Search Results

You are looking at 1 - 10 of 11 items for

  • Author or Editor: Gilbert S. Raynor x
  • Refine by Access: All Content x
Clear All Modify Search
Gilbert S. Raynor

Abstract

A radio-controlled air sampling system was developed for sampling tracer gases at an array of remote, portable sampling stations. Each sampling station contains a receiver-decoder, a battery pack and three evacuated metal cylinders fitted with hand-operated toggle valves, radio-controlled latching solenoid valves and critical orifices. The transmitting station includes an encoder and an FM base station radio. It may be operated from a fixed base with a tower-mounted antenna or from an aircraft for greater distances. Distance is limited only by line of sight transmission. Three sets of samples may be taken at any selected time and for any selected duration within the volume limitations of the sampling cylinders and the flow limitations of the critical orifices. Each set is simultaneous at all sampling stations. Samples may be either continuous or intermittent. The system has been utilized in the field and a small representative set of data is shown to illustrate the system capabilities.

Full access
Gilbert S. Raynor

The rotary rain indicator, an electrical device for recording the time of beginning and ending of periods of precipitation, was developed at the Brookhaven National Laboratory Meteorology Group and has operated successfully for eight months. Its sensitive element consists of a rotating grid whose circuit may be completed by a drop of water.

Full access
Gilbert S. Raynor
and
Janet V. Hayes

Abstract

A study of the atmospheric transport and diffusion climatology of the United States east and Gulf coasts was conducted to aid in planning and site selection for potentially polluting installations. This paper presents selected results from an extensive statistical study. Regular hourly observational data were obtained from 30 coastal stations from Maine to Texas and analyzed in terms of conditions important to emission transport and diffusion. The 30 stations included four pairs with one of each pair at a greater distance from the coast than the other but near the same latitude.

For each station, wind directions were classified into eight groups with reference to orientation of the local coastline. For some studies, fewer classes were desirable and these were combined into three groups—onshore, alongshore and offshore. Wind speeds were divided into four classes. A stability class for each observation was computed by a modified Pasquill method. This gave eight classes which were combined into three—unstable, neutral and stable—for some studies. Diffusion ratings ranging from very good to very poor were derived from combinations of wind speed and stability classes. Finally, the joint frequency distributions of wind direction and diffusion rating were calculated for each station. Data were then classified by season, time of day, wind direction, wind speed, stability class and combinations of these variables, and the percent of hours in each subgroup determined.

Onshore winds were least frequent along the New England and Mid-Atlantic coasts except from Cape Cod to New York City and along the west coast of Florida. Onshore winds were most frequent along the east coast of Florida and the Texas coast. Poor diffusion conditions occurred most frequently from the Carolinas to the Florida east coast and along the northern Gulf Coast. At all stations, diffusion conditions were better during the day than at night. Among the paired stations, the more inland had a greater frequency of poor diffusion hours than the one nearer the coast.

Full access
Gilbert S. Raynor
and
Janet V. Hayes

Abstract

About 700 cases of wind direction meander occurred in a three-year period during onshore flow at a Long Island coastal site. Most appeared to be caused by internal gravity waves but some by roll vortices. Each case was documented with respect to date, time, wind speed, wind direction and stability, and described by duration, number of waves, angular amplitude and period. Hourly wind data for the same years were examined to determine the frequency of onshore flows.

Most meander cases occurred in spring and summer, at low to moderate wind speeds and with stable conditions over the ocean. Duration varied from 4 to 438 min and averaged 94 min. The number of half-waves per case varied from 4 to 63 and averaged 10. Frequency varied from 0.3 to 30 with a mean of 4 waves per hour. Mean angular amplitude ranged from 4 to 68 and averaged 14°. Maximum amplitudes as large as 125° occurred. Results were compared to σy data from oil-fog smoke diffusion experiments. Calculations show that horizontal dispersion caused by a combination of meander and turbulent diffusion can be more than 30 times greater than that caused by diffusion alone and averaged 4 times greater. However, meander with angular amplitudes greater than 3° occurred only 15% of the time during onshore flow even though the air over the ocean was stable 59% of the time. Thus, the presence of significant meander cannot be assumed for diffusion calculations, although diffusion measurements indicate that minor meanders are frequent during stable conditions.

Full access
Irving A. Singer
and
Gilbert S. Raynor

In order to effect a more consistent grouping of hourly meteorological data influenced by the diurnal cycle, a chronology based on the time of sunrise and sunset was devised. A code classified all hours within each bi-weekly period by this time system. The classification was further extended by dividing the year into solar seasons, defined as periods of time during which the distribution of solar hours is uniform.

The use of solar time as a major classification in the analysis of two years of hourly wind and temperature data obtained from six levels on the 420-ft meteorological tower at Brookhaven National Laboratory resulted in a better understanding of the relationships between the variables than could have been obtained by the use of standard time. Results of several lapse-rate and wind-profile studies made using both standard and solar time demonstrated the advantage of the latter system. Application of this method to other problems and regions is discussed.

Full access
Gilbert S. Raynor
,
Paul Michael
,
Robert M. Brown
, and
S. Sethuraman

Abstract

A research program is in progress at Brookhaven National Laboratory to determine the nature of atmospheric diffusion from a representative oceanic site, to relate observed diffusion patterns to meteorological and oceanographic variables, and to develop models to describe such diffusion. The program was initiated in response to plans for construction of offshore nuclear power plants.

Tracer experiments are conducted utilizing oil-fog smoke released from a boat stationed from 1–3 mi off-shore during onshore flows. The smoke is photographed from above and from the side to document lateral and vertical spread. The crosswind concentration distribution is measured by vehicle- and boat-mounted densitometers during successive traverses across the plume. Wind, turbulence and temperature at several levels are measured on the beach by tower-mounted instruments. Temperature profiles at greater heights are measured by kytoon- and aircraft-borne sensors. Water temperatures are also measured. Winds aloft are determined by pibal ascents and turbulence at various altitudes is sampled by an aircraft-mounted variometer.

Preliminary results show that diffusion is governed primarily by water and air temperature differences. With colder water, low-level air is very stable and diffusion minimal but water warmer than the air induces vigorous diffusion. Measurements of plume width and height have been obtained which are smaller and of normalized concentration which are larger than those predicted for the Pasquill F category. Measured values of plume width can be predicted from Eulerian measurements at the beach.

Full access
Gilbert S. Raynor
,
Robert M. Brown
, and
S. SethuRaman

Abstract

Experiments were conducted to investigate the differences in diffusion from an obstacle to free air flow in the ocean and from an undisturbed ocean site. A small island was used as the obstacle and simultaneous releases of oil-fog smoke were made from the island and from a nearby boat. The widths of the plumes and their concentration distributions were measured quantitatively during traverses across the plumes by a second boat. Extensive series of photographs were taken of the plumes from the surface and from the air. Meteorological measurements were made at two locations on the island, from the boats and from an aircraft. One test series was conducted during unstable conditions and a second series with neutral and stable conditions.

Width of the island plume over short periods was from 1.5 to 4 times that of the boat plume with the greatest difference during stable periods. Over longer periods, the differences were somewhat greater and much of the dispersion was caused by plume meander. Height of the island plume averaged about twice that of the boat plume. Normalized maximum centerline concentrations from the boat plume were 1.4 times those of the island plume during unstable periods but about twice during stable and neutral conditions. Averaged over all tests, dispersion from the island was about twice as great as from the boat.

Full access
Gilbert S. Raynor
,
Janet V. Hayes
, and
Eugene C. Ogden

Abstract

Pollen transport and dispersion from generalized area sources was studied by 29 flights to distances of 100 km and heights of 3 km using an aircraft-mounted isokinetic sampler. Tree pollens and ragweed pollen served as tracers. Four types of flights were made to study various aspects of pollen transport: 1) ascents over a fixed location to investigate vertical distribution; 2) flights over a source-free area to document change of concentration with distance, 3) east-west flights along Long Island to study the influx of pollen from the mainland with westerly winds; and 4) vertical ascents and horizontal flights during sea breeze flows to determine their effect on pollen concentrations.

It was found that large quantities of pollen are transported in orderly fashion from their source regions but pollen often travels in large, discrete clouds. Pollen is transported to Long Island from the mainland in some quantity. Sea breeze flows greatly decrease low-level concentrations but pollen is carried aloft at the sea breeze front and recirculated in the return flow aloft. Vertical distribution is reasonably well related to lapse rate although secondary concentration peaks which often occur below elevated inversions cannot be explained by the data obtained.

Full access
Gilbert S. Raynor
,
Eugene C. Ogden
, and
Janet V. Hayes

Abstract

Dispersion and deposition of ragweed pollen released naturally from circular area sources of four sizes (5–27 m in diameter) and artificially from point sources were studied at Brookhaven National Laboratory. Concentrations were measured by wind-impaction samplers mounted on 20° radii at four heights (0.5–4.6 in) and four or five distances from the sources to a maximum of 69 m. Deposition was measured by greased microscope slides on the ground. Differences in dispersion patterns between point and area sources are analyzed. Normalized centerline concentrations, cross-wind integrated concentrations, plume widths, plume heights and mass flux are presented as functions of distance and related to source size and meteorological variables. Deposition data are also related to distance and source size. Most deposition velocities ranged from 2–6 cm sec−1 but values close to area sources were much greater. Loss of airborne particles between sampling circles is compared to deposition over the same distances. Results are compared to those of previous dispersion and deposition studies and to theory.

Full access
Gilbert S. Raynor
,
Lester A. Cohen
,
Janet V. Hayes
, and
Eugene C. Ogden

Abstract

Full access