Far-infrared spectroscopy of the troposphere: calibration with a cold background.

The far-infrared spectroscopy of the troposphere (FIRST) instrument is a Fourier-transform spectrometer developed to measure the Earth's thermal emission spectrum with a particular emphasis on the far-infrared. FIRST has observed the atmosphere from both the ground looking up and from a high-altitude balloon looking down. A recent absolute laboratory calibration of FIRST under ground-like operating conditions showed accuracy to better than 0.

Far-infrared spectroscopy of the troposphere: instrument description and calibration performance.

The far-infrared spectroscopy of the troposphere (FIRST) instrument is a Fourier transform spectrometer developed to measure the Earth's thermal emission spectrum with a particular emphasis on far-infrared (far-IR) wavelengths greater than 15 μm. FIRST was developed under NASA's Instrument Incubator Program to demonstrate technology for providing measurements from 10 to 100 μm (1000 to 100 cm(-1)) on a single focal plane with a spectral resolution finer than 1 cm(-1). Presently no spectrometers in orbit are capable of directly observing the Earth's far-IR spectrum.

Atmospheric hydroxyl radical (OH) abundances from ground-based ultraviolet solar spectra: an improved retrieval method.

The Fourier Transform Ultraviolet Spectrometer (FTUVS) instrument has recorded a long-term data record of the atmospheric column abundance of the hydroxyl radical (OH) using the technique of high resolution solar absorption spectroscopy. We report new efforts in improving the precision of the OH measurements in order to better model the diurnal, seasonal, and interannual variability of odd hydrogen (HO(x)) chemistry in the stratosphere, which, in turn, will improve our understanding of ozone chemistry and its long-term changes. Until the present, the retrieval method has used a single strong OH absorption line P(1)(1) in the near-ultraviolet at 32,341 cm(-1).