Ground based and airborne in-situ aerosol measurements during the APPRAISE-CLOUDS (Aerosol cloud interactions and climate) project from the Chilbolton Atmospheric Observatory, Hampshire (South West England) and on board the FAAM BAE-146 research aircraft. The data were collected for use in the CLOUDS project, which is one of multiple projects within the APPRAISE (Aerosol Properties, PRocesses And Influences on the Earth's climate) programme. Airborne measurements for the APPRAISE-CLOUDS project were also carried out using the FAAM BAe146 aircraft. In total 20 flights were carried out as part of this project with the aircraft operating from Cranfield, Exeter and Oberpffafenhofen, Germany. For the APPRAISE-CLOUDS project the aircraft was equipped with a range of cloud and aerosol instruments including FSSP (cloud droplets), CPI (ice particles), 2DS (ice particles), 2DC (ice particles), 2DP (ice particles), CAPS (droplets, ice, large aerosol), AMS (aerosol chemistry), SP2 (soot aerosol), PCASP (aerosol size), SMPS (aerosol size), Filters (aerosol chemistry), CVI (cloud particle residuals), Nephalometers (aerosol scattering), PSAP (soot aerosol), Whole Air Samplers (trace gases - post flight analysis), Trace gas analysers (NOx, O3, SO2). Missions typically involved flight legs above and below cloud to characterise aerosol in the vicinity of the clouds, and flight legs within cloud to characterise cloud properties and attempt to measure cloud particle residuals. In total 110 flight hours were allocated to this project. Flight No. Date Location B331 6/12/07 SW England B336 8/01/08 SW England B337 15/01/08 SW England B338 17/01/08 SW England B376 15/05/08 SW Germany B377 17/05/08 Switzerland B378 18/05/08 Switzerland B421 17/12/08 Cardigan Bay B422 15/01/09 SW England B423 20/01/09 Bristol Channel B424 21/01/09 SW England B425 22/01/09 SW England B426 28/01/09 SW England B430 18/02/09 SW England B431 26/02/09 SW England B432 27/02/09 Scotland B433 3/03/09 SW England B434 3/03/09 SW England B449 27/05/09 SW England B456 6/06/09 SW England

The MICROwave investigation of MIXed phase cloud (MICROMIX) project was a Facility for Airborne Atmospheric Measurements (FAAM) Campaign from late 2005, beginning of 2006, which aimed at testing and improving the representation of mixed phase clouds in radiative transfer models. The intention was to fly the FAAM BAE-146 aircraft in conjunction with the Chilbolton radar facility and ASMU overpasses in order to characterise the in-situ microphysics, spatial variability of the microphysics and the radiative properties respectively.

The Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) was a joint-mission between NASA and the French space agency Centre National d'Etudes Spatiales. The main objectives of the mission was to supply unique data set of vertical cloud and aerosol profiles. This dataset contains cloud and aerosol lidar level 2 1km cloud layer version 3-01 data product, which provides cloud data derived from Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) Level 1B product at 1 km horizontal resolution, with full complement of diagnostic and quality assurance parameters. The data provides range of parameters including vertical profile of cloud layers, optical depth. In Version 3-01, L2 products use enhanced daytime calibration, improved cloud-aerosol discrimination algorithm with removal of a bug in the cloud clearing code, and the newly introduced cloud thermodynamic phase assessment algorithm.

This dataset contains near-surface wind profile from four sonic anemometers distributed on the 15 m tower at Summit Station, Greenland, detected by Lufft VentusX, heated 2D sonic anemometer, and Metek uSonic-3 scientific, heated 3D sonic anemometer. Data are 1 minute averages concatenated into monthly files. These data were collected as part of the joint Natural Environmental Research Council (NERC) and US National Science Foundation (NSF) -funded Integrated Characterisation of Energy, Clouds, Atmospheric state, and Precipitation at Summit - Aerosol Cloud Experiment (ICECAPS-ACE) project. These data were continued through the 3 year extension to the ICECAPS-ACE project called ICECAPS-MELT.

This dataset contains point measurement of snow-air transition temperatures at 2 cm intervals on a 5 m thermistor chain installed spanning the snow-air transition at Summit Station, Greenland. Measurements were made using a Snow Ice Mass Balance Apparatus (SIMBA) with a bespoke 5 m chain. These data were collected as part of the joint Natural Environmental Research Council (NERC) and US National Science Foundation (NSF) -funded Integrated Characterisation of Energy, Clouds, Atmospheric state, and Precipitation at Summit - Aerosol Cloud Experiment (ICECAPS-ACE) project. These data were continued through the 3 year extension to the ICECAPS-ACE project called ICECAPS-MELT.

This dataset contains concentrations of condensation nuclei (> 5 nm diameter) measured at the surface at the Summit Station Greenland using a GRIMM 5.4 Condensation Particle Counter (CPC). Data are 1 minute averages concatenated into monthly files. These data were collected as part of the joint Natural Environmental Research Council (NERC) and US National Science Foundation (NSF) -funded Integrated Characterisation of Energy, Clouds, Atmospheric state, and Precipitation at Summit - Aerosol Cloud Experiment (ICECAPS-ACE) project.

This dataset contains the near-surface temperature profile from four temperature/ humidity sensors distributed on the 15 m tower at Summit Station, Greenland, detected by four Vaisala HMP155 Temperature/Relative Humidity sensors with a heated probe. Data are 1 minute averages concatenated into monthly files. These data were collected as part of the joint Natural Environmental Research Council (NERC) and US National Science Foundation (NSF) -funded Integrated Characterisation of Energy, Clouds, Atmospheric state, and Precipitation at Summit - Aerosol Cloud Experiment (ICECAPS-ACE) project. These data were continued through the 3 year extension to the ICECAPS-ACE project called ICECAPS-MELT.

The Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) was a joint-mission between NASA and the French space agency Centre National d'Etudes Spatiales. The main objectives of the mission was to supply unique data set of vertical cloud and aerosol profiles. This dataset contains cloud and aerosol lidar level 2 Aerosol Profile Version 3-02 data derived from Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) Level 1B product with uniform horizontal resolution of 5 km and ancillary data. There are no layer descriptors included in the datasets, and the spatial distribution of the aerosol layers depends on the aerosol layer fraction and atmospheric volume description parameters. The aerosol backscatter and extinction coefficients are obtained through the CALIPSO Lidar Ratio selection algorithm. Version 3-02 marks the transition to a new cluster computing system without any changes in the algorithm used in version 3-01. The resulting impact on the products are very minor.

This dataset contains the distance to the snow surface from the lowest level of instruments on the 15 m tower at Summit Station, Greenland, detected by a sonic-ranging sensor. Data are collected every 10 minutes and concatenated into monthly files. These data were collected as part of the joint Natural Environmental Research Council (NERC) and US National Science Foundation (NSF) -funded Integrated Characterisation of Energy, Clouds, Atmospheric state, and Precipitation at Summit - Aerosol Cloud Experiment (ICECAPS-ACE) project. These data were continued through the 3 year extension to the ICECAPS-ACE project called ICECAPS-MELT.

The European Arctic Stratospheric Ozone Experiment is a European Commission (EC) measurement campaign undertaken in the Northern Hemisphere winter of 1991-92 to study ozone chemistry and dynamics. This dataset contains ozone vertical column measurements.