Geography 417
California for Educators
Weather, Climate and Soils
Objectives
Students will
identify and describe the various climatic regions of California.
Students will
explain the basic factors that create common weather conditions in California.
Students will
explain the basic parameters of the relationship between climate and
agricultural and economic production in California.
Introduction
Of what
importance are the weather, climate and soils to Californias growth and
development?
How has the climate
of California
played a role in its (historical, economic, cultural, etc.) development ?
State Standards
4.1 Students
demonstrate an understanding of the physical and human geographic features that
define places and regions in California.
1. Explain and use the coordinate grid
system of latitude and longitude to determine the absolute locations of places
in California
and on Earth.
2. Distinguish between the North and South
Poles; the equator and the prime meridian; the tropics; and the hemispheres,
using coordinates to plot locations.
3. Identify the state capital and describe
the various regions of California,
including how their characteristics and physical environments (e.g., water,
landforms, vegetation, climate) affect human activity.
4. Identify the locations of the Pacific Ocean, rivers, valleys, and mountain passes and explain
their effects on the growth of towns.
5. Use maps, charts, and pictures to
describe how communities in California
vary in land use, vegetation, wildlife, climate, population density,
architecture, services, and transportation.
Climate
What is
climate?
What two factors
are used to characterize most climates?
1_________. 2._________
When and how much
of each is important too.
How do you know
when you are in a different climate?
California
Rain (fig)
Note the patterns
Californias Temps (fig)
Californias
Climates
California has
more climate types than any other state.
They include:
1.
Mediterranean
Cool Summer, Hot Summer
2.
Desert
High (cool) and Low (hot)
3.
Marine West Coast (Maritime)
Also called Mediterranean Foggy- SF, and North
Coast
4.
Desert
5.
Steppe or Semi-Desert
6.
Highland Montane (Mountain)
Mediterranean
Mildly wet winter
and a dry summer with mild temperatures year round.
Hot and cooler
zone, but includes much of Coastal California.
Rain is mostly
cyclonic and during the summer the subtropical high dominates.
Also prevails in
the Mediterranean areas, Santiago Chile, Perth Australia and Capetown South
Africa.
Specialized crops
and vegetation common.
Consider the
effects on migration and agricultural competition.
Monterrey, CA
Climograph (fig.)
Marine
West Coast
Also sometimes
the foggy subcategory of Mediterranean.
Very rainy,
especially in winter and with mild to cool temperatures year-round.
From San
Francisco north to Seattle, Western Europe, Southern Chile and New Zealand.
Only on the west
coasts and affected by the prevailing westerlies passing over oceans.
Very rainy,
especially in the winter and generally cool.
Frequently
forested and cropped with rain-tolerant crops.
Soils may be poor
because of leaching.
Vancouver,
BC
Climograph (fig.)
Mediterranean
and West Coast W (fig.)
Mediterranean
and West Coast W (fig.)
Steppe/Semi-Desert
May get very hot and
very cold
Rainfall is small
and varies only slightly throughout the year.
Many of these
regions are rainshadowed or continental.
Scattered
throughout California
Short grass
prairies are natural and wheat is cropped on most of the flatter areas.
With irrigation,
much else is cropped.
Peublo,
CO
Climograph
(fig.)
Deserts
Deserts must be
dry, but not necessarily hot.
Both high (cool)
and low (hot) deserts in California.
The Mojave is
__________ and the Colorado Desert is _______.
What tree is a
good indicator?
Alpine
Climates
California has
many locations that altitude plays the dominant role in the character of the
climate.
Factors
Influencing Temperature
What three
factors are primarily responsible for the climate in any one location?
L________
A________ and
Proximity to ________
Factor 1:
Latitude
Latitude
determines both sun angle (intensity) and daytime length, factors in the amount
of insolation (incoming solar radiation).
Sun Angles in
California
Northern Border 24.5 to 71.5 degrees
Southern Border: 34 to 81 degrees
Atmospheric
Pressure
Insolation
affects atmospheric pressure.
The greatest
amount of insolation is generally found near the equator.
Air that is
hotter than surrounding air rises, creating low pressure.
Air that is cooler
than surrounding air sinks, raising the barometer.
Air
Pressure as an Imaginary Column of Air (fig)
Effects
of Pressure
Rising air will
create clouds and rain sometimes.
Equatorial
rainforests are created by permanent low pressure systems.
Descending air
warms as it sinks and produces clear skies and frequently in California warmer
temperatures.
Clear skies bring
cooler temperatures during the evening and in the winter.
Winds always move
from high pressure towards low pressure.
Wind
Direction and Pressure (fig)
California
in Global Pressure Context
The pressure
systems and winds that affect California often are created by conditions that
generated 1000s of miles away, along the equator or near the North Pole.
Greater
insolation over the equator creates enormous lows there and in turn frequent
high pressure zones not far from California.
The Hawaiian High
brings sunny summer weather to most of California
it shrinks in the winter.
World Air
Temperature Patterns- July (fig)
July
Pressures and Winds (fig)
January
Pressure and Winds (fig)
Global
Heat Transfer and Hadley Cells (fig)
Global
Circulation
Local
Winds
A small scale
version of the global circulation system can be witnessed at the beach day and
night.
Keep in mind that
water heats up and cools down more slowly than land.
Similar effects
occur with mountains and valleys
Santa Ana Winds.
Land and
Sea Breezes (fig)
Land and
Sea Breezes (fig)
Mountain-Valley
Breezes
Santa Ana
Winds
Because the
Pacific Ocean takes longer to cool during the autumn than land far inland, high
pressure forms over the Great Basin, shifting the wind pattern from the common
summer pattern.
Santa Ana
Winds (fig)
(Chinooks, Foehn Winds)
Wildfire
(fig)
Wind Farm
in CA (fig)
Factor 2.
Proximity to Oceans
Climate at any
location is also greatly affected by its proximity a large body of water.
The prevailing
temperature of nearby ocean currents figures into local climate.
Inland locations
generally have a continental climate and seaside locations have marine
climates.
Marine climates
demonstrate modest seasonal and daily temperature swings.
Continental
climates have wilder temperature changes.
Continentality
(fig)
Continentality
(fig)
Annual
Temperature Ranges
Ocean
Currents
Like the air,
differences in temperature and the rotation of the earth move bodies of water.
Water is also
blown along at the surface by wind.
Gulf Stream Current
and the California Current
Upwelling off
Point Arguello and Pt. Conception.
How would you
characterize the temperature of the Pacific Ocean along Californias coast?
How does the
California Current affect the climate of California?
Ocean
Currents (fig)
Temperature
Inversions
Sometimes the
rule about warm air below and cold air above is reversed, creating an
inversion.
Common in cold
coastal regions, like California.
Summer and Winter
versions of inversions.
Why should these
concern us directly?
Winter inversions
affect the distribution of both wild and domestic plant species. Why?
Temperature
Inversion-Winter (fig)
Temperature
Inversions-Summer (fig)
El Nino
Created when
prevailing ocean temperatures are inverted over the Pacific Ocean.
Happens every 5-8
years.
Changes the
weather patterns especially in Southern California.
Can bring extra
rain and even potential for hurricanes! (what?)
El Nino,
ITC and Currents (fig)
Air
Pollution
The peculiar
mixture of air pressure, temperature and topography along with 10 million
people make Southern California, especially LA, one of the worst places
anywhere.
Most other
valleys around CA suffer too.
Ozone.
Government to the
rescue!
Factor 3:
Elevation
Gravity affects air,
pulling it down, compressing and heating it.
Air at higher altitude is less compressed and feels cooler.
Air cools about
3.5 d per 1000 feet.
It may be 100 in
the valleys around LA and only 60 in the nearby highlands.
Why do you still
get sunburned in the mountains?
Precipitation
Precipitation is
the other component of climate
There are
basically three types of precipitation:
cyclonic
convectional
orographic
You should know
how each is generated, where each type is common in California and when each type
is most likely to occur.
California
Rain (fig)
Note the patterns
A.
Cyclonic or Frontal
This type of
precipitation is created when air masses of different temperatures come in
contact.
Cold fronts may
bring a line of heavy clouds and rain that last only hours.
Warm fronts may
bring drizzly conditions for days.
Our winter
precipitation in Southern California is mostly frontal, but Northern California
gets this more frequently.
Winter
Storms
Occur when the
Hawaiian High pressure zone moves southward.
The jet stream
sometimes bring pools of the Aleutian low southward at the same time.
There is abundant
opportunity for frontal storms to develop.
Frequent in the
Northern part of the state.
Frontal
Boundaries (fig)
Frontal
Boundary Map (fig)
B. Convectional
Precipitation
These types of
showers are created when an air mass rises due to instability in the
atmosphere.
Think of them as
bubbles of moist air that are warmer than their surroundings and rise up, cool
and precipitate.
These types of
storms are more common in the summer and in inland areas, out in the
desert. Called mistakenly monsoon.
Generated from
moisture in the Gulf of California.
These storms
dont make it to the coast.
Very common in
the Midwest and Southeast US during the summer.
Convection
C.
Orographic Precipitation
A consequence of
our seaside location and mountainous terrain.
Air that is
forced to higher elevations by prevailing winds is forced to expand, lose
energy, cool and if it is filled with water vapor, condense and produce
precipitation.
Once over the
mountains, it may descend, compress, heat and begin drying out leeward
locations in the rainshadow.
Orographic
Effects (fig)
Orographic
Lifting (fig)
At dew point, cloud base begins
Rain? Snow? Depends on temperature
Lee side = rainshadow (hotter and dry at base)
Global
Warming and the Greenhouse Effect
Is the planet
warming or not?
Yes. But Why?
Is the warming
planet the result of CO2 and other greenhouse gases such as CH4 (methane) and
CFCs and NO (nitrous oxide)?
Is it a result of
changes in solar activity?
Is it a result of
a wobble in the earths rotation?
Is it a lack of volcanic
activity?
The
Temperature Record
There are dozens
of means to measure past climatic trends.
Varying results
have been posted.
Junk science and
endowed science.
CO2 and
Temp (figure)
Soils
Only a note about
soils, though they deserve more.
Are a product of
the local rocks, weather and climate and erosion.
Quality soil is
necessary for productive agriculture and since agriculture is the states
biggest industry, soils are very important.
US Soil
Map
US Soil
Map 2
US Soil
Map 2
CA Close
Up
MORE COMPLEX, but
Ultisols-too much
rain, not great for agriculture but OK for forestry
Alfisols- better
for agriculture
Aridsols-desert
soils, sometimes useless, but
Entisols- can be
great for agriculture and are common in the Great Central Valley.
Soil Profile: Central California
Alfisol
Farmland:
Lompoc, CA
Soil Profile: New Mexico
Aridisol
Vegetation:
Southeastern CA
Death
Valley: CA