A041-0005
Understanding size-resolved dust emission from field observations in Morocco
Tuesday, 8 December 2020
Poster
Cristina González-Flórez1, Martina Klose1, Andres Alastuey2, Sylvain Dupont3, Vicken Etyemezian4, Adolfo González-Romero1, Konrad Kandler5, George Nikolich6, Marco Pandolfi2, Agnesh Panta5, Xavier Querol2, Cristina Reche2, Jesús Yus-Díez2 and Carlos Pérez García-Pando1,7, (1)Barcelona Supercomputing Center (BSC), Barcelona, Spain, (2)Spanish National Research Council (CSIC), Institute of Environmental Assessment and Water Research (IDÆA), Barcelona, Spain, (3)INRAE, Bordeaux Sciences Agro, ISPA, F-33140, Villenave d'Ornon, France, (4)Desert Research Institute, Las Vegas, NV, United States, (5)Technical University of Darmstadt (TUDa), Darmstadt, Germany, (6)Desert Research Institute, Division of Atmospheric Sciences, Reno, NV, United States, (7)Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain
Abstract:
Mineral dust plays an important role in the Earth system as it has major impacts on the energy and carbon cycles and, therefore, upon climate. The physical and chemical properties of dust, i.e. its particle size distribution (PSD), mineralogical composition, shape and mixing state determine its effects. Despite the advances made on these aspects through experimental, theoretical and modelling work, there is still (1) an incomplete understanding of the emitted dust PSD and mineralogy; (2) fundamental disagreements among existing dust emission schemes; and (3) a lack of coincident measurements of individual mineral PSDs for emitted dust and the parent soil.
To overcome these deficits, comprehensive field measurements and laboratory analyses are conducted within the ERC project FRAGMENT, providing a detailed characterization of the soil, airborne particles and their properties, and meteorology obtained using a variety of field instruments (e.g. saltation sensors, aerosol spectrometers, low volume samplers, cascade impactors, 10 m meteorological tower). Here, we present preliminary results of the first FRAGMENT field campaign conducted near M’hamid El Ghizlane in Morocco, at the edge of the Sahara Desert, in September 2019.
In this study, we aim to advance our understanding of the dust PSD at emission based on size-resolved measurements of dust concentration obtained from three optical particle counters deployed at different heights. During the one-month measurement period, dust events occurred frequently (about every 1-2 days) at varying intensity, including a few haboobs. At 2 m height, the average daily maximum wind speed was around 12 m/s, with peak gusts up to 22 m/s. We analyse the temporal variability of the number and volume PSDs along with the associated size-resolved dust emission fluxes and we compare them to theoretical predictions.
