ALBERT

Description: The observations presented here were undertaken as a continuation of a broader program to investigate atmospheric convection. One phase of this study concerns the relation between convective motions, their energy sources, and the structure of the atmosphere prior to their onset. The structure of the atmosphere is described in terms of such parameters as temperature, humidity, velocity, turbulence, and distribution of these in space. An oceanic island was chosen as the site for this phase of the study primarily because it serves as a localized and clearly defined energy source for convective motions. Nantucket was selected from the many accessible islands in the Woods Hole area, nearly all known to produce convective cloud streets, mainly because of its flat, smooth topography. Because its elevation never exceeds 15 meters above sea level and because it contains no large trees, hills or other obstructions, the effect of heating the air from below is rather well isolated due to minimization of the barrier and frictional effects. Previous observational work (Malkus, Bunker, and McCasland, 1949) indicates that such heating is the main energy source for the observed convective motions and constitutes a necessary but not suffcient condition for their production. This conclusion is corroborated and extended by the present data.

Description: The series of observations described in this report were planned with the double purpose of measuring the evaporation and transport of water vapor from the ocean into an unstable atmosphere, and of studying the diffusion processes operating in air of this stability class. Measured values of the evaporation from ocean surfaces were conspicuously absent from the meteorological literature until Craig and Montgomery (1949) published values for hydrostatically stable air. The present set of measurements extends our knowledge to include evaporation into a hydrostatically unstable air mass. In addition to evaporation values at the surface, net transports of water vapor at many levels up to 2000 meters have been measured.

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.

Description: Originally issued as Reference No. 68-8, series later renamed WHOI-

Description: A C-54Q aircraft was bailed to the Woods Hole Oceanographic Institution to participate in the International Indian Ocean Expedition and other research projects in the fields of meteorology and oceanography. With the joint support of the Office of Naval Research and the National Science Foundation, the aircraft was modified and instrumented for meteorological research.

Description: Submitted to the National Science Foundation on Work Accomplished under Grant G 22389 to the Woods Hole Oceanographic Institution.

Description: Originally issued as Reference No. 68-62, series later renamed WHOI-.

Description: A C-54Q aircraft equipped with meteorological instruments was flown three times to India to participate in the International Indian Ocean Expedition. Flights were made out of Bombay, Gan, and Aden to observe winds, temperatures, humidities, clouds, radiation, carbon dioxide, tritium, turbulence, and turbulent fluxes of heat, water vapor, momentum and kinetic energy. The present paper reports the values of 405 measurements of the turbulence and turbulent fluxes and interprets them in terms of the monsoon circulation and the effect upon currents and temperatures of the Arabian Sea. Analyses of other data have been reported and interpreted elsewhere. The aircraft turbulence measuring system used was developed earlier by Bunker (1955) (1960). It consisted of a vertical accelerometer, a strain-guage air-speed transducer, a vertical gyro, a platinum wire thermometer and a microwave refractometer for humidity measurements. The data was recorded on a nine-channel oscillograph. A digitizing reader was used to read and punch the data on cards. The turbulent quantities and fluxes were computed and tabulated by machine. The accuracy and limitations of the system are discussed. While much is left to be desired in terms of accuracies and spectral range, the results are meteorologically useful and comparison shows good agreement with other techniques.

Description: Submitted to the National Science Foundation under Grants G-22389 and GA-1490.

Description: Scientists at Woods Hole routinely collect and analyze a considerable amount of data relating to the oceans of the world. Of the many different kinds of data, one particular subset concerns those events occurring at the sea surface. A large number of sea surface environmental observations have been collected at Woods Hole. These data, and the subsequent analyses generated from the Air/Sea Heat Flux and the Climatology study projects, have been collected and archived. This document describes the W.H.O.I./ Climatology and Air/Sea Interaction (WHOI/CASI) data collection and provides an initial index to its various components.

Description: Prepared for the Office of Naval Research under Contract N00014-74-C-0262; NR 083-004 and for the National Science Foundation (Climate Dynamics Program, Atmospheric Sciences Division) under Grant ATM 77-014?5.

Description: Includes Errata

Description: Time-series of monthly averages of latent, sensible and radiational heat fluxes and momentum fluxes at the surfaces of the North and South Atlantic Oceans were calculated from ship weather observations. These fluxes, together with values of meteorological variables have been averaged over entire Marsden squares (10X10° squares) for all months from January 1948 through December 1972. The method of computing fluxes from ship weather observations, listing of variables averaged, addition of sea-ice coverage of sub-polar regions, correction of albedos for the presence of sea ice, correction of infrared radiational exchange for humidity conditions of the upper atmosphere, and format of the data on magnetic tapes are described. Statistics of the fluxes and variables have been computed. Standard data tapes containing these time series and statistics are available.

Description: Prepared for Climate Dynamics Research Program~ Division of Atmospheric Sciences, National Science Foundation under Grant ATM 77-01475 A01.

Description: Also published as: Journal of Marine Research, Volwne 36, 3, 1978, pp. 311-322.

Description: From the wind stress computation of Bunker (1976) for the North Atlantic, the annual mean and seasonal vertical velocities which result from convergences in the Ekman Layers are computed. Charts of the geostrophic and total transport (geostrophic plus Ekman) are constructed using the Sverdrup relationship. Of particular interest are an intense current leaving the coast at the point where the Gulf Stream separates and a cyclonic gyre north of the Stream in this area. Good agreement exists between the computed features of the large scale circulation patterns and the observed ones. Close correspondence exists between the predicted and observed paths of the Gulf Stream; separation from the coast occurs at the maxima in the wind stress.

Description: Prepared for the Office of Naval Research under Contract N00014-74-C-0262; NR 083-004.

Description: Originally issued as Reference No. 56-65, series later renamed WHOI-.

Description: This report presents turbulence, flux, temperature and water vapor data obtained from an airplane flying over the Gulf of Maine and adjacent shores. Measurements of the root-mean-square turbulent deviation velocities, shearing stresses, and heat flows were made at many heights and offshore distances in air masses moving from land to water. Stability effects on the turbulence and fluxes of heat and momentum have been Observed over a wide range of conditions as air flowed over cooler or warmer surfaces. The following conclusions have been drawn from a study of the data: (1) The magnitudes of the root-mean-square turbulent deviation velocities δw and δu 3 increases with height in the lowest 100 meters and then decreases slowly with height up to the inversion where the velocities drop to very low values. (2) Shearing stresses were found to increase with height up to the 100 to 200 in level and then drop off with height. This height variation is in contrast to the generally accepted notion of a decrease of the stress from the surface to the geostrophic level. These observations confirm the findings of Scrase (1930) and others and demand an investigation of the acceleration of the air and the effects of thermal winds. (3) Both the horizontal and vertical components of the turbulent wind are increased by hydrostatic instability and decreased by stability. The horizontal component is affected less than the vertical component by stability differences. (4) The decrease in the turbulent velocities as air passes from land to cooler water is great and rapid while the increase in turbulent velocities as the air passes over warmer water is slight and slow. (5) The observed heat fluxes also first increase and then decrease with height and usually become negative near the top of the mixed ground layer where the potential temperature gradient becomes strongly positive. (6) The stability of the air above about 50 m is a very poor indicator of the temperature difference existing between the underlying surface and the air of the main mixed layer. Diffusion of heat downward from a layer of warm air above the ground layer frequently is the cause of a stable lapse rate regardless of the relative temperature of the surface below. (7) No comparison of the coefficient of turbulent mass exchange for water vapor, heat flow and momentum could be made since the temperature gradient was stable even when heat was flowing upward, and no wind profiles were made over the water.

Description: Office of Naval Research under contract Nonr-1721(00) (NR-082-021)