Snow-Pit Record from a Coastal Antarctic Site and Its Preservation of Meteorological Features

Abstract

Polar snow pits or ice cores preserve valuable information derived from the atmosphere on past climate and environment changes. A 1.57-m snow-pit record from the coastal site (Styx Glacier) in eastern Antarctica covering the period from January 2011 to January 2015 was discussed and compared with meteorological variables. The dominant contribution of the deposition of sea-salt aerosols due to the proximity of the site to the ocean and processes of sea ice formation was revealed in the ionic concentrations. Consistent seasonal peaks in δ 18 O, δ D, MSA, , and indicate the strong enhancement of their source during warm periods, whereas the sea-salt ions (Na + , K + , Mg 2+ , Ca 2+ , Cl − , and ) exhibit a distinct distribution. Monthly mean δ 18 O positively correlates with the air temperature record from an automatic weather station (AWS) located in the main wind direction. Despite the shortness of the record, we suspect that the slight depletion of the isotopic composition and lowering of the snow accumulation could be related to the cooler air temperature with the decrease of open sea area. Consistency with previous studies and the positive correlation of sea-salt ions in the snow pit indicate the relatively good preservation of snow layers with noticeable climate and environmental signals [e.g., changes in sea ice extent (SIE) or sea surface temperature]. We report a new snow-pit record, which would be comparative and supportive to understand similar signals preserved in deeper ice cores in this location.

Variability of sea salt and methanesulfonate in firn cores from northern Victoria Land, Antarctica: Their links to oceanic and atmospheric condition variability in the Ross Sea

“…As shown in Figure 2, the dating of the Styx-A core was determined primarily by counting the annual layers identified by the well-defined seasonal variations of the chemical composition (δ 18 O, δD, MS -, and nss-SO 4 2-) in PC2, showing their annual patterns with the summer maxima and winter minima in Antarctic precipitation (Dansgaard, 1964;Minikin et al, 1998;Pasteris et al, 2014). The same seasonality of SO 4 2-/ss-Na + and Cl − /ss-Na + ratios with maxima in summer (Hara et al, 2020;Nyamgerel et al, 2020Nyamgerel et al, , 2021 was also used to date the core (Figure 2). According to 23 summer maxima of these seasonalities (vertical orange bars in Figure 2), the top 9.29 m of the Styx-A core was dated to cover the time between 1989/ 90 and 2011/12 austral summer seasons.…”

“…Together with the effects of the sea salt source, the regionalscale (meso-to synoptic-scale) cyclones or large-scale atmospheric circulation can also play a critical role in the sea salt supply at coastal Antarctic sites (Carrasco et al, 2003;Sinclair et al, 2010;Bertler et al, 2018;Nyamgerel et al, 2021). The stacked ss-Na + to Lola AWS pressure and wind velocity data during June-August (JJA; winter) and September-November (SON; spring) were compared to examine the relationship between the ss-Na + flux record and the regional-scale cyclones.…”

“…This relationship was used to assess the suitability of ice core ss-Na + and MSrecords as proxies of the variability in oceanic and atmospheric conditions at the interannual timescale in this region. Nyamgerel et al, 2021). The annual accumulation rates are relatively high, ranging from 130 to 226 kg m −2 yr −1 (Han et al, 2015).…”

“…The distance between the two drilling sites was 174 m. The core samples were kept frozen in polyethylene bags, transported to the Korea Polar Research Institute (KOPRI), and stored in a cold room at a temperature under -15 °C before the analysis. More details for this study site and the firn cores are given elsewhere (Han et al, 2015;Yang J.-W. et al, 2018;Jang et al, 2019;Nyamgerel et al, 2020Nyamgerel et al, , 2021.…”

Polish Polar Research

“…Snowpit and ice cores provide robust records of the past climate and environmental changes, particularly in remote areas such as Antarctica, where instrumental data are sparse and have short observation periods (Jouzel et al 2007;Sinclair et al 2010;Klein et al 2019). In Antarctica, many of the chemical species and isotopic compositions of water retrieved from ice cores and snowpits show clear seasonal variations (Kuramoto et al 2011;Kwak et al 2015;Nyamgerel et al 2020Nyamgerel et al , 2021. Distinguishing seasonal patterns in stable water isotopes (δ 18 O and δD) and chemical impurities is crucial for the stratigraphic dating of accumulated snow layers, and are used as proxies for temperature, sea ice extent, atmospheric circulation, aerosol transport and depositional processes (Udisti 1996; Delmotte et al 2000;Ayling and McGowan 2006;Severi et al 2017;Du et al 2019;Servettaz et al 2020).…”