Physical Geography Chapters 8 through 12

Climate Classification 3

Why we classify?

To organize, simplify and generalize regions of similar characteristics

Visually represent data

Models can provide a predictive tool

Can help in understanding location of climate types and why

Climate Classification 4

Most significant features of classification are...

1) Temperature

2) Precipitation

We also subdivide zones based primarily on natural vegetation

Climate Classification 5

The Koppen System is a climate classification of the world

Created by Wladimir Koppen, 1918

Continuously revised throughout his life

Most widely used classification sys.

Uses mean annual & monthly value of temps & precip types

Zone boundaries are indicated by vegetation changes (floristic limits)

Each of 5 zones is subdivided according to temp and precip types

Climate Classification 6

The Modified Koppen System is the Koppen System with a variety of minor modifications

Text uses modified system

6 instead of 5 Zones

Other modifications

Climate Classification 7

Climographs

Monthly temperatures & precip in graph format

Usually 12 columns

Most useful when studying global climate classification

Shows details of specific locations

Can be used to classify the climate of a location

World Distribution of Major Climate Types and Subtypes 1

What you should know:

1) Where are the climate types and subtypes?

2) What are the characteristics of each?

3) Why are the particular characteristics found in each location?

World Distribution of Major Climate Types and Subtypes 2

Tropical Humid Climates (A)

Only true winterless climates

Moderately high temps

Among wettest regions in world

Warm, moist air masses off of oceans

Abundant uplift and humidity

Latitude molds character of zone

Dominate equatorial regions (15-20 degrees except where find mountains, etc.)

At some points extend to 25 degrees

World Distribution of Major Climate Types and Subtypes 3

Tropical Humid Climates (A) (Page 211-215)

3 Types of Tropical Humid Climates based on rainfall

1) Tropical Wet Climate (Af)

Usually extend 5-10 degrees from equator

Seasonless

Little seasonal temperature change

Average daily range changes more than average annual temp change, but still minimal!

Rainfall common, even multiple times per day

High humidity

Lack of wind, except along coasts

Examples: Amazon, Congo

World Distribution of Major Climate Types and Subtypes 4

Tropical Humid Climates (A)

2) Tropical Monsoonal (Am)

Similar to Tropical wet except...

Heavy rainfall and lower temps with summer monsoons

Winter brings more offshore winds

Annual temp changes minimal, but hottest temps occur in late spring prior to summer monsoons

Examples: India, Thailand

World Distribution of Major Climate Types and Subtypes 6

Dry Climates (B) (Pages 216-221)

Cover 30% of land surfaces (more than any other climate zone)

In general, aridity caused by lack of air uplift

Midlatitudes have many areas either far from surface moisture or topographic barriers

Divided into 4 subtypes

World Distribution of Major Climate Types and Subtypes 7

Dry Climates (B)

1)Subtropical desert (BWh)

Lies in or near the Subtropical High (STH)

Precip is scarce and unreliable

Can have dramatic daily temp changes

Sahara Desert, Arabia Desert, Australian Deserts, Atacama Desert

World Distribution of Major Climate Types and Subtypes 8

2) Subtropical Steppe (BSh)

Surrounds subtropical deserts

Similar temp and precip characteristics without extremes

Rainfall greater and more reliable than deserts

World Distribution of Major Climate Types and Subtypes 11

Mild Mid-Latitude Climates (C) (Pages 223-225)

Located on the equatorial side of mid-latitudes

A transition zone between tropical climates and severe midlatitude climates

Long & hot summers, mild & short winters

Precip is highly variable

Occasional winter frost

Subdivisions based on 1) precip seasonality and 2) summer temps

World Distribution of Major Climate Types and Subtypes 12

Mild Mid-Latitude Climates (C)

Created by latitude, general atmospheric & oceanic circulation

1) Mediterranean Climate (Csa, Csb)

Located on western side of continents

In general, small regions

Mild winters, hot summers

limited precip in winter, almost absent precip in summers

Influenced by westerlies

Precip

mid-latitude cyclones

Coastal Med areas have milder summers than inland Med areas

World Distribution of Major Climate Types and Subtypes 14

3) Marine West Coast(Cfb, Cfc)

40-60 degrees latitude on western side of continents (windward)

Milder temps, fewer temp extremes b/c oceanic influence

Wet, lowlands rarely get snow but higher west-facing slopes get very heavy snowfall

Rainfall probability high, but low-intensity rains

World Distribution of Major Climate Types and Subtypes 15

Severe Mid-Latitude Climates (D) (Pages 225-230)

Only in Northern Hemisphere 40-70 degrees (southern has no land at this location)

Experience 4 seasons

Long, cold winters get more severe as head north

Moderate precip

Divided into 2 subtypes based on temp

World Distribution of Major Climate Types and Subtypes 16

Severe Mid-Latitude Climates (D)

1) Humid Continental Climate (Dfa, Dfb, Dwa, Dwb)

35-55 degrees in N. America, up to 60 degrees in Europe, not found in Southern Hemisphere b/c lack of landmasses

Subdivided further into 4 subtypes based on latitude

Weather variability a common characteristic

Daily variability

Seasonal variability

Westerlies can cause changes

Experience dynamic atmospheric changes

Cold waves, heat waves, tornadoes, blizzards, etc.

Summers can be warm, but shorter than humid sub-tropical

World Distribution of Major Climate Types and Subtypes 19

Polar Climate (E) (Pages 230-234)

Average temp never rises above 50 degrees

Lowest annual temps in world

World Distribution of Major Climate Types and Subtypes 20

2 subtypes, classified by summer temps

1) Tundra (ET)

Complex mix of low-growing plants, no trees

Climate named after vegetation

Occurs in perennially cold climates, high latitudes or altitudes

Freezing can occur anytime (only 1-4 months have temps above freezing!)

Equatorward margin corresponds with treeline

Poleward margin corresponds with limit for plant growth

World Distribution of Major Climate Types and Subtypes 21

Polar Climate (E) cont...

2) Ice Cap Climate (EF)

In Greenland and most of Antarctica

Over 9% of world's land area!

All avg. monthly temps are below freezing

Veget can not grow

Permanent ice and snow

Strong winds and blowing snow are both common

World Distribution of Major Climate Types and Subtypes 22

Highland Climate (H) Page 235

Latitude less important than altitude and sun exposure

Complex local climate variation

Elevation, angle of sun exposure and wind are important

Exposure-big influence, greater likelihood of rain on windward sides

Daily temp range high

Climate impacts the environment

Flora

Fauna

Soil Development

Hydrology

Soil

Lithosphere zone of plant growth

Characterized by its ability to produce and store nutrients

Varied mixture of weathered mineral particles, decaying life, living organisms, gases and liquids

Regolith

A layer of broken and only partly decomposed rock particles

Cover bedrock

Soil Formation Factors 1

5 elements are involved with forming soil

1) Geologic Factor

Parent material source of rock fragments from which soil is made

Influences chemical composition of soil, soil development

Influence diminishes over time

Soil Formation Factors 2

2) Climatic Factor

Generally the most influential factor over time

Temp and moisture most significant

High temp and moisture--)accelerated biological and chemical processes

Soil Formation Factors 3

3) Topographic Factor

Slope and drainage are important

Soil Formation Factors 4

4) Biological Factor

Organic matter-living and dead plants and animals

Microorganisms make up 75% of soil's metabolic activity

Create humus-decomposed organic matter

Provide reservoirs for plant nutrients and soil water

makes up small fraction of soil, but of great importance

Pedoturbation is the mixing of soil by animals

Soil Formation Factors 5

5) Chronologic Factor

Most changes take place over vast time periods

Soil components 1

4 neutral components to soil

1. Inorganic materials

Bulk of soil is mineral matter

½ of avg. soil is small, granular mineral matter called silt or sand

Mineral composition depends on parent material

Clay is important storage for plant nutrients and soil water

Negatively charged means it attracts positively charged nutrients (cations)

Cation=an atom of group of atoms with positive electrical charge

Soil components 2

2. Organic Matter

Living and dead

Partially vs. fully decomposed

Decomposition rate depends on climate (temp and humidity)

"litter"=collection of dead plant parts at the surface of soil

Soil components 3

3. Soil Air

Pore spaces account for ½ + the volume of avg. soil

Allows for water and air to penetrate

Soil air is saturated with moisture, plants remove oxygen and respite CO2 into pore spaces

Soil components 4

4. Soil Water

Serves numerous purposes

Dissolves nutrients for roots

Helps complete chemical reactions

Assists microorganisms with production of humus

Mixes soil particles

Soil components 5

4. Soil Water cont...

A) Leaching-results from water dissolving soluble materials and washing them downward to lower levels

Common in TRF where a lot of daily rainfall

B) Eluviation-the process by which water picks up fine particles of soil from upper layers and carries them downward

C) Illuviation-the process by which fine soil particles from upper layers are deposited downward

D) Soil/Water Balance-relationship between gain, loss, and storage of soil water (evapotranspiration, vs. percolation)

Soil Properties 1

Color

175 gradations of color

Can provide clues to nature and capabilities of soil

Also can be misleading

Soil Properties 2

Texture

Determined by relative amts of various separates present

Separates = size groups within standard classification of soil particle sizes

3 principle soil separates:

1) sand

2) silt

3) clay

Soil Properties 3

Structure

Structure is key to soil's porosity and permeability

Ped

is a larger mass in which individual soil particles tend to aggregate

Determines the structure of the soil

4 basic ped shapes

A) spherical B) plate-like C) block-like D) prism-like

Soil Chemistry 1

Chemical reactions determine presence and availability of nutrients

Soil Chemistry 2

Colloids are organic and inorganic microscopic particles of soil that represent the chemically active portion of particles in soil

Organic colloids consist of decomposed organic material

Inorganic colloids consist of clay in thin, crystalline forms

Colloids are major determinants of water-holding capacity of soil

Soil Chemistry 3

Cation Exchange

Colloidal complex

the combo of colloid and attached cations

Created by colloids negative charges attracting swarms of nutrient cations (positively charged)

Cation Exchange Capacity (CEC)

Capacity of soil to attract and exchange cations

Generally, the higher the CEC, the more fertile the soil

Acidity/Alkalinity 1

Acidity/Alkalinity

Acid-produces hydrogen ions or hydronium ions when dissolved in water

Base-produces hydroxide ions when dissolved in water

Acidity-a measure of dissolved acids in a solution

Highly acidic tend to leach away nutrients quickly, making it difficult for plants to absorb them.

Acidity/Alkalinity 2

Alkalinity-measure of dissolved bases in a solution

Overly alkaline soil is inefficient at dissolving minerals and releasing nutrients

Acidity and Alkalinity range from 0-14pH based on relative concentration of hydrogen ions

pH 7 is neutral and best for most plants and microorganisms

Soil Profiles 1

4 processes deepen and age soils

1) addition 2) loss 3) translocation 4) transformation

Water also plays important role

Soil Profiles 2

Horizon-a fairly distinctly recognizable layer of soil, distinguished from another by differing characteristics and forming a vertical zone

6 horizons: O,A, E, B, C, R

O-organic litter; not typical for all soils to have

A-topsoil; mineral and organic

E-eluvial layer; sand and silt concentrations

B-subsoil; mineral layer containing materials removed from E

C-unconsolidated regolith; no organic matter

R-bedrock

Soil Profile

a vertical cross section of soil layers into the parent material beneath

Solum

true soil that includes only top 4 horizons

Pedogenic Regimes 1

Pedogenic regimes are soil forming regimes/environmental settings in which certain physical/chemical/biological processes prevail

Pedogenic Regimes 2

Climate and Pedogenic Regimes

Regimes generally distributed by climate, especially temp and moisture availability

Vegetation cover a secondary determinant

Pedogenic Regimes 3

Podzolization-found in areas with long, cold winters, esp. coniferous forests of mid and high latitudes

Slow chemical weathering of soils

Fast mechanical weathering from frost action

Soils are shallow and acidic

Generally low fertility

Soils referred to as "podzol"

Pedogenic Regimes 4

3. Gleization-found in areas with saturated soils due to poor drainage—usually cool climates

Slow decomposition due to lack of oxygen

Dark, highly organic soils

Usually highly acidic

Soil referred to as "Gley soils"

Pedogenic Regimes 5

5 major regimes

1) lateralization-dominant where temps are high year round

Rapid weathering of parent material

Dissolution of minerals

Quick decomposition of organic matter

These soils are sometimes referred to as "latisols"

Not good for agriculture

Pedogenic Regimes 6

4. Calcification-dominant in drier regions such as prairies, steppes and savannahs

Concentration of calcium carbonate in the B horizon which forms a hardpan

Pedogenic Regimes 7

5. Salinization-dominant in drier regions where evaporation leaves salts in or on soils

Limited plant life found b/c salts can be toxic

Water management can help situation, but can also exacerbate the problem

Pedogenic Regimes 8

Climate and Pedogenic Regimes

Regimes generally distributed by climate, especially temp and moisture availability

Vegetation cover a secondary determinant

Global Distribution of Major Soils 1

Entisols

Very little profile development

Least developed of all soil orders

No pedogenic horizons

Often thin and or sandy

Limited productivity

Global Distribution of Major Soils 2

Inceptisols

Immature order of soils

Faint characteristics

Global Distribution of Major Soils 3

Andisols

Volcanic ash soils

Deposited fairly recently

Global Distribution of Major Soils 4

Gelisols

Permafrost layer

young soils with minimal profile development

Develop slowly b/c cold temps and frozen conditions

Global Distribution of Major Soils 5

Histosols

Organic soils rather than mineral

Considered least important of soil orders

Occupy smallest portion of earth

Global Distribution of Major Soils 6

Aridisols

Dry soils

Not enough water to remove minerals from soil

Thin, sandy profile

Very extensive order, covers 1/8 of world's surface

Global Distribution of Major Soils 7

Vertisols

Swelling and cracking clays

Large capacity for absorbing water

Alternation between wet and dry/expansion and contraction

Produces churning/mixing effect on soil inhibiting horizon development

Global Distribution of Major Soils 8

Mollisols

Dark, thick, soft soils with humus

Most productive soil

Global Distribution of Major Soils 9

Alifsols

Clay with high bases

Subsurface clay horizon with plant nutrients and water availability

Fairly agriculturally productive

Global Distribution of Major Soils 10

Utilsols

Clay with low bases

Similar to alifsols, but more weathered and lacking bases

Global Distribution of Major Soils 11

Spodosols

Acidic, sandy forest soils

Very infertile

Global Distribution of Major Soils 12

Oxisols

Highly weathered

Leached

High degree of mineral alteration

If cleared for agric, nutrients are leached quickly

Earthworms

Earthworm is most important to soil formation and development

Movement creates crumbly soil structure

Movement brings deeper material to surface

Movement brings in leaf litter/organic matter

Tunnels facilitate drainage

Biosphere

Consists of all living organisms on Earth

Biosphere Impinges on other 3 spheres, difficult to create distinct boundary

True

Vegetation (of different types) used to cover most of Earth's surface, but humans are changing that

Development

Modifying locations of vegetation types

Genetically modified crops

Pesticides, fertilizers, etc.

The Biosphere

The Hydrosphere

Least well-defined of all spheres

Much overlapping between spheres

Includes:

Underground sources

Rivers

Lakes

Oceans

Swamps

Cloud crystals

Ice

Moisture stored in plants

Water is essential to all life on Earth

True

Water is the most abundant substance on Earth

Surface water makes up more than 70% of surface of Earth

Surface water makes up more than 70% of surface of Earth.

Water is H20 (2 hydrogen atoms, 1 oxygen atom)

Pure water is tasteless, colorless and odorless

Water occurs naturally in 3 states, easily changes state

In each change there is gain or loss of heat

Water has many unusual properties (REVIEW)

Liquid at ordinary Earth temps

Great heat capacity can absorb E with only small T changes

Expansion while cooling

Capillarity-water's ability to climb upwards as a result of high surface tension

Ability to dissolve other substances (very significant)

Functions as a weak acid

Contains various chemicals making it nearly always impure

Water is distributed unevenly on Earth

True

Most water is stored in:

Oceans

Lakes

Glaciers

Rocks below surface

Hydrologic Cycle

A series of storage areas are connected by various transfer processes, in which constant interchange occurs

Surface-to-Air Water Movement

Evaporation.

Of the moisture evaporated, 84%+ is from ocean surfaces. Evaporated water becomes water vapor and can travel vertically or horizontally

Air-to-Surface Water Movement

Water vapor either condenses to a liquid or sublimates to ice to form cloud particles

Clouds drop precip (rain, snow, hail)

Precip & evaporation/transpiration balance over time but not in place

Evaporation is greater than precip over oceans

Precip is greater than evaporation over land

Movement on and Beneath Earth's Surface

Runoff -the flow of water from land to oceans by overland flow, streamflow or groundwater flow

This is why oceans don't dry up and continents don't become completely flooded

Residence Times

At any given moment, the atmosphere only contains a few days of potential precip.

Residence time of a molecule of water can be hundreds of thousands of years or only a few minutes

How many oceans are there?

One vast ocean divided into 4 principal parts

Pacific

Atlantic

Indian

Arctic

Characteristics of Ocean Waters

Almost all known minerals are found (to some extent) in sea water

Differences according to location

Temperature decreases with increasing latitude

Western sides almost always warmer than eastern sides

Density varies with temp, salinity and depth

Salinity is a measure of the concentration of dissolved salts

Varies with evaporation rates and fresh water discharge rates

Movement of Ocean Waters

Most motion is in a) waves b) currents and c) tides

Movement affects surface more than deeper waters

Disturbances in Earth's crust under the ocean can cause motion

Tides

-cause the greatest vertical movements of ocean waters

-sea level fluctuation

-affected by the gravitational pull of the moon

-rhythmic oscillations occur every 6 hrs from gravitational attraction of bodies

Currents

Numerous currents

Shift water vertically and horizontally

Primarily caused by wind flow

Also caused by contrasts in temp and salinity

Influenced by size and shape of ocean, depth, and Coriolis Effect

2nd largest storage reservoir for moisture

Land ice is larger than oceanic ice

Land Ice

Permafrost is permanently frozen subsoil (beneath earth's surface)

Oceanic ice

fresh water b/c crystals don't take in minerals of sea water