1086 F. General OLR(1987)34(12)

Recent studies of Cameroon's 33 crater lakes indicate that only lakes Nyos and Monoun contain large amounts of dissolved CO2, suggesting that the other lakes do not pose a threat of gas release. The new data also suggest that the recharge rates for those two lakes, which released large clouds of CO, in 1986 and 1984, respectively, are very low. The discovery of a surface carbonated spring which generates large amounts of CO 2 supports the theory that rising CO 2 is dissolved in groundwater which feeds the lakes. (gsb)

87:7112 Staff, 1987. Warm oceans dissolve the greenlmuse

effect. New $cient., 114(1566):p.40.

Because carbon dioxide dissolves more readily in cold water, scientists were surprised to find that samples of North Pacific water show that most CO 2 is absorbed by the oceans in high summer (July to Sept.). Two factors are at work: plankton photo- synthesizes more in summer thereby consuming more CO2; warm ocean surface layers suppress the convection currents which bring CO-,-rich water to the surface. That natural processes may compensate for the 'greenhouse effect' is further suggested by studies showing some plants have adapted to increased CO., levels by changing stomatal density. (wbg)

8'7:7113 Tomlinson, Paul (ed.), 1987. Audits in environmental

assessment. Special issue. Environ. Monit. As- sessment, 8(3):261pp; 4 papers.

This special issue 'provides a timely review of research efforts into the role of potential feed-back mechanisms for environmental assessments.' Fol- lowing an introductory editorial, which takes note of criticisms levelled at current environmental as- sessment practices and emphasizes the need to improve predictive accuracy and define the range of predictive error, are four presentations treating environmental audits and the formulation of a consistent terminology to describe them; the role and need for a systematic feedback mechanism to ensure implementation of commitments made in an assessment; the results of a study to evaluate the precision and accuracy of U.S. environmental impact statements; and a literature review of environmental audits. (hbf)

87:7114 Waldichuk, Michael, 1987. Editorial. Natural versus

a n ~ lmlmOts. Mar. Pollut. Bull., 18(4): 143-144.

Although many natural events (volcanic eruptions, earthquakes, tornadoes, hurricanes and typhoons) involve enormous releases of energy and devasta- tion, they are usually of brief duration, and restor- ative processes begin almost immediately. Man's degradative activities, especially when combined with natural forces, may cause longterm and irre- versible damage. Examples cited include the effects of overfishing in concert with El Niflo on the Peruvian anchovy fishery; the impact of the anti- fouling agent, tributyltin, and the cold winter of 1962-63 on oysters along the east coast of England; and the possible effects of exploratory drilling in conjunction with 'late' springs on marine bird populations in the Canadian Arctic. (hbf)

F420. Miscellaneous

87:7115 Cragin, B.L., W.B. Hanson, R.R. Hodges, D.

Zuccaro (comment), L.A. Frank, J.B. Sigwarth and J.D. Craven (reply), 1987. Commeat on the papers 'On the influx of small comets into the Earth's upper atmmpltere I. Observations and II. Interpretation: Geophys. Res. Letts, 14(5):573- 580.

Frank et al. (1986) hypothesized that dark spots in ultraviolet images of a sunlit Earth are due to vapor clouds of small, snowy comets bombarding the upper atmosphere. Chubb (1986) argued that the holes were instrumental artifacts. That argument is extended theoretically in this comment (Cragin et al.) by statistical analysis of dark pixel events in 182 images supplied by Frank. Cragin et al. conclude that the single pixel nature of the events at all altitudes, the absence of darkening in neighboring pixels, and the lack of altitude dependence on occurrence frequency rule out a geophysical cause for the 'holes.' In reply, Frank et al. undertake a 'computationaUy tedius, rigorous treatment of the instrument responses,' which conflicts with the Cragin et al. analysis, said to contain 'serious errors and insufficiencies that eliminate the foundation of their claims.' Their own, more rigorous analysis, argue Frank et al., further supports a geophysical cause for the 'holes.' (fcs)