arXiv subjects

Mohammed El Abdioui

Publications and source records attributed to Mohammed El Abdioui.

2 recordsLinked to original sources

arXiv2025

Effects of Climate Change on Moroccan Coastal Upwelling: Relationships between the NAO, Upwelling Index, and Sea Surface Temperature (1978-2024)

This study investigates climate change impacts on Moroccan Atlantic coastal upwelling (21$^{\circ}$--35$^{\circ}$N), analyzing interrelationships among the North Atlantic Oscillation (NAO), Coastal Upwelling Index (CUI), and Sea Surface Temperature (SST) from 1978--2024 using ERA5 reanalysis data. Methods include index calculations, seasonal correlations, Granger causality tests, linear trends, and breakpoint detection to evaluate spatio-temporal dynamics and causality. Results reveal seasonal variability: strong NAO--CUI coupling in winter (DJF; $r = +0.65$), local upwelling dominance in summer (JJA; $r = -0.46$ CUI--SST), and a north--south gradient with intense southern upwelling (mean Ekman transport $37.1 \pm 34.5$ m$^3$/s/100m). Trends show significant SST warming ($+0.0736$ units/decade; $+0.149^{\circ}$C/decade spatially), summer upwelling decline ($-0.0635$ units/decade in JJA), and weak NAO shifts. Granger causality indicates rapid local forcing (CUI $\to$ SST, lag 1--3 months), delayed teleconnections (NAO $\to$ SST, lag 2--4 months), and ocean feedback (SST $\to$ NAO, lag 7--11 months). Breakpoints (1992--1997) signal warming acceleration, highlighting a paradox of global SST rise amid localized upwelling-induced cooling per Bakun's hypothesis. Findings underscore implications for fisheries, aquaculture, and tourism, advocating adaptive management via seasonal forecasting. Keywords: Coastal upwelling, NAO, SST, climate change, Granger causality, Moroccan Atlantic, Ekman transport, spatio-temporal variability.

physics.ao-ph↗

arXiv2025

Tropopause Detection and Analysis in the Mid Latitude Region

This study presents an advanced framework for tropopause detection and analysis using ERA5 reanalysis data, with particular application to extreme meteorological events affecting Morocco and Southern Europe. The research implements and compares multiple detection methodologies, including classical approaches (thermal/WMO and dynamical/1.5 PVU criteria) alongside novel hybrid techniques combining stability and humidity parameters originally developed by ECMWF. Through systematic validation against January 2010 monthly means and a detailed case study of the October 2024 DANA (Depression Aislada en Niveles Altos) event, this work demonstrates the superior performance of hybrid approaches in capturing tropopause dynamics. The development of an automated Python-based comparison tool enabled a quantitative evaluation against Water Vapor 6.2 μm satellite imagery, revealing that the hybrid method achieved the highest structural similarity (mean SSIM: 0.5327) and the most consistent performance across the studied meteorological conditions. The findings highlight the critical role of accurate tropopause detection in improving forecasting capabilities for extreme weather events, particularly in topographically complex regions like Southeast Morocco. This research contributes both methodological advancements in tropopause identification and practical insights for operational meteorology, providing a foundation for enhanced early warning systems and improved understanding of atmospheric processes governing high-impact weather phenomena.

physics.ao-ph↗