A5042792358- Aeolian processes and effects
- Atmospheric chemistry and aerosols
- Geology and Paleoclimatology Research
- Atmospheric aerosols and clouds
- Soil erosion and sediment transport
- Geological formations and processes
- Soil Carbon and Nitrogen Dynamics
- Immunodeficiency and Autoimmune Disorders
- Groundwater and Watershed Analysis
- Polar Research and Ecology
- Pediatric health and respiratory diseases
- Hydrology and Sediment Transport Processes
- Planetary Science and Exploration
- Biocrusts and Microbial Ecology
- Neonatal Respiratory Health Research
- Cryospheric studies and observations
- Geochemistry and Geologic Mapping
- Coastal and Marine Dynamics
- Plant Water Relations and Carbon Dynamics
- Wildlife Ecology and Conservation
- Chemical Analysis and Environmental Impact
- Child and Adolescent Health
- Maritime and Coastal Archaeology
- Groundwater and Isotope Geochemistry
- Microbial Community Ecology and Physiology
University of Cape Town
2016-2025
International Geographical Union
2014-2024
Medizinische Hochschule Hannover
2016
South African Environmental Observation Network
2012
Stellenbosch University
2012
United States Geological Survey
2010
University of Illinois Chicago
2010
Texas Tech University
2010
University of Botswana
1999-2007
University of Oxford
1997-2000
Abstract Nitrogen (N) cycling was analyzed in the Kalahari region of southern Africa, where a strong precipitation gradient (from 978 to 230 mm mean annual precipitation) is main variable affecting vegetation. The underlain by homogeneous soil substrate, sands, and provides opportunity analyze climate effects on nutrient cycling. Soil plant N pools, 15 natural abundance ( δ N), NO emissions were measured indicate patterns along gradient. importance biogenic 2 fixation associated with...
Research Article| September 01, 2012 THE EVOLUTION AND AGES OF MAKGADIKGADI PALAEO-LAKES: CONSILIENT EVIDENCE FROM KALAHARI DRAINAGE SOUTH-CENTRAL AFRICA A.E. MOORE; MOORE African Queen Mines, Box 66 Maun, Botswana., Department of Geology, Rhodes University, Grahamstown, 6140, South Africa., Earth Sciences, James Cook Townsville, Queensland, Australia, e-mail: andy.moore.bots@gmail.com Search for other works by this author on: GSW Google Scholar F.P.D. (WOODY) COTTERILL; COTTERILL AEON -...
Establishing mineral dust impacts on Earth's systems requires numerical models of the cycle. Differences between optical depth (DOD) measurements and modelling cycle emission, atmospheric transport, deposition indicate large model uncertainty due partially to unrealistic assumptions about emission frequency. Calibrating DOD typically in North Africa, are routinely used reduce magnitude. This calibration forces modelled emissions match but may hide correct magnitude frequency events at...
The processes which act in mineral dust source regions and factors contribute to interannual variability within plumes emanating from them are poorly understood. In this case study, we focus on modulating emissions of atmospheric aerosols a large ephemeral lake. We one key lake southern Africa, the Makgadikgadi Pans Botswana. A range satellite [for example, Total Ozone Mapping Spectrometer (TOMS), Moderate Resolution Imaging (MODIS)] climate data (from meteorological stations reanalysis...
Abstract We present a dust plume source inventory for southern Africa. In order to locate and track the local, short‐lived events, frequency data have been derived from Meteosat Second Generation (MSG) thermal infrared composite (4 km using 8.7, 10.8, 12.0 µm) Moderate Resolution Imaging Spectroradiometer (MODIS) visible (0.25 utilizing 0.620 – 0.670 µm, 0.545 0.565 0.459 0.479 µm). Between January 2005 December 2008, total of 328 distinct daytime plumes more than 10 in length were detected....
A new ion chromatography electrospray tandem mass spectrometry (IC-ESI/MS/MS) method has been developed for quantification and confirmation of chlorate (ClO3−) in environmental samples. The involves the electro-chemical generation isotopically labeled internal standard (Cl18O3−) using 18O water (H218O). was added to all samples prior analysis thereby minimizing matrix effects that are associated with common ions without need expensive sample pretreatments. detection limit (MDL) ClO3− 2 ng...
Abstract Surface roughness plays a key role in determining aerodynamic length ( z o ) and shear velocity, both of which are fundamental for wind erosion threshold potential. While can be quantified from measurements, large proportions prone surfaces remain too remote this to viable approach. Alternative approaches therefore seek relate morphological metrics. However, dust‐emitting landscapes typically consist complex small‐scale surface patterns few metrics exist these used predict modeling...
Abstract Hypolithic microbial communities are productive niches in deserts worldwide, but many facets of their basic ecology remain unknown. The Namib Desert is an important site for hypolith study because it has abundant quartz rocks suitable colonization and extends west to east across a transition from fog‐ rain‐dominated moisture sources. We show that fog sustains impacts hypolithic several ways, as follows: (1) effectively replaces rainfall the western zone central enable high (≥95%)...
Abstract Background Top-soil microbiomes make a vital contribution to the Earth’s ecology and harbor an extraordinarily high biodiversity. They are also key players in many ecosystem services, particularly arid regions of globe such as African continent. While several recent studies have documented patterns global soil microbial ecology, these largely biased towards widely studied rely on models interpolate diversity other where there is low data coverage. This case for sub-Saharan Africa,...
ABSTRACT African elephants ( Loxodonta africana ) are megaherbivores of the savannas requiring extensive ranges that can provide critical resources for their survival and reproduction at different spatiotemporal scales. We studied seasonal differences in home range sizes daily distance to nearest surface water sources by five male 10 female eastern Okavango Panhandle northern Botswana between 2014 2017. hypothesized (i) elephant would be larger wet than dry season (because tend less...
Abstract Mineral dust sources were identified in Sea‐viewing Wide Field‐of‐view Sensor (SeaWiFS) images along the south‐west coast of Africa. Up to 150 plumes observed over a 3 year period, and these are linked that either salt pans or dry river beds Namib Desert. This demonstrates supply is maintained by fluvial landforms associated hydrology. paper highlights need look more detail at source areas around globe, as this will further our understanding dust‐production processes.
Playas are common in arid environments and can be major sources of mineral dust that influence global climate. These landforms typically form crusts limit evaporation emission, modify surface erosivity erodibility, lead to over prediction or underprediction (1) dust-emission potential (2) water heat fluxes energy-balance modeling. Through terrestrial laser scanning measurements part the Makgadikgadi Pans Botswana (a Southern Hemisphere playa emits significant amounts dust), we show weeks,...
Abstract Dual‐scale analyses assessing farm‐scale patterns of ecological change and landscape‐scale in vegetation cover animal distribution are presented from transect studies away waterpoints, regional remotely sensed analysis numbers across the southern Kalahari, Botswana. Bush encroachment is prevalent semi‐arid sites where Acacia mellifera Benth. widespread communal areas private ranches, showing that land tenure changes over last 40 years have not avoided rangeland degradation....
Abstract Modeled estimates of eolian dust emission can vary by an order magnitude due to the spatiotemporal heterogeneity emissions. To better constrain location and emissions, a surface erodibility factor is typically employed in models. Several landscape‐scale schemes representing potential for use models have recently been proposed, but validation such has only attempted indirectly with medium‐resolution remote sensing mineral aerosol loadings high‐resolution land mapping. In this study,...
Abstract. Within the framework of Dust Observations for Models (DO4Models) project, performance three commonly used dust emission schemes is investigated in this paper using a box model environment. We constrain with field data (surface and particle properties as well meteorological parameters) obtained from dry lake bed crusted surface Botswana during 3 month period 2011. Our results suggest that all fail to reproduce observed horizontal flux. They overestimate magnitude flux by several...