TITLE:
Circulation-Type Classification over Mexico by the Era-Interim Database and Cost733
AUTHORS:
Sergio Natan González-Rocha, Juan Cervantes-Pérez, Fredy Juárez-Pérez, Z. Arturo González-Cerezo, Lizeth Ríos Velasco, Inés Palomino-Méndez, José María Baldasano Recio
KEYWORDS:
Cluster k-Mean, Synoptic Patterns, European Großwettertypes
JOURNAL NAME:
Atmospheric and Climate Sciences,
Vol.8 No.2,
April
30,
2018
ABSTRACT: In this paper an approach of a synoptic classification by cluster k-means (CKM) and the European Großwettertypes (GWT) was performed and executed in COST733 package. The methodology used a CKM with nine clusters and GWT with 16. The COST733 evaluated a dataset of 30-years since 1986 to 2015. The variables selected were mean sea level pressure (mslp), geopotential height (z500 and z850), wind speed and direction (u10, v10 and u, v at 850 hPa) and relative vorticity (vo) with a 0.75° × 0.75° resolution of the data grid at 00:00, 06:00, 12:00 and 18:00 UTC and 0 steps. These results were evaluated using COST733 to find the quality of measurements by the explained variance (EV) or reduction ratio in error and pseudo F value (PF) to determine the certainty of the results. GWT-16 showed better yearly values in the evaluation with 32.7 (EV) and 354.3 (PF) against the CKM-9 of 54.2 (EV) and 1621.8 (PF). Finally, it was concluded that GWT-16 could be used for classification of synoptic systems over Mexico and the analysis of meteorological phenomena triggers on increases or decreases of atmospheric pollution in areas over Mexico.