Natasha Wallum
Academic Profile
Current Research
The emission of mineral dust from dryland sources represents a critical component in models that predict our future climate as it plays a role in the reflection and absorption of solar radiation and ocean fertilisation. Remote sensing studies have identified ephemeral lakes in their dry phases (pans or playas) as globally significant dust sources. However, inherent complexities in dynamic sediment availability generate high spatial and temporal variability in emission from these sources, which are poorly depicted in model parametrisations developed from existing coarse-scale remote sensing observations.
Natasha's D.Phil research focusses on characterising the complex controls on sediment availability to refine our understanding of what defines the local-scale emissivity of sediment from ephemeral lakes through a detailed examination of the largest dust source in the Southern Hemisphere - Etosha Pan, Namibia. Using both high spatial and temporal resolution remote sensing data and field-based analyses to characterise the spatio-temporal dynamics of controls on sediment availability for aeolian erosion, combined with analysis of the mineralogical and geochemical composition of eroded sediment, the research will facilitate improvements in constraining control parameters of dust production from these significant source regions and thus improve assessments of the effects of emissions in response to changing environmental conditions in the future.