This dataset collection contains data collected from the Microbiology-Ocean-Cloud Coupling in the High Arctic (MOCCHA) project. MOCCHA aimed to study aerosol processes, the contribution of marine microbiology to their formation and properties, and their impact on the life cycle of low-lewel clouds in the central Arctic as part of the Arctic Ocean 2018 (AO2018) expedition. AO2018 took place between 1 August and 21 September 2018, departing from and returning to Longyearbyen. The expedition was centered around a 4-week long intensive observation period, where e icebreaker Oden was moored to an ice flow and drifted passively with the ice.

The Convective Storm Initiation Project (CSIP) aimed to further the understanding of the mechanisms responsible for the initiation of precipitating convection in the maritime environment of southern England; i.e. to understand why convective clouds form and develop into precipitating clouds in a particular location. The project was centred on the 3 GHz (CAMRa) and 1275 clear-air (ACROBAT) radars at Chilbolton and used a number of the new UK Universities' Facility for Atmospheric Measurement (UFAM) mobile instruments. This dataset includes measurements of wind speeds and wind directions and aerosol concentrations.

The University of Salford photograph data are digital photographs taken approximately every 30 minutes at the Faccombe wind turbine site, Hampshire. The dataset contains photographs taken on four days between the 11th of August 2005 and 25th of August 2005. The latitude and longitude of the field site is N 51°19.51’ and W 1°26.46’ respectively. Photographs were taken approximately every 30 minutes and the pictures are orientated to a bearing of 310°.

The University of Aberystwyth mobile ozone lidar data contain measurements of ozone mixing ratios and aerosol information. The data were collected at Chilbolton observatory, Hampshire on the 7th and the 8th of June 2005. The data collected on the 7th of June 2005 are of ozone mixing ratios only. The data collected on the 8th of June 2005 are of ozone mixing ratios, aerosol backscatter, and boundary layer height information.

The Institute of Meteorology and Climate Research (IMK) Lidar Data are images displaying the polar wind velocity and the polar aerosol concentration. For elevation scans there are figures at azimuth 0, 60 and 120 degrees, for the azimuth scan there are figures at elevations 7, 12 and 17 degrees available. Angles are indicated in the line above the colourscale. Vertical scans have been made at elevation 90 degree. The upper figures are showing polar (radial) velocity, the lower ones aerosol backscatter at the three different angles which are indecated in each figure above the colour scale. The diagrams are showing unaveraged data. They vizualize a snapshot of approx. 10 minutes measurements starting at the time stated in the filename. Data were recorded from the 19th of June 2005 to the 29th of August 2005.

This dataset contains composite lidar wind profile data from the NCAS AMF Halo Doppler lidar mounted on a motion stabilised platform on board the Swedish Icebreaker Oden during the joint Arctic Climate Across Scales (ACAS) and Microbiology-Ocean-Cloud Coupling in the High Arctic (MOCCHA) projects - both part of the Arctic Ocean 2018 (AO2018) expedition to the High Arctic. AO2018 took place in the Arctic from 1 August until 21 September 2018. These measurements were used to complement a suite of other observations taken during the expedition. Those of the UK contribution, as well as selected other data, are available within the associated data collection in the Centre for Environmental Data Analysis (CEDA) archives. Other cruise data may be available in the Bolin Centre for Climate Research MOCCHA/AO2018 holdings. Wind profiles are derived from a motion stabilised HALO Photonics Doppler lidar using 6-beam Velocity-Azimuth-Display (VAD) scans at two fixed elevations, 30° and 75°. Data are available only where the backscatter signal to noise ratio is better than -16dB, lidar internal QC checks and quality criteria for the VAD algorithm are all passed. Each profile is derived from 6 2-second dwell beams. Wind profiles were measured every 15 minutes, with 2 consecutive scans at 30 and 75°, 30 sec apart. The consecutive scans were merged into one wind profile with a vertical resolution of 10 m using a normalised weighted mean function. Documentation & validation of the motion stabilisation and derived winds can be found in: Achtert P, Brooks IM, Brooks BJ, Moat BI, Prytherch J, Persson POG, Tjernström M (2015) Measurement of wind profiles by motion-stabilised ship-borne Doppler lidar, Atmospheric Measurement Techniques, 8, 4993-5007. doi: 10.5194/amt-8-4993-2015" ; The UK participation of MOCCHA was funded by the Natural Environment Research Council (NERC, grant: NE/R009686/1) and involved instrumentation from the Atmospheric Measurement Facility of the UK's National Centre for Atmospheric Science (NCAS AMF).

Data from observations made at the Cape Verde Atmospheric Observatory (CVAO) which exists to advance understanding of climatically significant interactions between the atmosphere and ocean and to provide a regional focal point and long-term data. The observatory is based on Calhau Island of São Vicente Cape Verde at 16.848N, 24.871W, in the tropical Eastern North Atlantic Ocean, a region which is data poor but plays a key role in atmosphere-ocean interactions of climate-related and biogeochemical parameters including greenhouse gases. It is an open-ocean site that is representative of a region likely to be sensitive to future climate change, and is minimally influenced by local effects and intermittent continental pollution. The dataset collection contains mixing ratio measurements of Ozone, CO, ethane, propane, iso-butane, acetylene, iso-pentane, and halocarbons. Meteorological measurements (wind speed, wind direction, atmospheric pressure, air temperature, relative humidity, solar radiation, rainfall) and aerosol concentrations are also contained in the data set. The Cape Verde Observatory was previously used during the SOLAS (Surface Ocean / Lower Atmosphere Study) project, from which the present day continuous observations have evolved. As such the earlier SOLAS measurements are also included within this collection. Additionally, back trajectory plots for the site are also within this collection.

The dataset contains the data collected by radiosondes, released by IMK, in both Bath and Chilbolton, during the period from the 19th of June 2005 to the 25th of August 2005. The datset contains measurements of: The dataset contains measurements of: Height above sea level (m) Time since midnight (s) Time since midnight (hh:mm:ss) Height above ground (m) Dry-bulb temperature (degree Celsius) Relative Humidity (percentage) Wind speed (m/s) Wind direction (degree true) Pressure (hPa) Potential Temperature (degree Kelvin) Dew-point temperature (degree Celsius) Specific humidity (g/kg) Saturation mixing ratio (g/kg) u-component of wind velocity (m/s) v-component of wind velocity (m/s)

The University of Salford radiometer data describe observations taken by microwave radiometer that was situated at the Faccombe wind turbine field site, Hampshire and collected data from 24th June 2005 until 26th August 2005. T The dataset contains measurements of the following parameters: Liquid Water Path (LWP) time series – 1 second measurement time Integrated Water Vapour (IWV) time series – 60 seconds measurement time Humidity Profile (full troposphere) (HPC) – 60 seconds measurement time Temperature Profile (full troposphere) (TPC) – 60 seconds measurement time Temperature Profile (boundary layer) (TPB) – 200 s measurement time A boundary layer temperature profile was taken every 10 minutes which took 200 seconds to complete. When not operating a boundary layer scan, the radiometer operated in zenith mode and measurements of LWP, IWV and the tropospheric temperature and humidity profiles were made. Calibrations were performed every 20 minutes, 6 hours and 24 hours. The boundary layer temperature measurements (0 – 2000 m) have a vertical resolution of 50 m. The tropospheric temperature measurements (0 – 10000 m) have a vertical resolution of 200 m. The tropospheric humidity profiles (0 – 6000 m) have a vertical resolution of 200 m (0 – 2000 m) and 400 m (2000 – 6000 m). Two jpeg images files have been produced from the radiometer data for each day from 24th June 2005 until 26th August 2005. The first image file contains separate profiles of temperature up to 2 km and 10 km and profiles of absolute and relative humidity up to 10 km. The second image file contains a time series of the integrated water vapour and liquid water path.

The composition of the air present over the Weybourne Atmospheric Observatory (WAO), situated on the north Norfolk coast, depends on its origins. Plots showing the footprints of 10 day back trajectories arriving at WAO have been calculated using the UK Met Office's NAME Lagrangian atmospheric dispersion model.