Hector A. Ochoa

UV measurements at Marambio and Ushuaia during 2000–2010

Kaisa Lakkala1,2, Alberto Redondas3, Outi Meinander1, Laura Thölix1, Britta Hamari1, Antonio Fernando Almansa3, Virgilio Carreno3, Guillermo Deferrari4,5, Hector Ochoa6, Germar Bernhard7, Ricardo Sanchez8, and Gerardus de Leeuw1 1Finnish Meteorological Institute, Climate Research, Helsinki, Finland 2Finnish Meteorological Institute, Arctic Research, Sodankylä, Finland 3Izaña Atmospheric Research Center, Agencia Estatal de Meteorología, Tenerife, Spain 4Centro Austral de Investigaciones Cientificas (CADIC/CONICET), Ushuaia, Argentina 5Universidad Nacional de Tierra del Fuefo, Ushuaia, Argentina 6Dirección Nacional del Antártico-Instituto Antártico Argentino, Buenos Aires, Argentina 7Biospherical Instruments, Inc., San Diego, U.S.A 8Servicio Meteorológico Nacional, Argentina Correspondence to: Kaisa Lakkala (kaisa.lakkala@fmi.fi)

Active remote sensing observations for cirrus clouds profiling at subtropical and polar latitudes

Cirrus clouds are product of weather processes, and hence their occurrence and macrophysical/optical properties can vary significantly over different regions of the world, deriving in different implications in climate-related issues. In this sense, a few case studies of cirrus clouds observed at both subtropical and polar latitudes are examined. Observations are carried out in three stations: Sao Paulo (Brazil, 23.6°S/46.8°W) and Sta. Cruz de Tenerife (Spain, 28.5°N/16.3°W), being both subtropical sites, and the Belgrano II base (Argentina, 78ºS/35ºW) in the Antarctic continent. Active remote sensing (LIDAR) is used for profiling measurements, and cirrus clouds features are retrieved by using a recently proposed methodology. Local radiosounding profiles are also used for cirrus-temperature correlation analysis. Optical and macrophysical properties (COD-cloud optical depth, top/base heights and Lidar Ratio, mainly) of both the subtropical and polar cirrus clouds are reported. This study is focused on the classification of the daily cloud features into three Cirrus COD-related categories: svCi-subvisual (COD < 0.06), stCi-semitransparent (0.06 < COD < 0.3), and opCiopaque (COD < 0.3) clouds. In general, subtropical Cirrus clouds present lower LR values and are found at higher altitudes than those detected at polar latitudes. In addition, a higher svCi presence is observed over the polar station along the day, since svCi clouds are formed at lower temperatures. However, results are specific for those particular cases analyzed in this preliminary work. Similarities and differences can be plausibly provided, as long as a larger dataset can be available to be analyzed in each station.