The Extreme North African Haboob in October 2008: High‐Resolution Simulation of Organized Moist Convection in the Lee of the Atlas, Dust Recirculation and Poleward Transport

Abstract

This study investigates the mesoscale dynamics involved in the 8–11 October 2008 unseasonably strong African dust episode, during which dust was transported to the Iberian Peninsula (IP). We employ observational datasets and a high‐resolution Weather Research and Forecasting model coupled with Chemistry simulations. The analysis shows that during 0900–1200 UTC 9 October, a mesoscale convective system developed over the Atlas Mountains and resulted in a southwestward propagating convective cold pool outflow on the southern foothills of the Anti‐Atlas, which lifted dust from the source region. Between 1200 and 1800 UTC 9 October, new moist convection was enhanced over the Atlas Mountains due to intensifying confluence among a heat low, moist southwesterly Atlantic sea‐breeze front, and northeasterly flow associated with the convective cold pool near western Algeria. This new moist convection intensified the strength of the convective cold pool outflow and haboob, both of which continued propagating southwestward. At 1200 UTC 10 October, the low‐pressure system migrated poleward on the southern slopes of the Anti‐Atlas Mountains in association with a mountain‐plains solenoidal circulation due to the daytime differential heating between the southern slopes of the Anti‐Atlas and nearby atmosphere. The deepening low‐pressure and strengthening Atlantic sea‐breeze redirected an equatorward advancing dust plume into the poleward direction. The dust plume ultimately crossed the Saharan Atlas Mountains on 11 October and finally impacted the IP.

Aerosol–precipitation elevation dependence over the central Himalayas using cloud-resolving WRF-Chem numerical modeling

“…WRF-Chem is an advanced online coupled regional model which can simulate the emission, transport, and transformation of trace gases and aerosols with atmospheric feedback processes from radiation and meteorology (Chapman et al, 2009;Fast et al, 2006). WRF-Chem consists of several chemistry components, e.g., emission inventories, aerosolchemistry mechanism, aqueous and gas phase mechanism, dry and wet deposition, and photolysis, and has been widely used to study aerosol emission and transport (e.g., Dhital et al, 2022;Parajuli et al, 2019) and aerosol-cloud-radiationclimate interaction (e.g., Wu et al, 2018;Fan et al, 2015;Sarangi et al, 2015;Archer-Nicholls et al, 2016;Liu et al, 2020) around the globe.…”