Bobby W. Crissman

On the relationship between high ozone in the rural surface layer and high pressure systems

Abstract The relationship of high ozone (ozone in excess of the National Ambient Air Quality Standards—NAAQS) with high pressure systems was examined using data collected in the summer of 1973, 1974 and 1975. It was found that high surface ozone occurred most often when a high pressure system was near a reporting station. Long periods of high ozone were associated with long-term buildups of high pressure greater than 20 days. High ozone occurred most often on the back side of the high pressure system in air that had large residence times in the system. This suggested that time was required to develop large or critical concentrations of ozone precursors. It was shown that high ozone occurred most often when the high pressure system was in the eastern portions of the United States. The evidence indicated that as the high pressure system moved from west to east, the air in the high had larger concentrations of ozone precursors and destructive agents when it was in the east. This suggested an injection of these constituents in the east. Furthermore, there appeared to be a change in the role of synthesis and destruction of ozone between 1973 and 1974 or 1975.

A Theoretical Study of the St. Louis Heat Island: The Wind and Temperature Distribution

Abstract A three-dimensional primitive equation model was used to study the St. Louis heat island. In this paper, the influence of synoptic wind speed and wind direction on the heat island is presented. With respect to the synoptic wind speed, it was found that the temperature and wind distribution associated with the St. Louis heat island changed markedly as the wind speed increased. When the synoptic wind speed was small, the intensity of the heat island was independent of the wind direction. However, for large synoptic wind speeds, the intensity of the heat island changed, and the change was dependent on the wind direction. These changes were due to the influence of the local topography.

Some Aspects of Gulf Stream Western Boundary Eddies from Satellite and In Situ Data

Abstract NOAA-5 infrared images were used to determine statistics of existing and developing perturbations on the western boundary of the Gulf Stream. The satellite data were combined with oceanographic data to study both a new-born eddy and one that had been in existence for a considerable time. On the average, the perturbations are much more intense, have larger dimensions, and move more slowly when located immediately downstream of the Charleston Bump, a region where the flow is influenced by the Blake Plateau, than when located farther downstream in a region where the slope is steeper.

Gulf Stream Boundary Eddies off the East Coast of Florida

Abstract Satellite infrared data and in situ data were used to study eddies off the east coast of Florida. The surface thermal manifestation of the eddies identified in the infrared data were alternating cold and warm tongues, conforming to the cyclonic spin-off eddies observed by Lee (1975); however, the eddies identified in the satellite data were larger than those observed by Lee. Statistics derived from the satellite data indicated that the eddies had average major and minor axes of 136 and 36 km, respectively. assuming an elliptic shape. They moved northward at an average speed of 30 km day−1, and the average period was 9 days.

Further Studies of a Cold Eddy on the Eastern Side of the Gulf Stream Using Satellite Data and Ship Data

Abstract A cold eddy was observed in late March and early April 1975 to encounter the eastern boundary of the Gulf Stream and entrain warm Gulf Stream water into its outer fringes. Available evidence indicated that the entrainment of Gulf Stream water in the western and southern portions of the eddy enhanced the density stratification creating available potential energy which led to an increase in kinetic energy in those regions. A secondary, cold perturbation with a high-salinity core was detected south of the center of the cold eddy. It was not clear from the data whether the conversion of available potential energy into kinetic energy increased the kinetic energy of the cold eddy, produced the secondary perturbation, or both.

Case study of exchange processes on the western boundary of the gulf stream using NOAA-2 satellite data and ship data

Abstract Eddies on the western boundary of the Gulf Stream off the southeast coast of the United States were studied using NOAA-2 IR data and data collected by the R/V DALLAS HERRING. The eddies in question had short life cycles (not much more than 72 hours) and were of small vertical extent (at most 60 m deep). These eddies appear to be the result of the steering of currents in shelf water toward the Gulf Stream boundary by the shoals found off the various capes from Cape Hatteras southward. This led to the penetration of a tongue of shelf water into the Gulf Stream and an eventual isolation of a lens of Gulf Stream water on the shelf.

Aspects of the Evolution Of the Marine Boundary layer during Cold-Air Outbreaks off the Southeast Coast of the United States

Abstract Remote sensing and in situ measurements that were obtained in February 1986 were combined with the results from a boundary-layer model to study aspects of the evolution of the marine boundary layer (MBL) during two cold-air outbreaks (CAO) off the southeast coast of the United States. Maximum total heat fluxes occurred over the Gulf Stream northeast of Cape Hatteras where very cold, dry air encountered the Gulf Stream and where the wind speeds were very large. Maximum 6-h values for the total heat flux were as high as 2015 W m−2. The magnitude of the area-average heat flux in the MBL was influenced not only by the surface air and dewpoint temperatures and the surface wind speeds off the coast but also by the area covered by Gulf Stream water (sea surface temperature greater than 22°C). The heat flux distribution off the coast rapidly produced large horizontal temperature (∼10°C) and humidity (4 g kg−1) differences over distances on the order of 100 km. The large influx of moisture at the surface ...