I = Balloon-borne measurements of trace gases and ...
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Aerosol concentrations, solar intensity, atmospheric turbidity, and meteorological conditions encountered along the cruise route of uscoc Northwlnd from Wellington, New Zealand, to Campbell Island to McMurdo Sound, 19 December 1979-6 January 1980.
Balloon-borne measurements of trace gases and aerosols over the South Pole D. J. HOFMANN, J. M. Ros, A. F. Fui, J. W. HARD ER , N. T. Kio, and C. L. OlsoN Department of Physics and Astronomy University of Wyoming Laramie, Wyoming 82077
D. L. ALBRrrrON, A. L. SCHMELTEKOPF and P. D. GOLDAN Aeronomy Laboratory National Oceanic and Atmospheric Administration Boulder, Colorado 80303
In January 1980, nine balloon soundings were conducted from South Pole Station. This campaign marked the ninth and final summer of stratospheric research in Antarctica by 1980 REVIEW
the Department of Physics and Astronomy at the University of Wyoming. Measurements conducted included two sets of five trace gas samples to a height of 31 kilometers, aerosol particles (radius ^!t0.15 micrometers) and condensation nuclei (radius 2:0.01 micrometers) to 28 kilometers, and five short soundings of condensation nuclei to about 4 kilometers to study the surface condensation nuclei features. As in the past, the air samples were analyzed by the National Oceanic and Atmospheric Administration (No) Aeronomy Laboratory in Boulder, Colorado; the results for the two soundings are shown in figure 1. For the first time large plastic balloons were employed at South Pole. This allowed samples to be obtained above 30 kilometers. Samples of methyl chloroform (CH3CC13) were obtained in addition to nitrous oxide (N 20), and the fluorocarbons F-12 (CF2 0 2), and F-il (CFC1 3). This marks the fourth measurement of the latter three gases, each a year apart. While stratospheric levels do not show a consistent time dependence, probably because of transport effects, which require averaging over a much larger data set, the upper tropospheric (6 to 7 kilometers) samples apparently do. Figure 2 shows the time history of these gases at this level. 183
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The condensation nuclei soundings were consistent with those made last year (i.e., low concentrations of 100 to 200 per cubic centimeter at the surface) and increasing dramatically above the surface to values as high as several thousand per cubic centimeter just above the surface. Examples of similar results have been reported in the past. (Hofmann, Rosen, Fuller, Martell, Olson, Schmeltekopf, and Goldan 1978; Hofmann, Rosen, Kjome, Olson, Schmeltekopf, Goldan, and Winkler 1979). This work was supported in part by the National Science Foundation grant DPP 77-21202 and by Department of Commerce grant 04-6-002-44019. Authors Fuller, Harder, Kjome, and Olson performed the field work at South Pole Station during January 1980.
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Figure 1. Trace gas profiles measured a day apart at South Pole Station. (pptv = parts per trillion by volume) 400
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References Goldan, P. D., Kuster, W. C., Albritton, D. L, and Schmeltekoph, A. L. 1980. Stratospheric CFC13, C1720 2 and N20 profile measurements at several latitudes. Journal of Geophysical Research, 85, 413. Hofmann, D. J., Rosen, J . M., Fuller, A. L., Martell, D. W., Olson, C. L., Schmeltekopf, A. L., and Goldan, P. D. 1978. Trace gas and aerosol measurements to 30 km in Antarctica. Antarctic Journal of the U.S., 13(4), 185. Hofmann, D. J ., Rosen, J. M., Kjome, N. T., Olson, C. L, Schmeltekopf, A. L., Goldan, P. D., and Winkler, R. H. 1979. Stratospheric trace gas and aerosol profiles at McMurdo and South Pole Stations, Antarctic Journal of the U.S., 14(5), 200-201. Rosen, J. M., and Hofmann, D. J . In press. A stratospheric aerosol increase. Geophysical Research Letters.
Figure 2. Time history of trace gas measurements in the upper troposphere (6-7 kilometers altitude) at McMurdo and South Pole. The number (2) accompanying a data point Indicates that two soundings gave the same result. (pptv — parts per trillion by volume) Increases for CF20 2 (10.5 percent per year) and CFC13
(9 percent per year) are clear. These increased values are consistent with emission rates to the atmosphere during the 1977 period. N 20, on the other hand, does not show a substantial time variation. For a detailed analysis of data obtained prior to 1980 from Antarctica as well as other stations see Goldan, Kuster, Albritton, and Schmeltekopf (1980). Figure 3 shows the results of the aerosol sounding compared with one obtained at McMurdo a year earlier. The three layers in the 10 . to 15-kilometer region are thought to be caused by the eruption of La Soufriere on the island of St. Vincent (13.3°N 61.2°W) in April 1979 and subsequent transport to the Southern Hemisphere during the spring and summer of 1979. For a detailed analysis of this and related events as measured at several stations, see Rosen and Hofmann (in press).
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Figure 3. Aerosol mixing ratio profiles (radius a0.15 mlcrom.ters) obtained In Antarctica 1 year apart.
ANTARCTIC JOURNAL
