UBC, Department of Forest Science
Centre for Forest Gene Conservation
December 10, 2006
ClimateBC
web version is equivalent to the standalone MS WindowsÒ
ClimateBC v3.1. It extracts and downscales PRISM
1961-1990 monthly normal data (2.5 x 2.5 arcmin) to
scale-free and calculates seasonal and annual climate variables for specific
locations based on latitude, longitude and elevation (optional). The coverage
of ClimateBC includes

Figure 1. The coverage of the PRISM
data.
1) Annual
variables:
Directly calculated variables:
MAT mean
annual temperature (°C),
MWMT
mean warmest month temperature (°C),
MCMT mean
coldest month temperature (°C),
TD temperature difference between
MWMT and MCMT, or continentality (°C),
MAP
mean annual precipitation
(mm),
MSP
mean annual summer (May to September)
precipitation (mm),
AH:M annual
heat:moisture index (MAT+10)/(MAP/1000))
SH:M
summer heat:moisture
index ((MWMT)/(MSP/1000))
Derived variables:
DD<0 degree-days below 0°C, chilling
degree-days
DD>5 degree-days above 5°C, growing
degree-days
DD5100 the
Julian date on which DD>5 reaches 100, the date of budburst for most plants
DD<18 degree-days below 18°C, heating
degree-days
DD>18 degree-days above 18°C, cooling
degree-days
NFFD the number of frost-free days
FFP frost-free period
bFFP the
Julian date on which FFP begins
eFFP the
Julian date on which FFP ends
PAS precipitation as snow (mm)
EMT extreme minimum temperature over
30 years
2)
Seasonal variables:
Tave(12-2) winter
mean temperature (°C)
Tave(3-5) spring
mean temperature (°C)
Tave(6-8) summer
mean temperature (°C)
Tave(9-11) autumn
mean temperature (°C)
Tmax(12-2) winter
mean maximum temperature (°C)
Tmax(3-5) spring
mean maximum temperature (°C)
Tmax(6-8) summer
mean maximum temperature (°C)
Tmax(9-11) autumn
mean maximum temperature (°C)
Tmin(12-2) winter
mean minimum temperature (°C)
Tmin(3-5) spring
mean minimum temperature (°C)
Tmin(6-8) summer
mean minimum temperature (°C)
Tmin(9-11) autumn
mean minimum temperature (°C)
PPT(12-2) winter precipitation (mm)
PPT(3-5) spring precipitation (mm)
PPT(6-8) summer precipitation (mm)
PPT(9-11) autumn precipitation (mm)
3)
Monthly variables
Tave(1) – Tave(12) January -
December mean temperatures (°C)
Tmax(1) – Tmax(12) January - December maximum mean temperatures
(°C)
Tmin(1) – Tmin(12) January - December minimum mean temperatures
(°C)
PPT(1)
– PPT(12) January
- December precipitation (mm)
How
to refer
Wang, T., A. Hamann, D.L. Spittlehouse and S.N. Aitken.
2006. Development of scale-free climate data for western
Hamann, A. & Wang, T. 2005. Models of
climate normals for genecology and climate change
studies in BC. Agricultural and
Mitchell, T.D. and Jones, P.D. 2005. An improved method of constructing a database of monthly climate
observations and associated high-resolution grids. International Journal
of Climatology, 25, 693-712.
We would like to thank Marvin
Eng at the Research Branch, BC Ministry of Forests, Victoria for providing the
high-resolution digital elevation models. Funding for this study was provided
by the Forest Investment Account through both the BC Forest Science Program and
the Forest Genetics Council of BC and a joint Strategic Grant from NSERC and
the BIOCAP Canada Foundation.