Estimating changes in heat energy stored within a column of wetland surface water and factors controlling their importance in the surface energy budget

Abstract

[1] Changes in heat energy stored within a column of wetland surface water can be a considerable component of the surface energy budget, an attribute that is demonstrated by comparing changes in stored heat energy to net radiation at seven sites in the wetland areas of southern Florida, including the Everglades. The magnitude of changes in stored heat energy approached the magnitude of net radiation more often during the winter dry season than during the summer wet season. Furthermore, the magnitude of changes in stored heat energy in wetland surface water generally decreased as surface energy budgets were upscaled temporally. A new method was developed to estimate changes in stored heat energy that overcomes an important data limitation, namely, the limited spatial and temporal availability of water temperature measurements. The new method is instead based on readily available air temperature measurements and relies on the convolution of air temperature changes with a regression-defined transfer function to estimate changes in water temperature. The convolution-computed water temperature changes are used with water depths and heat capacity to estimate changes in stored heat energy within the Everglades wetland areas. These results likely can be adapted to other humid subtropical wetlands characterized by open water, saw grass, and rush vegetation type communities.Citation: Shoemaker, W. B., D. M. Sumner, and A. Castillo (2005), Estimating changes in heat energy stored within a column of wetland surface water and factors controlling their importance in the surface energy budget, Water Resour.

Evapotranspiration over spatially extensive plant communities in the Big Cypress National Preserve, southern Florida, 2007-2010

“…At the Pine Upland site, change in heat energy in the surface water (W) was generally the largest energy flux except for net radiation, available energy, and latent-and sensible-heat fluxes. These flux relations are consistent with German (2000) and Shoemaker and Sumner (2005), who demonstrated that changes in heat energy in the surface water (W) can be a considerable component of subdaily and daily surface-energy budgets. Changes in latent heat (∆LE) beneath the eddy covariance instrumentation were generally immaterial in all surface-energy budgets.…”

“…German (2000) completed a benchmark study using the Bowen-ratio method that estimated ET ranging from about 1,000 to 1,400 mm/yr at nine sites in the Everglades. Shoemaker and Sumner (2005) derived a new approach for computing changes in heat energy stored in wetland surface water, a considerable component of subdaily and daily surface-energy budgets. Shoemaker and Sumner (2006) also developed numerous corrections for estimating actual wetland ET derived from potential ET.…”

Variation and uncertainty in evaporation from a subtropical estuary: Florida Bay

“…However net average values of Q STORE computed over a month were less than 5% of the heat flux due to evaporation, as also found by Shoemaker et al (2005); and possibly this flux could be neglected in estimating evaporation over longer time periods.…”

Estoque de energia na biomassa e no ar do dossel de Vochysia divergens Pohl

“…Mudanças na temperatura do ar são usadas para calcular as mudanças de temperatura da água e, portanto, o armazenamento de calor na água em áreas úmidas/alagadas, como descrito por Shoemaker et al (2005). Em alguns estudos realizados em áreas alagadas (wetlands) considerou-se que as mudanças no armazenamento de calor da água foram maiores que as mudanças no armazenamento de energia na biomassa e no ar dentro do dossel (Bidlake et al, 1996;German, 2000) haja vista que a capacidade térmica da água é quase o dobro da capacidade térmica da vegetação, solo e matéria orgânica.…”