Prominent features in isotopic, chemical and dust stratigraphies from coastal East Antarctic ice sheet (Eastern Wilkes Land)

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>In this work we present the isotopic, chemical and dust stratigraphies of two snow pits sampled in 2013/14 at GV7 (coastal East Antarctica: 70°41′ S - 158°51′ E, 1950 m a.s.l.). A large number of chemical species are measured aiming to study their potentiality as environmental changes markers. Seasonal cluster backward trajectories analysis was performed and compared with chemical marker stratigraphies.</P> <P>Sea spray aerosol is delivered to the sampling site together with snow precipitation especially in autumn-winter by air masses arising from Western Pacific Ocean sector.</P> <P>Dust show maximum concentration in spring when the air masses arising from Ross Sea sector mobilize mineral dust from ice-free areas of the Transantarctic mountains.</P> <P>The clear seasonal pattern of sulfur oxidized compounds allows the dating of the snow-pit and the calculation of the mean accumulation rate, which is 242 ± 71 mm w.e. for the period 2008–2013.</P> <P>Methanesulfonic acid and NO<SUB>3</SUB> <SUP>−</SUP> do not show any concentration decreasing trend as depth increases, also considering a 12 m firn core record. Therefore these two compounds are not affected by post-depositional processes at this site and can be considered reliable markers for past environmental changes reconstruction.</P> <P>The rBC snow-pit record shows the highest values in summer 2012 likely related to large biomass burning even occurred in Australia in this summer.</P> <P>The undisturbed accumulation rate for this site is demonstrated by the agreement between the chemical stratigraphies and the annual accumulation rate of the two snow-pits analysed in Italian and Korean laboratories.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Ions, MSA, I, Br, BC and dust record from coastal East Antarctica are presented. </LI> <LI> Seasonal pattern of each markers is highlighted by comparison with δ<SUP>18</SUP>O. </LI> <LI> NssSO<SUB>4</SUB> <SUP>2−</SUP> and δ<SUP>18</SUP>O are chosen for annual layer counting. </LI> <LI> The mean accumulation rate over the period 2008–2013 is 242 ± 71 mm w.e.. </LI> <LI> Nitrate and MSA appear to be well preserved in this high accumulation rate site. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>