Deposition, accumulation, and alteration of Cl−, NO3−, ClO4− and ClO3− salts in a hyper-arid polar environment: Mass balance and isotopic constraints

Abstract

The salt fraction in permafrost soils/sediments of the McMurdo Dry Valleys (MDV) of Antarctica can be used as a proxy for cold desert geochemical processes and paleoclimate reconstruction. Previous analyses of the salt fraction in permafrost soils have largely been conducted in coastal regions where permafrost soils are variably affected by aqueous processes and mixed inputs from marine and stratospheric sources. We expand upon this work by evaluating permafrost soil/sediments in University Valley, located in the ultraxerous zone where both liquid water transport and marine influences are minimal. We determined the abundances of Cl-, NO 3

Trends of perchlorate in Antarctic snow: Implications for atmospheric production and preservation in snow

“…calculated between the 2010 snow surface and the volcanic sulfate deposition from the eruption of Mt. This data are similar to the range and variability of perchlorate thatJackson et al [2016] reported in surface snow in the McMurdo Dry Valleys, Antarctica. The snowpit covers the time period from 1967 to 2010.The WAIS Divide snowpit was dated by counting annual summertime non-sea-salt (nss) sulfate concentration maxima[Cole-Dai et al, 2009] (Figure S4).…”

“…Measurement of perchlorate in snow and ice will likely yield both short and long records of perchlorate in the environment. In addition, it is not known if the perchlorate trends found in the Arctic also exist in Antarctica, as few measurements have been made for perchlorate in Antarctic snow [Jackson et al, 2016;Jiang et al, 2013]. The investigations on perchlorate in Arctic snow suggest that perchlorate concentrations appear to be higher in recent snow (post-1980) than in older snow with the increase possibly attributable to anthropogenic influence [Peterson et al, 2015b].…”

Cryostratigraphy and the Sublimation Unconformity in Permafrost from an Ultraxerous Environment, University Valley, McMurdo Dry Valleys of Antarctica

“…OSL ages obtained from permafrost cores from four polygons in upper and middle University Valley (P1, P2, P8, P12) yielded ages of 17.9 ± 1.6 kyr for sediments at 2–5 cm depths, whereas those at 90–95 cm depths were dated to 170 ± 36 kyr (Lacelle et al, ; Trinh‐Le, ). These ages fit reasonably well with those derived from chloride accumulation in the upper 56 cm of sediments (Jackson et al, ). The undifferentiated till, which contains granite erratics, is probably associated with the Taylor 4b Drift (>2.7 Ma) or an older glaciation (Cox et al, ; Dickinson et al, ).…”

“…Apparent rates of ground‐ice accumulation in the icy permafrost were calculated by dividing the cumulative volume of water in the core by the surface area of core barrel and by age of the soils, estimated from OSL ages and chloride concentrations (Lacelle et al, ; Jackson et al, ). Since chloride‐derived ages were obtained for the top 56 cm of soils, the cumulative volume of water was calculated to this depth for sites with cores equal or longer than 56 cm (i.e.…”

Assessing the Seasonal Dynamics of Nitrate and Sulfate Aerosols at the South Pole Utilizing Stable Isotopes

“…This favors the release of NO x depleted in 15 N and can explain the extremely low aerosol δ 15 N(NO 3 − ) values found during periods of sunlight. The exportation out of the continental ice sheet of this locally produced NO 3 − with extremely low δ 15 N(NO 3 − ) values may explain the low δ 15 N(NO 3 − ) values observed in the Antarctic Dry Valleys region (Jackson et al, ; Michalski et al, ).…”