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Scala, John

Publications and source records attributed to Scala, John.

The Amazon Boundary-Layer Experiment (ABLE 2B) - A meteorological perspective

The Amazon Boundary-Layer Experiments (ABLE) 2A and 2B, which were performed near Manaus, Brazil in July-August, 1985, and April-May, 1987 are discussed. The experiments were performed to study the sources, sinks, concentrations, and transports of trace gases and aerosols in rain forest soils, wetlands, and vegetation. Consideration is given the design and preliminary results of the experiment, focusing on the relationships between meteorological scales of motion and the flux, transports, and reactions of chemical species and aerosols embedded in the atmospheric fluid. Meteorological results are presented and the role of the meteorological results in the atmospheric chemistry experiment is examined.

Garstang, Michael↗

Cumulus cloud model estimates of trace gas transports

Draft structures in convective clouds are examined with reference to the results of the NASA Amazon Boundary Layer Experiments (ABLE IIa and IIb) and calculations based on a multidimensional time dependent dynamic and microphysical numerical cloud model. It is shown that some aspects of the draft structures can be calculated from measurements of the cloud environment. Estimated residence times in the lower regions of the cloud based on surface observations (divergence and vertical velocities) are within the same order of magnitude (about 20 min) as model trajectory estimates.

Garstang, Michael↗

Trace gas exchanges and transports over the Amazonian rain forest

Early results are presented from a program to model deep convective transport of chemical species by means of in situ data collection and numerical models. Data were acquired during the NASA GTE Amazon Boundary Layer Experiment in July-August 1985. Airborne instrumentation, including a UV-DIAL system, collected data on the O3, CO, NO, temperature and water vapor profiles from the surface to 400 mb altitude, while GOES imagery tracked convective clouds over the study area. A two-dimensional cloud model with small amplitude random temperature fluctuations at low levels, which simulated thermals, was used to describe the movements of the chemical species sensed in the convective atmosphere. The data was useful for evaluating the accuracy of the cloud model, which in turn was effective in describing the circulation of the chemical species.

Garstang, Michael↗