The research aircraft DO-128, call sign D-IBUF, of the IFF (TU Braunschweig) measures numerous meteorological and chemical variables to get a better understanding of the atmospheric processes which cause the development of precipitation. The aircraft starts from the Baden Airpark and flys among different flight pattern which are described in the flight protocols. The meteorological variables are static pressure and dynamic pressure at the nose boom, surface temperature, humidity mixing ratio by a lyman-alpha sensor, dewpoint temperature by a dewpoint-mirror, relative humidity by an aerodata-humicap, air temperature by a PT-100 sensor, vertical and horizontal wind components by a five-hole probe and GPS, turbulence (100 Hz), shortwave (pyranometer) and longwave (pyrgeometer) radiance in upper und lower half space. The chemical variables are mole fractions of ozone, carbon dioxide, carbon monoxide, nitrogen dioxide, nitrogen monoxide and nitric oxides (NOx). There are also a few variables for the position and the velocity of the aircraft stored in the data file. Additionally to the measurements by the aircraft, up to 30 drop-sondes can be dropped out of the aircraft. By using these sondes, vertical profiles of temperature, pressure, humidity and wind can be detected (see also the meta data describing the drop-sonde data). Special events are also marked in the data files by the event counter (e.g. dropping times of the drop-sondes, marks concerning the flight patterns etc.). The specific action or flight manoeuvre indicated by the event_number can be identified in the flight protocol.

The two instuments were: Scintec Sodar (MFAS) at Igelsberg, located near a waste disposal site. The device measures wind vectors every ten minutes. Metek RASS-Sodar in Bad-Rotenfels, located near a sewage treatment plant. The vertical wind component in the netCDF-files has been set to dummy values due to quality check failure for this variable.

The energy balance stations run by University of Bayreuth continuously measured radiation and soil parameters over different land types with a sampling frequency of 1 Hz averaged to 1 min values within the data logger. After a check for plausibility the 1 min values have been averaged to 30 min intervals, which are provided in this data set. The instrumentation was different on each location. The following was measured depending on the station: - soil heat flux - soil temperature - volumetric soil water content - longwave radiation components - shortwave radiation components - tipping bucket rain gauge measurements The ground heat flux including the heat storage in the upper soil layer was determined from the measured soil heat flux, soil temperatures and volumetric soil water contents according to the 'simple measurement' (SM) method according to Liebethal and Foken (2007).

EARLINET climatological lidar observations are performed on a regular schedule of one daytime measurement per week around noon (on Monday), when the boundary layer is usually well developed, and two night-time measurements per week (on Monday and Thursday), with low background light, in order to perform Raman extinction measurements. This regular schedule for observations minimizes the bias in the dataset possibly related to specific measurement conditions. The resulting dataset is used to obtain unbiased data for climatological studies. This dataset contains profiles of aerosol extinction, backscatter and lidar ratio. Several aerosol extinction/backscatter datasets can be present for the same climatological measurement in order to provide profiles either with a better temporal resolution or with an extended height range by using a larger temporal average. This is by far the largest dataset on the aerosol vertical distribution, and it is the only one which is collected systematically and is covering a whole continent.

Several meteorological parameteres were measured at different stations run by FZK/IMK-TRO. Depending on the individual site i.e. wind direction, wind speed, global radiation, reflected irradiance, atmospheric longwave radiation, terrestric longwave radiation, surface temperature, precipitation, air pressure, soil heat flux, relative humidity. The respective set of parameters is described in the meta data of each station.

Surface layer scintillometer data derived from a Optical Energy Balance Measurement System OEBMS1 with a Scintillometer SLS20 system by Scintec AG at station UV1EG (Deckenpfronn). The system operated at a measurement height of 1.75 m and with a path length of 117 m over the target land use type meadow.

The geographical distribution of the EARLINET stations is particularlysuitable for dust observation, with stations located all around the Mediterranean(from the Iberian Peninsula in the West to the Greece and Bulgaria and Romania in the East) and in the center of the Mediterranean (Italian stations) where dust intrusions are frequent, and with several stations in the central Europe where dust penetrates occasionally. A suitable observing methodology has been established within the network, based on Saharan dust alerts distributed to all EARLINET stations. The dust alert is based on the operational outputs (aerosol dust load) of the SDS-WAS (Sand and Dust Storm- Warning and Advisory System of WMO), and the Skiron models. The alerts are diffused 24 to 36 hours prior to the arrival of dust aerosols over the EARLINET sites. Runs of measurements longer than 3-hour observations, typical for the EARLINET climatological measurements are performed at the EARLINET stations in order to investigate the temporal evolution of the dust events. All aerosol backscatter and extinction profiles related to observations of Saharan dust layers are collected in the "Saharan dust" category of the EARLINET database.

The field experiments ALKOR 2000 (consisting of three cruises: ALKOR 4/2000, 6/2000, 10/2000) and ALKOR 2001 (4/2001, 6/2001, 10/2001) took place in the central Baltic Sea. The six cruises of the German Research Vessel Alkor with duration of about seven days each led to a point of the Baltic Sea which is most remote from the adjacent lands and additionally a grid point of regional climate model REMO. The ALKOR experiments as well as BASIS 1998 and BASIS 2001 are part of the research compound BALTIMOS (BALTic sea Integrated MOdel System). BALTIMOS in turn is part of the Baltic Sea Experiment (BALTEX). The overall objective of all eight field experiments (ALKOR and BASIS) was to collect a comprehensive data set suited to validate the coupled model system BALTIMOS for the Baltic Sea region. The observations mainly focus on: - the atmospheric boundary layer structure and processes and the air-sea-ice interaction over areas with inhomogeneous sea ice cover - the atmospheric boundary layer structure over open water under different synoptic conditions such as cold-air advection, warm-air advection or frontal passages. In addition to the published datasets several other measurements were performed during the experiment. Corresonding datasets will be published in the near future and are available on request. Details about all used platforms and sensors and all performed measurements are listed in the fieldreport. The following datasets are available on request: ground data at RV Alkor

The Soundings were usually performed during the daytime of IOPs at two fixed locations. Scheduled launching times were at 05, 08, 11, 14, 17 and 20 UTC. Radiosounding at Burnhaupt le Bas, France: Sondes of the type DFM-06 manufactured by the Company GRAW (http://graw.de) have been used. Radiosounding at FZK, Karlsruhe, Germany Sondes of the type DFM-97 manufactured by GRAW (http://graw.de) have been used. From 26 July at 5:02 DFM-06 sondes of the same company have been used. On 25 July at 11:08 there was a test run of a DFM-06 sonde.

Reflectivity and radial velocity of Karlsruhe C-Band Doppler Radar located at Forschungszentrum Karlsruhe. Volume data in polar coordinates are delivered. Two scans have been performed: 1. 14 Elevation volume scan of reflectivity and radial velocity starting at 0.4 deg elevation up to 30 deg elevation, 120 km range, 500 m resolution, dual PRF (pulse repetition frequency; 1153 Hz/864 Hz): reflectivity and radial velocity. 2. 14 Elevation volume scan as 1, but only single PRF: reflectivity. The data is provided in two different data sets: reflectivity (ca. every 5 min; data from both scan modi) and radial_velocity (every 10 min; data from 1st scan mode).