Pivotal role of the North African Dipole Intensity (NAFDI) on alternate Saharan dust export over the North Atlantic and the Mediterranean, and relationship with the Saharan Heat Low and mid-latitude Rossby waves [Discussion paper]

• Main Authors: Cuevas Agulló, Emilio, Gómez Peláez, Ángel Jesús, Rodríguez González, Sergio, Terradellas, Enric, Basart, Sara, García Cabrera, Rosa Delia, García Rodríguez, Omaira Elena, Alonso Pérez, Silvia
• Format: Article in Journal/Newspaper
• Language: English
• Published: European Geosciences Union 2016
• Subjects: North African Dipole Intensity; Saharan dust; Saharan heat low; Rossby waves; North Atlantic
• Online Access: https://hdl.handle.net/20.500.11765/2190

In this study, we revise the index that quantifies the North African Dipole Intensity (NAFDI), and explain its relationship with the Saharan Heat Low (SHL) and mid-latitude Rossby waves. We find outstanding similarities of meteorological patterns associated with the positive NAFDI and the SHL West-phase on the one hand, and with the negative NAFDI and the SHL East-Phase, on the other hand. We introduce the daily NAFDI index and the daily SHL West-East Displacement Index (SHLWEDI). The Pearson correlation coefficient between the daily SHLWEDI 1-day lagged and the daily NAFDI for the period 1980–2013 20 June–17 September is fairly high (r = 0.77). The correlation reduces to 0.69 if the SHLWEDI is not lagged. We observe that the SHL West-phase is significantly more frequent than the SHL East-phase, and that the SHL is more intense during its East-phase. Part of this study was performed in the frame of AEROATLAN (grant 2015-66229), funded by the Ministry of Economy and Competitiveness of Spain.