<p>Pressure field analysis is the starting point for wind-based research. The region investigated, Europe, North Africa and the Middle East, is highly populated and influenced by steady pressure centres, and the time range extended over 76 years, 1948–2023. The first objective was to describe and parameterise the annual evolution. A dipole was observed between high and low latitudes with an annual oscillation, which allows alternation between zonal transport from September to March and meridional circulation during the rest of the year. The annual harmonic plays the main role in this cycle, with the half-annual pattern being a secondary contribution. Pressure evolution was compared and revealed a high dispersion at high latitudes whereas it was steadier at low latitudes, particularly over the last 40 years, although noticeable changes observed in the previous period indicated that pressure projections should be considered with caution. Finally, the Jenkinson-Collison method was used to calculate Lamb weather types. Only cyclonic, anticyclonic, and unclassified types were the most frequent, and were regulated by pressure centres. However, the northern coast of central Europe was also affected by the westerly flow, which played a prominent secondary role. The Middle East emerges as a region where research should be intensified. Frequencies of most of types were extremely low, revealing that this classification is suitable for specific situations, although it should be simplified for long-series analyses.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Pressure dipole, its evolution and weather types in Europe, North Africa and the Middle East

  • Isidro A. Pérez,
  • M. Ángeles García,
  • Elvis Sikapizye,
  • Beatriz Fernández-Duque

摘要

Pressure field analysis is the starting point for wind-based research. The region investigated, Europe, North Africa and the Middle East, is highly populated and influenced by steady pressure centres, and the time range extended over 76 years, 1948–2023. The first objective was to describe and parameterise the annual evolution. A dipole was observed between high and low latitudes with an annual oscillation, which allows alternation between zonal transport from September to March and meridional circulation during the rest of the year. The annual harmonic plays the main role in this cycle, with the half-annual pattern being a secondary contribution. Pressure evolution was compared and revealed a high dispersion at high latitudes whereas it was steadier at low latitudes, particularly over the last 40 years, although noticeable changes observed in the previous period indicated that pressure projections should be considered with caution. Finally, the Jenkinson-Collison method was used to calculate Lamb weather types. Only cyclonic, anticyclonic, and unclassified types were the most frequent, and were regulated by pressure centres. However, the northern coast of central Europe was also affected by the westerly flow, which played a prominent secondary role. The Middle East emerges as a region where research should be intensified. Frequencies of most of types were extremely low, revealing that this classification is suitable for specific situations, although it should be simplified for long-series analyses.