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Title: Spray irrigation effects on surface-layer stability in an experimental citrus orchard during winter freezes

Journal Article · · Journal of Applied Meteorology
;  [1];  [2]
  1. Florida State Univ., Tallahassee, FL (United States)
  2. Univ. of Florida, Gainesville, FL (United States)

Observations taken by two surface radiation and energy budget stations deployed in the University of Florida/Institute for Food and Agricultural Service experimental citrus orchard in Ginesville, Florida, have been analyzed to identify the effects of sprayer irrigation on thermal stability and circulation processes within the orchard during three 1992 winter freeze episodes. Lapse rates of temperature observed from a micrometeorological tower near the center of the orchard were also recorded during periods of irrigation for incorporation into the analysis. Comparisons of the near-surface temperature lapse rates observed with the two energy budget stations show consistency between the two sites and with the tower-based lapse rates taken over a vertical layer from 1.5 to 15 m above ground level. A theoretical framework was developed that demonstrates that turbulent-scale processes originating within the canopy, driven by latent heat release associated with condensation and freezing processes from water vapor and liquid water released from sprayer nozzles, can destabilize lapse rates and promote warm air mixing above the orchard canopy. The orchard data were then analyzed in the context of the theory for evidence of local overturning and displacement of surface layer air, with warmer air from aloft driven by locally buoyant plumes generated by water vapor injected into the orchard during the irrigation periods. 14 refs., 6 figs.

OSTI ID:
466977
Journal Information:
Journal of Applied Meteorology, Vol. 36, Issue 2; Other Information: PBD: Feb 1997
Country of Publication:
United States
Language:
English