Atms 3600 Climates of the World

Anthony R. Lupo

Day 1

Climate Classifications (Intro)

We have previously discussed general meteorology principles and ocean circulations now we will start to focus on general patterns of climate

The first test will follow this material, then we will look at regional climates all over the globe

Day 1

Koeppen Climate System

Wladimir Koeppen (Köppen) (1846-1940), Russian-born, German meteorologist

Developed a climate system in 1900 dealing with vegetation then revised in 1918 based on temperature and precipitation

Most widely used climate classification done, modified by many most notably by Glen Trewartha of University of Wisconsin

Day 1                                                                                                                         

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Day 1

Major Classification Divisions 5 basic climate categories

(A) Tropical moist climates Tropical moist climates extend northward and

southward from the equator to about 15 to 25 degrees of latitude. In these climates all months have average temperatures greater than 18 degrees Celsius. Annual precipitation is greater than 1500 mm.

Three further subdivisions of (A)

Day 1

Subdivisions of (A)

Af or tropical wet

precipitation occurs all year long. Monthly temperature variations less than 3 degrees

Celsius. Daily highs ~32 degrees Celsius while lows ~22 degrees Celsius. .

cumulus and cumulonimbus clouds form early in the afternoons.

Day 1

Am is a tropical monsoon climate.

Annual rainfall is equal to or greater than Af, but falls in the 7 to 9 hottest months. During the dry season very little rainfall occurs.

The tropical wet and dry or savanna (Aw)

has an extended dry season during winter. Precipitation during the wet season is usually less than 1000 millimeters. and only during the summer season.

Day 1

Dry Climates (B)

The most obvious climatic feature of these climate is potential evaporation and transpiration exceed precipitation. These climates extend from 20 - 35 degrees North and South of the equator and in large continental regions of the mid-latitudes often surrounded by mountains.

2 minor subdivisions

Day 1

Subdivisions of (B)

BW - dry arid (desert) is a true desert climate. It covers 12 % of the earth's land surface and is dominated by xerophytic (cacti) vegetation.

k mid-latitude desert, arid, cool h tropical desert, arid, hot

Day 1

BS - dry semiarid (steppe). Grassland climate that covers 14% of the earth's land surface. It receives more precipitation than the Bw either from the intertropical convergence zone (ITCZ) or from mid-latitude cyclones.

h, hot K, cool or cold

Day 2

Moist Subtropical Mid-Latitude Climates (C)

This climate generally has warm and humid summers with mild winters. Its extent is from 30 to 50 degrees of latitude mainly on the eastern and western borders of most continents. During the winter the main weather feature is the mid-latitude cyclone. Convective thunderstorms dominate summer months.

3 major subdivisions, other subdivisions

Day 2

3 Major Subdivisions

Cf: Humid Subtropical Cs: Mediterranean Cw: Monsoon Regions

Further Classify them by precipitation amount and temperature patterns

Day 2

7 Subdivisions

Cfa: Humid Subtropical, mild winter, moist in all seasons, long hot summer, Found on the Southeastern side of continents primarily between 30-40 degrees

Cfb: Marine. Mild winter, moist all seasons, warm summer. The west coast of U.S. from N. California Southern Chile

(narrow band because of mountains). NW Europe - extends far inland because of lack of North-South

trending mountains. Cfc: Marine. Mild winter, moist all seasons, cool short summer. Northern Europe Western N.A. coast in Alaska

Day 2

7 subdivisions (cont.)

Csa: Interior Mediterranean, mild winter, dry summer, hot summer

Csb: Coastal Mediterranean, mild winter, dry summer, short warm summer

Cwa: Subtropical monsoon, mild and dry winter, hot summer

Cwb: Tropical Upland. Mild and dry winter, short warm summer

Day 2

Moist Continental Mid-latitude Climates (D)

Moist continental mid-latitude climates have warm to cool summers and cold winters. The location of these climates is poleward of the C climates. The warmest month is greater than 10 degrees Celsius, while the coldest month is less than -30 degrees Celsius. Winters are severe with snowstorms, strong winds, bitter cold from Continental Polar or Arctic air masses.

Day 2

Like the C climates there are 2 Major Subdivisions: Dw - dry winters; Df - wet all seasons.

Additional Subdivisions

Moist all seasons

Dfa: Humid continental, severe winter, long, hot summer, North Central US

Day 2

Dfb: Humid continental, severe winter, short warm summers, Southern Canada, European Russia

Dfc: Subarctic, severe winter, short cool summer, Northern Canada, Russia

Dfd: Subarctic, extremely cold winter, short summer, exterior Siberia

Day 2

Additional Subdivisions (cont.) Dry winters Dwa: humid continental, severe winter, long hot

summer,Korea, Northern China Dwb: humid continental, severe winter, warm

summer, Eastern Russia Dwc: Subarctic, severe winter, short cool summer, NE

Russia Dwd: Subarctic, extremely cold, short cool summer,

interior Siberia

Day 2

Polar Climates (E)

Polar climates have year-round cold temperatures with warmest month less than 10 degrees Celsius. Polar climates are found on the northern coastal areas of North America and Europe, Asia and on the landmasses of Greenland and Antarctica. Two minor climate types exist.

Day 2

ET or polar tundra is a climate where the soil is permanently frozen to depths of hundreds of meters, a condition known as permafrost. Vegetation is dominated by mosses, lichens, dwarf trees and scattered woody shrubs.

EF or polar ice caps has a surface that is permanently covered with snow and ice.

Day 2

Highlands (H)

Additional climate classification to deal with the higher elevations generally greater than 1500 m. Most of Tibet is covered in this classification and there are many subdivisions due to the variations of the mountainous terrain.

Day 2

Summary

Handouts explain the temperature and moisture characteristics defining the major subdivisions

This is a general view of the climates of the world, after the first test we will start taking apart the continents one by one and further dividing up the world as we see necessary

Day 3

SE Asia and the Monsoon

This region is the largest in the world with rainfall over 100 inches in a year (windward mountains over 150 inches, rain shadows still get near 40 inches)

Highest precip during the retreating phase of the SW Indian Monsoon (autumn)

Day 3

Components of the SE Asia Monsoon

Australia High

Cross-equatorial jet

SW Monsoon

Day 3

Monsoon Trough (ITCZ)

Tropical Easterly Jet

Western Pacific High

Mei-Yu Front (China – Indochina) Bai-yu (Japan)

Mid-latitude distrubance

Day 3

Hurricanes, where do they occur (NASA)?

Day 3

They need: SST’s 80 F

Little wind shear

Initial Disturbance

ITCZ “seeds” hurricane regions.

Day 3

Zuki and Lupo (2008)

Hurricanes need both favorable atms and ocean conditions to form, favorable atms or ocean alone won’t do it.

Stolen from “wikipedia”

Stolen from NOAA

Day 3

Structure of the Atms. Boundary layer

(Show on board)

Day 3

Urban Heat Island effect (COHIX) Akyuz et al. (2004)

Temps

precip

We Are All Earthlings©1990 The Muppets

Some of us have feathers Some of us have fins Some of us are furry

And some of us have skins We swim and hop and slither

And leap and soar and run And we all live together On a planet of the sun

We are all earthlings We are all earthlings

Spinning around together On a planet of the sun

We live in the desert We live inside a tree

We live high in the mountains Or deep beneath the sea

We live in tents and cabins In houses just for one

And we all live together On a planet of the sun

We Are All Earthlings

We are all earthlings We are all earthlings

Spinning around together On a planet of the sun

Floating down a river Swinging through the trees

Climbing up a mountain Going with the breeze

All of us can have a happy healthy place to be If we can float and swim and climb in earthling harmony

We are all earthlings We are all earthlings

Spinning around together On a planet of the sun

Spinning around together On a planet of the sun

Day 4

Climate Change and modelling

Define Climate Change and then review 5 components of climate system

Early in the year we discussed 5 components of the climate system. Now let us examine how the modeller looks at the problem: (draw)

Day 4

Then discuss new drawing Do internal forcing and give examples positive feed backs ice albedo / global warming / generic Negative feedback clouds / temps and generic example

Then do external forcing and give examples. Key to climate change is balance of energy at the boundaries

Day 4

Concept of change in climate variable = sum of sources and sinks.

Day 4

Climate change: five important questions:

1 Climate change on time scales (go over 3 ways to infer past climate, obs, historical, and proxy), then go over climate since 200 BC and 20 KYA)

Day 4

2. Climate change regionally:

CO2 warming

3. Climate change driven by External or internal?

Day 4

4. Fast response versus slow response? Can we identify?

5. Model improvement?