scholarly journals Blowing snow detection from ground-based ceilometers: application to East Antarctica

2017 ◽  
Vol 11 (6) ◽  
pp. 2755-2772 ◽  
Author(s):  
Alexandra Gossart ◽  
Niels Souverijns ◽  
Irina V. Gorodetskaya ◽  
Stef Lhermitte ◽  
Jan T. M. Lenaerts ◽  
...  
Keyword(s):  
Wind Speed ◽  
Numerical Models ◽  
East Antarctica ◽  
Added Value ◽  
Polar Regions ◽  
Blowing Snow ◽  
Surface Mass ◽  
Direct Observations ◽  
Synoptic Conditions ◽  
Fresh Snow

Abstract. Blowing snow impacts Antarctic ice sheet surface mass balance by snow redistribution and sublimation. However, numerical models poorly represent blowing snow processes, while direct observations are limited in space and time. Satellite retrieval of blowing snow is hindered by clouds and only the strongest events are considered. Here, we develop a blowing snow detection (BSD) algorithm for ground-based remote-sensing ceilometers in polar regions and apply it to ceilometers at Neumayer III and Princess Elisabeth (PE) stations, East Antarctica. The algorithm is able to detect (heavy) blowing snow layers reaching 30 m height. Results show that 78 % of the detected events are in agreement with visual observations at Neumayer III station. The BSD algorithm detects heavy blowing snow 36 % of the time at Neumayer (2011–2015) and 13 % at PE station (2010–2016). Blowing snow occurrence peaks during the austral winter and shows around 5 % interannual variability. The BSD algorithm is capable of detecting blowing snow both lifted from the ground and occurring during precipitation, which is an added value since results indicate that 92 % of the blowing snow is during synoptic events, often combined with precipitation. Analysis of atmospheric meteorological variables shows that blowing snow occurrence strongly depends on fresh snow availability in addition to wind speed. This finding challenges the commonly used parametrizations, where the threshold for snow particles to be lifted is a function of wind speed only. Blowing snow occurs predominantly during storms and overcast conditions, shortly after precipitation events, and can reach up to 1300 m a. g. l.  in the case of heavy mixed events (precipitation and blowing snow together). These results suggest that synoptic conditions play an important role in generating blowing snow events and that fresh snow availability should be considered in determining the blowing snow onset.

scholarly journals Blowing snow detection from ground-based ceilometers: application to East Antarctica

2017 ◽  
Author(s):  
Alexandra Gossart ◽  
Niels Souverijns ◽  
Irina Valerievna Gorodetskaya ◽  
Stef Lhermitte ◽  
Jan Thérèse Maria Lenaerts ◽  
...  
Keyword(s):  
Wind Speed ◽  
Numerical Models ◽  
Detection Algorithm ◽  
Added Value ◽  
Polar Regions ◽  
Blowing Snow ◽  
Surface Mass ◽  
Satellite Retrieval ◽  
Direct Observations ◽  
Fresh Snow

Abstract. Blowing snow impacts Antarctic ice sheet surface mass balance by snow redistribution and sublimation. Yet, numerical models poorly represent blowing snow processes, while direct observations are limited in space and time. Satellite retrieval of blowing snow are hindered by clouds and only consider the strongest events. Here, we develop a blowing snow detection algorithm for ground-based remote sensing ceilometers in polar regions. Results show that 79 % of the detected events are in agreement with visual observations. The algorithm is capable to detect both blowing snow lifted from the ground and occurring during precipitation, which is an added value since most of the blowing snow occurs during synoptic events, often combined with precipitation. Our analysis of atmospheric meteorological variables during blowing snow shows that blowing snow occurrence strongly depends on fresh snow availability in addition to wind speed, while the threshold for snow particles to be lifted is commonly parametrized as a function of wind speed only. These results suggest that the effect of katabatics and wind speed might have been overestimated, and that fresh snow availability should be considered in determining the blowing snow onset.

scholarly journals Cloud and precipitation properties from ground-based remote sensing instruments in East Antarctica

2014 ◽  
Vol 8 (4) ◽  
pp. 4195-4241 ◽  
Author(s):  
I. V. Gorodetskaya ◽  
S. Kneifel ◽  
M. Maahn ◽  
K. Van Tricht ◽  
J. H. Schween ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Bimodal Distribution ◽  
Snow Accumulation ◽  
East Antarctica ◽  
Blowing Snow ◽  
Precipitation Radar ◽  
Radiative Fluxes ◽  
Near Surface ◽  
Surface Mass ◽  
Meteorological Observatory

Abstract. A new comprehensive cloud-precipitation-meteorological observatory has been established at Princess Elisabeth base, located in the escarpment zone of Dronning Maud Land, East Antarctica. The observatory consists of a set of ground-based remote sensing instruments (ceilometer, infrared pyrometer and vertically profiling precipitation radar) combined with automatic weather station measurements of near-surface meteorology, radiative fluxes, and snow accumulation. In this paper, the observatory is presented and the potential for studying the evolution of clouds and precipitating systems is illustrated by case studies. It is shown that the synergetic use of the set of instruments allows for distinguishing ice, mixed-phase and precipitating clouds, including some information on their vertical extent. In addition, wind-driven blowing snow events can be distinguished from deeper precipitating systems. Cloud properties largely affect the surface radiative fluxes, with liquid-containing clouds dominating the radiative impact. A statistical analysis of all measurements (in total 14 months mainly occurring in summer/autumn) indicates that these liquid-containing clouds occur during as much as 20% of the cloudy periods. The cloud occurrence shows a strong bimodal distribution with clear sky conditions 51% of the time and complete overcast conditions 35% of the time. Snowfall occurred 17% of the cloudy periods with a predominance of light precipitation and only rare events with snowfall > 1 mm h−1 water equivalent (w.e.). Three of such intensive snowfall events occurred during 2011 contributing to anomalously large annual snow accumulation. This is the first deployment of a precipitation radar in Antarctica allowing to assess the contribution of the snowfall to the local surface mass balance. It is shown that on the one hand large accumulation events (>10 mm w.e. day−1) during the measurement period of 26 months were always associated with snowfall, but that on the other hand snowfall did not always lead to accumulation. In general, this promising set of robust instrumentation allows for improved insight in cloud and precipitation processes in Antarctica and can be easily deployed at other Antarctic stations.

Water vapor isotopic signature along the EAIIST traverse (East Antarctica Plateau)

2021 ◽  
Author(s):  
Mathieu Casado ◽  
Christophe Leroy-Dos Santos ◽  
Elise Fourré ◽  
Vincent Favier ◽  
Cécile Agosta ◽  
...  
Keyword(s):  
Water Vapor ◽  
Isotopic Composition ◽  
Ice Cores ◽  
East Antarctica ◽  
Polar Regions ◽  
Surface Mass ◽  
Antarctic Plateau ◽  
Starting Point ◽  
Weather Stations ◽  
The Impact

<p>Stable water isotopes are effective hydrological tracers due to fractionation processes throughout the water cycle, and thus, the stable isotopes from ice cores can serve as valuable proxies for past changes in the climate and local environment of polar regions. Proper interpretation of these isotopes requires to understand the influence of each potential fractionating process, such as initial evaporation over the ocean and precipitation events, but also the effects of post-depositional exchange between snow and moisture in the atmosphere. Thanks to new developments in infrared spectroscopy, it is now possible to continuously monitor the isotopic composition of atmospheric water vapor in coordination with discrete snow sampling. This allows us to readily document the isotopic and mass exchanges between snow and vapor as well as the stability of the atmospheric boundary layer, as has recently been shown on the East Antarctic Plateau at Kohnen (Ritter et al., TC, 2016) and Dome C (Casado et al., ACP, 2016) stations where substantial diurnal isotopic variations have been recorded.</p><p>In this study, we present the first vapor monitoring of an East Antarctic transect that covered more than 3600 km over a period of 3 months from November 2019 to February 2020 as part of the EAIIST mission. The isotopic record therefore describes the evolution from typical coastal values to highly depleted values deep inside the continent on the high-altitude plateau. In parallel, we also monitored the vapor isotopic composition at two stations: the coastal starting point of Dumont D’Urville (DDU) and the plateau halfway point of Dome C. Two automatic weather stations (at Paleo and Megadunes sites) were also installed in a previously unexplored region of the East Antarctic plateau that was covered by this transect. This suite of cross-calibrated vapor isotope observations and weather stations, coupled with Modele Atmospherique Régional (MAR) climate modeling, offers a unique opportunity to compare the spatial and temporal gradients of humidity, temperature, and water vapor isotopic composition in East Antarctica during the summer season, and to estimate how the water vapour isotope measurements at Dome C and DDU are representative of the conditions in East Antarctica. The quantitative agreement between the EAIIST record and those recorded at DDU and Dome C stations at the times the raid was nearby, gives confidence in the quality of the results acquired on this traverse. Although further comparisons with the surface snow isotopic composition are required to quantify the impact of the snow-atmosphere exchanges on the local surface mass balance, these initial results of vapor isotopic composition show the potential of using water stables isotopes to evaluate hydrological processes in East Antarctica and better reconstruct past climate changes through ice cores.</p>

scholarly journals Present weather-sensor tests for measuring drifting snow

2011 ◽  
Vol 52 (58) ◽  
pp. 176-184 ◽  
Author(s):  
Hervé Bellot ◽  
Alexandre Trouvilliez ◽  
Florence Naaim-Bouvet ◽  
Christophe Genthon ◽  
Hubert Gallée
Keyword(s):  
Numerical Models ◽  
Blowing Snow ◽  
Weather Station ◽  
Experimental Site ◽  
Surface Mass ◽  
Drifting Snow ◽  
Empirical Calibration ◽  
Snow Particle ◽  
Set Up ◽  
Better Than

AbstarctIn Antarctica, blowing snow accounts for a major component of the surface mass balance near the coast. Measurements of precipitation and blowing snow are scarce, and therefore collected data would allow testing of numerical models of mass flux over this region. A present weather station (PWS), Biral VPF730, was set up on the coast at Cap Prud’homme station, 5 km from Dumont d’Urville (DDU), principally to quantify precipitation. Since we expected to be able to determine blowing-snow fluxes from the PWS data, we tested this device first on our experimental site, the Lac Blanc pass. An empirical calibration was made with a snow particle counter. Although the physics of the phenomenon was not well captured, the flux outputs were better than those from FlowCapts. The first data from Antarctica were reanalyzed. The new calibration seems to be accurate for estimating the high blowing-snow flux with an interrogation of the precipitation effects.

scholarly journals Impact of model resolution on simulated wind, drifting snow and surface mass balance in Terre Adélie, East Antarctica

2012 ◽  
Vol 58 (211) ◽  
pp. 821-829 ◽  
Author(s):  
Jan T.M. Lenaerts ◽  
Michiel R. Van Den Broeke ◽  
Claudio Scarchilli ◽  
Cécile Agosta
Keyword(s):  
Wind Speed ◽  
Mass Balance ◽  
East Antarctica ◽  
Surface Mass Balance ◽  
Model Resolution ◽  
Surface Mass ◽  
Drifting Snow ◽  
Victoria Land ◽  
Terre Adélie ◽  
Simulated Wind

AbstractThis paper presents the impact of model resolution on the simulated wind speed, drifting snow climate and surface mass balance (SMB) of Terre Adélie and its surroundings, East Antarctica. We compare regional climate model simulations at 27 and 5.5 km resolution for the year 2009. The wind speed maxima in Terre Adélie and the narrow glacial valleys of Victoria Land are better represented at 5.5 km resolution, because the topography is better resolved. Drifting snow sublimation is >100 mm a-1 in regions with high wind speeds. Our results indicate a strong feedback between topography, wind gradients and drifting snow erosion. As a result, SMB shows much more local spatial variability at 5.5 km resolution that is controlled by drifting snow erosion, whereas the large-scale SMB gradient is largely determined by precipitation. Drifting snow processes lead to ablation in the narrow glacial valleys of Victoria Land. The integrated SMB equals 86 Gt. Although wind climate, drifting snow processes and SMB variability are better represented at 5.5 km, the area-integrated SMB is not significantly different between the simulations at 27 and 5.5 km. A horizontal resolution of 27 km is sufficient to realistically simulate ice-sheet wide SMB.

scholarly journals Cloud and precipitation properties from ground-based remote-sensing instruments in East Antarctica

2015 ◽  
Vol 9 (1) ◽  
pp. 285-304 ◽  
Author(s):  
I. V. Gorodetskaya ◽  
S. Kneifel ◽  
M. Maahn ◽  
K. Van Tricht ◽  
W. Thiery ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Bimodal Distribution ◽  
East Antarctica ◽  
Blowing Snow ◽  
Precipitation Radar ◽  
Radiative Fluxes ◽  
Near Surface ◽  
Surface Mass ◽  
Cloud Properties ◽  
Meteorological Observatory

Abstract. A new comprehensive cloud–precipitation–meteorological observatory has been established at Princess Elisabeth base, located in the escarpment zone of Dronning Maud Land (DML), East Antarctica. The observatory consists of a set of ground-based remote-sensing instruments (ceilometer, infrared pyrometer and vertically profiling precipitation radar) combined with automatic weather station measurements of near-surface meteorology, radiative fluxes, and snow height. In this paper, the observatory is presented and the potential for studying the evolution of clouds and precipitating systems is illustrated by case studies. It is shown that the synergetic use of the set of instruments allows for distinguishing ice, liquid-containing clouds and precipitating clouds, including some information on their vertical extent. In addition, wind-driven blowing snow events can be distinguished from deeper precipitating systems. Cloud properties largely affect the surface radiative fluxes, with liquid-containing clouds dominating the radiative impact. A statistical analysis of all measurements (in total 14 months mainly during summer–beginning of winter) indicates that these liquid-containing clouds occur during as much as 20% of the cloudy periods. The cloud occurrence shows a strong bimodal distribution with clear-sky conditions 51% of the time and complete overcast conditions 35% of the time. Snowfall occurred during 17% of the cloudy periods with a predominance of light precipitation and only rare events with snowfall >1 mm h−1 water equivalent (w.e.). Three of such intense snowfall events occurred during 2011 contributing to anomalously large annual surface mass balance (SMB). Large accumulation events (>10 mm w.e. day−1) during the radar-measurement period of 26 months were always associated with snowfall, but at the same time other snowfall events did not always lead to accumulation. The multiyear deployment of a precipitation radar in Antarctica allows for assessing the contribution of the snowfall to the local SMB and comparing it to the other SMB components. During 2012, snowfall rate was 110 ± 20 mm w.e. yr−1, from which surface and drifting snow sublimation removed together 23%. Given the measured yearly SMB of 52 ± 3 mm w.e., the residual term of 33 ± 21 mm w.e. yr−1 was attributed to the wind-driven snow erosion. In general, this promising set of robust instrumentation allows for improved insight into cloud and precipitation processes in Antarctica and can be easily deployed at other Antarctic stations.

First glaciological investigations at Ridge B, central East Antarctica

2021 ◽  
pp. 1-10
Author(s):  
Alexey A. Ekaykin ◽  
Alexey V. Bolshunov ◽  
Vladimir Ya. Lipenkov ◽  
Mirko Scheinert ◽  
Lutz Eberlein ◽  
...  
Keyword(s):  
East Antarctica ◽  
Snow Density ◽  
Deep Drilling ◽  
Surface Mass ◽  
Annual Variations ◽  
First Results ◽  
Vostok Station ◽  
Water Stable Isotope ◽  
Isotope Content ◽  
Firn Core

Abstract The region of Ridge B in central East Antarctica is one of the last unexplored parts of the continent and, at the same time, ranks among the most promising places to search for Earth's oldest ice. In January 2020, we carried out the first scientific traverse from Russia's Vostok Station to the topographical dome of Ridge B (Dome B, 3807 m above sea level, 79.02°S, 93.69°E). The glaciological programme included continuous snow-radar profiling and geodetic positioning along the traverse's route, installation of snow stakes, measurements of snow density, collection of samples for stable water isotope and chemical analyses and drilling of a 20 m firn core. The first results of the traverse show that the surface mass balance at Dome B (2.28 g cm−2 year−1) is among the lowest in Antarctica. The firn temperature below the layer of annual variations is −58.1 ± 0.2°C. A very low value of heavy water stable isotope content (-58.2‰ for oxygen-18) was discovered at a distance of 170 km from Vostok Station. This work is the first step towards a comprehensive reconnaissance study of the Ridge B area aimed at locating the best site for future deep drilling for the oldest Antarctic ice.

scholarly journals An exemplary case of a bromine explosion event linked to cyclone development in the Arctic

2016 ◽  
Vol 16 (3) ◽  
pp. 1773-1788 ◽  
Author(s):  
A.-M. Blechschmidt ◽  
A. Richter ◽  
J. P. Burrows ◽  
L. Kaleschke ◽  
K. Strong ◽  
...  
Keyword(s):  
Numerical Models ◽  
Weather Conditions ◽  
Conveyor Belt ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Blowing Snow ◽  
Air Stream ◽  
Combined Use ◽  
Arctic Sea ◽  
Development Duration

Abstract. Intense, cyclone-like shaped plumes of tropospheric bromine monoxide (BrO) are regularly observed by GOME-2 on board the MetOp-A satellite over Arctic sea ice in polar spring. These plumes are often transported by high-latitude cyclones, sometimes over several days despite the short atmospheric lifetime of BrO. However, only few studies have focused on the role of polar weather systems in the development, duration and transport of tropospheric BrO plumes during bromine explosion events. The latter are caused by an autocatalytic chemical chain reaction associated with tropospheric ozone depletion and initiated by the release of bromine from cold brine-covered ice or snow to the atmosphere. In this manuscript, a case study investigating a comma-shaped BrO plume which developed over the Beaufort Sea and was observed by GOME-2 for several days is presented. By making combined use of satellite data and numerical models, it is shown that the occurrence of the plume was closely linked to frontal lifting in a polar cyclone and that it most likely resided in the lowest 3 km of the troposphere. In contrast to previous case studies, we demonstrate that the dry conveyor belt, a potentially bromine-rich stratospheric air stream which can complicate interpretation of satellite retrieved tropospheric BrO, is spatially separated from the observed BrO plume. It is concluded that weather conditions associated with the polar cyclone favoured the bromine activation cycle and blowing snow production, which may have acted as a bromine source during the bromine explosion event.

Climate Conditions at Perennially Ice-Covered Lake Untersee, East Antarctica

2015 ◽  
Vol 54 (7) ◽  
pp. 1393-1412 ◽  
Author(s):  
Dale T. Andersen ◽  
Christopher P. McKay ◽  
Victor Lagun
Keyword(s):  
Wind Speed ◽  
Austral Summer ◽  
Solar Flux ◽  
East Antarctica ◽  
Daily Maximum ◽  
Mean Annual Temperature ◽  
Secondary Source ◽  
Climate Conditions ◽  
Wind Speeds ◽  
Strong Winds

AbstractIn November 2008 an automated meteorological station was established at Lake Untersee in East Antarctica, producing a 5-yr data record of meteorological conditions at the lake. This dataset includes five austral summer seasons composed of December, January, and February (DJF). The average solar flux at Lake Untersee for the four years with complete solar flux data is 99.2 ± 0.6 W m−2. The mean annual temperature at Lake Untersee was determined to be −10.6° ± 0.6°C. The annual degree-days above freezing for the five years were 9.7, 37.7, 22.4, 7.0, and 48.8, respectively, with summer (DJF) accounting for virtually all of this. For these five summers the average DJF temperatures were −3.5°, −1.9°, −2.2°, −2.6°, and −2.5°C. The maximum (minimum) temperatures were +5.3°, +7.6°, +5.7°, +4.4°, and +9.0°C (−13.8°, −12.8°, −12.9°, −13.5°, and −12.1°C). The average of the wind speed recorded was 5.4 m s−1, the maximum was 35.7 m s−1, and the average daily maximum was 15 m s−1. The wind speed was higher in the winter, averaging 6.4 m s−1. Summer winds averaged 4.7 m s−1. The dominant wind direction for strong winds is from the south for all seasons, with a secondary source of strong winds in the summer from the east-northeast. Relative humidity averages 37%; however, high values will occur with an average period of ~10 days, providing a strong indicator of the quasi-periodic passage of storms across the site. Low summer temperatures and high wind speeds create conditions at the surface of the lake ice resulting in sublimation rather than melting as the main mass-loss process.

scholarly journals Field test of a new snow-particle counter (SPC) system

1993 ◽  
Vol 18 ◽  
pp. 149-154 ◽  
Author(s):  
Takeshi Sato ◽  
Tadashi Kimura ◽  
Taminoe Ishimaru ◽  
Toshisuke Maruyama
Keyword(s):  
Wind Speed ◽  
Mass Flux ◽  
Particle Trajectory ◽  
Particle Diameter ◽  
Blowing Snow ◽  
Fraunhofer Diffraction ◽  
Wind Speed Profile ◽  
Particle Counter ◽  
Sampling Volume ◽  
Snow Particle

The optical system of the snow-particle counter (SPC), which was developed by Schmidt in 1977, has been improved. A laser diode is used as a light source, achieving uniform sensitivity to a blowing snow particle regardless of the location of particle trajectory within a sampling volume. The light entering a slit, which may be affected by a blowing snow particle, is perfectly detected by use of a piano-cylindrical lens and a dual-type photodiode. A signal processor has been developed to get output voltage proportional to the mass flux of blowing snow.From the estimates based on blowing snow characteristics and wind speed profile, the new SPC system can accurately detect all the particles of effective sizes at least at a height above 0.1 m when the wind speed at a height of 1 m is less than 15 m s−1.Considering the Fraunhofer diffraction by both the wire and the particle, the relation between a particle diameter and sensor output of the new SPC system is derived from the calibration with spinning wires.Mass flux obtained with the new SPC system was found to be close to that with a snow trap. The system was operated continuously for at least nine days using two 35 A h lead batteries.

Sign in / Sign up

Export Citation Format

Share Document