Jonathan,
I wanted to make a minor addition to the definition of the total totals
index to include coordinate variables for the 850 and 500 hPa pressure
levels. It seems that this information might be useful to have in a
netCDF file, but not be specifically required. Please let me know if
you think this sentence is unnecessary and I can remove.
Standard Name:
atmosphere_stability_total_totals_index
Definition:
The atmosphere_stability_total_totals_index indicates the
likelihood of severe convection and is often referred to as simply the
total totals index. The index is derived from the difference in air
temperature between 850 and 500 hPa (the vertical totals) and the
difference between the dew point temperature at 850 hPa and the air
temperature at 500 hPa (the cross totals). The vertical totals and cross
totals are summed to obtain the index.Coordinate variables can be specified
which
indicate the 850 and 500 hPa pressure levels.
Canonical Units: K
Does this standard name/definition/units seems suitable to the CF board?
FYI, I will be submitting two other stability indices this week. Sincerely,
Jonathan
On 5/22/2013 1:42 PM, Jonathan Wrotny wrote:
Dear Jonathan,
Thanks for your feedback. I agree with your suggested modifications
the definition and have included them below.
Also, there is an e-mail from John Graybeal who is suggesting a more
generalized version of the standard name. I have thought about
attempting to come up with a similar, general, name for the total
totals index. But, this name was so long that I believe that it would
itself become a full description, which I was trying to avoid. John's
suggested name boils it down more generally and succintly, but it
turns out that this name could also be applicable to the stability
index, "k index," which I am going to submit in the coming days (which
also uses differences of the ambient and dew point temperatures), so
there would be conflict with the "k index" name. Also, remember that
the total totals is not a name that I have personally constructed to
describe the mathematics of the quantity, but it is actually the name
of an commonly used meteorological quantity.
Given Jonathan's previous direction (see e-mails concerning "lifted
index") to attempt to standardize all names except for those specific,
complex quantities that don't lend themselves to generalization, I
think keeping total_totals_index in the standard name is a good idea.
I think the lifted index is complex and specific enough that it falls
into the category or meriting a unique name (similar to, say, the NDVI).
Standard Name:
atmosphere_stability_total_totals_index
Definition:
The atmosphere_stability_total_totals_index indicates the
likelihood of severe convection and is often referred to as simply the
total totals index. The index is derived from the difference in air
temperature between 850 and 500 hPa (the vertical totals) and the
difference between the dew point temperature at 850 hPa and the air
temperature at 500 hPa (the cross totals). The vertical totals and cross
totals are summed to obtain the index.
Canonical Units: K
Sincerely,
Jonathan
On 5/21/2013 5:39 PM, Jonathan Gregory wrote:
Dear Jon
I agree with your assessment, and I like your proposed name. My
only question remains with the definition. It seems like there
could be two approaches given the specific nature of the product: 1)
write the definition as below with hard-wired pressure levels part
of the definition. Based on my understanding of the product, I have
never seen any other pressures levels other than 500 and 850 hPa
used for the index, but I could be wrong. -or- 2) attempt to
generalize the definition so that it does not mention the specific
pressure levels. This would help to generalize the definition, but
may not add that much value since other pressure levels do not
appear to be commonly used (ever?).
If that is the case, then (1) seems the better choice
Standard Name: atmosphere_stability_total_totals_index
Definition:
Option 1)The atmosphere_stability_total_totals_index indicates the
likelihood of severe convection and is often referred to as simply
the total totals index. The index is derived from the difference in
air temperature between 850 and 500 hPa (the vertical totals) and
the difference between the dew point temperature at 850 hPa and the
air temperature at 500 hPa (the cross totals). The vertical totals
and cross totals are summed to obtain the index.
You could insert
often referred to as simply the total totals index
as in your other definition. This bit:
Air temperature is
the bulk temperature of the air, not the surface (skin) temperature.
The term "surface" means the lower boundary of the atmosphere.
doesn't seem necessary in this case, since "surface" is not mentioned.
Canonical Units: K
Oh, good. :-)
If we define it specifically now, that does not preclude the later addition of
a more general standard name if required.
Cheers
Jonathan
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