Current Research Themes :

  1. Impact of mineral aerosols on radiation

  2. Dust Emissions at High Latitudes

  3. Measurement Modelling of Dust Emissions

  4. Saline Lakes as Indicators for Environmental Degradation

  5. Role of Vegetation in Semi-arid Environments

Impact of mineral aerosols on radiation

A recent collaboration with dendrochronologists has revealed a strong correlation between mineral aerosol transported over the Caribbean and reduced cell production of a slash pine community. This discovery provides an opportunity to seek other similar direct impacts that mineral aerosols have on vegetation communities as well as the estimated, but rarely measured positive indirect impacts such as fertilization. Funding is currently being sought to establish this research further in other low latitude regions with annual ring forming vegetation under the premise that this record could provide a dust proxy chronology.


Dust Emissions at High Latitudes

Dust Emissions at high latitudes have been attracting much attention due to the recent activity detected in these regions from increased climate change impacts. For many regions, these dust storms have occurred in the past as witnessed in the loess soils that blanket the Canadian northwest, the majority of which were deposited in the last 10,000 years. A recently submitted proposal, collaboration with the Arctic Institute, and future monitoring plans are scheduled to link the activity of dust emissions to supporting disconnected high-latitude regions of grasslands. These grasslands still exist today and are hypothesized to be the same biomes responsible for maintaining the megafauna population up until their extinction around 6 Ka BP.

False colour SPOT5 image of the Slims River proglacial valley change in 2015
False colour SPOT5 image of the Slims River, Yukon proglacial valley change over May to August in 2015

Here is a quick video of a dust storm recording from a site in the Yukon taken from a timelapse camera installed in the summer of 2017:

Measurement Modelling of Dust Emissions

Funded through the NERC as a Postdoctoral Fellow at the University of Oxford and an internal Fell Fund grant until 2014 and currently as a Senior Visiting Research Assistant this project is investigating the spatial and temporal links between ground-based measurements, remotely sensed measurements, and large-scale modelling of dust emissions from southern Africa. Through the deployment of a comprehensive set of climatology instrumentation, sediment transport detection and measurement network, and aerosol monitoring equipment, the project aimed to characterize the key driving factors for the variation in dust emissions from large source areas. Publications include Nield et al. 2013 and Nield et al. 2014, while currently being prepared for submission include papers on spatio-temporal dynamics of erodibility, 2011 field results and box-model results.

DO4 Models
Range of surfaces found on Sua Pan, Botswana within a 12 x 12 km section due to differences in antecedent rainfall.

Saline Lakes as Indicators for Environmental Degradation

Salton Sea

Collaborations with the USGS has provided fruitful field trips investigating the role of soluble salts on the threshold for sediment transport (using the DRI portable wind tunnel, PI-SWERL), transport of toxic elements through capillary action, and dust emission mineralogy, rate, and seasonality, within the Mojave Desert. Opportunities for outreach and inclusion of these results with land managers has been one output of this research, but at papers are currently being developed based on this work already presented at AGU. Research conducted at the Salton Sea through a grant from the California Department of Water Resources was the first investigation of the role that salt minerals have to modify the threshold of aeolian sediment transport and have been subsequently published in King et al., 2011 and Buck et al., 2011.

Role of Vegetation in Semi-arid Environments

A post-doctoral fellow position at Desert Research Institute, Nevada, provided the opportunity to be involved in a project sponsored by BLM on the meteorological investigation of Holocene sand ramp activity related to the stability of a threatened plant species. Its main objectives were to assess the dependence of a threatened plant species (Penstemon albomarginatus) on its current environment within the two Nevada county populations for insight into its future. Development of a laboratory wind tunnel as a research and teaching tool aided by internal funding will continue this critical research on roughness on reducing wind erosion as applications to agriculture, degraded lands, and reducing transportation hazards. Its thorough testing with other proven wind tunnels has been previously published, but the output of this research on the effects of surface roughness on the shear stress calibration was recently published in Aeolian Research.

Field site MNORT at Jornada Experimental Range, New Mexico