Where?
The Sonoran Desert stretches from the Mexican States of
Baja California del Norte and the western half of Sonora to the southern third
of Arizona and southeastern corner of California, covering about 120,000 square
miles. [15] It includes the large US cities of Palm Springs, Phoenix,
and Tucson, which are known to attract tourists during their mild winters. The orange region of the figure below define the Sonoran
Desert.
What?
The
Sonoran Desert has highly variable temperatures and rainfall, typically
receiving 120-300mm of precipitation per year.[16] Thus, it is lusher than most
deserts, and it's mountainous terrain and proximity to the Gulf of California
and Pacific Ocean creates a wide range of varying conditions. This North
American Desert is a center of biodiversity, home to over 2,000 different
plants species and many animals, too. [1] One of the most common plant forms of
the region, the Saguaro Cactus, shown below, is unique to the Sonoran,
and to many serves as a general symbol of the Sonoran Desert. Its wildflower,
as shown below on the bottom, is the state flower of Arizona.
Picture Source: http://en.wikipedia.org/wiki/Saguaro |
Climate Change in the Sonoran Desert
Already
the hottest desert in North America, the Sonoran Desert, like the rest of the
world, is facing current and future climate changes that will without a doubt
have biological impacts. Significant decreases in monthly extreme minimum
temperatures along with increasing average daily minimum temperatures have been
seen since the 1970s and are expected to continue at even greater rates. [9]
However, in a region that experiences temperatures that reach extremes below
0 degrees Celsius but maxima over 40 degrees Celsius, the number of
days near extreme values, rather than the values themselves, may be of greater
importance to biology.[9]
Like
temperatures, precipitation levels vary greatly throughout the year. The region
experiences bimodal precipitation, with rainy seasons occurring July-August and
December-March. Unlike many regions of the world, the Sonoran Desert has and is
expected to become increasingly drier as total annual rainfall trends show a
significant negative trend.[8] The cooler rainy season, December to March, has
seen a significant increase in precipitation variability over the past fifty
years.[6]
The
Sonoran Desert has been facing drought conditions for over a decade, which has
increased the occurrence of wildfires, a historically rare phenomenon in these
desert shrub lands.[9] These wildfires are most typical in the dry months of
May and June before the monsoon rains hit in July.
Figure 1 of Abatzoglou, John T., and Crystal A. Kolden. "Climate Change in Western US Deserts" |
The figure to the right summarizes trends of two of the principle components of climate- precipitation and temperature- since 1950 along with frequency of "extreme fire danger" since 1979. [6] Note the clear increases in average minimum temperature and high variability in cool season precipitation.
love this page- its got graphs, pictures and a map. It may be a good idea to outline the map as to indicate better where the sopnoran desert actually is. You can do this in many programs or even use paint and draw a circle around it
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