COMPLETED RESEARCH PROJECTS

Observational research projects are rarely 'finished' - the data sets are still valuable and analysis and modelling studies associated with them may continue for years, sometimes decades. The grants, however, do run out, and the formal projects. These are some projects for which the funding has ended...we're still working with the data.

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 Study
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]

ASCOS : Arctic Summer Cloud-Ocean Study
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]

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]

SO-SAFE : Southern Ocean Sea-spray Aerosol Flux Experiment
A joint project with Will Drennan at the University of Miami - a CLASP aerosol probe was installed on Miami's Air-Sea Interaction Spar (ASIS) buoy to measure sea-spray aerosol fluxes as part of a major US field project - the Southern Ocean Gas Exchange Experiment (SO-GASEX or GASEX-III) - which took place during March-April 2008.
[NERC grant: NE/F00950X/1]

Balloon validation of remotely sensed aerosol properties
Based at the Chilbolton Observatory, this project aims to test new lidar retrievals of aerosol properties. A group from Leeds led by Dr Barbara Brooks made in-situ measurements of boundary layer structure and aerosol spectra using instruments carried by a tethered balloon during a month-long field campaign in April 2008. These measurements are being used to develop and test remote sensing retrievals of aerosol properties made using the multiple lidars installed at Chilbolton. Ulitimately the results of this study will be applied to satellite-based lidars to provide global information on atmospheric aerosol properties. Additional measurements of turbulence are being used to validate doppler lidar estimates of turbulence dissipation rate. The study is a joint project with Prof. Anthony Illingworth and Dr Ewan O'Connor at Reading University.

SEASAW : Field Observations of SEA Spray, Gas Fluxes, And Whitecaps
A SOLAS project to study surface exchange processes, particularly of CO2, and the production of sea-salt aerosol under high wind conditions. Two cruises on the RRS Discovery were undertaken: D313 (November-December 2006) and D317 (March-April 2007).
[SEASAW project page][NERC grants: NE/C001842/1 and NE/G000107/1]

Atmosphere-Canopy Interactions over Complex Terrain: a field-based study of the effects of turbulent drag on atmospheric flow over forested hills, led by Dr Andy Ross.
[NERC grant: NE/C003691/1]