TY - JOUR
T1 - The behavior of the Snow White chilled-mirror hygrometer in extremely dry conditions
AU - Vömel, Holger
AU - Fujiwara, M.
AU - Shiotani, M.
AU - Hasebe, F.
AU - Oltmans, S. J.
AU - Barnes, J. E.
PY - 2003/11
Y1 - 2003/11
N2 - The Snow White hygrometer, made by Meteolabor AG, Switzerland, is a new chilled-mirror instrument using a thermoelectric Peltier cooler to measure atmospheric water vapor. Its performance under dry conditions is evaluated in simultaneous measurements using the NOAA/CMDL frost-point hygrometer at Boulder, Colorado; San Cristóbal, Galápagos Islands, Ecuador; Watukosek, Indonesia; and Mauna Loa Observatory, Hawaii. The Snow White exhibits a lower detection limit of about 3%-6% relative humidity, depending on the sensor configuration. This detection limit is determined by the temperature depression attainable by the thermoelectric cooler. In some cases, loss of frost-point control within layers with relative humidity below this detection limit caused inaccurate measurements above these dry layers, where the relative humidity was within the detection range of the instrument. The sensor does not operate in the stratosphere because of the large frost-point depression and the large potential for outgassing of water from the instrument box and the sensor housing. The instrument has some capabilities in the tropical tropopause region; however, the results are somewhat mixed.
AB - The Snow White hygrometer, made by Meteolabor AG, Switzerland, is a new chilled-mirror instrument using a thermoelectric Peltier cooler to measure atmospheric water vapor. Its performance under dry conditions is evaluated in simultaneous measurements using the NOAA/CMDL frost-point hygrometer at Boulder, Colorado; San Cristóbal, Galápagos Islands, Ecuador; Watukosek, Indonesia; and Mauna Loa Observatory, Hawaii. The Snow White exhibits a lower detection limit of about 3%-6% relative humidity, depending on the sensor configuration. This detection limit is determined by the temperature depression attainable by the thermoelectric cooler. In some cases, loss of frost-point control within layers with relative humidity below this detection limit caused inaccurate measurements above these dry layers, where the relative humidity was within the detection range of the instrument. The sensor does not operate in the stratosphere because of the large frost-point depression and the large potential for outgassing of water from the instrument box and the sensor housing. The instrument has some capabilities in the tropical tropopause region; however, the results are somewhat mixed.
UR - https://www.scopus.com/pages/publications/0344182682
U2 - 10.1175/1520-0426(2003)020<1560:TBOTSW>2.0.CO;2
DO - 10.1175/1520-0426(2003)020<1560:TBOTSW>2.0.CO;2
M3 - Article
AN - SCOPUS:0344182682
SN - 0739-0572
VL - 20
SP - 1560
EP - 1567
JO - Journal of Atmospheric and Oceanic Technology
JF - Journal of Atmospheric and Oceanic Technology
IS - 11
ER -