The Far-Infrared Spectroscopy of the Troposphere (FIRST) project

The radiative balance of the Earth is influenced strongly by radiative cooling associated with emission of radiation by water vapor at far-infrared (far-IR) wavelengths greater than 15 μm and extending out beyond 60 μm. the distribution of water vapor and cirrus cloud associated far-IR radiative forcings and feedbacks are well-recognized as major uncertainties in understanding and predicting future climate. Despite this fundamental importance, far-IR emission (spectra or band-integrated) has rarely been directly measured from space, airborne, or ground-based platforms. Current and planned operational and research satellites typically observe the mid-infrared only to about 15.4 μm. The Far-Infrared Spectroscopy of the Troposphere (FIRST) project is an investment by NASA through the Instrument Incubator Program (IIP) to develop a space-based capability to measure the infrared spectrum to 100 μm.