Probing the atmospheric precipitable water vapor with SOFIA, Part I, Measurements of the water vapor overburden with FIFI-LS

TL;DR

This paper presents a systematic analysis of telluric water vapor overburden using FIFI-LS on SOFIA, based on 469 in situ measurements across various locations, altitudes, and seasons since 2018.

Contribution

It introduces the first systematic in situ measurement analysis of atmospheric water vapor overburden using SOFIA's FIFI-LS instrument.

Findings

Identified trends in water vapor overburden with respect to flight parameters.

Provided detailed measurement principles and calibration methods.

Analyzed seasonal and altitude variations in water vapor levels.

Abstract

We report on the measurements of telluric water vapor made with the instrument FIFI-LS on SOFIA. Since November 2018, FIFI-LS has measured the water vapor overburden with the same measurement setup on each science flight with about 10 data points throughout the flight. This created a large sample of 469 measurements at different locations, flight altitudes and seasons. The paper describes the measurement principle in detail and provides some trend analysis on the 3 parameters. This presents the first systematic analysis with SOFIA based on in situ observations.