An Analysis of Airborne Measurements of Vertical Water Vapor Flux During BOMEX

Self Cite

The complex structure of the earth's surface influenced atmospheric parameters pertinent to modeling the diffusion process during the 1978 'STATE' field study. The Information Theory approach of statistics proved useful for analyzing the complex structures observed in the radiometric surface temperature signals as measured from an aircraft. Results show that regardless of their complexities, these temperature processes are well approximated as Gaussian processes. Turbulent kinetic energy is shown to increase as the surface temperature signals become more complex. The nature of these variations is examined for five different categories of agricultural land as defined by percent cultivation and percent forestation.

Section: Measurementscontrasting

confidence: 57%

A study of turbulent energy over complex terrain (STATE, 1978)

Bean¹,

Repoff²

1983

Self Cite

“…Reinking (1977) and Nicholls and LeMone (1980) have shown that the dominant scales in vertical eddy motion for the GATE data are essentially the same for both along-and cross-wind samples in a given height interval and therefore a separation of this type will not be undertaken here. As has been discussed before (Reinking, 1980), this is in marked contrast with the results obtained by Bean et al (1972) and Grossman and Bean (1973) from data taken during BOMEX where the dominant length scales observed along-wind were from 1.5 to 4 times larger than those observed across-wind at 150 m. The roll vortex structure which was evidently present during the BOMEX experiment is generally absent from the data taken during GATE.…”

Section: Power Spectra and Cospectramentioning

confidence: 98%

Analysis of aircraft measurements of momentum flux in the subcloud layer over the tropical atlantic ocean during gate

Greenhut¹

1981

The momentum flux data obtained by the gust probe aboard the NOAA DC-6 aircraft during GATE are analyzed. Vertical profiles are obtained for Phases I and III and correlated with vertical wind velocity profiles using the geostrophic departure method. Reasonable agreement is obtained using the horizontal equations of motion with negligible advective acceleration. The vertical profiles of momentum flux and wind speed variance compare well with the numerical model results of Deardorff (1972) and Wyngaard et al. (1974). Vertical distributions of power spectra for vertical eddy motion and cospectra corresponding to the momentum flux components are obtained along with the height variation of the dominant length scales of vertical eddy motion and the dissipation rate of turbulence kinetic energy. When normalized by mixed-layer similarity, these results agree well with previous determinations in the boundary layer over tropical oceans and over land.

“…The gust probe data taken in BOMEX were among the first available to atmospheric scientists. The primary objective was to measure a, the water vapor flux (Bean et al, 1972). Extending the analysis to investigate momentum and heat fluxes came after the field program.…”

Section: )mentioning

confidence: 99%

An analysis of vertical velocity spectra obtained in the bomex fair-weather, trade-wind boundary layer

Grossman

1982

106

Spectra of vertical velocity fluctuations measured on board an aircraft flying over the sea along and across the wind during the Barbados Oceanographic and Meteorological Experiment (BOMEX) are stratified and composited according to estimates of the Monin-Obukhov stability length.This was done to test the hypothesis that a hierarchy of physical mechanisms, responding to wind shear and buoyancy, is active in the turbulent transfer processes of the oceanic subcloud layer. Despite the possibility that the data contain a heading-independent bias, it is concluded that a major change of eddy structure occurs over a narrow range of stability. This agrees well with an early theory on convection over land and observations of herring gull flight characteristics.The vertical variation of the spectral-composites compares favorably with other observations over land and sea. Physical models are suggested to explain the data. One of these models is in agreement with theoretical results concerning ringlike convection. The spectral data, which begin to lose confidence at about 10 km, suggest that a limiting size ofeddies over the ocean is approximately twice the depth of the subcloud layer (in this case 600 m) regardless of the kind of eddy structure.