[RegCNET] A possible inconsistency in ICBC

[Travis O'Brien]

Dear RegCM3 users:

I think that I found a slight inconsistency in ICBC:

In the subroutine JULIAN(), which calculates the time-weight factor for 
linearly interpolating SSTs from month to month, part of the calculation 
of the weight factor involves the midpoint day of each month (length of 
the month rounded up).  When counting leap years, the routine sets the 
number of days in February to 29, but it keeps the midpoint day of 
February at 14; to be consistent with the midpoint day of the other 
months, I believe that on leap years, the midpoint day should be set to 
15 (since 29/2 rounded up is 15).

Also, the leap year check doesn't discount years that are divisible by 4 
and 100 (400 excepted): 2100 will be mistakenly counted as a leap year 
for the purposes of interpolating SSTs in ICBC.

I'm not sure that this makes much of a difference in the ICBC files, but 
I think its something that we should be aware of.

Regards,
Travis O'Brien

-- 
Travis A. O'Brien
Graduate Student Researcher
Earth and Planetary Science Dept.
UC Santa Cruz

tobrien at ucsc.edu
(831) 459-3504