C₁-C₄ hydrocarbons in the North and South Pacific¹

Abstract

Low molecular weight hydrocarbons in the surface waters of the North and South Pacific have been measured. Methane concentrations average 4.2 x Inl/l, while the Cz-C, hydrocarbons averaged 1-5 x 10-6 ml/l. A large broad peak was found between 10" N and 10" S for the unsaturated hydrocarbons. Large concentrations of the C,-C, hydrocarbons were found in the different types of Antarctic sea ice. Atmospheric methane concentrations averaged 1.44 0.04 ppm and decreased t o 1.36 kO.04 pprn at the Intertropical Convergence Zone (ITC).

Ethylene and methane in the upper water column of the subtropical Atlantic

“…Strong regional variations of ethylene concentrations in surface waters are observed in several studies of various marine areas including the Atlantic Lamontagne et al 1974;Plass et al 1992;Plass-Dülmer et al 1993, 1995. Investigations by Swinnerton and Lamontagne (1974) (Brooks & Sackett 1973).…”

“…Brooks and Sackett (1973) suggest that ethylene in the Gulf of Mexico is associated with primary productivity. Lamontagne et al (1974) assume variations of ethylene concentrations in the Pacific to be the result of biologic activity. Zang et al (1993) found indications for ethylene production in the red algae Porphyra perforata.…”

Volatile organic compounds in seawater

“…Numerous reports have been made concerning the occurrence of Cl to C4 hydrocarbons in seawater (Unnenbom and Swinnerton, 1970;Frank et aL., 1970;Lamontagne et al, 1971; Swinn.erton and Lamontagne et al, 1974;Lamontagne et al, 1976;Scranton, 1977). Methane typically occurs at about 30 ng/kg seawater (2.2 nM), ethane at 0.6 ng/kg (0.02 nM), and propane at 0.6 ng/kg (0.014 nM).…”

Untitled

“…This process is of particular importance for those stations located at latitudes south of 30° S where the land surface and thus the continental C O production is negligible. The oceanic CO source strengths, either by direct CO emission from the oceans (Conrad et al, 1982) or by CO formation of hydrocarbons emitted from the ocean (Lamontagne et al, 1974(Lamontagne et al, , 1975Singh et al, 1978;Rudolph et al, 1982) are very small if compared with the total C O source strengths. Thus, the "excess CO" to balance the photochemical production and destruction of C O at 35"s must be advected from northerly latitudes.…”