Abstract
The determination of nocturnal surface fluxes in low wind conditions is a major problem for micrometeorological studies. The eddy correlation technique, extensively used in field measurements, becomes inappropriate if not enough turbulent activity exists. At the same time, the phenomenon of turbulence intermittency is responsible for the existence of localized events of short duration within which a large fraction of the total nighttime scalar exchange occurs. The scalar flux within a certain intermittent event varies considerably depending on the window used for the flux calculation. In many cases, events with very different time durations occur in the same night, and therefore, the proper determination of the surface flux would require averaging within data windows of different sizes for each event. In this work, the surface exchanges of temperature, moisture and carbon dioxide are analysed at a micrometeorological tower at southern Brazil. Intermittent turbulence is a common occurrence at the location. The analysis shows that the fluxes vary with turbulence intensity and the estimation technique. A variable-window size method for flux estimation is suggested and shown to cause an increase in the magnitude of the nocturnal surface fluxes
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Acevedo O.C., Fitzjarrald D.R. (2003). ‘In the Core of the Night – Effects of Intermittent Mixing on a Horizontally Heterogeneous Surface’. Boundary-Layer Meteorol 106:1–33
Coulter R.L., Doran. (2002). ‘Spatial and Temporal Occurrences of Intermittent Turbulence During CASES-99’. Boundary-Layer Meteorol 105:329–349
Doran J.C. (2004). ‘Characteristics of Intermittent Turbulent Temperature Fluxes in Stable Conditions’. Boundary-Layer Meteorol 112:241–255
Goulden M.L., Munger J.W., Fan S.-M. et al. (1996). ‘Measurements of Carbon Storage by Long Term Eddy Correlation: Methods and a Critical Evaluation of Accuracy’. Global Change Biol 2:169–182
Howell J.F., Sun J. (1999). ‘Surface-Layer Fluxes in Stable Conditions’ Boundary-Layer Meteorol 90: 495–520
Nappo C.J. (1991). ‘Sporadic Breakdowns of Stability in the PBL over Simple and Complex Terrain’. Boundary-Layer Meteorol 54:69–87
Poulos G.S., Burns S.P. (2003). ‘An Evaluation of Bulk Ri-based Surface Layer Flux Formulas for Stable and Very Stable Conditions with Intermittent Turbulence’. J. Atmos. Sci. 60:2523–2537
Sakai R.K., Fitzjarrald D.R., Moraes O.L.L., Staebler R.M., Acevedo O.C., Czikowski M.J., Silva R., Brait E., Miranda V. (2004). ‘Land-use Change Effects on Local Energy, Water and Carbon Balances in an Amazonian Agricultural Field’. Global Change Biol 10:895–907
Sun J., Burns S.P., Lenschow D.H., Banta R., Newsom R., Coulter R., Frasier S., Ince T., Nappo C., Cuxart J., Blumen W., Lee X., Hu X.-Z. (2002). ‘Intermittent Turbulence Associated with a Density Current Passage in the Stable Boundary Layer’. Boundary-Layer Meteorol 105:199–219
Sun J., Lenschow D.H., Burns S.P., Banta R.M., Newsom R.K., Coulter R., Frasier S., Ince T., Nappo C., Basley B.B., Jensen M., Mahrt L., Miller D., Skelly B. (2004). ‘Atmospheric Disturbances that Generate Intermittent Turbulence in Nocturnal Boundary Layers’. Boundary-Layer Meteorol 110:255–279
Van de Wiel B.J.H., Ronda R.J., Moene A.F., De Bruin H.A.R., Holtslag A.A.M. (2002). ‘Intermittent Turbulence and Oscillations in the Stable Boundary Layer over Land. Part I: A Bulk Model’. J. Atmos. Sci. 59:942–958
Vickers D., Mahrt L. (2003). ‘The Cospectral Gap and Turbulence’ Flux Calculations’. J. Atmos. Ocean. Tech. 20:660–672
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Acevedo, O.C., Moraes, O.L.L., Degrazia, G.A. et al. Intermittency and the Exchange of Scalars in the Nocturnal Surface Layer. Boundary-Layer Meteorol 119, 41–55 (2006). https://doi.org/10.1007/s10546-005-9019-3
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DOI: https://doi.org/10.1007/s10546-005-9019-3