Summertime measurements of selected nonmethane hydrocarbons in the Arctic and Subarctic during the 1988 Arctic Boundary Layer Expedition (ABLE 3A)

Abstract

Approximately 1000 whole air samples were collected and assayed for selected C2‐C5 hydrocarbons during the 6‐week Arctic Boundary Layer Expedition (ABLE 3A). Transit flights enabled latitudinal (40°N to 83°N) and longitudinal (70°W to 155°W) profiles to be obtained for altitudes between 4000 and 6000 m yielding summertime background mixing ratios for ethane, ethyne, propane and n‐butane of 1050±200, 100±40, 120±80 and 10±8 pptv, respectively. Drilling associated with oil exploration in the Alaskan North Slope area is suggested to be a probable source of the enhanced levels of alkanes observed in the Arctic region within a radius in excess of 300 km from Prudhoe Bay, Alaska. A significant number of pollution plumes were encountered which could be attributed to wildfires. Factors describing the emissions caused by biomass burning relative to ethane for ethyne (0.40) and propane (0.08) were determined. An increase of hydrocarbon mixing ratios with altitude was observed during all but two of the missions. Therefore, the Arctic and sub‐Arctic are significantly influenced by the long‐range transport of pollutants from nonlocal sources. A single vertical profile made in the vicinity of Wallops Island, Virginia, revealed elevated levels of isoprene, numerous hydrocarbons of the types associated with the leakage of natural gas and fossil fuel combustion, and substantial concentrations of nitrogen oxides and ozone. This implies that long‐range transport of various gases from urban areas, combined with local biogenic emissions of isoprene, are significant sources of regional tropospheric ozone.

Isoprene emissions from a tundra ecosystem

“…In a vertical flight profile near Bethel, Alaska, over tundra and boreal forest ecosystems, isoprene concentrations ranged between 0.50 and 0.53 ppb below an altitude of 1000 m (see Fig. 17a in Blake et al, 1992). While these observed concentrations are lower than modelled, the strength of isoprene emissions in the flight source region is unknown.…”

“…Another snow-depth study found that either increased soil temperatures (due to direct warming) or drifting snow lead to increases in growing season length and greater biomass (Walker et al, 1999) for both moist and dry ecosystem types. This predicted increase in the dominance of shrubs has been seen in aerial photographs (Tape et al, 2006), detected in the Russian Arctic using tree-ring growth (Forbes et al, 2010) and is the current focus of remote sensing studies (e.g., Boelman et al, 2011). Changing species-composition effects on ecosystem BVOC emissions in the Arctic are complex.…”

“…While detailed knowledge of methane sources and sinks (Bartlett et al, 1992) as well as NO x and O 3 deposition fluxes (Jacob et al, 1992) were obtained during ABLE-3A, BVOC exchange measurements were not quantified. Non-methane hydrocarbon measurements on the NASA Electra research aircraft, however, indicated the abundance of important biogenic reactive trace gases in the Arctic (isoprene, Blake et al, 1992).…”

Non-methane Hydrocarbons and Their Ozone Formation Potentials in Foshan, China

“…Their sources in urban air are often dominated by anthropogenic emissions such as vehicular emission, industrial emission, evaporative emission, liquefied petroleum gas (LPG) and natural gas (NG) leakages (Barletta et al, 2005;Tang et al, 2007;Duan et al, 2008). In urban area where NMHCs concentrations are high, OH radicals attack on the various NMHCs plays a critical role in atmospheric photochemical reaction cycle (Blake et al, 1992;Sharma et al, 2000;Offenberg et al, 2011).…”

Comparison of atmospheric nonmethane hydrocarbons from the oil and gas field area in Niigata and areas without oil and gas fields in Ibaraki and Gunma in Japan, May and June 1995

“…Many studies have been done for atmospheric nonmethane hydrocarbons from the ocean (Rudolph and Enhalt, 1981;Donahue and Prinn, 1993), urban area (Uno et al, 1985;Seinfeld, 1989), rural area (Lonneman et al, 1978), polar regions (Blake et al, 1992) and tropical areas (Zimmerman et al, 1988). There are many sources that emit hydrocarbons such as engines, biomass burning and the ocean (Rudolph, 1988).…”