Isoprene is the single most important non‐methane biogenic volatile organic compound (BVOC) in the atmosphere. Emitted from terrestrial vegetation, especially in the tropical forests, its annual emissions comprise nearly half the global BVOC budget. Isoprene contributes the largest source of reactive carbon to the atmosphere, and is a precursor for tropospheric ozone, a greenhouse gas and surface air pollutant affecting the human respiratory system and agricultural crop yields. Tropospheric ozone is the dominant source of the OH radical, which initiates tropospheric oxidation chemistry, and is an important chemical sink of other greenhouse gases (e.g., methane). Isoprene is also a precursor for secondary organic aerosols that affect air quality, cloud properties, and influence direct radiative forcing. Quantifying the magnitude of isoprene emissions is therefore crucial for understanding atmospheric chemistry and its impacts on climate, air quality and human health.
This project will provide the unique opportunity for a student to become involved in a leading area of atmospheric science, namely the measurement of isoprene from satellite, an area very much in its infancy. Accurate satellite observations of isoprene can enable us to study the biosphere-atmosphere exchange of terrestrial ecosystems, and continuously monitor global isoprene emissions over multiple years. Satellites offer the only means of observing ecosystem dynamics over large, remote regions such as the tropics.
Recently, isoprene signals have been detected for the first time in radiances measured by the Cross-track Infrared Sounder (CrIS) instrument, a Fourier transform spectrometer (FTS) onboard the Suomi National Polar-Orbiting Partnership satellite (NPP). Currently, CrIS instruments are scheduled to be in orbit until the 2030s. The Infrared Atmospheric Sounding Interferometer (IASI) instruments, of which there are currently three in orbit and a next generation series planned for launch in 2021, are FTSs with similar performance characteristics and high observational sampling.
This project will determine isoprene concentrations from CrIS and IASI measurements, through the application of an optimal estimation retrieval algorithm. These observations will be evaluated against in-situ data, and compared with the output of the chemical transport model GEOS-Chem.
The studentship includes a 3.5 year tuition fee waiver at UK/EU rates
An annual tax free stipend (For 2019/20 this is currently £15,009)
Research Training Support Grant (RTSG) of £8,000
Project Enquiries: Dr Jeremy Harrison, [email protected]
Funding Enquiries: [email protected]
How to apply
Please refer to the How to Apply section at https://le.ac.uk/study/research-degrees/funded-opportunities/centa-phd-studentships
and use the PHYSICS Apply button to submit your PhD application. Upload your CENTA Studentship Form in the proposal section of the application form.
In the funding section of the application please indicate you wish to be considered for NERC CENTA Studentship
Under the proposal section please provide the name of the supervisor and project title/project code you want to apply for.
Available for UK and EU applicants only
Applicants must meet requirements for both academic qualifications and residential eligibility: http://www.nerc.ac.uk/skills/postgrad/
Fu, D., et al.: Direct retrieval of isoprene from satellite-based infrared measurements, Nature Communications, 10, 3811, doi: 10.1038/s41467-019-11835-0, 2019.
Guenther, A.: The Model of Emissions of Gases and Aerosols from Nature version 2.1 (MEGAN2.1): an extended and updated framework for modelling biogenic emissions, Geosci. Model Dev., 5, 1471-1492, doi:10.5194/gmd-5- 1471-2012, 2012.
Illingworth, S. M., et al.: ULIRS, an optimal estimation retrieval scheme for carbon monoxide using IASI spectral radiances: sensitivity analysis, error budget and simulations, Atmos. Meas. Tech., 4, 269-288, doi:10.5194/amt-4- 269-2011, 2011
Razavi, A.: Global distributions of methanol and formic acid retrieved for the first time from the IASI/MetOp thermal infrared sounder, Atmos. Chem. Phys., 11, 857-872, doi:10.5194/acp-11-857-2011, 2011.