Most dust in the Earth system originates in the low-latitude dust belt, however recent studies suggest >5% of global dust emissions comes from sources in the high latitudes (≥50°N and ≥40°S) – more than from Australia or southern Africa. A substantial proportion of this dust remains within the high latitudes and is deposited in the sensitive marine, terrestrial and cryospheric environments of the Arctic and Antarctic; it may also affect air quality and human health. Until very recently sources of high-latitude dust have largely been considered in isolation and limited to specific regional areas such as Iceland (Figure 1) and Patagonia.
Dust sources in the low to middle latitudes have been well-mapped and well-studied, but less information is available from dust observations poleward of these limits. There are many reasons for this including remoteness, very low temperatures, snow and ice cover and lack of daylight during winter months, all of which hamper year-round field investigations. At lower latitudes some of these difficulties have been overcome through the use of satellite remote sensing data but this is more challenging for the polar regions due to high year-round cloud cover and seasonal light limitation. This means that to date, no attempt has been made to systematically quantify the magnitude, frequency, intensity or timing of high latitude dust emissions. This in turn limits our ability to understand the impact of high latitude dust both within Polar regions and at the global scale.
A potential solution to the challenges of remote sensing at high latitudes is to adopt a multi-scale approach using a wide range of satellite sensors and data products alongside existing secondary ground-surface measurements. The aim of this studentship is to provide the first multi-scale, systematic, remote-sensing led quantification of high latitude dust sources, dynamics and transport pathways, providing an essential dataset for validating future global dust modelling outputs.
Different satellites have different spatial and temporal resolutions which can be manipulated to discern information about high latitude dust. The student will use both satellite reflectance and existing aerosol products to identify and map the distribution and pathways of high latitude dust events. A particularly novel approach of this project will be to use aerosol products at a coarse spatial (1x1°) and temporal (8-day) scale to facilitate some of the first continuous remote sensing enquiries in to seasonality of high latitude dust emissions. This will be applied to the eight high latitude dust regions of the world. The availability of MODIS data from 2000 onwards will provide >15 years of data increasing the confidence in seasonal and spatial patterns as well as allowing quantification of inter-annual variability. Satellite retrievals will be cross-referenced to multiple independent secondary ground-based measurements including meteorological data, aerosol databases and AERONET.
Training and Skills
CENTA students are required to complete 45 days training throughout their PhD including a 10 day placement. In the first year, students will be trained as a single cohort on environmental science, research methods and core skills. Throughout the PhD, training will progress from core skills sets to master classes specific to CENTA research themes.
The student will be trained in the use of satellite remote sensing data for environmental applications, specifically the identification atmospheric dust sources, total emissions and pathways. They will be supported to develop expertise in quality control of satellite data and the use of secondary data sources (meteorological data, AERONET aerosol data). The student will receive training in the use of industry-standard remote sensing software and geospatial data analysis platforms and techniques.
Year 1: Student will obtain and analyse MODIS imagery for the 8 main high latitude dust source regions including full colour composite images and 1x1° and 8-day MODIS Aerosol Optical Depth product for the full MODIS record (2000-date).
Year 2: For selected dust events, high resolution MODIS and other satellite data will be cross-referenced to evaluate the accuracy and precision of coarse scale analysis. Remote-sensing data for all regions will be validated by cross-referencing against multiple independent secondary ground-based measurements including meteorological data, aerosol databases (e.g. EBAS database; NOAA Earth System Research Laboratory database) and AERONET.
Year 3: Results will be used to construct inventories of high latitude dust sources, to quantify seasonality of dust emissions and compare this across regions, and to validate existing modelling outputs.
Partners and collaboration (including CASE)
The external partner for this project is Dr. Santiago Gassó at NASA who has worked extensively on developing remote sensing approaches to mapping and tracking dust pathways in Patagonia and Alaska. The student will have the opportunity to undertake a short (2-3 week) internship at NASA working with Dr. Gassó in the USA.
For information about this project, please contact Dr Matthew Baddock (firstname.lastname@example.org). For enquiries about the application process, please contact the School of Social, Political and Geographical Sciences Research (email@example.com).
Please quote CENTA when completing the application form: http://www.lboro.ac.uk/study/apply/research/.