Predictability and Dynamics of Weather Systems in the Atlantic-European Sector (PANDOWAE)

Description:

This special collection comprises the results of the Research Group “Predictability and Dynamics of Weather Systems in the Atlantic-European Sector” (PANDOWAE), which was funded by the Deutsche Forschungsgemeinschaft (German Research Council), and which constitutes a major European contribution to the WMO World Weather Research Programme THORPEX. The research interests of PANDOWAE are the predictability and dynamics of weather systems that may lead to high impact weather in the midlatitudes. PANDOWAE research is organised into the three research areas "A: Upper-level Rossby wave trains: generation, propagation and wave-breaking", "B: Moist processes and diabatic Rossby waves", and "C: Ensembles and adaptivity (numerical modeling & predictability)". It includes theoretical studies, numerical modeling, and process studies. Part of these studies were performed in collaboration with major field campaigns such as T-PARC, HyMeX, T-NAWDEX-Falcon and future NAWDEX.

www.pandowae.de

Collection organizers:
Sarah C. Jones, Deutscher Wetterdienst, Offenbach, Germany, and Institute for Meteorology and Climate Research, Karlsruhe Institute of Technology, Germany
Aurelia Müller, Institute for Meteorology and Climate Research, Karlsruhe Institute of Technology, Germany

Predictability and Dynamics of Weather Systems in the Atlantic-European Sector (PANDOWAE)

Florian Harnisch
and
Martin Weissmann

Abstract

For the first time, joint tropical cyclone (TC) surveillance missions by several aircraft were conducted in the western North Pacific basin within the framework of The Observing System Research and Predictability Experiment (THORPEX) Pacific Asian Regional Campaign (T-PARC) 2008. The collected dropsonde observations were divided into three different subsets depending on their location relative to the TC to investigate which observations are most beneficial for typhoon track forecasting. Data denial experiments with the European Centre for Medium-Range Weather Forecasts (ECMWF) global model were performed to analyze the influence of the different dropsonde subsets. In these experiments, the largest TC track forecast improvements are found for observations in the vicinity of the storm, placed at a circular ring at the outer boundary of the TC. In contrast, observations in remote regions indicated to be sensitive by singular vectors seem to have a relatively small influence with a slight positive tendency on average. Observations in the TC core and center lead to large analysis differences, but only very small mean forecast improvements. This is likely related to the fact that even modern high-resolution global models cannot fully resolve the TC center and thus can only use a relatively small part of the information provided by observations within the TC center. Times prior to landfall and recurvature are stronger affected by additional observations, while the influence on the track forecast after recurvature is relatively weak.

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