Black carbon concentrations from a Tibetan Plateau ice core spanning 1843–1982: recent increases due to emissions and glacier melt

Abstract

Abstract. Black carbon (BC) deposited on snow and glacier surfaces can reduce albedo and lead to accelerated melt. An ice core recovered from Guoqu glacier on Mt. Geladaindong and analyzed using a Single Particle Soot Photometer provides the first long-term (1843–1982) record of BC concentrations from the Central Tibetan Plateau. The highest concentrations are observed from 1975–1982, which corresponds to a 2.0-fold and 2.4-fold increase in average and median values, respectively, relative to 1843–1940. BC concentrations post-1940 are also elevated relative to the earlier portion of the record. Causes for the higher BC concentrations include increased regional BC emissions and subsequent deposition, and melt induced enrichment of BC, with the melt potentially accelerated due to the presence of BC at the glacier surface. A qualitative comparison of the BC and Fe (used as a dust proxy) records suggests that if changes in the concentrations of absorbing impurities at the glacier surface have influenced recent glacial melt, the melt may be due to the presence of BC rather than dust. Guoqu glacier has received no net ice accumulation since the 1980s, and is a potential example of a glacier where an increase in the equilibrium line altitude is exposing buried high impurity layers. That BC concentrations in the uppermost layers of the Geladaindong ice core are not substantially higher relative to deeper in the ice core suggests that some of the BC that must have been deposited on Guoqu glacier via wet or dry deposition between 1983 and 2005 has been removed from the surface of the glacier, potentially via supraglacial or englacial meltwater.

Impact of snow darkening via dust, black carbon, and organic carbon on boreal spring climate in the Earth system

“…As summarized in Qian et al . [], many modeling studies have mainly focused on BC SDE [e.g., Jacobson , ; Flanner et al ., ; Koch et al ., ; Qian et al ., , ; Menon et al ., ; Skeie et al ., ; Lee et al ., ; Jiao et al ., ], and measurements of BC (or elemental carbon) in snow (ice cores and/or snow samples) have been recently carried out in many regions [ Xu et al ., , , , ; McConnell et al ., ; Ming et al ., , , , ; Forsström et al ., , ; Doherty et al ., , , ; Kaspari et al ., , , ; Ye et al ., ; Jenkins et al ., ; Wang et al ., ; Zhang et al ., ; Ginot et al ., ; Kuchiki et al ., ; Pedersen et al ., ], following the pioneer measurement work by Clarke and Noone []. The dust SDE has also been addressed in observational and modeling studies [e.g., Higuchi and Nagoshi , ; Warren and Wiscombe , ; Krinner et al ., ; Painter et al ., , ; Skiles et al ., ; Gautam et al ., ; Ginot et al ., ; Kaspari et al ., , ].…”

“…Based on the recent updates in current understanding of RF for BC on snow and sea ice (changes for 2010 relative to 1750) summarized in Bond et al [2013] (+0.046 W m À2 , selected from the range spanning +0.015 to +0.094 W m À2 ), the Fifth Assessment Report (AR5) of IPCC [Intergovernmental Panel on Climate Change, 2013; Boucher et al, 2013] adopted the magnitude of the RF for BC on snow and sea ice of +0.04 W m À2 (from the uncertainty range spanning +0.02 to +0.09 W m À2 ) (further information regarding RF for the LAAs on snow and ice is available in a recent review paper by Qian et al [2015]). As summarized in Qian et al [2015], many modeling studies have mainly focused on BC SDE [e.g., Jacobson, 2004;Flanner et al, 2007;Koch et al, 2009a;Qian et al, 2009Qian et al, , 2014Menon et al, 2010;Skeie et al, 2011;Lee et al, 2013;Jiao et al, 2014], and measurements of BC (or elemental carbon) in snow (ice cores and/or snow samples) have been recently carried out in many regions [Xu et al, 2006[Xu et al, , 2009a[Xu et al, , 2009bMcConnell et al, 2007;Ming et al, 2008Ming et al, , 2009Ming et al, , 2012Ming et al, , 2013Forsström et al, 2009Forsström et al, , 2013Doherty et al, 2010Doherty et al, , 2013Doherty et al, , 2014bKaspari et al, 2011Kaspari et al, , 2014Kaspari et al, , 2015Ye et al, 2012;Jenkins et al, 2013;Wang et al, 2013;Zhang et al, 2013;Ginot et al, 2014;Kuchiki et al, 2015;…”

A 10 year record of black carbon and dust from a Mera Peak ice core (Nepal): variability and potential impact on melting of Himalayan glaciers

“…The southern margin of the Himalayan range is influenced by the seasonal alternation of the westerlies and the Indian monsoon: ice cores extracted from the Mount Everest East Rongbuk glacier (28 • N, 87 • E) have used this alternation for example, to determine seasonal cycles even though this glacier is situated on the northern flank of the Himalaya range. The East Rongbuk site has provided a wide range of climatic and environmental records including chemistry and isotopes (Kang et al, 2002;Kaspari et al, 2009;Zhang et al, 2009;Lee et al, 2011), dust (Xu et al, 2010) and the first profile of BC (Ming et al, 2008;Kaspari et al, 2011;Jenkins et al, 2013). The southern flank of the Himalaya range, where the Mera Glacier drilling site is located, is more influenced by monsoon and by southern pollution events than the Rongbuk site.…”

Black carbon variability since preindustrial times in Eastern part of Europe reconstructed from Mt Elbrus, Caucasus ice cores

“…Ice core rBC analysis using the SP2 has been reported previously (Bisiaux et al, 2012a, b;Ginot et al, 2014;Jenk- ins Kaspari et al, 2014;Wang et al, 2015). Specifically, recent papers describe a detailed analytical evaluation for rBC in liquid samples, e.g., rain, snow and ice cores, using the SP2 (Lim et al, 2014;Mori et al, 2016;Schwarz et al, 2012;Wendl et al, 2014).…”