Dear Pierre et al,
We have already agreed the addition of the following new surface types
to the area_type table to accompany the carbon cycle names:
primary_evergreen_trees;
secondary_deciduous_trees;
secondary_evergreen_trees;
c3_plant_functional_types;
c4_plant_functional_types.
Looking again at the CMIP5 output, area_fractions will be saved for a
number of other surface types for which we will also need additions to
the area_type table:
trees;
shrubs;
natural_grass;
crops;
anthropogenic_pasture;
burnt_vegetation.
I hope Pierre may be able to help with some questions regarding the
definitions of these items:
1) What is the difference (in models) between "tree" and "shrub"? Is it
a question of canopy height, vegetation density, or other deciding
factors?
2) Do "crops" include fruit trees and "anthropogenic pasture" or are
these all separate categories?
3) Similarly, do c3 and c4 plants include trees, shrubs, etc., or is the
c3/c4 classification entirely independent of plant morphology?
The CMIP5 document asks for bare_soil area fraction. We already have an
area_type of bare_ground, which actually isn't defined. I suppose it
could mean rock outcrops as well as soil. I'd welcome opinions on
whether we should introduce bare_soil as a separate surface type.
Finally, there is a requirement for a "non-vegetation", "non-bare-soil"
land type which covers areas such as urban, ice and lakes. I'm
struggling to think of a concise label for this one. Perhaps
"inland_water_bodies_and_covered_land_excluding_vegetation" would be an
adequate description. Again, does "bare soil" mean only soil or can it
include bare rocks? Comments are invited.
Best wishes,
Alison
------
Alison Pamment Tel: +44 1235 778065
NCAS/British Atmospheric Data Centre Fax: +44 1235 446314
Rutherford Appleton Laboratory Email: alison.pamment at stfc.ac.uk
Chilton, Didcot, OX11 0QX, U.K.
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Received on Thu Sep 30 2010 - 05:59:41 BST
