Yeah, the overestimation by application of T-BC was in my mind as well. That's why I've tried to use transfer BC. Do you have any recommendations regarding this values. Let's say I know thermal conducitivty, what should I use for thickness? Both, model layer thickness as well as lithological layer thickness seem not optimal...
I think I'll try a high discretization to see changes at lower depths.
Anyway, as you've already mentinoned there are many processes that influence groundwater temperature. So it might be a possibility to adjust my input temperature as kind of calibration of my observation. So all these processes are involved by some degree?
I'm trying to simulate the influence of solar energy on groundwater temperature in an annual trend. Therefore I have set up a model of 3 different units (different cp and thermal conductivity) with a thickness of 5 m for each. As input for solar energy I used temperature BC as well as heat transfer BC combined with a time series of temperatures. Both simulation showed changes in temperature of +/- 0.3 K. According to mesurement values I expect changes of at least +/- 3 .
Does any one has some ideas to solve the problem, or should I rethink my model concept?