A new millimeter wave radiometer installed in the NDACC site of Río Gallegos, Argentina

MIZUNO, A, J. SALVADOR, P. F. ORTE, E. WOLFRAM, R. DELIA, T. NAGAHAMA, Y. KOJIMA, R. TANADA, T. KUWAHARA, A. MORIHIRA, E. QUEL, H. NAKANE

St. Denis, La Reunión-Francia

Simposio; Symposium Network for the Detection Atmospheric Composition Change; 2011

With the aim of contribution to the study of atmospheric ozone layer, a new sensitive radiometer for atmospheric minor constituents has been installed in the Observatorio Atmosférico de la Patagonia Austral, División LIDAR, CEILAP (CITEDEF-CONICET), in October 2010. This observatory is established in the city of Río Gallegos (51º 36’ S, 69º 19’ W) Argentina, close to the spring ozone hole. The millimeter wave radiometer was developed in STEL (Solar Terrestrial Environment Laboratory), Nagoya University, Japan. This passive remote sensing instrument is able to measure the ozone (O3) amount in the high stratosphere and mesosphere continuously and automatically with a high time resolution each thirty minutes. The millimeter wave radiometer ozone profiles will be supplemented with the ozone profiles obtained from the DIAL system existent in the observatory as part NDACC. The millimeter wave radiometer is based on the spectral signal detection from the atmosphere due to the molecular rotational transition of molecules under study. The operation is based on a superheterodyne system which uses a Superconductor-Insulator-Superconductor (SIS) mixer receiver operating at 203.6GHz. The SIS mixer junction consists of a sandwich structure of Nb/AlOx/Nb, and is cooled to 4.2K with a closed cycle He-gas refrigerator. Two additional heterodyne-mixed stages are realized with the aim to shift the measured spectral line until a frequency around of 500 MHz. A FFT (Fast Fourier Transform) spectrometer system is used as a back end. The aims of this work are to show the potential of the millimeter wave radiometer installed in the subpolar latitudes close to the polar ozone hole and to present the preliminary result of the first measurements.