The atmospheric budgets of mass, water vapor, heat, momentum, and mechanical energy have been analyzed for a 5-day undisturbed period (June 22-26, 1969) during the Barbados Oceanographic and Meteorological Experiment (BOMEX). Data were obtained from rawinsondes launched every 1% hr from the four corner ships of the BOMEX array. Computations were limited to the lowest 500 mb within a 500-km square centered a t 15'N, 56'30'W. The mass budget is characterized by mean, low-level divergence and downward motion. Maximum divergence (5 X 10-8 s-l) is found approximately 80 mb above the surface and maximum subsidence near the base of the trade-wind inversion. The computed average evaporation is 6.0 mm/day. The computations show an upward flux of moisture through the trade inversion by subgrid-scale eddies, but the mean downward flux dominates, leading to a net downward transfer of moisture through the trade inversion. A surface stress of 0.065 Newtons (N).m-z is computed from the momentum balance with the top of the friction layer approximately 130 mb above the surface. Computed frictional loss of grid-scale kinetic energy within the boundary layer is 0.8 W.m+. Heat balance computations indicate a Bowen ratio of approximately 0.1. Comparison of profiles of subgrid-scale moisture flux and nonradiative diabatic heating suggests that condensation and evaporation processes associated with the development and dissipation of trade-wind cumulus can make a significant contribution to the heat balance of the cloud and trade inversion layers.

Carbon monoxide (CO) and ozone (03) play a central role in the oxidizing capacity of the atmosphere. Standard meteorological parameters and concentrations of these trace gases at Big Meadows, Shenandoah National Park, Virginia, were monitored almost continuously from October 1988 to October 1989. The National Park Service has been measuring 03 at this and two other sites in the park since 1983. Seasonal, monthly, and diurnal variations of hourly averages are examined. In the winter, dry deposition dominates; ozone values are relatively low with CO and 03 negatively correlated. In the summer, photochemistry dominates; ozone values are relatively high, and CO and 03 are positively correlated. Ozone shows a yearly mean mixing ratio of 33 (c•= 12) ppbv and did not exceed the ambient air quality standard during this year. CO mixing ratios averaged 204 (c•= 51) ppbv with no discernible diurnal or seasonal variation. Histograms of hourly means of 03 and CO appear lognormal, but the chi-square tests for goodness of fit reject the hypotheses. Several lines of evidence suggest that the data are little affected by local sources and are reasonably representative of the regional air quality. The summer of 1989 was cooler than normal, and the average ozone concentration was lower than the 7-year mean, although an analysis of the full record illustrates no statistically significant trend. INTR OD U CTIONThe downward transport of ozone (03) from the stratosphere was thought to be the main source of tropospheric ozone [Junge, 1962], but the appearance of urban, Los Angeles type smog stimulated research on photochemical ozone production in the troposphere, where 03 is formed as a by-product of the photoxidation of hydrocarbons and is destroyed by dry deposition.The current interest in tropospheric ozone has two roots. One is the global importance of ozone in generating hydroxyl radicals (OH) by the photoproduction of O(1D) and its reaction with water vapor (reactions (R1) and (R2)). The concentration of OH in turn influences the concentrations of many trace species, such as CH4, CO, SO2, CH3CC13 (reactions (R3) and (R4), for example). O3+ hv --> O2+ O(1D) O(1D) + H20 --> 2OH OH + CO (+ 02) --> CO2 + HO2 The increase of tropospheric ozone over North America, Europe, and Japan [Logan, 1985] results in the greater oxidation of hydrocarbons. The second root is the oxidation strength of 03, which can be dangerous to human health [Folinsbee et al., 1988]. It is deleterious to vegetation and is thought to be responsible for most of the crop damage caused by air pollution in the United States [Heck et al., 1982, 1983, 1984; Douchelie et al., 1982; Reich and Aroundson, 1985] and to contribute to the observed decline of forests in Europe and the eastern U.S. [Skarby and Sellden, 1984]. Ozone plays a key role in biogeochemical cycles, air quality, and global change. As a pollutant and greenhouse gas, 03 should be brought under effective control, but the variability of its natural background level in the boundary layer makes difficult the def...

The principal objective of the Barbados Oceanographic and Meteorological Experiment (BOMEX) was to measure the rate of exchange of the "properties" heat, water substance and momentum between the tropical ocean and atmosphere over a 500-km square. The Sea-Air Interaction Program of BOMEX (called the "Core Experiment") determined the ship and aircraft array configuration and observation schedule during the period from 1 May to 2 July 1969. Intensive and in many cases redundant observations by several methods were made to permit for each property: a) direct measurement of vertical eddy flux of the property in the surface layer of the atmosphere; b) computation of horizontal flux divergence of the property in the lower 600 mb of the atmosphere, integrated over the array area; c) vertical transport of the properties through the top surface of this volume due to the mean vertical velocity; d) local rate of change of the volume integral of the property; and e) internal sources and sinks (i.e. radiation, precipitation, stress). Ranges of spatial resolution from 10 m to 500 km and temporal resolution from milliseconds to days are provided by the various sensor systems. Data reduction and analysis are underway. Preliminary results indicate that the goal of obtaining values of the significant energy transfer rates and conversions, with accuracy and resolution about an order of magnitude better than any previously available, will be attained. If so, a test of available parameterization formulae will be possible even under the relatively constant and uniform conditions over the tropical oceans.

This article, written a few days before the beginning of the field operations, summarizes the scientific and operational plans for BOMEX, the “Barbados Oceanographic Meteorological Experiment.” The basic concept of BOMEX has been described earlier by its former director, Ben Davidson (1968). His untimely death created a temporary crisis in the scientific direction of the project; however, his experiment design and his underlying thoughts have proved sound and no major changes in the layout or scientific objectives have been necessary. In the opinion of the project staff, Ben Davidson remains the man behind BOMEX. Continuity has been preserved throughout the BOMEX preparations by the Project Manager, William Barney, and his multi-agency staff. At this time, ships, airplanes and scientists are converging on Barbados. Therefore, the plans described here are by necessity final. Only facts of life can change them.

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