CLIWA-NET: Baltex cloud liquid water network

• Research unit: EU RFP
• Project number: 99.0216

Key words (English)

Climate; clouds; radiative forcing; microwave radiometry; remote sensing

Alternative project number (English)

EU project number: EVK2-1999-00007

Research programs (English)

EU-programme: 5. Frame Research Programme - 1.4a.2 Global change, climate and biodiversity

Short description (English)

See abstract

Partners and International Organizations (English)

Coordinator: Royal Netherlands Meteorological Inst., De Bilt (NL)

Abstract (English)

' The objective of the Cloud Liquid Water Network (CLIW ANet) project is to measure cloud properties with various types of instruments in an area of northern and central Europe. A major part of the project consists of ground based radiometric measurements, to which we are contributing with our Topopspheric Water-Vapour Radiometer (TROWARA), consisting of channels at 21.3 and 31.5 GHz for the detection of integrated tropospheric water vapour and integrated liquid water and of an infrared radiometer at 10 microns for cloud-base temperature measurements.
In April and May 200 1 the CNN II campaign took place. The goal of this campaign was to map clouds in the CLIW ANet area. For this purpose, the radiometers of the 12 participating groups measured at their own stations. The data were collected and preprocessed in near-real time and fed to a central data base for further analysis. Besides the TROW ARA data, we also delivered meteorological data and zenith wet delay data from our GPS station. The whole data set from all stations is available through the CLIW ANET homepage (http://www.knmi.nl/samenw/cliwa-net/).
In August and September 2001, the BBC campaign took place. In a first part, all radiometers were brought to Cabauw, NL, for an instrument intercomparison. In the second part, the radiometers were spread over the Netherlands in order to map clouds in this area. The results from the intercomparison campaign are very promising. At the frequency of 31.5GHz a direct comparison with two other instruments is possible, the consistency with TROW ARA for times without rain is usually better than +/- lK.

References in databases (English)

Swiss Database: Euro-DB of the
State Secretariat for Education and Research
Hallwylstrasse 4
CH-3003 Berne, Switzerland
Tel. [phone]
Swiss Project-Number: 99.0216