Earth's Radiation to Space at 15 Microns: Stratospheric Temperature Variations

Abstract Nimbus III carried a Satellite Infra-Red Spectrometer (SIRS) with which the temperature structure of the atmosphere can be observed. The most opaque spectral interval on SIRS was centered at 669.3 cm−1 (∼15 μ). At this frequency only the stratosphere essentially contributes to the outgoing radiation. A description of the measured radiances at 669.3 cm−1 is also a description of a weighted mean stratospheric temperature for the upper 100 mb of air. With the aid of additional spectral intervals, however, the temperature structure in thinner layers of the stratosphere can also be investigated. Radiance measurements at 669.3 cm−1 are discussed in relation to several different stratospheric phenonmena. The phemomena discussed are: Moving and stationary “waves.” In May 1909, westward moving waves were discernible in the tropics. A stationary wavenumber 1 pattern was also seen. Wave motions were also shown at latitudes 60N and 60S. A stratospheric warming area was present in early May over the Indian Oc...