Urban Surface Energy Balance Models: Model Characteristics and Methodology for a Comparison Study - Meteorological and Air Quality Models for Urban Areas - page 99

Table 11.9 Methods used to model outgoing shortwave and long wave radiation

Number of
reflections Model Albedo L ↑

BEP02 multiple canyon Result of multiple reflections in the canyon,

from walls and canyon floors at each grid
level

BEP05 multiple canyon Result of multiple reflections in the canyon

CAT one by facet By facet, with one emission and one

reflection among facets

CLMU multiple by facet By facet with multiple reflections and one

emission

ENVImet one by facet From energy balance of all facets

GCTTC multiple by facet Prescribed

HIRLAM-U one bulk/town Fast broadband schemes for solar and termal

radiation (Savijärvi, 1990). emissivity
function and Stefan-Boltmann law,
STRACO scheme for clouds, water vapour
(Sass, 2001)

LUMPS one bulk Prata (1996)

MM5u one bulk/town Stefan-Boltmann law, plus parameterization

schemes for the clouds and water vapour
(e.g. Stephens, 1978; Garand, 1983)

MOSES1T one bulk Prescribed bulk emissivity

MOSES2T one canyon, roof Prescribed emissivity values for canyon and

roof

MOUSES multiple bulk/effective Effective emissivity by multiple reflections

MUCM two by facet

MUKLIMO From energy balance of all facets

NSLUCM one by facet One reflection

SM2U infinite bulk/effective Effective emissivity

SUEB one bulk/town By emissivity

SUMM multiple facet Result of multiple reflections

SUNBEEM multiple by facet By facet with multiple reflection

TEB infinite canyon, roof Result of two reflections in the canyon

TEB07 infinite canyon, roof Result of two reflections in the canyon

TUF2D,
TUF3D

multiple
(min 2)

patches/facet Multiple reflection (minimum 2) between

patches (and emission by patches initially)

UCLM two facet Emitted longwave radiation computed for

each facet (no reflections) using energy
budget.

VUCM three canyon, roof One reflection

models use a single assigned bulk value (e.g. albedo) and have just one reflection
(e.g. LUMPS). Thus they do not account for the different material characteristics in
urban area as do CLMU and TEB, for example.
As already noted there are a wide range of approaches to account for the anthro-
pogenic heat flux (Table 11.10). Currently this is the flux for which the least sophis-
ticated approaches are adopted. The term most typically is prescribed although
some, but not all, components may be calculated (e.g. fixed or mobile sources) in