Historical Trends of Biogenic SOA Tracers in an Ice Core from Kamchatka Peninsula

Abstract

Biogenic secondary organic aerosol (SOA) is ubiquitous in the Earth's atmosphere, influencing climate and air quality. However, the historical trend of biogenic SOA is not well known. Here, we report for the first time the major isoprene-and monoterpene-derived SOA tracers preserved in an ice core from the Kamchatka Peninsula. Significant variations are recorded during the past 300 years with lower concentrations in the early-to-middle 19th century and higher concentrations in the preindustrial period and the present day. We discovered that isoprene SOA tracers were more abundant in the preindustrial period than the present day, while monoterpene SOA tracers stay almost unchanged. The causes of the observed variability are complex, depending on atmospheric circulation, changes in emissions, and other factors such as tropospheric oxidative capacity. Our data presents an unprecedented opportunity to shed light on the formation, evolution, and fate of atmospheric aerosols and to constrain the uncertainties associated with modeling their atmospheric concentrations. ■ INTRODUCTION Palaeoclimate archives containing annual layers (e.g., ice cores, tree rings, speleothems, and coral reefs) have played a central role in reconstructing decadal-scale climatic oscillation of the past. 1 This insight has proved an invaluable tool to constrain climate model projections of future climate change by validating model hindcasts. Similarly, analysis of particles preserved in ice cores provides an unprecedented opportunity to elucidate the distribution, concentration, size distribution, and even chemical composition of atmospheric aerosols in the past. Such data would allow us to deduce the influence of aerosol radiative forcing on past climate change. Previously, aerosol particles preserved in high altitudinal or high latitudinal ice cores have been examined for inorganic species (e.g., sulfate), black carbon, and organic species such as polycyclic aromatic hydrocarbons, carboxylic acids, biomass burning tracers, and humic-like substances. 2−7 To date, little was known about the historical trends of secondary organic aerosols at a molecular level. 3,8 Here, we present the findings of the analysis of ice cores for evidence of organic compounds formed from biogenic trace gases. Terrestrial vegetation emits large quantities (∼1 Pg C y −1) of biogenic volatile organic compounds (BVOCs), including reactive species such as isoprene and monoterpenes, to the atmosphere. 9 The role of their atmospheric reactions in 50 governing the production and loss of tropospheric ozone is 51 well studied and relatively well understood, but BVOC 52 oxidation has also been shown to lead to aerosol 53 formation. 10−12 Organic particles formed by the photooxidation 54 of BVOCs are considered "secondary" organic aerosols (SOA) 55 and are believed to be more abundant than directly emitted 56 "primary" organic aerosols (POA) in the Earth's atmos-57 phere. 11,13−16 It is believed that SOA could be a significant 58 source of new nanoscale particles, especially in...

Prospects for reconstructing paleoenvironmental conditions from organic compounds in polar snow and ice

“…d GLVE=Goulden large-volume extractor. e SFE=Supercritical Fluid Extraction (Fu et al, 2009), Boreal Forest Finland (Kourtchev et al, 2013;Kourtchev et al, 2005), Forested areas China (Wang et al, 2008), Amazonian Forest Brazil (Claeys et al, 2004a), Tibetan Plateau (Shen et al, 2015), Alaskan ice core (Pokhrel et al, 2016), Kamchatka ice core (Fu et al, 2016) 2-methylglyceric acid Canadian High Arctic (Fu et al, 2009), Boreal Forest Finland (Kourtchev et al, 2013;Kourtchev et al, 2005), Forested areas China (Wang et al, 2008), Tibetan Plateau (Shen et al, 2015), Alaskan ice core (Pokhrel et al, 2016), Kamchatka ice core ) C 5 -alkene triols:…”

“…Canadian High Arctic (Fu et al, 2009), Boreal Forest Finland (Kourtchev et al, 2005), Forested areas China (Wang et al, 2008), Tibetan Plateau (Shen et al, 2015), Alaskan ice core (Pokhrel et al, 2016) Monoterpene SOA Location 3-hydroxyglutaric acid Canadian High Arctic (Fu et al, 2009), Forested areas China (Wang et al, 2008), Alaskan ice core (Pokhrel et al, 2016), Kamchatka ice core (Fu et al, 2016) pinic acid, pinonic acid Canadian High Arctic (Fu et al, 2009), Boreal Forest Finland (Kourtchev et al, 2013), Tibetan Plateau (Shen et al, 2015), Alaskan ice core (Pokhrel et al, 2016), Kamchatka ice core pinanoldehyde; pinanediol mononitrate; norpinonic acid; terebic acid; ketolimononic acid; limonic acid; homoterpenylic acid; deterpenylic acid acetate; caric acid; caronic acid; 2-hydroxyterpenylic acid; HHDCA (1-hydroxy-3-(hydroxymethyl)-2,2 dimethylcyclobutane-carboxylic acid); DHHMDMCP (2,3-dihydroxy-2-(hydroxymethyl)-7,7-dimethylbicycloheptan6-one); HODSA (3-(2-hydroxy-3-oxobutyl)-2,2-dimethylsuccinaldehyde); 2,6,6trimethylbicycloheptane-2,3,-diol Boreal Forest Finland (Kourtchev et al, 2013) norpinic acid Canadian High Arctic (Fu et al, 2009), Boreal Forest Finland (Kourtchev et al, 2013), Forested areas China (Wang et al, 2008) 3-hydroxyglutaric acid, 3-hydroxy-4,4dimethylglutaric acid Tibetan Plateau (Shen et al, 2015) MBTCA (3-methyl-1,2,3butanetricarboxylic acid)…”

“…Canadian High Arctic (Fu et al, 2009), Boreal Forest Finland (Kourtchev et al, 2013), Forested areas China (Wang et al, 2008), Tibetan Plateau (Shen et al, 2015), Kamchatka ice core (Fu et al, 2016) Sesquiterpene SOA Location β-caryophyllinic acid Canadian High Arctic (Fu et al, 2009), North Carolina, USA (Jaoui et al, 2007), Boreal Forest Finland (van Eijck et al, 2013, Tibetan Plateau (Shen et al, 2015) Austfonna, Svalbard, ice core (Hermanson et al, 2005); Seawater and pack ice, Terra Nova Bay, Antarctica (Desideri et al, 1991) Chlordane Insecticide; Used on home lawn and garden pests. Also used extensively to control termites.…”

“…The most widely used pre-concentration method is solid phase extraction (SPE) which is applied to non-polar anthropogenic compounds, like polycyclic aromatic hydrocarbons (PAHs), pesticides, polychlorinated biphenyls (PCBs) and perand polyfluoroalkyl substances (PFASs). For non-volatile compounds, another common preconcentration method is solvent evaporation, often using a rotary evaporator (Fu et al, 2016;Kawamura, 1993;Pokhrel et al, 2015;Pokhrel et al, 2016). For some compounds stir bar sorptive extraction has shown potential (Müller-Tautges et al, 2014), however SPE via cartridge and disc materials are currently more versatile due to the availability of a wider range of sorbents, which allows more targeted method optimisations.…”

“…Table 2 lists a compilation of isoprene and terpene-sourced SOA compounds identified over a range of forested canopy locations and in snow samples from more remote locations. Despite this complexity, and with both degradation pathways and atmospheric concentrations still needing further study (Kroll et al, 2011), a transition in detection of some key SOA components from laboratory-confined experiments to detection in natural atmospheric samples, as well as in some surface snow and ice core studies, provides promising results for use of SOA constituents as climate markers (Fu et al, 2009;Fu et al, 2016;Pokhrel et al, 2016).…”