the location and time of their formation. Due to the sparsity of the observational network, only few data of polar low structures are available from conventional measurements. Valuable in-situ data have been obtained by a few aircraft campaigns. With the advent of more advanced satellite sensors comprehensive studies of e.g. the near-surface wind field and moisture structure have been possible. Despite the problems of forecasting PLs in operational weather prediction, numerical models have been a valuable tool in investigating the mechanisms of PL development. Process studies allow for the separation of individual mechanisms such as convection and baroclinic instability. Today's operational forecasts of PLs have improved, but it is still a challenging task and involves some empirical knowledge.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2007
- Bibcode:
- 2007AGUFM.A24A..02H
- Keywords:
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- 3329 Mesoscale meteorology;
- 3349 Polar meteorology