stomatal resistance in nighttime ?

[ncepulee@126_com]

Hi,all!  I had run the CLM4.5 in a forest site which is Needleleaf evergreen tree, using own half-hour forcing data.When i check the diurnal cycle of sunlit leaf's  stomatal resistance(rs), it shows rs equal 0 and is very high in midnoon.Howerver,sunshade shaded leaf's rs has the opposite trend and rs is very high in nighttime.Notely,the total lai of the forest is 5.6,but shaded leaf's area index is up to 5.1. I can't understand why sunlit leaf's rs show such trend ? Can anyone give me some advice? Thanks a lot ahead for anyone's reply. 

 

[oleson]

rs sun is zero at night because sunlit lai is zero at night. In this case rs sun is set to zero in CanopyFluxesMod.F90.At night, shaded lai is not zero, but stomata are shut and so rs shade will be large.  

 

[ncepulee@126_com]

Hi,oleson!Thank you so much for your reply. As your direction, i had understand it by checking the code. May you have a good day!

 

[ncepulee@126_com]

 Hi,oleson. When i check rs sun in a grassland site which consist of 90% C3 and 10% C4, the rs sun didn't equal zero in night. i had checked  the code again,but have no idea about it. so i have to turn to your help again. Thanks a lot in advance.

 

[oleson]

I think you'll just have to look at the code to understand that, I don't know why offhand.

 

[ncepulee@126_com]

OK,i get it.Thanks a lot for your help.May  you have a good day!