1994 Arctic Ocean Section
AOS-94 light hydrocarbon concentrations and ratios compared with
those from other researchers for Alaska and the Norwegian Arctic.
Ethane
Acetylene Propane Acetylene/ Propane/
(pptv)
(pptv)
(pptv)
Ethane
Ethane
Pacific (7380N)
836 68
56 6
69 12
0.061
0.084
High Latitude (8087N)
726 36
64 7
64 8
0.088
0.089
Atlantic (879080N)
765 51
65 8
87 59
0.085
0.113
865 59
57 17
53 15
Alaska*
0.066
0.061
1195 27
67 18
87 30
Norwegian Arctic†
0.056
0.073
* From Blake, D.R., D.F. Hurst, T.W. Smith, W.J. Whipple, T. Chen, N.J. Blake and F.S.
Rowland (1992) Summertime measurements of selected nonmethane hydrocarbons in
the Arctic and Subarctic during the 1988 Arctic Boundary Layer Expedition (ABLE 3A).
Journal of Geophysical Research, 97: 16,55916,588.
† From Hov, O., S.A. Penkett, I.S.A. Isaksen and A. Semb (1984) Organic gases in the
Norwegian Arctic. Geophysical Research Letters, 11: 425428.
Ratios of acetylene and propane to ethane concentrations were also calcu-
lated for this data set. The acetylene-to-ethane ratio for the Pacific side data is
consistent with the one for Alaska, but the Atlantic-side ratio is higher than
for the Norwegian Arctic. This difference is due to the lower AOS-94 ethane
results for the Atlantic side. Propane-to-ethane ratios are slightly higher than
those reported by other researchers for both the Pacific side and Atlantic side.
The difference on the Pacific side is attributable to the somewhat higher pro-
pane concentrations, and on the Atlantic side the difference is again due to
lower ethane concentrations.
The preliminary data from the light hydrocarbon canister sampling pro-
gram agree well with work that has been done previously in the Alaskan and
Norwegian Arctic. The lower ethane concentrations on the Atlantic side of
the Arctic Ocean are probably attributable to increased distance from terres-
trial sources. The ethane concentrations observed in the high-latitude portion
of the transect may be useful for determining the degree of aging of the air
mass encountered in this area. These light hydrocarbon concentrations will
provide additional data for estimating the background tropospheric volatile
organic compound levels used to input advective inflows for continental atmo-
spheric modeling. In addition, although only data from the high Arctic regions
have been presented here, we collected hydrocarbon and some additional atmo-
spheric data throughout the entire circumnavigation of the North American
continent during AOS-94. This has yielded a unique data set for assessing the
nature of continental and oceanic air masses, as well as providing an extended
latitudinal profile from 7 to 90N for these atmospheric species. Finally, once
the Arctic data are available from all the compounds analyzed with the in-situ
gas chromatograph, it is expected that an improved understanding of back-
ground atmospheric chemical processes will have been derived from the sam-
pling carried out on this unique expedition.
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