Project highlights

  • Improving observations to close the energy budget of the Earth in support of UNFCCC objectives
  • Merging of LST data from different sensors to produce global temperature fields under all-sky conditions (cloudy and non-cloudy).
  • Evaluation of climate models

 

Overview

The main impact of GHGs on the Earth’s system is a reduction in energy exiting the top of the atmosphere and increased energy storage in the Earth system. The ability of observations to close the energy budget of the Earth is therefore important. Improving quantification of land surface temperature, latent and sensible heat fluxes from land to the atmosphere should reduce the budget imbalance. A key objective for the UN Framework Convention on Climate Change (UNFCCC) is how Earth observations could support the UNFCCC and the Paris Agreement.

Land surface temperature (LST) is a fundamental, spatial quantity which is a fascinating, emerging observable for environmental science. LST is a key boundary condition state variable in land surface models, which determine the surface-to-atmosphere fluxes of heat, water and carbon compounds and represents the boundary condition in climate models. It also influences cloud cover, precipitation and atmospheric chemistry predictions within these models. Model deficiencies in representing LST often provide an indication of problems in surface energy fluxes and soil moisture that can affect the actual performance of Earth System Models at various temporal scales. There is an increasing focus on the opportunity to exploit satellite LST data to confront the challenges of climate science; and our research group is leading the international effort on LST science.

LST can be determined from thermal emission in either infrared (IR) or microwave (MW) atmospheric windows. Retrievals in the IR are generally more accurate than MW retrievals. Nevertheless, microwave measurements have been shown to complement those in the IR due to their lower sensitivity to clouds, thus increasing sampling in cloudy conditions; although their spatial resolutions are significantly lower than their IR counterparts.

Use of LST for climate studies has been hindered because longer-term datasets are based on IR observations, which are limited to clear-sky. This presents a problem for many applications as resulting trends may be clear-sky biased, and climate models include both cloudy and clear-sky simulations. This project will progress our ability to overcome this by better understanding the physical differences between the observations and how robust relationships can be developed to enable observations to be merged into a consistent record and thus to better improve climate model prediction skill.

Host

National Centre for Earth Observation

Theme

  • Climate and Environmental Sustainability

Supervisors

Project investigator

  • Dr Darren Ghent, NCEO Leicester

 

Co-investigators

  • Prof John Remedios, NCEO Leicester

How to apply

Methodology

To meet the most significant LST requirements for climate science, integrated products can take advantage of the strengths of each data stream (IR and MW; polar orbiting and geostationary; and where available, in situ). The ultimate aim is to provide sub-daily, near-global coverage to better understand the diurnal (24hr) variability in LST. The first steps are to perform some initial comparisons of the IR and MW datasets and then to develop a draft process for merging the data. Much of the detailed research will develop from these key factors and will establish robust relationships between temperature measured from the two different techniques as a function of other parameters such as cloud thickness and wind speed. The results will improve IR and MW retrievals, build a definitive LST dataset derived from the individual data sets and utilise the product to evaluate climate models and other surface temperature datasets.

Training and skills

In the first year, students will be trained on environmental data science, research methods and core skills. Throughout the PhD, training will progress from core skillsets to master classes specific to this project’s themes. Specialist training will include sensor techniques, radiative transfer for infra-red and microwave, non-linear data methods and general remote sensing. The National Centre for Earth Observation will provide access to its Researcher Forum, staff conferences/workshops and national-level training. There is good access to international summer schools, and the student will gain experience from attending European Space Agency Climate Change Initiative events.

Partners and collaboration

This project will fall within the National Centre of Earth Observation (NCEO), which is the leading collective of satellite remote sensing in the UK. Furthermore, the project will feed directly into the framework of the Climate Change Initiative programme run by the European Space Agency (ESA). The student will have an excellent opportunity to work alongside the leading scientists across Europe and beyond in measuring the temperature of the Earth from space. Specific collaborations on developing the methods with leading centres include the UK Met Office, and EUMETSAT Land Surface Analysis Satellite Applications Facility.

Further details

Dr Darren Ghent is the lead scientist on the international Climate Change Initiative LST Project, and leads the LST activities for the operational Sentinel-3 satellite mission. The student will have a chance to be part of a national EO community complementing the environmental science focus of CENTA. Professor Remedios is Director of NCEO and Professor at University of Leicester. NCEO is a national centre funded by NERC and distributed across key Earth Observation (EO) groups at Universities and research laboratories.


Applications need to be submitted via the University of Birmingham postgraduate portal, https://sits.bham.ac.uk/lpages/LES068.htm, by midnight 11.01.2021. Please first check whether the primary supervisor is within Geography, Earth and Environmental Sciences, or in Biosciences, and click on the corresponding PhD program on the application page.

This application should include

  • a brief cover letter, CV, and the contact details for at least two referees
  • a CENTA application form
  • the supervisor and title of the project you are applying for under the Research Information section of the application form.

Referee’s will be invited to submit their references once you submit your application, but we strongly encourage applicants to ensure referees are aware of your submission and expecting a reference request from us. Students are also encouraged to visit and explore the additional information available on the CENTA website.

Possible timeline

Year 1

Training in software usage and development, and attendance at dedicated workshops. Initial evaluation of IR and MW data and data analysis to produce a first merged dataset.

Year 2

Determination of robust relationships and construction of blending approach. Conference attendance, preparation of manuscript for journal submission. Continued development of thesis chapters.

Year 3

Merged product suitable for climate studies and evaluation of models.. Manuscript submission and revision, International conference attendance, thesis preparation.

Further reading

Ghent, D., Corlett, G., Goettsche, F., & Remedios, J. (2017) Global land surface temperature from the Along-Track Scanning Radiometers. Journal of  Geophysical Research – Atmospheres, 122, 12167-12193

Ermida, S.L., DaCamara,  C. C. Trigo,  I. F. Pires,  A. C. Ghent,  D. and Remedios,  J. (2017) Modelling directional effects on remotely sensed land surface temperature. Remote Sens. Env., 190, 56-69. Doi: 10.1016/j.rse.2016.12.008

ESA DUE GlobTemperature Project, www.globtemperature.info

ESA Climate Change Initiative Land Surface Temperature (http://cci.esa.int/lst)

 

COVID-19

There are no direct impacts of COVID-19 on the successful scheduling of this project. All activities are expected to be computer-based rather than laboratory or field-based. This could be supported either physically in the office environment or remotely if the need arises through future COVID-19 restrictions. No impact is envisaged for software and data availability to undertake the research in line with the objectives of the project. Agencies and institutions now have well organised procedures for online meetings, workshops and conferences if future restrictions prevent physical presence.