Application of the Priestley-Taylor evaporation model to assess the influence of soil moisture on the evaporation from a large weighing lysimeter and class a pan     

Mukammal  E. I.  Neumann  H. H. 《Boundary-Layer Meteorology》1977,12(2):243-256

The influence of soil moisture on evaporation from a 6-m grass-covered lysimeter and from Class A pans was assessed for one summer using the -parameter of the Priestley-Taylor evaporation model appropriate for the individual surfaces computed on a daily basis. Net radiation over the pan was estimated from above-grass measurements using a correlation established between the two, using measurements made in the previous two summers. Changes in heat storage of the water were considered in the derivation of for the pan. A unique relationship for the particular conditions of the site was determined between the for the lysimeter and soil moisture, approaching 1.29 at soil moisture near field capacity, but decreasing to as low as 0.5 for dry soil. The corresponding relationship for the pan showed more scatter, but this was improved by using 5-day running means of evaporation and stratifying the data in terms of wind speed to yield a family of curves. Values for at wet soil conditions varied from 1.07 for 100 km day^–1 wind run to 1.17 for 250 km day^–1 wind run. For each curve, values of increased by about 20%; as the soil dried. The relationships may be used to reduce observed Class A pan evaporation to equivalent values for wet-soil conditions and to estimate near-surface soil moisture and actual evapotranspiration for this particular site. Extension of the technique to other areas requires derivation of similar relationships appropriate for those other locations  相似文献   

Mechanical balance-electrical readout weighing lysimeter     

E. I. Mukammal  G. A. McKay  V. R. Turner 《Boundary-Layer Meteorology》1971,2(2):207-217

As part of the research programme of the Atmospheric Environment Service, a large, sensitive weighing lysimeter was constructed on the Atmospheric Environment Service research site north of Toronto. Features of the instrument include: measurement of runoff, percolation, drainage of water held in tension, addition of water from below during dry conditions, equalization of soil temperature profile inside with that outside the lysimeter, humidity control to eliminate condensation, low area of discontinuity at the rim to reduce edge effects, and quasimonolith filling. This paper describes the construction and installation of the lysimeter, the problems encountered and some infrequently considered sources of error.  相似文献   

Some features of the ozone climatology of Ontario,Canada and possible contributions of stratospheric ozone to surface concentrations     

E. I. Mukammal  H. H. Neuman  T. R. Nichols 《Meteorology and Atmospheric Physics》1985,34(2):179-211

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Comparison of aerodynamic and energy budget techniques in estimating evapotranspiration from a cornfield     

Dr. E. I. Mukammal  K. M. King  H. F. Cork 《Theoretical and Applied Climatology》1966,14(3-4):384-395

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Some aspects of radiant energy in a pine forest     

Dr. E. I. Mukammal 《Theoretical and Applied Climatology》1971,19(1):29-52

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