Stratospheric Aerosol and Gas Experiment III (SAGE III) was an instrument on board a Meteor-3M spacecraft, launched on December 10, 2001. Routine measurement operations began in March 2002 until the SAGE III mission was terminated in March 2006. The specific measurement objectives of SAGE III provide 1 km vertical resolution profiles of: aerosols and clouds at seven wavelengths from the mid-troposphere into the stratosphere and where appropriate, the mesosphere; O3 from the mid-troposphere to 85 km; H2O from the planetary boundary layer to 50 km; NO2 from the tropopause to 45 km; NO3 from 20 to 55 km; OClO from 15 to 25 km; and, O2 from the mid-troposphere to 70 km. This dataset contains level 2 version 3 cloud product data.

Stratospheric Aerosol and Gas Experiment III (SAGE III) was an instrument on board a Meteor-3M spacecraft, launched on December 10, 2001. Routine measurement operations began in March 2002 until the SAGE III mission was terminated in March 2006. The specific measurement objectives of SAGE III provide 1 km vertical resolution profiles of: aerosols and clouds at seven wavelengths from the mid-troposphere into the stratosphere and where appropriate, the mesosphere; O3 from the mid-troposphere to 85 km; H2O from the planetary boundary layer to 50 km; NO2 from the tropopause to 45 km; NO3 from 20 to 55 km; OClO from 15 to 25 km; and, O2 from the mid-troposphere to 70 km. This dataset contains level 2 version 3 cloud product data.

ACID-PRUF was a three year NERC directed programme that investigated the complex interaction of aerosols and clouds. The overall aims of ACID-PRUF were to reduce the uncertainty in the radiative forcing associated with the aerosol indirect effects though a targeted laboratory and modelling programme. This dataset collection contains measurements of freezing fraction of water solution droplets-solute and suspended matter during the immersion freezing of pollen extracts (birch pollen, Betula fontinalis occidentalis, Sigma-Aldrich, P6895-1G), with a new cold electrodynamic balance (CEDB).

Anthropogenic influence on Upper Tropospher-Lower Stratosphere (UTLS) clouds and aerosol (CIRRUS) UTLS round 5 project led by Prof. Tom Choularton. The dataset contains the total number of Condensation Nuclei (CN), CCN, IN and the size distribution of optically active particles in clean and polluted air in the UTLS region over the UK, the number, size distribution, phase and morphology of droplets and crystals in cirrus cloud. Objectives -To measure the total number of Condensation Nuclei (CN), CCN, IN and the size distribution of optically active particles in clean and polluted air in the UTLS region over the UK. Assessment of their spatial distribution and their likely source based on tracer measurements and air mass history. -To use a unique suite of state of the art instruments to quantify the extent to which air mass history, and gas and particle loading can affect the microphysical properties of cirrus clouds in the UTLS region, in particular, the size distribution, phase and morphology of cloud particles. -To obtain estimates of HNO3 loss to cirrus clouds and the subsequent effect on the aerosol population after the cloud has evaporated using case studies involving one or more wave clouds. -To make observations of the number, size distribution, phase and morphology of droplets and crystals in cirrus cloud and the number and size distribution of interstitial particles and correlate these with measurements of tracers that identify anthropogenic anthropogenic influence. Hence building on objective 3 to investigate the influence of cirrus on the distribution of aerosol and gases in the UTLS region as cloud and precipitation evaporate. -To make an assessment of the chemical composition of the particulate in the UTLS region as a function of their size, their spatial variability and the effect different sources have on their composition. -To use measurements of the masses of key components as a function of size of cirrus particle dry residues and interstitial particles to determine if there are distinct chemical differences between activated and unactivated particles. -To establish the partitioning of oxidised nitrogen between the gas and aerosol phases as a function of air mass history and source region. Methodology These studies were performed during the spring/summer of 2005 over the UK using the BAE 146 aircraft for in situ sampling Experiments were undertaken in a wide range of meteorological conditions i.e. in frontal cirrus, in convective conditions and in anticyclonic conditions. The aircraft made measurements below and within the cirrus cloud.

This project was funded by the Natural Environment Research Council (NERC) with the grant reference - NE/I021012/1 - and was led by Dr Christopher Holloway (University of Reading). This dataset collection contains MetUM model data and observed convective aggregation data for the Tropics. This project aimed to clearly identify processes important for self-aggregation of convection in idealized models and then to test whether these processes, or different processes, are active in convective organization in nature. The second part of this goal was an open question in the field, and this fellowship has the potential to connect a rapidly expanding theoretical research area with ongoing efforts to improve the understanding and prediction of tropical variability. The focus on the Unified Model benefited weather and climate prediction in the UK by exchanging ideas with Met Office scientists who were directly involved in testing and improving the model.

ACID-PRUF was a three year NERC directed programme that investigated the complex interaction of aerosols and clouds. The overall aims of ACID-PRUF were to reduce the uncertainty in the radiative forcing associated with the aerosol indirect effects though a targeted laboratory and modelling programme. This dataset collection contains measurements of freezing fraction of water solution droplets-solute and suspended matter during the immersion freezing of pollen extracts (birch pollen, Betula fontinalis occidentalis, Sigma-Aldrich, P6895-1G), with a new cold electrodynamic balance (CEDB).

The Chilbolton Observatory, Hampshire, have had a Vaisala CT75K lidar ceilometer deployed since 13th September 1996. This dataset contains measurements of the range of first, second, and third cloud base from the lidar and attenuated backscatter coefficients of aerosols within the atmosphere. Plots of the attenuated backscatter coefficient at different heights are also available. The instrument has been regularly calibrated using the method described by O'Connor, Ewan J., Anthony J. Illingworth, Robin J. Hogan, 2004: A Technique for Auto-calibration of Cloud Lidar. J. Atmos. Oceanic Technol., 21, 777–786. doi: http://dx.doi.org/10.1175/1520-0426(2004)021<0777:ATFAOC>2.0.CO;2 . Prior to April 2014 this technique had been applied manually, but from 2014 this was automated to provide a routine, automated application of O'Connor et al's calibration technique. This also highlighted an instrument calibration drift not previously spotted in earlier data and so a corrected data have been added to the archive for the following periods (denoted by "_cor1" in the filename): 1st July 2003 – 31st December 2003, January 2006 to December 2012 and February and March 2013. Users should see the data quality notes for further details. This dataset incorporates the earlier published and citable 1996 - 2013 collection of lidar data, but continues this dataset to present

The Chilbolton Observatory, Hampshire, have had a Vaisala CT75K lidar ceilometer deployed since 13th September 1996. This dataset contains measurements of the range of first, second, and third cloud base from the lidar and attenuated backscatter coefficients of aerosols within the atmosphere from 1996 to 2013. Plots of the attenuated backscatter coefficient at different heights are also available. The instrument has been regularly calibrated using the method described by O'Connor, Ewan J., Anthony J. Illingworth, Robin J. Hogan, 2004: A Technique for Auto-calibration of Cloud Lidar. J. Atmos. Oceanic Technol., 21, 777–786. doi: http://dx.doi.org/10.1175/1520-0426(2004)021<0777:ATFAOC>2.0.CO;2 . Prior to April 2014 this technique had been applied manually, but from 2014 this was automated to provide a routine, automated application of O'Connor et al's calibration technique. This also highlighted an instrument calibration drift not previously spotted in earlier data and so a corrected data have been added to the archive for the following periods (denoted by "_cor1" in the filename): 1st July 2003 – 31st December 2003, January 2006 to December 2012 and February and March 2013. Users should see the data quality notes for further details. For post 2013 data please refer to the "all-years" dataset.

This dataset collection contains global profiles of aerosols and clouds, ozone, nitrogen dioxide and water vapour from the Stratospheric Aerosol and Gas Experiment III (SAGE III) instrument on board a Meteor-3M spacecraft, launched on December 10, 2001. Routine measurement operations began in March 2002 until the SAGE III mission was terminated in March 2006. The specific measurement objectives of SAGE III provided 1 km vertical resolution profiles of: aerosols and clouds at seven wavelengths from the mid-troposphere into the stratosphere and, where appropriate, the mesosphere; O3 from the mid-troposphere to 85 km; H2O from the planetary boundary layer to 50 km; NO2 from the tropopause to 45 km; NO3 from 20 to 55 km; OClO from 15 to 25 km; and, O2 from the mid-troposphere to 70 km.

This dataset contains scan data from the National Centre for Atmospheric Science's (NCAS) mobile X-band radar collected at the Davidstow Airfield, Cornwall, between June and August 2013 as part of the MICROphysicS of COnvective PrEcipitation (MICROSCOPE) project. This version 2 dataset contains improved metadata and uses a revised processing method to improve data accuracy. Users should also note the change in filenaming convention for this instrument whereby the volume number given after the date-time part is no longer provided. The X-band radar is operated as part of the NCAS Atmospheric Measurement Facility's (AMF).