Download Climates - Hewlett

 Climate

Introduction
 Climate
is a generalized pattern for
weather over a period of time
 Weather describes the changes that
occur to the atmospheric conditions over
short periods of time.

Major Climate Groups
 Factors Determining Climate
 Temperature
 Moisture
 Movement of Air
Low Latitudes
 Have vertical solar radiation at noon some times of the
year
 High Latitudes
 Have no vertical solar radiation at noon some times of
the year.
 Middle Latitudes
 Between high and low latitudes.


Latitude groups based on incoming solar radiation. The low
latitudes receive vertical solar radiation at noon some time of
the year, the high latitudes receive no solar radiation at noon
during some time of the year, and the middle latitudes are in
between.
Tropical Climate Zone
 Near the equator and receives the greatest angle of
sunlight throughout the year.
 Polar Climate Zone
 The Sun never sets during the summer and never rises
during the winter.
 Temperate Climate Zone
 Average temperatures that are between the two extremes


Regional Climate Influence
 Altitude
 Higher altitudes radiate more energy back into
space.
 Temperature decreases with altitude
 Mountains
 Decreasing temperature with altitude
 Uplifting effect on air masses
 Large
Bodies of Water
 high specific heat and loses energy by
evaporation.
 This has the effect of keeping the temperatures
more constant from night to day on a land mass
near a large body of water
 Ocean Currents
 Currents move large amounts of water from
different parts of the world.
 Can warm or cool land depending upon the
origin of the current

Ocean currents can move large quantities of warm or cool
water to influence the air temperature of nearby landmasses.
In science, climate is determined by the use of a P/Ep ratio.
P = the amount of precipitation an area receives over the
year
Ep = the amount of liquid water that
evaporates/transpires into water vapor throughout the
year.
Ratio of 1.2 or higher = Humid Climate
Ratio of 0.8 to 1.2
= Sub-humid Climate
Ratio of 0.4 to 0.8
= Semi-arid Climate
Ratio of 0.4 or less
= Arid Climate
10
The top number
goes into the
calculator first!!!
Climate Change
Climate Cooling – Ice ages have occurred Four major continental
glaciations are recorded in North America.
These periods can be caused by:
1. Decrease in the Sun’s energy output, indirectly related to Sunspots.
2. Change is the Earth’s orbital period.
3. Change in the inclination (tilt) of the Earth’s axis (Procession).
4. Volcanic eruptions release ash that blocks the Sun’s rays.
5. Asteroid/Meteor impacts shoot dirt into the atmosphere that block
the Sun’s rays.
6. Plate Tectonics move the continents around the Earth. Each
location will have a different climate.
7. During an ice age, more light gets reflected back into space and
keeps the atmosphere from heating up again.
11
Climate Warming – rock layers show that this does happen.
These periods can be caused by:
1. Increase in the amount of greenhouse gasses (carbon dioxide,
and water vapor) added to the atmosphere. This holds in
more infrared (heat) that the Earth tries to release at night.
2. Destruction of rain forests stops the process of plants/trees
removing the carbon dioxide from the air and releasing
oxygen back into the air.
3. Changes in the Earth’s orbit.
4. Change in the inclination (tilt) of the Earth’s axis.
5. Increase in the Sun’s energy output.
6. Volcanic eruptions can release a lot of carbon dioxide into the
atmosphere which will trap the heat b/c it is a greenhouse gas.
7. Plate tectonics will move the continents into different
locations.
8. Urbanization
12
El Nino
Every three to five years, driven by a reversal
in the trade winds, an El Nino, a huge bulge
of warm water under a blanket of tropical
storms, hits the west coast of USA and
South America., burying the cool Humboldt
Current and dropping heavy rains and a great
deal of bad weather on the west coasts of
Peru and Ecuador, and Calfiornia, often
around Christmas--hence the name El Nino
(the boy), in honor of the Christ Child.
La Niña is characterized by unusually
cold ocean temperatures in the
Equatorial Pacific, compared to El
Niño, which is characterized by
unusually warm ocean temperatures in
the Equatorial Pacific.
13
14
 Humid
 Moist
 More
than 50 cm (20 in) of rain per year
 Semiarid
 Between arid and humid
 25 – 50 cm (10 – 20 in) of rain per year

Local Climates
 Microclimates
 A local pattern of climate influenced greatly by the
local conditions.

This map highlights the approximate location of the major
types of climates in North America.