Description: Das Projekt "Metrology for pressure, temperature, humidity and airspeed in the atmosphere: Upper air measurements: sensors and techniques" wird vom Umweltbundesamt gefördert und von Physikalisch-Technische Bundesanstalt durchgeführt. Water vapour is the most important greenhouse gas in the earths atmosphere and a key component for physical and chemical atmospheric effects. Measurement of atmospheric humidity (in terms of volume concentration of water, or relative humidity) is absolutely essential to understand atmospheric radiation transport, atmospheric chemistry, cloud formation or precipitation and thus also for advanced climate models needed to simulate climate change effects. One of the big challenges of water vapour measurements is the wide dynamic range of the water content in the atmosphere covering nearly five orders of magnitude. While under standard ambient conditions (20 C, 1013 hPa) the average volume fraction of water in temperate climate zones is in the range of 1 to 2 percent and about 5 percent in the tropic regions, in higher elevations humidity decreases as temperature decreases and reaches its minimum (of only a few ppm) near the tropopause in a heights between 8 and 15 km depending in latitude. This wide dynamic range with a factor of more than 10 000 is a real challenge for humidity sensors of any type. Numerous humidity sensors have been developed for atmospheric measurements on platforms from ground to airborne like planes or balloons, as well as various more or less home made protocols for their calibration. However, the very few intercomparisons for field instruments to validate their performance revealed significant uncertainties of 10Prozent and beyond even in between the best, well established instruments and a severe lack of consistent calibration protocols not to mention traceability to national humidity standards. In order to provide consistent atmospheric humidity data especially in field situations improved calibration instruments and protocols (preferably traceable to national standards) need to be developed and established in the community and a new generation of traceable field humidity sensors is needed.
Types:
SupportProgram
Origin: /Bund/UBA/UFORDAT
Tags: Wolkenbildung ? Luftdruck ? Lack ? Aerologie ? Messgerät ? Meteorologie ? Geografische Koordinaten ? Kalibrierung ? Absorptionsspektralanalyse ? Sensor ? Strahlenwirkung ? Wasserdampf ? Wassertemperatur ? Anfechtung ? Lufttemperatur ? Messtechnik ? Flugzeug ? Strahlungsmessung ? Temperaturmessung ? Wasserreinigung ? Feuchtigkeitsmessung ? Volumenmessung ? Chemikalien ? Daten ? Tropengebiet ? Tropopause ? Wasseraufbereitung ? Wassergehalt ? Klimamodell ? Analyseverfahren ? Luftfeuchtigkeit ? Wasser ? Gemäßigte Zone ? Effektkonzentration ? Klimafolgen ? Atmosphäre ? Niederschlag ? Volumenreduktion ? Atmosphärenchemie ? Treibhausgas ? Laseranwendung ? Selektivität ? Tunable-Diode-Laser-Absorption-Spectrometer (TDLAS) ? Nachweisbarkeit ? Hygrometer ?
Region: Lower Saxony
Bounding box: 9.16667° .. 9.16667° x 52.83333° .. 52.83333°
License: cc-by-nc-nd/4.0
Language: Deutsch
Time ranges: 2011-10-01 - 2014-09-30
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