Length of Growing Season

[mankoff]

According to drind,

Growing season is the length of time between the last frost in the Spring
and the first frost in the Fall. If done properly, the GCM should record the
freezing temps and make that calculation.

The Length of Growing Season variable in the model outputs

• Changes value from month to month
• Has an abrupt & straight-lined change at the equator
• Appears flipped (July has longer growing days in the S.H).

It appears that this diagnostic has bugs in it.

[mankoff]

This variable looks similar to Palmer Drought Index, a known bug. See #273

[mankoff]

Not just related to #273... These variables are identical. Diff results in 0.

[mankoff]

updating priority and severity because this is the same (yet not a duplicate) of #273

[mankoff]

LOGS & Palmer in PRT files

[mankoff]

Attachment shows LOGS & Palmer are buggy in PRT files.

• LOGS differs month-to-month. Should be yearly values.
• LOGS has abrupt change at equator
• Palmer is 0.

in netCDF, Palmer == LOGS.

Bug must be in sumAndPD because it is not limited to netCDF...

attachment:logs.png

http://dev.edgcm.columbia.edu/attachment/ticket/295/logs.png?format=raw

[mshopsin]

The length of the growing season appears to work correctly in the 1.0.7 version of the model. See attached image.

[mshopsin]

Length of the Growing Season in Model 1.0.7 for the run Modern_PredictedSST

[mankoff]

Attached image (GrowingSeasonLength.gif) most definately still contains the bug.

• There is a horizontal line at the equator. Nature never has straight lines except the horizon
• What month is that? Do all months display the same result?

[mankoff]

Further investigation provides the following hint: December == Annual.

FYI, I have invistigated the LOGS problem and have a snapshot of the data used by SumAndPD to create this variable (see 3rd incantation of 'LENGTH OF GROWING SEASON' in source:trunk/GCM_processing/Output/pdC/pd_DB11pdC9/DB11pd_v2C9.f90?rev=273 (273 at the time of this writing)).

I plan on reviewing both the data and the algorithm with MAC in Madison next week.

[mankoff]

Oops... that should be rev 237 not 273.

[mankoff]

Do not close tickets without explanation why/how this bug has been fixed.

[mankoff]

Mark and I discovered that LOGS is valid in January.