## Abstract A typical agricultural water reservoir (AWR) of 2400 m^2^ area and 5 m depth, located in a semi‐arid area (southern Spain), was surveyed on a daily basis for 1 year. The annual evaporation flux was 102·7 W m^−2^, equivalent to an evaporated water depth of 1310 mm year^−1^. The heat stor
Evaporation and energy balance of a sub-Arctic hillslope in northern Finland
✍ Scribed by R. J. Harding; N. A. Jackson; E. M. Blyth; A. Culf
- Publisher
- John Wiley and Sons
- Year
- 2002
- Tongue
- English
- Weight
- 762 KB
- Volume
- 16
- Category
- Article
- ISSN
- 0885-6087
- DOI
- 10.1002/hyp.353
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✦ Synopsis
Abstract
This paper presents measurements of the energy balance (radiation, sensible heat flux, evaporation) from a sub‐arctic hillside in northern Finland for a summer season. Comparisons are also made with a nearby wetland site. The hillslope measurements show an equal partition of the radiant energy into sensible and latent heat flux. The evaporative ratio of just over one half was remarkably constant throughout the season, despite very large day‐to‐day and diurnal variations of temperature, humidity deficit and radiation input. This conservative behaviour of the evaporation was caused by a strong rise in effective surface resistance to evaporation with increasing vapour pressure deficit. This suggests a strong physiological control on the evaporation, with stomata closing at times of high evaporative demand. There was no obvious impact of soil‐water stress on the evaporation. However, a comparison with the evaporation measured at a nearby mire site in 1997 suggests that the mire has a significantly lower surface resistance, even when the impact of a significantly lower humidity deficit in the earlier year is taken into account.
The measurements are used to test, off‐line, the performance of MOSES (Meteorological Office Surface Exchange Scheme), a simple, but comprehensive, land surface model. The sensitivity of the energy exchanges to the thermal properties of the top soil layer (a surrogate for the upper soil/vegetation layer) is investigated with the use of the model. It is found that the evaporation is insensitive to these properties; they do, however, influence the partition of energy between the sensible heat flux and the ground heat flux (and hence the soil temperatures). It is suggested that the model needs to represent the thermal properties of the canopy more realistically. Copyright © 2002 John Wiley & Sons, Ltd.
📜 SIMILAR VOLUMES
The main objective of this study was to assess the impact of a suspended cover on the evaporation loss of an agricultural water reservoir (AWR). To this aim, a detailed data collection was carried out in a typical AWR located in south-eastern Spain during 2 consecutive years. During the first year,