The NERC URGENT thematic programme was set up to integrate urban environmental research across the geological, ecological, freshwater and atmospheric sciences. It worked in partnership with city authorities, industry and regulatory bodies.

The thematic programme began in 1998 and lasted for 7 years.

This project provided facilities in the form of a low cost, highly instrumented aircraft designed for probing the turbulent and aerosol-cloud microphysical structure of the atmospheric boundary layer (ABL). Priority use was given to the PUMA (Pollution of the Urban Midlands) consortia during the field trials planned for June 1999 and January / February 2000. The main objectives were:

-to provide high resolution 3-D wind turbulence, temperature and trace-gas variances of the urban ABL

-to provide measurements of the vertical and horizontal profile of aerosol concentration and volumetric size distribution over the Birmingham conurbation

-to provide a database of aircraft urban ABL case studies, which will be available to the PUMA and ASURE modelling communities via the appropriate NERC database committee

-to provide, where current UMIST instrumentation and facilities allow, the aircraft as a measurement platform for specific URGENT user measurement requests

-to measure the vertical entrainment and venting rates of trace-gas and aerosol between the urban ABL and the lower troposphere

-to measure the net aerosol / condensation nucleus flux downwind over an urban environment

-to construct and install a low cost aerosol collection sampling system to provide complementary aerosol chemical composition data to the PUMA measurement campaigns and to the PUMA modelling efforts.

A flight programme of ten flight days / case studies was designated solely to the PUMA consortia. Five additional flights were made available for either (a) instrument testing required by PUMA, which required the removal of the base-line instruments due to space and weight limitations, or (b) specific flights to accommodate other URGENT requirements.