Mineral dust variability in central West Antarctica associated with ozone depletion

Abstract

We present here data of mineral dust variability retrieved from an ice core of the central West Antarctic, spanning the last five decades. Main evidence provided by the geochemical analysis is that northerly air mass incursions to the coring site, tracked by insoluble dust microparticles, have declined over the past 50 yr. This result contrasts with dust records from ice cores reported to the coastal West Antarctic that show increases since mid-20th century. We attribute this difference to regional climatic changes due to the ozone depletion and its implications to westerly winds. We found that the diameters of insoluble microparticles in the central West Antarctica ice core are significantly correlated with cyclone depth (energy) and wind intensity around Antarctica

Ionic content in an ice core from the West Antarctic Ice Sheet: 1882-2008 A.D.

“…Dust particles play an important role as modifiers of the chemical composition of the atmosphere, through water adsorption mechanisms and the formation of deliquescent layers around them, thereby creating in clouds a humid and reactive environment for trace acid gases, mainly H 2 SO 4 and HNO 3 (Cwiertny et al 2008). Regarding the insoluble fraction, Cataldo et al (2013) show that 53% of the total identified particles found within an ice core collected at the same site have Si, Al, Fe and Ti as main components and diameters between 1 and 3 µm, compatible with particle sizes transported for long distances. According to Li et al (2008), the main sources of mineral dust deposited in the Austral Ocean and Antarctica are quantitatively Australia and South America.…”

A 125-year record of climate and chemistry variability at the Pine Island Glacier ice divide, Antarctica

“…These impurities are transported over long distances to the polar regions through the troposphere (Petit and Delmonte, 2009) and stratosphere, e. g. volcanic emissions (Krinner et al, 2010). Sea salt and mineral dust can be used to reconstruct climate conditions as well as atmospheric transport patterns (Albani et al, 2012;Chewings et al, 2014). These chemical elements are strongly influenced by the climate conditions in the source region, and the depositional record provides important information about cyclone activity, wind intensity (Koffman et al, 2014a), sea ice conditions (Criscitiello et al, 2014), and aridity and vegetation cover (McConnell et al, 2007).…”

Southwestern Tropical Atlantic coral growth response to atmospheric circulation changes induced by ozone depletion in Antarctica

“…reefs and coral communities from nearly 0 to 23 • S (Castro and Pires, 2001). For Siderastrea stellata, that often grows in shallow water in reef tidal pools (where temperatures normally range between 25 and 31 • C), optimum calcification has been observed at temperatures between 28 and 30 • C. For this particular species, the aragonite saturation seems to play a less relevant role than SST for calcification, especially when SST reaches ∼ 26 • C (da Silva et al, 2009).…”

“…Several authors have reported a close relationship between wind stress and SST (Lindzen and Nigam, 1987;Hashizume et al, 2001;Chelton et al, 2007) through modulation of surface heat flux and upper ocean mixing. In general, warmer SST can be associated with deeper boundary layers and higher wind stress (Cayan, 1992;O'Neill et al, 2010). The Southern Hemisphere mid-to-high latitude circulation has undergone marked changes in wind dynamics over the past few decades.…”