Why is the atmosphere becoming drier? The roles of atmospheric processes and vegetation feedbacks, and their implications for future climate change

Lead supervisor: Dr Julie Jones, Geography
Co-supervisor(s): Professor Colin Osborne, Animal and Plant SciencesDr Robert Bryant, GeographyDr Kate Willett, Met Office

Deadline: Thursday 23 February 2017

Applications for this project have now closed.

Project description

Relative humidity (RH) over land has declined steeply since 2000. This signal was largely unexpected and does not appear clearly in historical reconstructions from climate models although large scale drying over land is expected in the longer term. The drying signal is relatively consistent from the edge of the deep tropics to the mid-latitudes of both hemispheres, whereas regions equatorward and poleward show increasing RH trends. Potential drivers for these signals, such as faster warming over land than ocean, and the El Niño Southern Oscillation have been discussed, but not systematically explored. This atmospheric drying therefore remains poorly understood, and its implications for future climate changes are unknown. This project will explore the potential atmospheric and dynamical drivers behind these trends, by quantifying feedbacks from terrestrial vegetation, and investigate whether these key drivers are adequately represented in climate models exploring their implications for future climate impacts.

This project, in collaboration with the Climate Monitoring and Attribution Group of the Met Office provides an exciting opportunity to undertake interdisciplinary research in climate and ecosystem science on a key issue in environmental change. The project will significantly improve our understanding of the mechanisms and impacts of climate change, aiding model development, and improving our ability to prepare good adaptation and mitigation strategies.

The student will work with global monitoring products such as the global gridded land surface humidity dataset HadISDH (www.metoffice.gov.uk/hadobs/hadisdh) and other global monitoring products including reanalyses (e.g. ERA Interim); the CMIP5 climate model data archive, and earth observation datasets for terrestrial land use, evapotranspiration and soil moisture. They will also use model simulations based on earth observation datasets, and ecosystem studies including those using Free-Air CO2 Enrichment (FACE).

They will develop a good understanding of basic climate change science, the uncertainties around observational climate monitoring records, atmospheric physics, ecosystem and global change ecology, plant physiology and climate model uncertainties. They will develop skills in analysis and interpretation of observational, experimental and climate and ecosystem model data.

This is an interdisciplinary PhD, involving both climate and ecosystem science, and will therefore suit applicants with experience of, or the capability to develop skills in, interdisciplinary work, for example with a background in Environmental Science, Atmospheric Physics, Plant Sciences, Biology or Geography.

Keywords: climate change; climate modelling; remote sensing; ecosystem science; vegetation feedbacks

Subject areas: Earth Sciences: Climatology and Climate Change; Meteorology, Environmental Science, Ecology and Conservation, Geography; Physical Sciences: Geography; Medical / Biological Sciences: Botany / Plant Science, Ecology and Conservation

Funding notes

This four-year studentship will be fully funded at Home/EU or international rates. Support for travel and consumables (RTSG) will also be made available at standard rate of £2,627 per annum, with an additional one-off allowance of £1,000 for a computer in the first year.  Students will receive an annual stipend of £17,336.