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Temperature and precipitation scenarios for the Caribbean from the
PRECIS regional climate model
J. Campbell, M. A. Taylor, T. S. Stephenson, F. S. Whyte and R. Watson
jayaka.campbell@uwimona.edu.jm
Scenarios of rainfall and temperature changes into
the 2080s under the A2 and B2 SRES scenarios are
examined using the Hadley Centre PRECIS
(Providing Regional Climates for Impacts Studies)
regional climate model (RCM). The model
simulates ‘present-day’ (1979-93) rainfall and
temperature climatologies reasonably well,
capturing the characteristic bi-modality of
Caribbean rainfall and the boreal summer maximum
and winter minimum temperatures. Observed annual
spatial patterns are reproduced, albeit rainfall
amounts are underestimated (~ 4cm) over Cuba,
Jamaica, Hispaniola and Puerto Rico. Temperatures
over the region are overestimated by 1°- 3°C. For
seasonal maps, the November-January (NDJ)
pattern was not as well simulated as the other
seasons. The study highlights 3 key features evident
from the climate change scenarios obtained. (i)
There is an intensification of the climatological
gradient pattern for NDJ, i.e. the northern Caribbean
(i.e. north of 22 o N) is projected to get wetter and
southern (i.e. south of 22 o N) drier. This potentially
points to an intensification of the northern
hemisphere winter circulation patterns; (ii) There is
a robust June-October drying signal which bolsters
the projections of summer drying obtained from
global climate models simulations; and (iii) While
there is evidence of increased temperatures across
all seasons, the rainfall response varies with seasons
(i.e. the northern Caribbean is wetter for November-
April but largely drier for May-October). This
points to a need to investigate circulation parameters
to determine what changes produce this response
under increased temperatures.