Gonza´lez, J. E., C. Luvall, D. Rickman, D. Comarazamy, A. Picon,
E. Harmsen, H. Parsiani, N. Va´squez, R. Williams, and R. W. Waide
(2005), Urban heat islands developing in coastal tropical cities, Eos
Trans. AGU, 86(42), 397, doi:10.1029/2005EO420001.
Abstract:
Beautiful and breezy cities on small tropical
islands, it turns out, may not be exempt
from the same local climate change effects
and urban heat island effects seen in large
continental cities such as Los Angeles or
Mexico City. A surprising, recent discovery
indicates that this is the case for San Juan,
Puerto Rico, a relatively affluent coastal tropical
city of about two million inhabitants that
is spreading rapidly into the once-rural areas
around it.
A recent climatological analysis of the surface
temperature of the city has revealed that
the local temperature has been increasing over
the neighboring vegetated areas at a rate of
0.06°C per year for the past 30 years.This is
a trend that may be comparable to climate
changes induced by global warming.
These results encouraged the planning and
execution of an intense field campaign in
February 2004, referred to as the San Juan Atlas
Mission, to verify the spatial and temporal
extent of this urban heat index. Results of this
field campaign recently have been analyzed
and are the main topic of this article.
These results reveal the warming of a tropical
coastal city that is significantly higher than
typical temperatures in vegetated areas.This
may be the first set of high-resolution thermal
images taken in a tropical coastal city. Figure 1
shows that the daytime surface temperatures
of a portion of San Juan at fi ve-meter resolution
are as high as 60°C,and that differences
between urbanized and limited vegetation
areas are in excess of 30°C.