ATMOSPHERIC TRANSMISSION AT SUBMILLIMETER WAVELENGTHS FROM MAUNA-KEA

Measurements of the submillimetre solar spectrum through the 350- and 450-mu-m windows of the atmosphere using a Michelson interferometer on the James Clerk Maxwell Telescope have been used to determine the transmission spectrum of the atmosphere above Mauna Kea, Hawaii. This spectrum is shown to be in close agreement with that generated by the FASCOD synthesis program using the HITRAN database. The majority of absorption features can be attributed to H2O (which dominates the overall window shape), O2 and O3, although several significant but so far unassigned absorption features are noted. These results demonstrate the feasibility, under drier and more stable atmospheric conditions, of obtaining broad-band, intermediate resolution spectra from the JCMT with a Fourier spectrometer.