high winds is associated with the surface tearing. Coll. of Mar. Studies, Univ. of Delaware, 700 Pilottown Rd., Lewes, DE 19958, USA.
B250. Clouds 90:6973 Detwiler, Andrew, 1990. Analysis of cloud Imagery using box counting. Int. J. Remote Sens, 11(5): 887-898. Photographic images of portions of an altocumulus cloud field were obtained from a rising balloon. They spanned a range of resolutions as the balloon rose. The fractal dimension of this field is estimated using a box-counting procedure. It is shown that the field is characterized by multiple fractal dimensions that vary with both intensity and scale. Inst. of Atmos. Sci., South Dakota School of Mines and Tech., 501 E. St. Jospeph St., Rapid City, South Dakota 57701, USA.
B270. Precipitation 90:6974 Andersson, TaRe and Stefan Nilsson, 1990. Topographically induced convective snowbands over the Baltic Sea and their precipitation distribution. Weather Forecasting, 5(2):299-312. Swedish Meteorol. and Hydrol. Inst., S-60176 Norrkoping, Sweden. 90:6975 Moiler, Dctlev, 1990. The Na/CI ratio in rainwater and the seasalt chloride cycle. Tellus, (B)42(3): 254-262. Heinrich Hertz Inst. of Atmos. Res. and Geomagnetism, Acad. of Sci. of the GDR, Rudower Chaussee 5, DDR-1199 Berlin, DRG.
B310. Chemistry 90:6976
Khalil, M.A.K. and R.A. Rasmussen, 1990. Constraints on the global sources of methane and an analysis of recent budgets. Tellus, (B)42(3):229236. Recent observations show that methane concentrations have increased at an average rate of 16.5 ppbv/yr over the last decade. The present lifetime of methane is 8-12 years. Taking into account the 9 possibilities that the lifetime of methane has gotten longer over the last century because of a possible
decline in the natural sinks and that emissions from natural sources have also changed, we show that the anthropogenic fraction should be 40%-70%, and the total present emissions should be 420-620 Tg/y. Of 11 methane budgets analyzed over the last decade, only 2 meet these conditions. Inst. of Atmos. Sci., Oregon Grad. Ctr., 19600 N.W. Von Neumann Dr., Beaverton, OR 97006, USA. 90:6977 Rodhe, IIenning, 1990. A comparison of the contribution of various gases to the greenhouse effect. Science, 248(4960): 1217-1219. The current concern about an anthropogenic impact on global climate has made it of interest to compare the potential effect of various human activities. A case in point is the comparison between the emission of greenhouse gases from the use of natural gas and that from other fossil fuels. This comparison requires an evaluation of the effect of methane emissions relative to that of carbon dioxide emissions. A rough analysis based on the use of currently accepted values shows that natural gas is preferable to other fossil fuels in consideration of the greenhouse effect as long as its leakage can be limited to 3-6%. 9 by AAAS. Dept. o f Meteorol., Stockholm Univ., S-106 91 Stockholm, Sweden. 90:6978
Yurganov, L.N., 1990. Surface layer ozone above the Weddell Sea during the Antarctic spring. Antarct. Sci, 2(2):169-174. Ozone concentrations in the atmospheric surface layer above the Weddell Sea during the Antarctic spring, 1989, varied significantly. Lower levels of ozone were associated with colder Antarctic air masses and higher values with warmer mid-latitude air. The lowest ozone concentration was measured in the centre of a low pressure system. A definite diurnal variation of tropospheric ozone observed during clear days with low total ozone amount may be interpreted as a consequence of the occurrence of photochemical reactions under conditions of increased ultraviolet solar radiation. Arctic and Antarctic Res. Inst., 199226 Leningrad, USSR.
B320. Particulates (dust, aerosols, etc.) 90:6979
ttandler, Paul and Karen Andsager, 1990. Volcanic aerosols, El Nifio and the Southern Oscillation. [Comments on Nicholls, 1988.] Int. J. Climatol, 10(4):413-424. Dept. of Phys., Univ. of Illinois, 110 W. Green St., Urbana, IL 61801, USA.
OLR (1990) 37 (12)
Nicholls, N., 1990. Low-latitude volcanic eruptions and the El Nifiu/Southcrn Oscillation. [Comments on ttandler and Andsager, 1990.] Int. J. Climatol, I0(4):425-429. Bur. of Meteorol. Res. Ctr., GPO Box 1289K, Melbourne 3001, Australia.
Wagner, G.H. and K.E. Steele, 1990. Rain scavenging of tepKra aerosols from Mount St. lleleus 1980 eruptions. J. appl. MeI~ 29(5):368-374. Tephra in the atmosphere from the three major eruptions in 1980 was traced by analyzing the particulate matter from weekly rain collections at 62 sites across the U.S. Dilution of the tephra by other aerosols varied from 20'70 near Mount St. Helens to about 300'70 at downwind sites, which were two days and 3000 km from Mount St. Helens. Atmospheric cleanup of the tephra at a given site occurred in I-2 weeks, sometimes in a few days, as measured by the particulate matter in rain. Dept. of Geol., Univ. of Arkansas, 118 Ozark Hall, Fayetteville, AR 72701, USA.
B350. Pollution (see also C210-Chernical pollution, E300--Effects of pollution, F 2 5 0 Waste disposal) 90:6982
Steyn, D.G. and M. Segal, 1990. Enhancement of cross~ind pollutant dispersion by steadily veering winds in sea breezes. J. appL Afet, 29(5):429-432. An estimate is given of the relative importance of wind veering and turbulent diffusion in the mean horizontal spread of pollutant plumes in the atmosphere. Documented veering rates in sea breezes are used to illustrate the effect, and it is concluded that for typical sea breeze induced veering, the effect will be significant over much of the range of applicability of the Gaussian plume model. Dept. of Geogr., 128-1984 West Mall, Univ. of British Columbia, Vancouver, BC V6t IW5, Canada.
B380. Forecasting 90:6983 Leslie, L.M. et al., 1990. The skill of tropical cyclone position forecasting in the Australian region. Aust. met. Mag~ 38(2):87-92. Bur. of Meteorol. Res. Ctr., Melbourne, Australia.
C. CHEMICAL OCEANOGRAPHY
CI0. Apparatus and methods 90:6984
Berger, G. et al., 1990. Preparation and purification of chlorophylls, bacteriochlorophylls and of their derivatives. J. liquid Chromatog, 13(2):333-344. Service de Biophys., Dept. de Biol., CEN Saclay 91191, Gif sur Yvette Cedex, France. 90:6985
Bishop, J.K.B., 1990. Determination of barium in seawater using vanadium/silicon modifier and direct injection graphite furnace atomic absorption spectrometry, dnalyt. Chem~ 62(6):553-557. Lamont-Doherty Geol. Observ., Palisades, NY 10964, USA.
90:6986 Blain, Strphane et al., 1990. Application of a tetraaza macrocycle immobilized on an organic polymer to the determination of trace amounts of manganese in seawater. Analytica china. Acta, 232(2):331336. Inst. d'Etudes Mar., Univ. de Bretagne Occidentale, 6 Ave. le Gorgeu, 29287 Brest Cedex, France. 90:6987 Cofino, W.P., 1989. Methodology of chemical monitoring in the marine env'h'onment. Helgolfmder Mceresunters~ 43(3-4):295-308. Monitoring strategy and critical aspects in the execution are discussed. Examples from the recently