Evaporation of water from a soil surface is a complex process that can be strongly tied to the distribution of temperature in the soil. One way of examining this coupling is through linearization and analytic solution of the partial differential equations and boundary conditions that govern the distributions of moisture and temperature. The solution for a step change in temperature and matric head at the surface of a soil that is initially isothermal and uniformly wetted suggests that evaporation can be calculated accurately by neglecting the dependence of moisture content on temperature, even when the associated “thermal liquid flux” is the largest moisture flux immediately beneath the soil surface. The resulting error decreases with the hydrothermal diffusivity ratio η, which is the ratio of soil moisture diffusivity to soil thermal diffusivity, and increases with the thermal liquid force ratio ξ, which is proportional to the poorly understood temperature coefficient of matric head. In contrast, the solution for diurnally varying evaporation from a relatively dry soil shows that the relative error induced by neglecting vapor diffusion due to thermally induced vapor concentration gradients is approximately equal to the relative magnitude of the neglected flux itself. This error is roughly equal to ση½, where the thermal vapor force ratio σ; is the ratio of characteristic thermal to isothermal driving forces. Furthermore, when ση½ is large, the daytime switches from a time of maximum evaporation to a time of minimum. This behavior is not reproduced if the thermal vapor flux is ignored.
Water Resources Research – Wiley
Published: Aug 1, 1984
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.
All for just $49/month
Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly
Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.
Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.
Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.
All the latest content is available, no embargo periods.
“Hi guys, I cannot tell you how much I love this resource. Incredible. I really believe you've hit the nail on the head with this site in regards to solving the research-purchase issue.”Daniel C.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud
“I must say, @deepdyve is a fabulous solution to the independent researcher's problem of #access to #information.”@deepthiw
“My last article couldn't be possible without the platform @deepdyve that makes journal papers cheaper.”@JoseServera