Submillimeter Atmospheric Transparency at Maunakea, at the South Pole, and at Chajnantor

TL;DR

This study compares submillimeter atmospheric transparency at Maunakea, the South Pole, and Cerro Chajnantantor using identical tipping radiometers, revealing superior conditions at the South Pole and Cerro Chajnantor summit.

Contribution

It provides a direct, systematic comparison of atmospheric transparency at key astronomical sites using identical instruments, highlighting site differences.

Findings

South Pole and Chajnantor area have better atmospheric conditions than Maunakea.

Cerro Chajnantor summit has significantly better transparency than the plateau.

Identical instruments enable direct site comparison.

Abstract

For a systematic assessment of submillimeter observing conditions at different sites, we constructed tipping radiometers to measure the broad band atmospheric transparency in the window around 350 $\mu$m wavelength. The tippers were deployed on Maunakea, Hawaii, at the South Pole, and in the vicinity of Cerro Chajnantor in northern Chile. Identical instruments permit direct comparison of these sites. Observing conditions at the South Pole and in the Chajnantor area are better than on Maunakea. Simultaneous measurements with two tippers demonstrate conditions at the summit of Cerro Chajnantor are significantly better than on the Chajnantor plateau.