Changeset 2788 for LMDZ5/trunk/libf/phylmd/tropopause_m.F90

Changes in ce0l about the way ozone forcing files are generated:

1) 3D raw input files "climoz.nc" are now handled.
2) Default behaviour is now to let the gcm interpolate in time online.

This helps to avoid huge forcing files (in particular for 3D fields).
In this case, the output files "climoz_LMDZ.nc" all have 14 records:

• records 2-13 are obtained with records 1-12 of "climoz.nc".
• records 1 and 14 are obtained respectively with:
  • record 12 of "climoz_m.nc" if available, of "climoz.nc" otherwise.
  • record 1 of "climoz_p.nc" if available, of "climoz.nc" otherwise.

3) If ok_daily_climoz key is TRUE, the time interpolation (one record

a day) is forced, using the 14 records described below.
This now depends on the calendar (it was on a 360 days basis only).

Changes in the gcm about the way zone forcing files are read/interpolated:

1) 3D horizontally interpolated "climoz_LMDZ.nc" files are now handled.
2) Daily files (already interpolated in time) are still handled, but their

number of records must match the expected number of days, that depends
on the calendar (records step is no longer 1/360 year).

3) 14 records monthly files are now handled (and prefered). This reduces

the I/O to a minimum and the aditional computational cost is low (simple
online linear time interpolation).

4) If adjust_tropopause key is TRUE, the input fields are stretched using

following method:

• LMDZ dynamical tropopause is detected: Ptrop_lmdz = MAX ( P(Potential Vorticity==2PVU), P(theta==380K) )
• file chemical tropopause is detected: Ptrop_file = P( tro3 == o3t ), where:

o3t = 91. + 28. * SIN(PI*(month-2)/6) (ppbV)

This formula comes from Thouret & al., ACP 6, 1033-1051, 2006.
The second term of the expression is multiplied by TANH(lat_deg/20.)
to account for latitude dependency.

• File profile is streched in a +/- 5kms zone around the mean tropopause to ensure resulting tropopause matches the one of LMDZ. See procedure regr_pr_time_av for more details.