DATE2022-06-22 18:56:24
TITLEConnection between geopotential-jet North-Atlantic weather regimes and surface weather and climate extremes over Morocco
AUTHORSRachida El Ouaraini (1) ,Fatima Driouech (2) ,Saloua Balhane (2) ,Joshua Dorrington (3)
  1. 1) Direction Régionale De La Météorologie Nord-est, Fes (Morocco) ,2) Mohammed Vi Polytechnic University, Iwri, Benguerir (Morocco) ,3) Karlsruhe Institute of Technology, Institute for Meteorology and Climate (KIT IMK-TRO), Baden-Württemberg (Germany)
ABSTRACTMorocco belongs to a region that is highly vulnerable to climate change. Nowadays, the frequency and impacts of extreme weather in this country are very sensitive, both socially and economically. Hence, enhancing the understanding of the changes in the Moroccan climate is of great importance. In this work, we investigate the link between the large-scale modes of variability and the local climate in Morocco. Weather conditions over Morocco are, in fact, influenced by the North Atlantic atmospheric circulation which is usually described in terms of regimes: a discretization of the continuous atmospheric state into a small number of qualitatively distinct, recurrent, quasi-stationary, and persistent flow patterns. The literature shows two main approaches for diagnosing North‐Atlantic weather regimes. The first one consists of applying clustering algorithms to geopotential height at 500 hPa or to mean sea level pressure. The second approach uses the latitude of the North Atlantic jet. Recently, a hybrid approach that combines both the jet and geopotential height data was developed in order to compute North-Atlantic weather regimes. It has been shown that these regimes are particularly suited for the analysis of climate data, with considerable reductions in sampling variability compared to classical regime approaches. The hybrid method is used here to evaluate how weather regimes are connected to surface weather, in particular extremes, over Morocco. Comparisons with the classical regimes are done to check whether the geopotential-jet regimes are better correlated with the Moroccan observations. The obtained results will be used for climate model capabilities assessment and analysis of potential changes of regime behavior under global warming and related effects on Moroccan climate.