Dynamical Constraints on Katabatic Wind Cessation in Adélie Land, Antarctica

Gallée, Hubert; Pettré, Paul

doi:10.1175/1520-0469(1998)055<1755:dcokwc>2.0.co;2

Cited by 43 publications

(52 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Increases in both Hg(II) and Hg(p) have been reported in conjunction with decreases of Hg(0) (Lu et al, 2001;Lindberg et al, 2002;Aspmo et al, 2005). Conversely, low Hg(0) concentrations that were not correlated or anti-correlated with O 3 were observed at Neumayer and Troll Pfaffhuber et al, 2012), while elevated Hg(II) concen- Due to strong katabatic winds flowing out from the Antarctic Plateau -generated by the negative buoyant force that develops in the stable cooled layer along the ice sheet slopes (Gallée and Pettré, 1998) -, a fraction of this inland atmospheric reservoir can be transported toward the coastal margin. The influence of the flows from the Antarctic plateau on coastal locations varies depending on the location.…”

Section: Implications On a Continental Scalementioning

confidence: 99%

New insights into the atmospheric mercury cycling in central Antarctica and implications on a continental scale

et al. 2016

Self Cite

View full text Add to dashboard Cite

Abstract. Under the framework of the GMOS project (Global Mercury Observation System) atmospheric mercury monitoring has been implemented at Concordia Station on the high-altitude Antarctic plateau (75 • 06 S, 123 • 20 E, 3220 m above sea level). We report here the first year-round measurements of gaseous elemental mercury (Hg(0)) in the atmosphere and in snowpack interstitial air on the East Antarctic ice sheet. This unique data set shows evidence of an intense oxidation of atmospheric Hg(0) in summer (24-hour daylight) due to the high oxidative capacity of the Antarctic plateau atmosphere in this period of the year. Summertime Hg(0) concentrations exhibited a pronounced daily cycle in ambient air with maximal concentrations around midday. Photochemical reactions and chemical exchange at the air-snow interface were prominent, highlighting the role of the snowpack on the atmospheric mercury cycle. Our observations reveal a 20 to 30 % decrease of atmospheric Hg(0) concentrations from May to mid-August (winter, 24 h darkness). This phenomenon has not been reported elsewhere and possibly results from the dry deposition of Hg(0) onto the snowpack. We also reveal the occurrence of multi-day to weeklong atmospheric Hg(0) depletion events in summer, not associated with depletions of ozone, and likely due to a stagnation of air masses above the plateau triggering an accumulation of oxidants within the shallow boundary layer. Our observations suggest that the inland atmospheric reservoir is depleted in Hg(0) in summer. Due to katabatic winds flowing out from the Antarctic plateau down the steep vertical drops along the coast and according to observations at coastal Antarctic stations, the striking reactivity observed on the plateau most likely influences the cycle of atmospheric mercury on a continental scale.

show abstract

Section: Implications On a Continental Scalementioning

confidence: 99%

New insights into the atmospheric mercury cycling in central Antarctica and implications on a continental scale

et al. 2016

Self Cite

View full text Add to dashboard Cite

show abstract

“…In summer, the surface wind direction sometimes changes from 120-160 • E to North as temperature rises over midday (Pettré et al, 1993;Gallée and Pettré, 1998), giving birth to an apparent sea breeze. This phenomenon usually lasts half a day or less and air masses cannot be referred to as oceanic (see Sect.…”

Section: (A) Role Of Penguin Emissionsmentioning

confidence: 99%

Multi-year record of atmospheric mercury at Dumont d'Urville, East Antarctic coast: continental outflow and oceanic influences

et al. 2016

View full text Add to dashboard Cite

Abstract. Under the framework of the Global Mercury Observation System (GMOS) project, a 3.5-year record of atmospheric gaseous elemental mercury (Hg(0)) has been gathered at Dumont d'Urville (DDU, 66 • 40 S, 140 • 01 E, 43 m above sea level) on the East Antarctic coast. Additionally, surface snow samples were collected in February 2009 during a traverse between Concordia Station located on the East Antarctic plateau and DDU. The record of atmospheric Hg(0) at DDU reveals particularities that are not seen at other coastal sites: a gradual decrease of concentrations over the course of winter, and a daily maximum concentration around midday in summer. Additionally, total mercury concentrations in surface snow samples were particularly elevated near DDU (up to 194.4 ng L −1 ) as compared to measurements at other coastal Antarctic sites. These differences can be explained by the more frequent arrival of inland air masses at DDU than at other coastal sites. This confirms the influence of processes observed on the Antarctic plateau on the cycle of atmospheric mercury at a continental scale, especially in areas subject to recurrent katabatic winds. DDU is also influenced by oceanic air masses and our data suggest that the ocean plays a dual role on Hg (0) concentrations. The open ocean may represent a source of atmospheric Hg(0) in summer whereas the sea-ice surface may provide reactive halogens in spring that can oxidize Hg(0). This paper also discusses implications for coastal Antarctic ecosystems and for the cycle of atmospheric mercury in high southern latitudes.

show abstract

“…6 and 7 are probably caused by redistribution of snow by the wind due to gravity waves that are triggered at breaks in a slope (Gallée and Pettré, 1998). This phenomenon was described in Adelie Land coastal areas by Pettré et al (1986), where 40 km wavelength isochronal undulations were observed below the break point at 230 km from the coast.…”

Section: Undulating Structuresmentioning

confidence: 99%

Snow accumulation variability derived from radar and firn core data along a 600 km transect in Adelie Land, East Antarctic plateau

et al. 2012

View full text Add to dashboard Cite

Abstract. The mass balance of ice sheets is an intensively studied topic in the context of global change and sealevel rise. However -particularly in Antarctica -obtaining mass balance estimates remains difficult due to various logistical problems. In the framework of the TASTE-IDEA (Trans-Antarctic Scientific Traverses Expeditions -Ice Divide of East Antarctica) program, an International Polar Year project, continuous ground penetrating radar (GPR) measurements were carried out during a traverse in Adelie Land (East Antarctica) during the 2008-2009 austral summer between the Italian-French Dome C (DC) polar plateau site and French Dumont D'Urville (DdU) coastal station. The aim of this study was to process and interpret GPR data in terms of snow accumulation, to analyse its spatial and temporal variability and compare it with historical data and modelling. The focus was on the last 300 yr, from the preindustrial period to recent times. Beta-radioactivity counting and gamma spectrometry were applied to cores at the LGGE laboratory, providing a depth-age calibration for radar measurements. Over the 600 km of usable GPR data, depth and snow accumulation were determined with the help of three distinct layers visible on the radargrams (≈ 1730(≈ , 1799(≈ and 1941. Preliminary results reveal a gradual increase in accumulation towards the coast (from ≈ 3 cm w.e. a −1 at Dome C to ≈ 17 cm w.e. a −1 at the end of the transect) and previously undocumented undulating structures between 300 and 600 km from DC. Results agree fairly well with data from previous studies and modelling. Drawing final conclusions on temporal variations is difficult because of the margin of error introduced by density estimation. This study should have various applications, including model validation.

show abstract

Dynamical Constraints on Katabatic Wind Cessation in Adélie Land, Antarctica

Cited by 43 publications

References 27 publications

New insights into the atmospheric mercury cycling in central Antarctica and implications on a continental scale

New insights into the atmospheric mercury cycling in central Antarctica and implications on a continental scale

Multi-year record of atmospheric mercury at Dumont d'Urville, East Antarctic coast: continental outflow and oceanic influences

Snow accumulation variability derived from radar and firn core data along a 600 km transect in Adelie Land, East Antarctic plateau

Contact Info

Product

Resources

About