Ensuring the continuity of long-term, high-quality UTLS water vapor measurement records with NOAA frost point hygrometers the proposed work will ensure that long-term, high-quality vertical profile…

The Regents of the University of Colorado, through its Office of Contracts and Grants Division, was awarded a $519,733.58 grant from the National Aeronautics and Space Administration (NASA) to ensure the continuity of long-term, high-quality measurements of upper troposphere and lower stratosphere (UTLS) water vapor using NOAA's balloon-borne frost point hygrometers (FPHs). This grant supports the existing FPH sounding programs at three critical monitoring sites: Boulder, Colorado; Hilo, Hawaii; and Lauder, New Zealand. The in-situ FPH measurements help detect and correct biases in NASA's space-borne UTLS water vapor instruments, fill potential data gaps, and contribute to international observational networks focused on atmospheric composition and climate change monitoring. The award does not mention a set-aside designation. As a public research university, the University of Colorado has extensive experience conducting fundamental scientific research and technology development for federal agencies like NASA across disciplines including space physics, climate science, and STEM education.

Ensuring the continuity of long-term, high-quality UTLS water vapor measurement records with NOAA frost point hygrometers the proposed work will ensure that long-term, high-quality vertical profile measurements of water vapor in the upper troposphere and lower stratosphere (UTLS) by balloon-borne NOAA frost point hygrometers (FPHS) will continue at three monitoring sites: boulder, colorado (40 N), hilo, hawaii (20 N) and lauder, new zealand (45 S). The NOAA FPH record over boulder, colorado, is the longest observational data set in existence for UTLS water vapor (36.2 YR). Similar but shorter FPH sounding programs at lauder, new zealand (12.8 YR) and hilo, hawaii (5.5 YR) provide critically important records of UTLS water vapor mixing ratios in the southern middle latitudes and northern tropics, respectively. The FPH measurement programs are in jeopardy because financial support from NOAA S climate program office has continued to decrease. Supporting funds will help to continue and improve the existing FPH sounding programs that are beneficial to NASA S space-borne UTLS water vapor measurements in several ways. First, the in situ measurements create a basis for detecting and correcting any biases and/or drifts in satellite instruments like the aura microwave limb sounder (MLS) and the soon-to-be-deployed stratospheric aerosol and gas experiment (SAGE-III) on the international space station (ISS). Trends in upper atmospheric water vapor are often small and therefore difficult to detect without the excellent long-term accuracy of FPH measurements. Second, monthly FPH soundings would also help to fill any temporal GAP that may occur in the availability of UTLS water vapor measurements by space-born sensors. Third, the FPH soundings at boulder, hilo and lauder are now vital to two international observational networks focused on the detection of trends in atmospheric species and essential climate variables: the network for the detection of atmospheric composition change (NDACC) and the global climate observing system (GCOS) reference upper air network (GRUAN). Site operations for both networks are self-funded, hence there is a fundamental need for a number of core sites with sustainable monitoring programs, such as boulder, hilo and lauder.