Seasonal variability in the response of the airflow characteristics to the changes in the macro‐scale westerly flow intensity over Europe, 1971–2000

• Published in: International Journal of Climatology
• Main Author: Marosz, Michal
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2008
• Subjects: North Atlantic
• Online Access: http://dx.doi.org/10.1002/joc.1708; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjoc.1708; https://rmets.onlinelibrary.wiley.com/doi/pdf/10.1002/joc.1708

Abstract The aim of the research was to identify the seasonal variability of correlation between the air motion characteristics and common zonal circulation index (Rossby's Index). Air flow characteristics comprised divergence and vorticity. The spatial coverage of the research was the so called Euro‐Atlantic Region covering parts of North Atlantic and Europe (40W–40E, 35N–75N). Temporal extent was 1971–2000 thus matching the latest WMO normal period. The data used was the components of the wind vector (u—zonal component, v—meridional component) and geopotential heights (hgt) from NCEP/NCAR Reanalysis. The response of the vorticity field is apparent and the greatest variability is noted at 1000 hPa. The mid and upper levels in the troposphere reveal quite homogenous response of vorticity to the macro‐scale forcing. The response of the divergence field is also apparent though more complex in the vertical profile of the troposphere. The analysis of correlation was followed by the description of annual as well as seasonal shape of vorticity and divergence fields in the extremes of Rossby Index. Copyright © 2008 Royal Meteorological Society