This dataset contains operational NWP (Numerical Weather Prediction) output from the global atmospheric part of the Met Office global atmospheric Unified Model. The Met Office Unified Model is the numerical modelling system developed and used at the Met Office (it is run operationally for weather forecasting). It is 'seamless' in that different configurations of the same model are used across all time and space scales. This model can produce several datasets of which CEDA holds the following: Met Office Global Atmospheric Model data Met Office North Atlantic/European (NAE) Mesoscale Model data The Met Office Global Atmospheric Model has 25 km resolution with 70 vertical levels. It Covers the entire globe and 144 hours in the future twice a day. The Global model provides boundary information for the NAE model, for which additional shorter runs (48 hours) are produced twice a day. The model is kept close to the real atmosphere using hybrid 4D-Var data assimilation of observations. 17km resolution with 70 vertical levels is now also available. Analyses and first forecast steps are stored to give a time resolution of 1 hour up to 6 hours after each analysis timestep. The NWP global output archive starts on 1 January 2012, and is ongoing.

The Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP) was organized under the auspices of Atmospheric Chemistry and Climate (AC&C), a project of International Global Atmospheric Chemistry (IGAC) and Stratospheric Processes And their Role in Climate (SPARC) under International Geosphere Bisosphere Programme (IGBP) and World Climate Research Programme (WCRP). The Atmospheric Chemistry and Climate Model Intercomparison Project (ACC-MIP) consists of several sets of simulations that have been designed to facilitate useful evaluation and comparison of the AR5 (Intergovernmental Committee on Climate Change Assessment Report 5) transient climate model simulations. The proposed list of experiments and diagnostics was aimed at providing necessary information for scientific studies spanning the AC&C interests. This dataset collection contains chemistry and climate model measurements.

Global analyses from the European Centre for Medium-Range Weather Forecasts (ECMWF) from 1994 - present. This dataset collection follows on from the ECMWF Re-Analysis (ERA-15 and ERA-40) datasets with the same parameters at identical resolutions. Data is available in a number of resolutions and vertical level types. Some Monthly means and Seasonal Forecast data (1987-present) are also available.

The Quantifying the Amazon Isoprene Budget: Reconciling Top-down versus Bottom-up Emission Estimates project ran a unique high resolution model for the Amazon basin, able to simulate isoprene emissions and atmospheric chemistry. Model outputs are available through CEDA. This was a NERC funded project (NE/G013810/1).

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.

This dataset collection contain data concerning stratospheric temperature, geopotential height and wind components produced by the Stratospheric Data Assimilation System at the UK Met Office. The data assimilation system is a development of the scheme used at the Met Office for operational weather forecasting, which has been extended to cover the stratosphere. The primary product is a daily analysis (at 1200 UTC) which is produced using operational observations only. For short periods of particular interest the analyses are available at 6-hourly intervals. Assimilation experiments using UARS (Upper Atmosphere Research Satellite) data in addition to operational meteorological observations have been carried out for limited periods. These data consist of 3-dimensional gridpoint analyses of temperature, geopotential height and wind components fields at 2.5 x 3.75 degree resolution from the ground to 0.3 hPa (for the period from 17th October 1991 (UARS day 36) to 2006-03-13) and on a smaller grid size 0.5625 degree x 0.375 degree on 27 (or 26 depending on variable) pressure levels, (note, this does not apply for the UARS versions of the data files), for the period 2006-03-03 to present day.

RAPIT was looking at the problem of estimating the risk of the collapse of the overturning circulation. Using modern statistical methods for the analysis of complex numerical models, large ensembles of two Atmosphere Ocean General Circulation Models (HADCM3 and CHIME) were analysed. This dataset collection contains meteorology, climatology and ocean outputs from ensemble runs xfel, xfgb, xfha and xgym. Studies of large excursions of the strength of the overturning in existing control runs were used to guide the choice of metrics and diagnostics.

Measurements were made using the FAAM BAE-146 aircraft throughout the troposphere in the locality of the Tropospheric Organic Chemistry (TORCH) field campaign in Writtle, Essex to determine the influence of regional transport and local chemistry on ozone concentrations. The Production of Ozone of South-east England (POSE) project aimed to further the understanding of the factors governing ozone chemistry during summer periods in the UK. In particular, the relative sources of ozone: general Northern Hemisphere background, regionally produced products and local/in situ generation. The transport of pollutants from Europe within the boundary layer has been implicated in the very high levels of ozone seen in the UK during summer 2003. During the TORCH field campaign in Writtle, Essex, high levels of ozone and other reactive species were seen during the 2003 heatwave, and results suggest that this may be a result of mixing down of polluted air from aloft during the collapse of the night-time shallow inversion layer to form the day time boundary layer. In order to better understand this behaviour, the FAAM BAE-146 aircraft perfomed a series of profiles close to the Writtle site, to determine the influence of regional transport and local chemistry on ozone concentrations. Measurements included CO, ozone, hydrocarbons and oxygenated VOCs, throughout the troposphere.

PDSI consists of global maps of monthly self-calibrating Palmer Drought Severity Index (scPDSI) which have been calculated for selected periods of time based on the CRU TS data sets. The PDSI datasets are produced by KMNI in partnership with the Climatic Research Unit (CRU) at the University of East Anglia. The Palmer Drought Severity Index (PDSI) is a measure of soil moisture availability that has been used extensively to study droughts and wet spells in the contiguous USA and elsewhere, particularly as the primary indicator of the severity and extent of recent droughts. Recently, the PDSI has become more popular as a drought metric in studies quantifying possible trends in future soil moisture availability and it has been used as the basis for reconstructing past variations in drought.

The project was a QinetiQ applied research programme 3G23, funded by Ministry of Defence (MOD). The project duration was from April 2004 to March 2007. Field experiment in May 2006 was to investigate noise modelling of helicopters with regard to long range sound propagation. The trial sought to understand more fully the meteorological effects on sound propagation over a land sea interface. This dataset collection contains profiles of the radial velocity at points along the aircraft flight path and standard meteorological measurements from an automatic weather station. The Universities Facility for Atmospheric Measurement (UFAM) Doppler lidar system and automatic weather station were operated by the University of Salford.