Abstract
The first results of a campaign of intensive observation of
precipitation in Dumont d'Urville, Antarctica, are presented. Several
instruments collected data from November 2015 to February 2016 or longer,
including a polarimetric radar (MXPol), a Micro Rain Radar (MRR), a weighing
gauge (Pluvio2), and a Multi-Angle Snowflake Camera (MASC). These
instruments collected the first ground-based measurements of precipitation in
the region of Adélie Land (Terre Adélie), including precipitation
microphysics. Microphysical observations during the austral summer 2015/2016
showed that, close to the ground level, aggregates are the dominant
hydrometeor type, together with small ice particles (mostly originating from
blowing snow), and that riming is a recurring process. Eleven percent of the measured
particles were fully developed graupel, and aggregates had a mean riming
degree of about 30 %. Spurious precipitation in the Pluvio2 measurements
in windy conditions, leading to phantom accumulations, is observed and partly
removed through synergistic use of MRR data. The yearly accumulated
precipitation of snow (300 m above ground), obtained by means of a
local conversion relation of MRR data, trained on the Pluvio2 measurement
of the summer period, is estimated to be 815 mm of water equivalent,
with a confidence interval ranging between 739.5 and 989 mm. Data obtained in
previous research from satellite-borne radars, and the ERA-Interim reanalysis
of the European Centre for Medium-Range Weather Forecasts (ECMWF)
provide lower yearly totals: 655 mm for ERA-Interim and 679 mm for the
climatological data over DDU. ERA-Interim overestimates the occurrence of
low-intensity precipitation events especially in summer, but it compensates
for them by underestimating the snowfall amounts carried by the most intense events.
Overall, this paper provides insightful examples of the added values of
precipitation monitoring in Antarctica with a synergistic use of in situ and
remote sensing measurements.
Citation
ID:
182667
Ref Key:
grazioli2017themeasurements