Field Studies of Warmed Dewpoint Temperature Sensors

In climate observations the possible dew or ice formation makes accurate and reliable air humidity measurements difficult and it results in erroneous humidity measurements. To avoid this problem, a warmed dew point temperature sensor recently emerged and it has been deployed to replace the conventional chilled mirror dew point sensor in the ASOS network since 2002 and possibly the similar dew point temperature sensor will be deployed in the future climate networks (e.g., the U. S. CRN ). Therefore, this instrument change motivates us to conduct a field study for investigating the performance of this new solid-state dew point sensor by an inter comparison with retrospective conventional dew point temperature sensors. In this study, we examined our two-year field comparison observations and investigated the measurement theory, measurement differences relative to conventional dew point temperature sensors, and difference dependencies on the ambient microclimate.