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Role of mineral dust in the nitrate preservation during the glacial period: Insights from the RICE ice core.

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Title: Role of mineral dust in the nitrate preservation during the glacial period: Insights from the RICE ice core.
Authors: Venugopal, Abhijith U.1,2 (AUTHOR) abhi.ulayottilvenugopal@vuw.ac.nz, Bertler, Nancy A.N.1,2 (AUTHOR), Pyne, Rebecca L.1 (AUTHOR), Kjær, Helle A.3 (AUTHOR), Winton, V. Holly L.2 (AUTHOR), Mayewski, Paul A.4 (AUTHOR), Cortese, Giuseppe1 (AUTHOR)
Source: Global & Planetary Change. Feb2022, Vol. 209, pN.PAG-N.PAG. 1p.
Subjects: Glaciation, Ice cores, Mineral dusts, Nitrate minerals, Dust, Westerlies
Geographic Terms: Antarctica
Abstract: Nitrate (NO 3 −), an abundant aerosol in polar snow, is a complex environmental proxy to interpret owing to its diverse sources and susceptibility to post-depositional processes. During the last glacial period, when dust concentrations in the Antarctic ice were upto ~50 times than today, mineral dust appears to have a stabilizing effect on the NO 3 − concentration in snow. However, the mechanism leading to the stabilization remains unclear. Here, we present the new and highly resolved records of NO 3 − and non-sea salt calcium (nssCa2+, a proxy for mineral dust) from the Roosevelt Island Climate Evolution (RICE) ice core. We focus on the glacial period from 83 to 26 kilo years Before Present (ka BP). The data show a statistically significant correlation between NO 3 − and nssCa2+ over this period. To put our findings into a spatial context, we compare RICE data with existing records from east Antarctica (EPICA Dome C [EDC], Vostok and central Dome Fuji) and West Antarctica (West Antarctic Ice Sheet Divide Ice Core [WDC]). Spatial analysis suggests that nssCa2+ is contributing to the effective scavenging of NO 3 − from the atmosphere perhaps through the formation of calcium nitrate (Ca(NO 3) 2). The geographic pattern implies that the process of Ca(NO 3) 2 formation occurs during the long-distance transport of mineral dust from mid-latitude source regions by Southern Hemisphere Westerly Winds (SHWW). The data also suggest that the correlation observed at various Antarctic locations may depend on the level of dust reaching the sites from the mid-latitude sources. • A new Antarctic coastal record for mineral dust and nitrate for the last glacial. • Mineral dust-nitrate association is an Antarctic wide phenomenon during the glacial. • Mineral dust scavenges nitrate from the atmosphere. • Dust bound nitrate is dispersed to Antarctic atmosphere by westerly winds. • Scavenging efficiency increases when the atmospheric dust loading is high. [ABSTRACT FROM AUTHOR]
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Database: Engineering Source
Description
Abstract:Nitrate (NO 3 −), an abundant aerosol in polar snow, is a complex environmental proxy to interpret owing to its diverse sources and susceptibility to post-depositional processes. During the last glacial period, when dust concentrations in the Antarctic ice were upto ~50 times than today, mineral dust appears to have a stabilizing effect on the NO 3 − concentration in snow. However, the mechanism leading to the stabilization remains unclear. Here, we present the new and highly resolved records of NO 3 − and non-sea salt calcium (nssCa2+, a proxy for mineral dust) from the Roosevelt Island Climate Evolution (RICE) ice core. We focus on the glacial period from 83 to 26 kilo years Before Present (ka BP). The data show a statistically significant correlation between NO 3 − and nssCa2+ over this period. To put our findings into a spatial context, we compare RICE data with existing records from east Antarctica (EPICA Dome C [EDC], Vostok and central Dome Fuji) and West Antarctica (West Antarctic Ice Sheet Divide Ice Core [WDC]). Spatial analysis suggests that nssCa2+ is contributing to the effective scavenging of NO 3 − from the atmosphere perhaps through the formation of calcium nitrate (Ca(NO 3) 2). The geographic pattern implies that the process of Ca(NO 3) 2 formation occurs during the long-distance transport of mineral dust from mid-latitude source regions by Southern Hemisphere Westerly Winds (SHWW). The data also suggest that the correlation observed at various Antarctic locations may depend on the level of dust reaching the sites from the mid-latitude sources. • A new Antarctic coastal record for mineral dust and nitrate for the last glacial. • Mineral dust-nitrate association is an Antarctic wide phenomenon during the glacial. • Mineral dust scavenges nitrate from the atmosphere. • Dust bound nitrate is dispersed to Antarctic atmosphere by westerly winds. • Scavenging efficiency increases when the atmospheric dust loading is high. [ABSTRACT FROM AUTHOR]
ISSN:09218181
DOI:10.1016/j.gloplacha.2022.103745