Abstract
Turbulence and heat fluxes in the marine atmospheric boundary layer (MABL) for the roll vortex regime, observed during the Genesis of Atlantic Lows Experiment (GALE) over the western Gulf Stream, have been studied. The spectral analysis suggests that cloud streets (roll vortices) are vertically organized convection in the MABL having the same roll scale for both the cloud layer and subcloud layer, and that the roll spacing is about three times the MABL depth. The roll circulations contribute significantly to the sensible (temperature) and latent heat (moisture) fluxes with importance increasing upward. Near the MABL top, these fluxes are primarily due to roll vortices which transfer both sensible heat and moisture upward in the lower half of the convective MABL. Near the MABL top, the roll circulations transfer sensible heat downward and moisture upward in the clear thermal-street region, but roll vortices influenced by evaporative cooling can transfer sensible heat upward and moisture downward in the cloud-street region. Near the cloud-top, the upward buoyancy flux due to evaporative cooling is highly related to the roll circulations near the inversion.
For the lower half of the MABL, the normalized temperature flux decreases upward more rapidly than the humidity flux, which is mainly because potential temperature (θ) increases slightly upward while humidity (q) decreases slightly upward above the unstable surface layer. The gradient production (associated with the θ gradient) is a source for the temperature flux in the unstable surface layer but changes to a sink in the mixed layer, while the gradient production (associated with the q gradient) acts as a source for the humidity flux in both the unstable surface and mixed layers. The results suggest that the entrainment at the MABL top might affect the budgets of temperature and humidity fluxes in the lower MABL, but not in the unstable surface layer.
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Agee, E. M. and Howley, R. P.: 1977, ‘Latent and Sensible Heat Flux Calculations at the Air-Sea Interface During AMTEX 74’, J. Appl. Meteorol., 16, 443–447.
Bane, J. M. and Osgood, K. E.: 1989, ‘Wintertime Air-Sea Interaction Processes Across the Gulf Stream’, J. Geophys. Res. 94, 10,755–10,722.
Budyko, M. I.: 1963, ‘Atlas of Heat Balance of the Earth's Surface’, USSR Glavnaia Geofizicheskaia Observatoriia, Moscow, 69 pp.
Bunker, A. and Worthington, L. V.: 1976, ‘Energy Exchange Charts of the North Atlantic Ocean’, Bull. Amer. Meteorol Soc. 57, 450–467.
Chou, S.-H. and Yeh, E.-N.: 1987, ‘Airborne Measurements of Surface Layer Turbulence over the Ocean During Cold Air Outbreaks’, J. Atmos. Sci. 44, 3721–3733.
Chou, S.-H. and Zimmerman, J.: 1989, ‘Bivariate Conditional Sampling of Buoyancy Flux during an Intense Cold-Air Outbreak’, Boundary-Layer Meteorol. 46, 93–112.
Chou, S.-H., Atlas, D. and Yeh, E.-N.: 1986, ‘Turbulence in a Convective Marine Atmospheric Boundary Layer’, J. Atmos. Sci. 43, 547–564.
Deardorff, J. W.: 1972, ‘Numerical Investigation of Neutral and Unstable Planetary Boundary Layers’, J. Atmos. Sci. 29, 91–115.
Deardorff, J. W.: 1980, ‘Cloud Top Entrainment Instability’, J. Atmos. Sci. 37, 131–147.
Deardorff, J. W.: 1985, ‘Laboratory Experiments on Diffusion: The Use of Convective Mixed-Layer Scaling’, J. Clim. Appl. Meteorol. 24, 1143–1151.
Dirks, R. A., Kuettner, J. P., and Moore, J. A.: 1988, ‘Genesis of Atlantic Lows Experiment (GALE): An Overview’, Bull. Amer. Meteorol. Soc. 69, 148–160.
Druilhet, A., Frangi, J. P., Guedalia, D. and Fontan, J.: 1983, ‘Experimental Studies of the Turbulence Structure Parameters of the Convective Boundary Layer’, J. Clim. Appl. Meteorol. 22, 594–608.
Friehe, C. A., Grossman, R. L., and Pann, Y.: 1986, ‘Calibration of an Airborne Lyman-Alpha Hygrometer and Measurement of Water Vapor Flux Using a Thermoelectric Hygrometer’, J. Atmos. and Ocean. Tech. 3, 299–304.
Grossman, R. L.: 1982, ‘An Analysis of Vertical Velocity Spectra Obtained in the BOMEX Fair-Weather, Trade-Wind Boundary-Layer’, Boundary-Layer Meteorol. 23, 323–357.
Grossman, R. L. and Betts, A. K.: 1990, ‘Air-Sea Interaction During an Extreme Cold Air Outbreak from the Eastern Coast of the United States’, Mon. Wea. Rev. 118 (in press).
Jenkins, G. M. and Watts, D. G.: 1968, Spectral Analysis and its Application, Holden-Day, 525 pp.
Jensen, N. O. and Lenschow, D. H.: 1978: ‘An Observational Investigation of Penetrative Convection’, J. Atmos. Sci. 35, 1924–1933.
Kaimal, J. C., Wyngaard, J. C., Izumi, Y., and Cote, O. R.: 1972, ‘Spectral Characteristics of Surface-Layer Turbulence’, Quart. J. Roy. Meteorol. Soc. 98, 563–589.
Kaimal, J. C., Wyngaard, J. C., Haugen, D. A., Coté, O. R., Izumi, Y., Caughey, S. J. and Readings, C. J.: 1976, ‘Turbulence Structure in the Convective Boundary Layer’, J. Atmos. Sci. 33, 2152–2169.
Kondo, J.: 1975, ‘Air-Sea Bulk Transfer Coefficients in Diabatic Conditions’, Boundary-Layer Meteorol. 9, 91–112.
Kung, E. C. and Siegel, A. J.: 1979, ‘A Study of Heat and Moisture Budgets in the Intense Winter Monsoon over the Warm Ocean Current’, J. Atmos. Sci. 36, 1880–1894.
Lanczos, C.: 1956, Applied Analysis, Prentice Hall, Englewood Cliffs, NJ, 539 pp.
LeMone, M. A.: 1973, ‘The Structure and Dynamics of Horizontal Roll Vortices in the Planetary Boundary Layer’, J. Atmos. Sci. 30, 1077–1091.
LeMone, M. A.: 1976, ‘Modulation of Turbulence Energy by Longitudinal Rolls in an Unstable Boundary Layer’, J. Atmos. Sci. 33, 1308–1320.
LeMone, M. A. and Pennell, W. T.: 1980, ‘A Comparison of Turbulence Measurements from Aircraft’, J. Appl. Meteorol. 19, 1420–1437.
Lenschow, D. H., Wyngaard, J. C., and Pennell, W. T.: 1980, ‘Mean-Field and Second-Moment Budgets in a Baroclinic, Convective Boundary Layer’, J. Atmos. Sci. 37, 1313–1326.
Lilly, D. K.: 1968, ‘Models of Cloud-Topped Mixed Layers under a Strong Inversion’, Quart. J. Roy. Meteorol. Soc. 94, 292–309.
Mahrt, L.: 1976, ‘Mixed Layer Moisture Structure’, Mon. Wea. Rev. 104, 1403–1407.
Mahrt, L. and Paumier, J.: 1982, ‘Cloud-Top Entrainment Instability Observed in AMTEX’, J. Atmos. Sci. 39, 622–634.
Nicholls, S.: 1984, ‘The Dynamics of Stratocumulus: Aircraft Observations and Comparisons with a Mixed Layer Model’, Q.J.R. Meteorol. Soc. 110, 783–820.
Nicholls, S.: 1989, ‘The Structure of Radiatively Driven Convection in Stratocumulus’, Q.J.R. Meteorol. Soc. 115, 487–511.
Nicholls, S. and LeMone, M. A.: 1980, ‘The Fair Weather Boundary Layer in GATE: The Relationship of Subcloud Fluxes and Structure to the Distribution and Enhancement of Cumulus Clouds’, J. Atmos. Sci. 37, 2051–2067.
Pennell, W. T. and LeMone, M. A.: 1974, ‘An Experimental Study of Turbulence Structure in the Fair-Weather Trade Wind Boundary Layer’, J. Atmos. Sci. 31, 1308–1323.
Phelps, G. T. and Pond, S.: 1971, ‘Spectra of the Temperature and Humidity Fluctuations and of the Fluxes of Moisture and Sensible Heat in the Marine Boundary Layer’, J. Atmos. Sci. 28, 918–928.
Randall, D. A.: 1980, ‘Conditional Instability of the First Kind Upside Down’, J. Atmos. Sci. 37, 125–130.
Reinking, R. F., Doviak, R. J., and Gilmer, R. O.: 1981, ‘Clear-Air Roll Vortices and Turbulent Motions as Detected with an Airborne Gust Probe and Dual-Doppler Radar’, J. Appl. Meteorol. 20, 678–685.
Reitan, C. H.: 1974, ‘Frequencies of Cyclones and Cyclogenesis for North America, 1951–1970’, Mon. Wea. Rev. 102, 861–868.
Sanders, F. and Gyakum, J. R.: 1980, ‘Synoptic Dynamic Climatology of the Bomb’, Mon. Wea. Rev. 108, 1589–1606.
Sheu, P. J. and Agee, E. M.: 1977, ‘Kinematic Analysis and Air-Sea Heat Flux Associated with Mesoscale Cellular Convection During AMTEX 75’, J. Atmos. Sci. 34, 793–801.
Stage, S. A. and Businger, J. A.: 1981, ‘A Model for Entrainment into a Cloud-Topped Marine Boundary Layer. Part II: Discussion of Model Behavior and Comparison with Other Models’, J. Atmos. Sci. 38, 2230–2242.
Warsh, K. L.: 1973, ‘Relation of Air-Sea Interface Energy Fluxes to Convective Activity in the Tropical Atlantic Ocean’, J. Geophys. Res. 78, 504–510.
Willis, G. E. and Deardorff, J. W.: 1974, ‘A Laboratory Model of the Unstable Planetary Boundary Layer’, J. Atmos. Sci. 31, 1297–1307.
Wyngaard, J. C., Coté, O. R., and Izumi, Y.: 1971, ‘Local Free Convection, Similarity, and the Budgets of Shear Stress and Heat Flux’, J. Atmos. Sci. 28, 1171–1182.
Wyngaard, J. C., Pennell, W. T., Lenschow, D. H., and LeMone, M. A.: 1978, ‘The Temperature-Humidity Covariance Budget in the Convective Boundary Layer’, J. Atmos. Sci. 35, 47–58.
Zeman, O. and Tennekes, H.: 1977, ‘Parameterization of the Turbulent Energy Budget at the Top of the Daytime Atmospheric Boundary Layer’, J. Atmos. Sci. 34, 111–123.
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Caelum Research Corporation, Silver Spring, MD, 20901, U.S.A.
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Chou, S.H., Ferguson, M.P. Heat fluxes and roll circulations over the western Gulf Stream during an intense cold-air outbreak. Boundary-Layer Meteorol 55, 255–281 (1991). https://doi.org/10.1007/BF00122580
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DOI: https://doi.org/10.1007/BF00122580