Prof Ian M. Brooks
My research interests lie mostly within the area of boundary-layer meteorology and turbulent exchange processes - air-sea interaction, entrainment, and polar boundary layers - straying occasionally into aerosol and cloud microphysical processes. While primarily an experimental/observational scientist, I have become increasingly involved with modelling studies, using large eddy simulation to study boundary-layer processes directly, and confronting large-scale models with measurements to try and figure out why they don't work as well as we'd like them to.
Publications | Conference papers | C.V. | Fieldwork Blog | Google Scholar
CURRENT RESEARCH PROJECTS
Arctic Cloud Summer Expedition (ACSE)
A collaboration between Leeds, the University of Stockholm, and NOAA-CIRES - ACSE aims to study the response of Arctic boundary layer cloud to changes in surface conditions in the Arctic Ocean. Based on the Swedish Icebreaker Oden for a 3-month cruise from Tromso, Norwayto Barrow, Alaska and back over the summer of 2014 we are measuring surface turbulent exchange, boundary layer structure, and cloud properties. Many of the measurements use remote sensing approaches - radar, lidar, and microwave radiometers - to retrieve vertical profiles of thedynamic and microphysical properties of the lower atmosphere and cloud.
[NERC grant: NE/K011820/1]
High Wind Gas Exchange Study (HiWinGS)
A NERC funded collaboration between Leeds, the National Oceanography Centre (Robin Pascal), and the University of Southampton (Helen Czerski, Timothy Leighton, and Steve Gunn). This is a contribution to a US project to study the exchange of gases (CO2, CO, DMS, and maybe others) between the ocean and atmosphere at high wind speeds where wave breaking and bubbles become important factors. We will be deploying an 11-m spar buoy, designed and built at NOC for a previous SOLAS study, instrumented to measure wave spectra, wave breaking, and bubbles in the upper ocean; the surface coverage of whitecaps, and sea-spray aerosol fluxes. US teams from the University of Hawai'i (Barry Huebert and Jeff Hare) and NOAA (Chris Fairall) will measure gas fluxes. Other teams have proposals pending to add further measurements to the cruise, schuduled to take place in October/November 2013.
Blowing snow and sea ice surfaces as a source of polar sea salt aerosol (BLOWSEA)
The concentration of salt in ice cores has been proposed as a sea ice proxy for use in assessing past climate - several lines of evidence suggest that sea salt aerosol generated from the sublimation of blowing snow over sea ice is the major source of salt in the cores. While this has been applied by a number of studies of past climate, without quantification of the source it is difficult to specify exactly what aspect of sea ice is being recorded within the ice core. This study will characterise the rate of production of sea-salt aerosol from the evaporation of blowing snow over sea ice and provide a means to quantify the deposition rate to glacial ice in the past and thus constrain past climate conditions inferred from the salt concentration in ice cores. BLOWSEA is led by Eric Wolf at the British Antarctic Survey (BAS) in collaboration with Anna Jones (BAS), Phil Anderson (SAMS), and John Pyle and Xin Yang (University of Cambridge).
Aerosol-Cloud Coupling and Climate Interactions in the Arctic (ACCACIA)
A £3M NERC-funded consortium project in collaboration with the Universities of Manchester, York, and East Anglia, and the British Antarctic Survey, along with the Met Office and project partners in the US and Europe. ACCACIA aims to improve our understanding of aerosol-cloud interactions in the Arctic, and the potential changes and feedbacks that may result from decreasing Arctic sea ice cover in the future. In situ measurements will be made during two field campaigns utlising ship-based measurements of surface aerosol sources and airborne measurements of aerosol and cloud microphysical properties, boundary layer dynamics, and radiative forcing. The observations will be complemented by modelling studies on a range of scales: from explicit aerosol and cloud microphysics process modelling, through large eddy simulation and mesoscale models, up to global climate models.
ACCACIA background, news, and project blog: http://arcticaccacia.wordpress.com/
Follow ACCACIA on twitter @_ ACCACIA_
WAGES : Waves Aerosol and Gas Exchange
A joint project with members of the Surface Processes group at the National Oceanography Centre, Southampton, WAGES will make continuous measurements of air sea fluxes of CO2 and sea-spray aerosol as well as momentum, heat and moisture, coupled with measurements of forcing processes: mean wind, wurface wave spectrum, whitecap fraction, etc. Autonomous measurements will be ongoing over a period of more than 2 years, supplemented with manned campaigns where additional measurements will be made, primarily in-situ wave measurements from a spar buoy. The project aims to develop improved air-sea flux parameterizations that include the effects of wave state and bubble-mediated exchanges.
[NERC grant: NE/G00353X/1][WAGES pages]
ASIST : Air-Sea Interaction &
Sea-spray in Typhoons
The evaporation of water from sea-spray is thought to modify the exchange of heat and moisture between the ocean and atmosphere. At low wind speeds the effect is negligible, but at high wind speeds (>15 m/s), significant volumes of spray are generated, and the impact on heat and moisture fluxes is believed to be significant. Most of the work on this effect has relied upon theoretical arguments or modelling studies, and evidence from discrepancies between existing bulk flux algorithms and observations under high winds. This study is a collaboration with collagues at the Rosenstiel School of Marine & Atmospheric Science at the University of Miami, and part of a much larger programme aimed at improving the forecasting of Pacific Typhoons: ITOP (Impact of Typhoons on the Ocean in the Pacific). We will make direct measurements of air-sea fluxes, and the sea-spray aerosol spectra within Typhoons in the East/South China Seas, in order to make direct estimates of the impact of spray production on the air-sea fluxes.
[NERC grant: NE/H004238/1][ASIST pages]
ASCOS : Arctic Summer Cloud-Ocean
An international project, coordinated by Stockholm University, to investigate the interactions between the Arctic icecap, the overlying boundary layer, and the ubiquitous low-level stratiform cloud. A 6-week field campaign was conducted from the Swedish Icebreaker Oden during the summer of 2008. The Leeds group ran the surface & boundary layer micrometeorology measurement campaign in collaboration with a group from University of Stockholm, making extensive measurements of turbulent exchange and boundary layer structure over sea ice from 15-m and 30-m masts erected on the ice, along with a turbulence-sonde carried by a tethered balloon. We also ran a SODAR to make wind profile & BL structure measurements up to about 500m.
[NERC grant: NE/E010008/1 - field campaign][ASCOS pages]
[NERC grant: NE/H02168X/1 - analysis]
Details of some recently completed research projects can be found here.
Dr. Sarah Norris - PDRA - working on sea-spray aerosol fluxes using measurements from multiple field campaigns, including the SEASAW, SO-SAFE, and WAGES projects.
Dominic Salisbury - PDRA - after completing his PhD within the group, using satellite retrievals of ocean whitecaps to study their relationships with environmental forcing variables, Dom is now working on surface atmosphere exchange and boundary layer mixing in the Arctic.
John Prytherch - PDRA - John undertook his PhD at the National Oceanography Centre, studying air-sea gas exchange. After a brief diversion in to satellite retrievals of humidity over the oceans he joined the air-sea interaction group in Leeds to work on air-sea exchange under high wind conditions.
Peggy Achtert - PDRA - Peggy completed her PhD at Stockhom University, using lidar to study upper tropospheric clouds. She moved to Leeds in 2014 to work on the ACSE project, studying Arctic boundary layer clouds and their interaction with the surface over sea ice.
Rebecca Jansen - PhD student - Having undertaken a Masters project using data from Antarctica Rebecca is switching hemispheres and is now studying for a PhD on Arctic boundary layer clouds, working on the ACCACIA project. In between degrees she worked on data processing and analysis of whitecap data from the WAGES project.
Matthew Amison - PhD Student - Matt joins the group after completing a degree in maths & geography at Leeds. He is studying the impact of waves on air-sea exchange process.
Former Group Members
Dr Cathryn Birch - 2006-2009 - Cathryn completed a PhD on Arctic meteorology funded by NERC and a CASE award from the MetOffice. She worked on turbulent exchange processes over the Arctic icecap as part of the ASCOS programme, and investigating the representation of these processes and boundary layer structure within the Met Office Unified Model. She has now moved on to warmer topics, working on land-atmosphere interactions over West Africa.
Thomas Pleavin - 2008-2013 - Completed a PhD funded via a NERC Open CASE award with the MetOffice, Tom studied the dynamics of arctic stratus clouds utilizing the MetOffice Large Eddy Model and observations from the ASCOS campaign. In particular he focussed on understanding the processes that allow Arctic stratus to extend into the temperature inversion at boundary layer top
Dr Guylaine Canut - 2011-2012 - worked with the ASCOS data set to investigate coupling processes between the surface and low level Arctic stratus cloud. She obtained her PhD from the University of Toulouse, France, working on boundary layer processes in the Sahara using the AMMA project data. She now holds a permanent position with the boundary-layer measurement group at Meteo-France.
Dr Dave Sproson - 2010-2013 - worked as a PDRA on sea-spray fluxes; currently working at the University of Upsalla, Sweden, with Anna Rutgersson.
David Tupman - 2009-2013 - completed a PhD as part of the WAGES project. Dave studied and developed corrections for the impact of flow distortion over the ship on fluxes calculated via the direct eddy covariance technique. Now at
Masters project students
Rebecca Jansson - MRes (2010/11) - Analysis of aircraft measurements of surface fluxes over heterogeneous Antarcic sea ice: partitioning by surface properties and testing of flux aggregation models (in collaboration with British Antarctic Survey)
Ruth Loughrey - MRes (2009/10) - turbulent coupling of cloud and sea-ice in the Arctic Ocean.
Andrew Fish - MRes (2008/9) - a study of the vertical structure of the arctic boundary layer using ASCOS data, particularly the SODAR and tethersonde measurements.
Anthony Bloom - MRes (2006/7) - worked on CO2 flux data from the SEASAW project.
Alison Fowler - MRes (2005/6) Alison used the MetOffice Large Eddy Model to study entrainment processes in convective boundary layers. She went on to do a PhD in data assimilation at Reading and is now a post-doc there.
Introduction to MATLAB - introductory course on MATLAB programming for research students - this course is not currently running, but feel free to use the slides and online exercises linked here.