Journal Article

Thermal Variability in a Tidal River

Doyle, Laura P., Schladow, S. Geoffrey, Fong, Derek A., Monismith, Stephen G., Hench, James L., Nidzieko, Nicholas J., Fleenor, William E.

2009

Overview

In this paper, we discuss observations of temperature variability in the tidal portion of the San Joaquín River in California. The San Joaquín River makes up the southern portion of the Sacramento San Joaquín Delta, the eastern end of San Francisco Bay. Observations made in August 2004 and August 2005 show significant diurnal variations in temperature in response to surface heat exchange. However, to account for observed changes in heat content a sizeable downstream heat flux (approximately 100 W m⁻²) must be added to the surface heat flux. To account for this flux via Fickian dispersion, a flow-dependent dispersion coefficient varying from 500 to 4,000 m² s⁻₁ is needed. These values are much larger than would be predicted for a river of this size, suggesting that the complex topology of the Delta greatly enhances longitudinal dispersion. Building on these observations, we present a simple theory that explores how the subtidal temperature field varies in response to changes in flow rate, dispersion, and heat exchange.

• Publisher: Spring Science + Business Media,Springer-Verlag,Springer,Springer Nature B.V
• Subject: Advection / Animal and plant ecology / Animal, plant and microbial ecology / Biological and medical sciences / Brackish / Brackish water ecosystems / Coastal Sciences / Diurnal variations / Earth and Environmental Science / Ecology / Environment / Environmental Management / Estuaries / Flow coefficients / Flow rates / Fluctuations / Fresh water ecosystems / Freshwater & Marine Ecology / Fundamental and applied biological sciences. Psychology / Heat / Heat exchange / Heat flux / Original Paper / River deltas / River water / Rivers / Surface temperature / Synecology / Temperature / Temperature distribution / Tidal rivers / Tides / Topology / Water and Health / Water temperature