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

Cirrusclouds 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 cirrusclouds observed at both subtropicaland 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 subtropicalsites, and the Belgrano II base (Argentina, 78oS/35oW) in the Antarctic continent. Active remote sensing (LIDAR) is used for profiling measurements, and cirrusclouds 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 subtropicaland polar cirrusclouds are reported. This study is focused on the classification of the daily cloud features into three CirrusCOD-related categories: svCi-subvisual (COD < 0.06), stCi-semitransparent (0.06 < COD < 0.3), and opCiopaque (COD < 0.3) clouds. In general, subtropical Cirrusclouds 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.