Study of Dust Storms: Observation and Modeling

Abstract

Through the lens of the Wind-blown Sand Experiment (WISE), a first-of-its-kind in-situ study conducted by the ENGEOS lab, this thesis explores the complexity of dust storms in the Empty Quarter (EQ) desert. The WISE-UAE experiment started on 25 July 2022 at Madinat Zayed (23.5761o N, 53.7242o E; elevation: 119 m), located 120 km southwest of Abu Dhabi in the United Arab Emirates (UAE). This thesis presents a detailed mineralogical and granulometric analysis of surface and airborne dust particles, uncovering that ground samples predominantly consist of 55% Quartz (SiO2), 18% Calcite (CaCO3), and other minerals. In contrast, suspended particles have a similar makeup, with a higher Quartz content (63%). The granulometry analysis indicates that ground samples fall within the medium sand category (1.99 phi), and suspended particles are fine sand (2.78 phi), with saltation events most frequent between 08:00 and 18:00 local time. The critical finding of a 7.71 m s-1 wind speed threshold for saltation enhances our understanding of dust storm dynamics. This study uses WISE meteorological data to provide groundbreaking insights into dust emission mechanisms and evaluates biases in two leading reanalysis products, ERA5 and ERA5 Land. These evaluations will enhance the accuracy of dust storm forecasts, marking a significant advancement in our capability to predict dust storm dynamics. This research fills a crucial gap and sets a new standard for future hyperarid dust storm studies, emphasizing the value of precise, in-situ data collection and model calibration.

Date of Award	10 May 2024
Original language	American English
Supervisor	Diana Francis (Supervisor)