Geoscience Reference
In-Depth Information
Global Climates
Now that the geography of global climates has been dis-
cussed, it is a good time to review them in an interactive
way. Go to the
Geo Media Library
and select
Global Cli-
mates
. This animation is a tour of Köppen climate regions.
It provides an example of each climate zone along with a
representative city from that region. The discussion includes
a climograph from that locality, as well as photographs of
the city and associated vegetation. As a result, you should
be able to better visualize the characteristics of each climate
zone. Once you complete the exercise, be sure to answer the
questions at the end to test your understanding of Köppen
climate regions.
Remote Sensing and Climate
Global climates and the factors associated with them can be
analyzed in many different ways, including by satellite remote
sensing. With such technology, we can see the pattern of global
climates around Earth and some of the variables associated
with them, such as atmospheric pressure systems and veg-
etation. To see some of these patterns, go to the
Geo Media
Library
and select
Remote Sensing and Climate
. This anima-
tion allows you to see how remote sensing can be used to ob-
serve climate patterns on Earth. You will be asked, for example,
to identify a variety of atmospheric features, such as the ITCZ,
the STH, and midlatitude cyclonic systems. You can also test
your ability to locate hurricanes and determine the effect that
cold ocean currents have on climate. As you work your way
through this module, try to integrate all the concepts discussed
so far in this topic and visualize how they it together to form
distinctive geographic patterns. Once you complete the mod-
ule, be sure to answer the questions at the end to make sure
you understand these concepts.
This climate zone also reflects the fact that the environ-
mental characteristics in mountainous areas are extremely com-
plex, with abrupt changes taking place over short horizontal
distances and vertical slopes. These complexities are related to
such factors as slope orientation (does the slope face the Sun?),
time of day (does the Sun face the slope in the morning or af-
ternoon?), and direction of airflow (windward or leeward?). As
you recall from Chapter 7, orographic processes may be a very
important part of a highland area, with abundant precipitation
on the windward side of a mountain range and relatively dry
conditions in the lee. Perhaps the best way to view highland
(
H
) climates is to observe that they can vary dramatically over
short distances and that local conditions can change very quick-
ly over time. If you plan to spend time in the mountains, you
should be aware of these characteristics.
latitude location, chances are that the summers will be very
warm and the winters cold every year. However, climate condi-
tions on Earth have fluctuated in the past for a variety of rea-
sons. Short-term fluctuations on decadal scale have been caused
by volcanic eruptions, in which resulting ash in the atmosphere
blocks insolation, causing lower temperatures. Climate changes
have also occurred over much longer periods of time. For ex-
ample, the global climate during the Jurassic period (a part of
the dinosaur age), approximately 175 million years ago, was
generally warmer and more humid than it is today.
KEY CONCEPTS TO REMEMBER ABOUT
POLAR (ET, EF) ANd HIGHLANd (H)
CLIMATES
Reconstructing Past Climates
1.
Three major subcategories of very cold climates are
recognized: (a) the tundra climate (
ET
); (b) the ice cap
and sheets climate (
EF
); and (c) highland climates (
H
).
The global climates discussed in the previous section on the
Köppen system are essentially stable entities on human time
scales, with fairly predictable conditions occurring from one
year to the next. For example, if you live in a continental mid-
2.
The tundra climate (
ET
) is a high-latitude maritime
climate associated with tundra vegetation. It has a
narrower average annual temperature range than
