Preliminary results from an Instrumental Network for solid precipitation retrieval at the coastal site of Terra Nova bay, Antarctica

Knowledge of the spatial and temporal variability of snowfall in Antarctica and its impact on the Antarctic Ice sheet mass balance is essential to define the contribution of Ice sheet on sea level rise. States of art model projections assess an increase in snowfalls in the next century, but large uncertainties in current estimates prevent to provide a reliable long term forecast. Moreover, in situ continuous observations of precipitation are rare and sparse over Antarctica due to experimental difficulties and harsh climatic conditions. In order to increase the knowledge of snowfall impact over surface mass balance, a project using a multidisciplinary methodology has been carried out over the Antarctic coastal area of Terra Nova Bay during the 2015-2016 and 2016-2017 summer Italian Antarctic campaigns. Several snowfall events during Antarctic summer months were observed at the Mario Zucchelli station (MZS, 74°41?42? S, 164°07?23? E) using a comprehensive set of instruments including: two small radar sensors, an infrared thermometer, a net radiometer, Meteorological observations from preexisting Automatic Weather station, a celiometer, a laser pluviometer, a sky image camera, radiosonde profiles (both provided by Meteo-Climatological Observatory). Other instrumentations over the area such as snow height measurements, AWSs and stake farms provide information on the snow accumulation over the region. During the 2015-2016 summer season events were concentrated between the end of December and first days of January, while during 2016-2017 snowfalls arise along the whole season. Each event lasted on average from about 12 to 48 hours and was related mainly to large low pressure off shore Ross Sea, which established a local instability and/or cyclonic circulation over TNB area. First estimation of total precipitation for the period ranges between 40 and 60 mm water equivalent depending on instrumentation and parametrization used. Collected data in specific examples are discussed and compared with model data.