[RegCNET] discussion about the frequency of lateral boundary condition

[XUNQIANG BI]

Dear all:

The change frequency of lateral boundary condition issue was discussed
in several emails at RegCNET.

My understanding is that it is not good to use 12 hourly LBC data, 
instead, we should use 6 (or 3) hourly LBC data, in order to have
the right diurnal cycle at lateral boundary places.

By default, RegCM use the exponential relaxation LBC scheme, Both
fields (U, V, T, and Q) and the trend fields (dU, dV, dT and dQ)
are used. so 12 hourly LBC data is not suitable to provide the right
diurnal cycle. For example, 0 UTC and 12 UTC data cannot describe
the diurnal temperature variation for regions around 90E.

Is my understanding correct ?

Regards,
Xunqiang Bi

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   Dr. Xunqiang Bi         email:bixq at ictp.it
   Earth System Physics Group
   The Abdus Salam ICTP
   Strada Costiera, 11
   P.O. BOX 586, 34100 Trieste, ITALY
   Tel: +39-040-2240302  Fax: +39-040-2240449
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