|Description||The observations presented and discussed in this paper were obtained as part of a
research project conducted under contract NObs-2083 with the Bureau of Ships of
the U. S. Navy by the Woods Hole Oceanographic Institution. The observations
and their original reduction were carried out under the direction of Jeffries Wyman.
The airplane soundings were undertaken by Kenneth McCasland and Alfred Woodcock.
The sea surface temperature was measured on the surface ships by David F. Barnes
and Roger Patterson. The necessary airplane (PBY-SA) and surface boats (PC's) were
made available by the U. S. Navy.
All observations were made during the spring of 1946 at about 19.5°N latitude,
66°W longitude, north of San Juan, Puerto Rico, and at about lO°N latitude, 79.5°W
longitude, north of Coco Solo, Panama. An extensive preliminary report on the results of the expedition with a limited circulation was prepared by Wyman and his collaborators
during the summer of 1946.
The present paper deals with certain phases of the work in a more detailed fashion.
Special attention is given to the temperature and humidity distributions in the vertical
and to their interpretation in the light of meteorological principles. A discussion of
atmospheric turbulence based on airplane measurements has already been published
elsewhere (Langwell, 1948), and an application of the airplane soundings to the theory
of cumulus clouds has been studied by Stommel (1947).
The second and third chapters of this publication deal with the description of observational
techniques used by the expedition, with the methods of reduction and present
the data on which the later discussion is based. It has been thought desirable to publish
these data in extenso because they may be of interest to other meteorologists in view
of the sparsity of upper-air observations in this region. The actual preparation of
Chapters II and III is largely the work of Bunker and Stommel.
In order to show how the observations made off Puerto Rico fit into the general
pattern of climatic and weather conditions in the Caribbean area Chapter iv presents
a survey of the climate of this region and of the weather conditions during the time when
the observations were taken. This Chapter was contributed by Joanne Malkus. It is
pertinent to include in this general introduction the conclusion drawn in Chapter IV
namely that the weather situations encountered represented, in general, a relatively
undisturbed trade-wind regime of early spring.
The homogeneous layer of nearly dry-adiabatic lapse-rate of temperature and almost
constant mixing ratio is one of the most characteristic phenomena in the lowest atmosphere
of this region. It is also of utmost importance for the energy budget of the hydrosphere
and the atmosphere. Therefore, a special discussion of this layer by Bunker is
given in Chapter V.
Because of the nearly dry-adiabatic lapse-rate in the homogeneous layer most of the
heat transfer between water and air in the trade-wind zone must be in the form of latent
heat of vaporization, a conclusion whose thermodynamic implications were discussed
thoroughly by Ficker (1936). For this reason the distribution of water vapor deserves
special attention, and Chapter VI deals with this variable as a problem in turbulent mass
exchange. The analysis presented in this chapter is due to Haurwitz and Stommel.||en