Measurements of the Latitudinal Distribution of Light Hydrocarbons and Halocarbons Over the Atlantic

Rudolph, J.; Jebsen, C.; Khedim, A.; Johnen, F. J.

doi:10.1007/978-94-009-6505-8_52

Cited by 9 publications

(3 citation statements)

References 16 publications

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“…The southern hemispheric mixing ratios were about 1-2 pptv, not much different from those of the March 1990 trip. Overall, our reported mixing ratios fall in the lower end of published values, but are in good agreement with the measurements made by Koppmann et al [1993] in August/September, 1989 and the measurements made by Rudolph et al [1984] in spring 1983. Our data also agree with the summer and winter measurements made in Hokkaido, Japan between 42 ø-45øN [Makide et al, 1987].…”

Section: Methodssupporting

confidence: 90%

Seasonal variations in the atmospheric distribution of a reactive chlorine compound, tetrachloroethene (CCl₂=CCl₂)

Wang

Blake

Rowland

1995

Geophysical Research Letters

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Tropospheric mixing ratios of CCl2=CCl2 were measured at remote surface locations in the Pacific between 71°N and 47°S during September and December of 1989, and March and June of 1990. The observed gradient of decreasing concentrations from the northern to southern hemisphere, and very low concentrations in the southern hemisphere throughout the year, indicates a predominant input from the northern hemisphere. Our seasonal measurements in the northern hemisphere showed maximum CCl2=CCl2 concentrations occurring in the late winter and minimum concentrations occurring in the late summer. This distinct seasonal variation is strongly coupled to the atmospheric abundance of hydroxyl radical, the only important species responsible for CCl2=CCl2 removal. Using the estimated global CCl2=CCl2 emissions the lifetime is calculated to be about 5.4 months which is in good agreement with the 4.0 month estimate obtained from the inverse ratio of its measured hydroxyl reaction rate constant compared with that of methylchloroform (CH3CCl3).

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Section: Methodssupporting

confidence: 90%

Seasonal variations in the atmospheric distribution of a reactive chlorine compound, tetrachloroethene (CCl₂=CCl₂)

Wang

Blake

Rowland

1995

Geophysical Research Letters

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“…The decrease with latitude found in our measurements is a factor of 2 lower than the gradient reported by Rudolph and Ehhalt (1981) for January/February 1979 and by Rudolph et al (1984) for FebruarylMarch 1983. Furthermore, on the average the absolute mixing ratios differ by a factor of 2, which probably indicates a seasonal variation in the Northern Hemisphere.…”

Section: The Distributions Ofethene Propane and Acetylenecontrasting

confidence: 72%

The distribution of light nonmethane hydrocarbons over the mid-Atlantic: Results of the Polarstern cruise ANT VII/1

et al. 1992

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Abstract. During the cruise ANT VII/I (September/October 1988) of the German research vessel Po/arstern the latitudinal distributions of several nonmethane hydrocarbons were measured over the Atlantic between 45" N and 30' S by in-situ gas chromatography.On the average, the highest mixing ratios of ethane, propane, i-and n-butane, ethene and acetylene were observed in the Northern Hemisphere around 40" N and just north of the intertropical convergence zone, respectively. South of the equator, a bulge in the mixing ratios of ethane and acetylene was observed indicating aged biomass burning emissions. This observation coincided with enhanced tropospheric ozone found in this region at this season. On the average ethane and acetylene mixing ratios were around 500 and 100 ppt, respectively, whereas the levels of the other NMHC were in the range of some ppt up to 100 ppt.Compared with the results of the cruise ANT V/5 (March/April, 1987), the ethane mixing ratios in September/October proved to be a factor of 3 lower in the Northern Hemisphere and a factor of 2 higher in the Southern Hemisphere, probably due to seasonal effects. Possible causes are the higher OH radical concentrations in summer, which result in a faster removal of ethane or stronger emission from biomass burning which also peaks in the dry season.The relative pattern of the hydrocarbons just north of the ITCZ was very similar for both measurement series. In this region, the NMHC were advected by long-range transport from the continent, whereas generally the ocean itself acts as a major NMHC source. This is supported by the results of a balance calculation between oceanic emissions and atmospheric removal rates.

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“…In the past years, several investigations of light nonmethane hydrocarbons (NMHCs) in the remote marine atmosphere have been published [cf. Bonsang and Lambert, 1985;Bonsang et al, 1988;Ehhalt et al, 1985;Greenberg and Zimmermann, 1984;Rasmussen and Khalil, 1982; Rudolph and Ehhalt, 1981;Rudolph et al, 1982Rudolph et al, , 1984Rudolph, 1988; $ingh and $alas, 1982]. The results of these measurements indicate that several light NMHCs have substantial oceanic sources [cf.…”

Section: Introductionmentioning

confidence: 99%

Measurements of light atmospheric hydrocarbons over the Atlantic in regions of low biological activity

Rudolph¹,

Johnen²

1990

J. Geophys. Res.

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133

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More than 200 in situ measurements of several selected nonmethane hydrocarbons (NMHCs) were made in the remote marine atmosphere over the Atlantic between 40øS and 50øN. Ethane, the by far longest lived of the NMHCs, showed southern hemispheric mixing ratios around 280 ppt, comparable in magnitude to most other previous measurements. The mixing ratios of ethene, propene, propane, and i-and n-butane in the southern hemisphere were in the range of 10-30 ppt. For i-pentane and n-pentane the atmospheric mixing ratios in the southern hemisphere were below the detection limit of 15-20 ppt. These values are rather low compared to other published measurements in the marine atmosphere. This is due to the remoteness of the measuring locations and the very low biological activity in the surrounding ocean areas. For all alkanes the latitudinal profiles exhibit a considerable decrease from north to south. The relative hydrocarbon patterns show that the alkanes in the northern hemisphere are primarily due to long-range transport from continental or coastal areas. In general the transport times exceed several days. Consequently, the observed northern hemispheric ethene and propene mixing ratios must be, with few exceptions, primarily the result of oceanic emissions. The average difference of these compounds by a factor of 2 between the southern and the northern hemisphere can be explained by change of the phytoplankton concentration in ocean water. There is little or no indication for the existence of significant diurnal cycles for these two alkenes.

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Measurements of the Latitudinal Distribution of Light Hydrocarbons and Halocarbons Over the Atlantic

Cited by 9 publications

References 16 publications

Seasonal variations in the atmospheric distribution of a reactive chlorine compound, tetrachloroethene (CCl₂=CCl₂)

Seasonal variations in the atmospheric distribution of a reactive chlorine compound, tetrachloroethene (CCl₂=CCl₂)

The distribution of light nonmethane hydrocarbons over the mid-Atlantic: Results of the Polarstern cruise ANT VII/1

Measurements of light atmospheric hydrocarbons over the Atlantic in regions of low biological activity

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Measurements of the Latitudinal Distribution of Light Hydrocarbons and Halocarbons Over the Atlantic

Cited by 9 publications

References 16 publications

Seasonal variations in the atmospheric distribution of a reactive chlorine compound, tetrachloroethene (CCl2=CCl2)

Seasonal variations in the atmospheric distribution of a reactive chlorine compound, tetrachloroethene (CCl2=CCl2)

The distribution of light nonmethane hydrocarbons over the mid-Atlantic: Results of the Polarstern cruise ANT VII/1

Measurements of light atmospheric hydrocarbons over the Atlantic in regions of low biological activity

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Product

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Seasonal variations in the atmospheric distribution of a reactive chlorine compound, tetrachloroethene (CCl₂=CCl₂)

Seasonal variations in the atmospheric distribution of a reactive chlorine compound, tetrachloroethene (CCl₂=CCl₂)