ARM tropospheric and stratospheric water vapor profiling with the cryogenic frost point hygrometer in support of GRUAN
Authors
Martin Stuefer — University of Alaska, Fairbanks
Douglas L Sisterson — Argonne National Laboratory
Donna Holdridge — Argonne National Laboratory
Jenni Kyrouac — Argonne National Laboratory
Chris Martin — Southern Great Plains
James Edward Martin — U.S. Department of Energy/ARM Program
David Kent Breedlove — Southern Great Plains
Matthew Dalton Gibson — U.S. Department of Energy/ARM Program
Mark Benjamin Smith — Southern Great Plains
John R Schatz — ARM Climate Research Facility
Nicki Hickmon — Argonne National Laboratory
Category
General topics – Clouds
Description
Cryogenic Frost Point Hygrometer (CFH) launches are performed at the ARM Southern Great Planes Central Facility since September 2014. Operational monthly CFH water vapor profiles are derived as a joint effort between the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility and the National Oceanic and Atmospheric Administration (NOAA)/National Centers for Environmental Information’s Center for Weather and Climate. DOE ARM provides the mentorship and effort, while NOAA is providing the reference CFH sondes and related materials. The CFH is a balloon borne instrument capable to accurately measure water vapor at elevations from the earth’s surface to the middle stratosphere. The instrument is highly sensitive with measurement uncertainties of less than 10% throughout its entire altitude range of operations. CFH launches are cost effective compared to airborne measurements while having an altitude range similar to standard radiosondes.
The ARM CFH launch and data processing protocols that have been adopted are in support of the Global Climate Observing System (GCOS) Reference Upper Air Network (GRUAN). GRUAN is an international reference-observing network, designed to meet climate requirements and to fill a major void in the current global observing system. Upper air observations within the GRUAN network will provide long-term high-quality climate records, will be used to constrain and validate data from space based remote sensors, and will provide accurate data for the study of atmospheric processes.
Herein we describe the CFH instrument characteristics and our experiences with the CFH launches, and show performance characteristics derived from the monthly observations at SGP. Vaisala RS-92 radiosondes have been routinely included in the CFH launch package enabling us to compare the CFH and RS-92 water vapor profiles. The CFH-radiosonde data comparison and a humidity bias analysis will be presented at the 2016 ARM/ASR Meeting.
