GEOGRAPHY 101 Front PageCLIMATE
MATERIALS NEEDED FOR CLASS:
Daily Lesson Plans. H.K.C--Take roll and announcements.TEXT: Essential of Physical Geography: 6th Edition, Robert E. Gabler, Robert J. Sager, Daniel L. Wise, and James Peterson. Saunders College Publishing, Harcourt Brace College Publishers 1999. Rand McNally GOODE's WORLD ATLAS
NOTE--I'LL BE USING MATERIAL FROM SEPARATE CHAPTERS SO PAY CLOSE ATTENTION LOOK AT THE GENERAL OUTLINE AND THE CHAPTER HEADING I'LL TRY TO TELL YOU IN THE NOTES ON PAGES BUT I MIGHT MISS SOMETHING SO JUST WATCH IT. LIKE ALWAYS THE TEST WILL USE THE THE NOTES--DEPENDING ON HOW FAR WE GET IS WHAT YOU WILL BE TESTED ON.
GENERAL OUTLINE: PAGES LISTED BELOW ARE JUST GENERAL I'LL SKIP AROUND A LITTLE SO WATCH THE NOTES AND RELATE THE MATERIAL. REMEMBER THAT THE NOTES ARE THE MOST IMPORTANT SOURCE OF INFORMATION.
IX Climate and Climate Change--PP. 210 214
A. To briefly discuss Climate and Climate change.
B. To discuss the Historical Classification of Climates
C. To stress the Koppen system of Climate classification and the Simplified Koppen classification.
D. To identify ClimographsX. Low-Latitude and Arid Climatic Regions--236--270
A. To briefly explain the importance of Climate.
B. To compare World Distribution of Major Climatic Types and subtypes
C. To describe Climatic Regions and identify zones of transition.
D. To examine Humid Tropical Climatic Regions and the three major types.
E. To outline the Arid Climatic Regions and the two major types.XI. Mid-Latitude and Arid Climatic Regions--271--307
A. To outline Middle-Latitude Climates and define Humid Mesothermal Climatic Regions.
B. To describe the Mediterranean Climates
C. To examine the Humid Subtropical Climate and compare it to the Mediterranean climate as far as location.
D. To sketch the Marine West Coast Climates.
E. To paint the differences in Humid Microthermal Climatic Regions
F. To recall the Humid Continental Hot Summer Climate and Humid Continental Mild Summer Climate.
G. To depict the Subarctic Climate--the Taiga, a land of trees
H. To compare and contrast the two types of Polar Climates.
I. To describe Highland Climates.
ANTICIPATORY SET What is the Distribution of Major Climatic Types and Subtypes ? Overview: What are the variables in climate? Where are the Tropical Climates? How are Climate Classified? Where are the Dry Climates? What is the Koppen System and the Modified Koppen System.? Where are the Mild Midlatitude Climates? NOTE Where are Severe Midlatitude Climates? This one is difficult, the six major types is not to bad, but the sub-types are very difficult. Where are the Polar Climates? When I want a sub type I'll label it in the notes, there are only a few that I think you could know. I'll try to bold face, but do ask me. Where are the Highland Climates? BEHAVIORAL OBJECTIVES To identity the spatial aspects of geography. To recall some problems with the Koppen system. To depict past and possible future changes in Earth's climate. To contrast KOPPEN SYSTEM AND THE MODIFIED KOPPEN SYSTEM. To recall the efforts of the Greeks. TO KNOW THE CODE IS KEY TO THE SYSTEM To define the two measures of climate classification--Temperature and Precipitation. To relate the Six Zones of the Modified Koppen System. To identify a system for classification of climates. To identify Climographs. To explain that vegetation is the best indicator for climate. To describe in general the World Distribution of Major Climatic types and sub-types. To describe the KOPPEN SYSTEM BASED ON The next several are tied together with Tropical VEGETATION.
To depict Tropical Humid Climates (Zone A) To recall Midlatitude Steppe Climate BSk. To locate Tropical Humid Climate Zones. To discuss human problems with Midlatitude Steppes--Dust Bowl. To trace Tropical Wet Climates Af. To evaluate Mild Midlatitude Climate Zone C. To locate Tropical Wet Climates To define Mesothermal Climates To locate and identify the Amazon Basin as the largest area To recall most people on Earth live in Midlatitude locations. To identify the Tropical Rain Forest as Selva. To outline Mediterranean Climate Csa, Csb. To describe Slash and Burn Agriculture To locate Mediterranean climates and to point out the differences between the two types. To outline Plantation Agriculture To recall Humid Subtropical Climate Cfa, Cwa. To recognize Tropical Monsoonal Climate Am To located Humid Subtropical Climates. To recount Tropical Savanna Climate Aw To evaluate Marine West Coast Climate Cfb Cfc. To located Tropical Savanna Climates To locate Marine West Coast Climates especially Western Europe To depict the precipitation patterns of Tropical Savanna Climates To describe why the West Coast Climate is limited in North America. To sketch Dry Climates (Zone B) To describe the West Coast Marine Climate--Bring a rain coat. To discern how Dry Climates are divided into two categories . To define Microthermal Climates. To explain that Subtropical Deserts are caused by Subtropical highs. To explain why the Southern Hemisphere does not have a Zone D climate. To locate Subtropical Deserts. To define Continentality as a key to Midlatitude climates. To paint Subtropical Desert Climate BWh. To outline Humid Continental Climate Dfa, Dfb, Dwa, Dwb. To delineate Midlatitude Desert Climate BWk. To discuss Agricultural Production in Humid Continental Climates. To locate Midlatitude Deserts To describe Humid Continental Mild Summer Climates Dfb, Dwb To explain that Midlatitude Deserts are caused by mountains. To investigate Severe Midlatitude Climates
Zone DTo identify Subtropical Steppe Climate Bsh To classify Subarctic Climate Dfc, Dfd, Dwc, Dwd. To describe Desert Climates. To identity Xerophytic Vegetation. To recall agriculture in Desert climates. To point out the difference between Steppes and Deserts. To identify the Sahel.
To know the different names for this type of climate taiga and bora. To analyze the complex nature of Highland Climate Zone H. To define Permafrost. To discuss altitude is more important than latitude To list the Polar Climate Zone E. To relate exposure and to remember the lapse rate. To identify the Tundra Climate ET To describe the idealized Global Pattern. To relate the Ice Cap Climate EF as a polar desert.
INSTRUCTIONAL INPUT
Content Methods:Lecture and Classroom discussionTHE TEXT REFERENCE FROM OVERVIEW TO CLIMOGRAPHS IS ON PP 210--214
OVERVIEW: Remember that weather is short term, climate is long term.
The study of climate is like all branches of geography it is to analyze the spatial aspects of the planet. The question asked is how are Climate Zones distributed over the Earth. Climate is a little tricky because of the fickle nature of climates. There are many variables involved in climate. Climate is based on things like average annual precipitation and temperature, wind direction, temperature, and precipitation patterns, number of sunny days or cloudy days. Climate is the sum total of several elements, which for the most part are separate and variable. Climate is so variable that it can range from a side of a mountain to areas taking up half a continent.
In Earth's very long history there have been many different climates and future climates will be different than present climates. The major concern for the future climate is man impact on the environment. The burning of fossil fuels which has increased Carbon Dioxide in the atmosphere which can lead to "Global Warming," and a change in the climate. There are other examples which also could be used.
I. CLASSIFYING CLIMATES
A. Like almost every thing else the first study of climate was made by the Greeks. They knew the shape of the world and the approximate size. They knew their world very well, it's southern limit was sixth cataract, waterfall on the Nile, where the temperature was hotter. The coast of the Black Sea, along the Danube was the northern extent of their real knowledge and the temperature was colder. To the Greeks, their land fell within the temperate zone in their early classification of climate. They divided the world into three zones, the Temperate Zone of Midlatitudes, the Torrid Zone or Hot Zone of the South, and the Frigid Zone of the North.
Since the earth was round they theorized, a similar pattern would be in the Southern Hemisphere. (Does anyone remember the Greek who first measured the size of the world?)TEMPERATURE AND PRECIPITATION--THE TWO ELEMENTS
B. The amount of data to understand a climate is tremendous. Therefore, a method is needed to bring the facts into some type of order, or system. There are several measures which could be used, but those who measure climate usually use tools. Two weather elements are used most often as indicators of climate are precipitation and temperature. There are other guidelines as well.
THE PURPOSE OF CLASSIFYING CLIMATES
C. The desire to simplify, organize, and generalize the vast array of climatic data into a comprehensive system that helps us understand the distribution of climates over Earth leads to classification. (Take a look at Figure 9.1 on p. 213.) A classification organizes similar entities together into groups that are distinguished by particular characteristics that they share to the exclusion of other groups. A climate clarification based upon statistical parameters or physical characteristics is termed an empirical classification. All classification systems are generalizations and may not always describe a real weather situation and only gives a typical look for any given region.
II THE KOPPEN SYSTEM.
A. The best systems which describe climate have three characteristics. First, they are simple to comprehend and to use. Second, they have an ordered framework for the entire world. In short, you can hang your hat on them. Third, they should give some indication where the zone starts.
VEGETATION AS INDICATOR FOR CLIMATE
B. Most major climatic classification schemes use natural vegetation as the principal indicator of major climatic regions. It is only one part of the major classification system there are other things that are used to measure climate. If you grew up in the mountain west, certain vegetation is not linked with climate, but elevation. It is the same thing in this case.(What is the line called that is usually around 10,000 feet on most mountains? There are some conditions where it does vary a little. In Switzerland the line is about eight or nine thousand feet.) The basic five zone system is subdivided into different types and subtypes. The people who classify climates are called climatologists.
KOPPEN SYSTEM--KNOW THE PRINCIPLES OF HIS SYSTEM
VEGETATION IS THE MOST IMPORTANT ELEMENTC. The most widely used system today for climate classification is the Koppen system or modified Koppen system. This system or its modified forms meets the needs for climate classification. Wladimir Koppen (1846--1940) was a German climatologist and an amateur botanist who first published his system in 1918 and kept changing it until the end of his life, the last revision was in 1936. The Koppen system of climatic classification was the first to use a numerical system based on average temperatures or average precipitation, and the zonal boundaries of climate are determined by vegetation boundaries. The example used most often to illustrate the point on vegetation is timberline. There is usually a link between temperature and precipitation and vegetation.
D. The system uses a data base employing the mean, the average, annual and monthly values of temperature and precipitation. The points on the map are charted at weather stations and the climate type is quickly determined. These numbers are readily available and are quickly added. The system works on the specific and general level.
LIMITATIONS TO THE KOPPEN SYSTEM
E. There are some limitations to the Koppen system. Winds, daily temperature extremes, precipitation intensity, the amount of insolation, humidity, and cloud cover. The system regardless of its problems is close to the real world and the input, the data from weather stations, are standardized and are very accessible. Despite these limitations the Koppen system has been the springboard for other systems and the terms coined by Koppen like steppe, tundra, and rain forest are widely used in the popular press.
III THE SIMPLIFIED KOPPEN CLASSIFICATION
A. Koppen himself was not entirely pleased with his results and did not think the final edition published was the last word in the matter of climatic classification. Other geographers and climatologists have modified the Koppen System. Your textbook use a modified or simplified Koppen system. The goal of the text is to learn the general system on climate classification. In the modified system, the five Koppen major climatic zones are retained, but a sixth one is added. The five climatic zones of Koppen and the sixth added zone run from A to H.
HIGHLAND CLIMATES ARE THE EXCEPTION
B. The zone which is added is the highland climate zone. Most of the climate zones can easily be figured by the spatial pattern they form over the Earth's surface. There is an exception. The major climate category in the Koppen system that does not owe its location to latitude or conform to a general climate pattern is highland. The control in Highland climates is elevation. Perhaps you have figured out that highland climates are just another name for mountains.
KNOW THE CODE
C. The Koppen system specifies four of his five major climatic zones by temperature, the other B zone on moisture. The system subdivides each zone into types by the temperature and precipitation relationships.
Like many scientific systems, there is a form of short hand of letters, with each letter have a very precise meaning. The first letter in the most important. It is like the classification system used to define air masses.FOR REFERENCE
D. Take a look at Table 1 in the Appendix on pp 614-615 and read the table to see how the system works. It would not hurt you to read the description as added reinforcement. If you are very ambitious you can go though the steps in determining a climate.
I am putting the six zones of the modified Koppen System and expect you to know them. DO KNOW THE BASIC A, B, C, D, E and H. If you know these the other types and subtypes are not quite so hard!!! There are a few subtypes I want you to know. I'll point it out in the text. It would be a good idea to refer back to the list from time to time. Example: I might want to know the the climate of eastern Colorado which is BSk Midlatitude Steppe Climate and is in western North America, but I will try to boldface those I want you to know.
ZONE DESCRIPTION A. TROPICAL HUMID B. ARID Tropical Rain forest Steppe Tropical Monsoon Desert Tropical Savanna C. Humid Mesothermal. D. Humid Microthermal Mild winters--midlatitudes Severe winters--midlatitudes Mediterranean Humid Continental--Hot Humid Subtropical Humid Continental--Mild Marine West Coast Subarctic. E. POLAR H. HIGHLAND Tundra Mountains Ice-Cap
CLIMOGRAPHS
E. Geographers love maps, give them a chance they draw you a map. Climatologists who study climates, have the same type of love affair with Climographs. Climographs are charts showing average monthly temperatures and precipitation amounts.
The text uses these Climographs a great deal, you might even get sick of them in the course of the chapter. The first of the many examples of Climographs is Figure 9.2 on p. 215. Climographs are useful in classifying climate.NOTE: CHANGE OF CHAPTER
NOW IN CHAPTER 10
You need to read 238 to 244 for a quick overview on climates; you are intelligent people and probably know most of this material anyway.THE DISTRIBUTION OF CLIMATIC TYPES
F. The rest of the chapter will go into detail about low-latitude and arid climate regions different climatic type and subtypes. There are three questions that will help you in exploring the second half of the notes.
1 Where are the various climatic types and subtypes?
2. What are the characteristics of each?
3. Why are these characteristics found in these locations?I'll go into details on each one. It would not hurt to take a look at the pictures on p. 239.
REMEMBER THIS IS GEOGRAPHY AND MAPS ARE IMPORTANT SO TAKE A LOOK AT FIGURE 10.4 ON PP. 246--247. IT WOULD NOT HURT TO KNOW THIS MAP FROM TIME TO TIME.
IV HUMID TROPICAL CLIMATIC REGIONS--ZONE A
GENERAL CHARACTERISTICS OF ZONE A CLIMATES THEY ARE BROKEN DOWN TO THREE SUBTYPES KNOW THE SUBTYPES AS WELL
Some of this information is on p. 241 and 244.
MOST OF THIS INFORMATION IS ON 248 TO 268THREE TYPES OF A ZONE CLIMATES--QUICK INTRODUCTION DETAILS LATER
A. The location of the humid climates of the world take up all the land area of the planet both north and south of the equator at about 15-20š F. (See Figure 10.5 on p. 248) This climate zone is called Zone A. Zone A climates straddles the middle section of the world. It is only slightly checked in small places by mountains or some small areas of aridity and can even can range further poleward to about 25š F in windward coastal lowlands. Zone A climates have an average temperature of 64š F for the coolest month in some places and it is not so much warmth as a lack of coldness. Monthly average temperatures are in the 70'sš and 80'sš F. They are the only places in the world that have no winter. The sun is high in the sky all year round, and the shortest days are not that much different than the longest days. The determining factor for Zone A is their latitudinal location.
TROPICAL ZONE A CLIMATES OCCUPY THE LARGEST AREA OF EARTH
B. Another common characteristic of tropical humid Zone A is moisture, it is very wet. Some types of Zone A climates have periods where there is not as much rainfall, but have enough to be classed as some of the rainiest places on the planet. Sometimes the rainfall is just greater at certain parts of the year. Sometimes there is a cycle of wet and dry seasons. (Take a look at Table 10.2 for zone characteristics on p. 249.) A Zone climates are the wettest in the world. It is warm, moist, unstable air masses over the oceans of the equatorial oceans and the intertropical convergence, which are most associated with the A zones of climates. Tropical Zone A climates occupy the largest area of Earth. (Take a look at Figure 10.5 on p. 248) They take up about 36% of the total surface of the planet including land and sea. In all humid tropical climates summers are never dry.
TROPICAL WET CLIMATE Af--Know this subtype.
C. The last description is just generic for all type A zones, but they are broken down into three types. The first type is called Af, where it rains above 2.5 inches every month of the year. The second type is called Am, tropical monsoonal type, I have discussed this type a little before. The third type is called Aw. It is the tropical savanna type which has a longer dry season, three to six months and important but an extraordinary wet season. I am going into detail on each one so pay attention.
AMAZON BASIN IS THE LARGEST AREA OF RAIN FOREST SELVA
D. The most extensive areas of Af are the upper Amazon basin in South America, the northern Zaire, the Congo, (The Congo river basin. There have been recent name changes in area and I have trouble keeping up the countries names) and the islands of the East Indies like Indonesia. There are also some other pockets of Af scattered elsewhere in the world. (What movie is set on a beat-up boat which stared Humphrey Bogart and Katherine Hepburn and what type of climate is it set in?)
ANNUAL RANGE OF TEMPERATURE RANGE VERY SMALL
CONSTANT HEAT AND HUMIDITYE. The term monotonous for this type of climate can be used for the Af climate, except for the hurricanes which do not happen in all parts of this climate. It is a region of constant heat and humidity. Temperatures do not change that much through out the year. The Af climatic type has by far, the smallest annual temperature range of any climatic type. (Take a look at the Climographs, Figure 10.6 on p. 251) This is a place of endless summer, although the term is used loosely because there is no major difference between winter and summer. Sometimes the words summer and winter are used in this type of climate to discuss the monsoon periods, but they are only used to indicate time of year. It would not hurt to take a look at (Table 10.2 for zone characteristics on p. 249.)
TROPICAL RAIN FOREST--SELVA--A DELICATE BALANCE
F. It should be remembered that Koppen was German and his works were first published in German. Therefore, it does make sense that the f in the system stands for moist in German. Climates of the Af type are located in a belt along the equator and range from 5 to 10š both north and south, but sometimes it can reach 25š from the equator. This may be the Af type climate, when we think of the tropics. Just look at (Figure 10.4 p. 246--247 or if that map is not detailed enough look at Figure 10.5 on pp. 248 and look for Af on the map.) These are the lands of tropical rain forest, also called selva and it is a very delicate ecosystem.
PRECIPITATION CONVECTIVE
G. The temperature readings are deceptive, climates like eastern Colorado which is BSk Midlatitude Steppe Climate have higher temperatures, but the Af climates are sticky or humid even at night. In the tropical rain forest, selva, precipitation is mainly convective and is most likely in mid-afternoon. Most of the moisture is trade-wind convergence in the ITC zone, but there is another factor as well, orographic ascent, the mountains. Af climates are found in Central America, the east coast of North America, and Madagascar, they are the furthest poleward of any Af climate.(Take a look at Table 10.2 for zone characteristics on p. 249.)
HUMAN ACTIVITIES
H. Throughout the tropical rain forest, selva, human activities are limited and is one of the least inhabited regions of the world. Most of the animals have adopted to the forest environment and the most common life form are the insects. Many of these insects carry diseases like malaria, sleeping sickness, deugue fever, and a list that is very long. (During the building of the Panama Canal American doctors found the cause for what insect carried disease and what did they do to prevent it? What American doctor is credited for this achievement--Clue a big Army Hospital in Washington D.C is named after him.)
SLASH AND BURN AGRICULTURE
I. Agriculture is difficult in these areas for centuries small farmers have practiced slash and burn agriculture. It is also called swidden, or shifting cultivation. Slash and Burn is when a small area is cleared for farming by cutting trees and then burning them along with any undesirable plant life. The resulting fields might last a few years or little longer and the process was repeated. Sometimes this practice can have very bad results for the environment especially then vast areas of cleared areas are affected. (What type of animals are now being raised in some cleared areas?)
PROBLEMS WITH PLANTATION AGRICULTURE
J. Many times these areas are dependent on plantation agriculture like cotton, cacao, coffee, tobacco, and others. These crops are boom or bust depending on the world market place. (What plantation crop hit highs during the oil crisis of the mid-1970s that your instructor made a great deal of money for other people, but missed out for himself?)
V TROPICAL MONSOONAL CLIMATE Am
A. The tropical monsoon climate bears a letter classification of Am the m = monsoon. As you might remember it is on the windward side, the west-facing coasts of the Indian sub-continent, there are also minor monsoons in other areas like western Africa, northeastern South America, East Asia, and northern Australia. There location on the map is about 20š to 25š on both sides of the equator. (Take a look at Table 10.2 for zone characteristics on p. 249.)
MONSOONS
B. The rainfall pattern, as you remember, is seasonal. It is during the early summer when the monsoons come and drop tremendous amounts of precipitation. Am climates are similar to Af climates in location and temperature the exception is the rainfall pattern of the monsoon. (Take a look at Figure 10.9 the Climographs on p. 256 for typical monsoonal precipitation patterns.)
C. A small difference between Af and Am climates is late spring, just before the the monsoon is the warmest time of the year. The increased cloudiness of the Tropical Monsoonal shields some of the insolation during the summer.
VI TROPICAL SAVANNA CLIMATE Aw
LOCATION OF THE LARGEST AREA OF Aw CLIMATES
A. The largest of all A climates is the tropical savanna, w = winter dry, Aw. Aw climates as a rule of thumb, lie north of Af and Am climates. The most sustained area of Aw is in Africa, east of the wet Af climates and extend poleward usually to latitudes 5š and 20š . Aw also has broad areas in South America, southern Asia, and smaller areas in northern Australia, Central America, and the Caribbean islands. (Figure 10.4 p. 246 and 247 or if that map is not detailed enough look at Figure 10.5 on pp. 248 and look for Aw on the map.)
TRANSITIONAL FEATURES OF THE SAVANNA
DIFFERENT NAMES FOR SAVANNAB. The characteristics of tropical savanna is transitional most of the time it is located between the steppes and the humid rain forest. A quick look at Africa the largest area of type A climates will demonstrate the point. Aw climates have a definite difference between wet and dry seasons. The reason for this is they lie between unstable, converging air on the equatorial side, and stable, anticyclonic air on the poleward side. As the patterns of wind and pressure change during the seasons, Aw have drastic variations in weather. (Take a look at Figure 10.12 p. 259, the Climographs, for examples of tropical savanna areas.) Tropical monsoonal and tropical savanna areas have dry winter, but precipitation is greater in Am areas. The savanna has different names in different parts of the world in Brazil it is called the campos and the llanos in Venezuela.
PRECIPITATION PATTERNS--KNOW WHAT HAPPENS DURING EACH SEASON
C. Tropical savanna climates, Aw, have three seasons. The wet season, the rainy season, is like all rainy seasons in A type climates. In the tropical savanna climate most of the rain falls in the high-sun season. In the early part of the dry season is a period of clearing skies and some cooling. The late dry season (low sun) is a time of desiccated grasses and shrubs is also a season for fire. The trees have deep roots to reach water and they are fire resistant. All life forms have adopted to the seasonal nature of the rains. If you have not figured this out the savannas of Africa contain an absolute zoo of great herd animals like elephant, giraffe, wildebeest, zebra and others along with the lion, leopard, cheetah, and those which prey on them. These animals are being pushed into crowed overgrazed national parks because man's growing cattle herds.
D. The precipitation, rainfall, is less than the other A climates. In Aw climates there is a time of drought, which typically last for about three or four months. Temperatures in Aw areas are about the same as Af, but there is greater month-to-month variations in Aw climates.(Take a look at Table 10.2 for zone characteristics on p. 249.)
VII ARID CLIMATIC REGIONS--ZONE B
TWO TYPES OF DESERTS
A. Another type of climate is the Dry Climate B. Dry climates occupy around thirty percent of the land region of the world and are widely spread over the planet. (Take a look at Figure 10.4 on pp. 246--247 or if that map is not detailed enough look at Figure 10.16 on pp. 261 and look for B on the map.) Remember that there are two B types and and four subtypes. The world's largest expanse of middle latitude dry climates is on the continent of Asia, but all continents some dry areas, with Europe having the smallest area of dry climates. There are two types of deserts subtropical deserts and mid-latitude deserts. They are caused by different climatic factors I'll go into details for each one.
SUBTROPICAL DESERT CLIMATE BWh
SUBTROPICAL HIGHS ARE THE REASONB. The appearance of Dry Climate B dry climates might look random, but are very predictable if you know the pattern. There are two concentrations of deserts in the world. The first is centered near the Tropics of Cancer and Capricorn, 23.5 š north and south and expands poleward and equatorward about 10š to 15š. The main reason for the occurrence of subtropical deserts around the world is the locations of subtropical high pressure systems. This is the reason for the first concentration of deserts.
LOCATIONS OF SUBTROPICAL DESERTS
C. If you have not gotten the hang of it yet the codes are again in German, the W= desert and h=hot. An almost continuous stretch of desert beginning in northern Africa and ending in the Asian nations of Pakistan and India includes the Sahara, the Arabian Desert and the Thar Desert, straddle a large section of the world in the Afro-Eurasian landmass. BWh, are larger the all the deserts of the entire world combined.
SUBTROPICAL DESERTS OUT SIDE OF THE AFRO-EURASIAN LANDMASS
D. Subtropical deserts, BWh outside of the Sahara and Arabian deserts are more longitudinally situated, in short they run north to south instead of east to west. There are two examples of this. The first is located in southern Africa called the Namibia. The "longest desert" is the Atacama located along the west coast of South America. It is one of the driest of all deserts. It is in a "double rain shadow," the Andes Mountains to the east, of the Atacama, act as a barrier from the moist air of the Atlantic and the cold Humboldt current blocks moist Pacific air from the west. (What is usual about the Namibia Desert?)
MIDLATITUDE DESERT CLIMATE BWk--COLD DESERTS
OROGRAPHIC--MOUNTAINS ARE REASONE. BWk climates are Wuse German for desert and k= kalt= cold. The second concentration of deserts is in the interior of the continents and are called cold deserts.The reason why they are cold deserts far distance or blocked from any oceanic influence. Midlatitude deserts are caused by primarily by Orographic, mountain barriers. (See Figure 10.17 on p. 265.)
LOCATION OF MIDLATITUDE COLD DESERTS
F. The deserts of central Asia, the greatest area of a BWk a cold desert, is distant from any ocean, and blocked from monsoon winds, by the Himalayas to the south. In North American, the land forms should be familiar, the mountains are in the far western area of the continent parallel to the west coast. This allows the moist maritime air from the Gulf to affect the climate of the eastern half of North America. The Cold Deserts, BWk, are moved to the west. The area in the United States lie between the Rockies and the West Coast and are in the states of eastern California, Nevada, Utah, and Northern Arizona. (What is another name for this area, more or less?) Midlatitude deserts experience their maximum precipitation in summer.
DESERT CLIMATES
G. Deserts can be found in almost all latitudes and it should be remembered that there are two types of deserts. The major difference between subtropical BWh deserts and midlatitude deserts BWk is winter temperatures. Low latitude deserts have annual high temperatures while midlatitude deserts have real seasons and have temperatures below freezing temperatures in winter. (Take a look at Table 10.3 on p. 263) In midlatitude deserts, BWk climate, the annual range of temperature is greater than in subtropical desert BWh climates. In the cold deserts, BWk have severe cold winters, normally below freezing, and in some places they have six months below freezing. There is a 50š temperature range between January and July mean temperatures are not uncommon.
THREE CHARACTERISTICS OF DESERTS
H. Of course, deserts mean a lack of moisture, but there is a little more to it than just that, three words: scarce, unreliable, and intense, describe deserts a little better. I'll go into more detail.
1. Scarce--Subtropic deserts are generally rainless. Unofficial reports record no rainfall several with no moisture from the sky. However, many BWh climates have some precipitation sometimes, two to eight inches, and some areas have as much as fifteen inches.
2. Unreliable--is another word for spotty in BWh climates. The idea of "average" is very misleading sometimes an area will get up to seven inches of rainfall, but in other years they might only get a half inch. In short sometimes it rains, many times it does not.
3. Intense--With desert areas rainfall is localized and very short. These storms are caused by convection, and are called "cloud bursts" and are very short. They can cause flash floods.
I. The temperatures in BWh climates have a particular patterns. Since they are in the low latitudes and lack cloud cover during the day they can get very hot, but at night they cool off very quickly. They are also places of great winds during the day, but are calm at night. Since there is little vegetation a great deal of sand and dust is carried from place to place.
XEROPHYTIC VEGETATION
J. The desert is a harsh environment and the big technical word for the vegetation which have adapted to this environment is xerophytic. Plants use several adaptation strategies by developing thick bark, thorns, a very little foliage, waxy leaves which limit loss of moisture by transpiration. Plants also tend to store moisture in their stems or leaf cells examples would be the cactus family. Other plants like the creosote bush, mesquite, and acacias have developed deep roots.
K. Given a supply of water the desert can bloom and become very productive agricultural land but care must be taken. If too much water is used salts near the surface can leach out of the soil and make the land unusable. Early civilizations developed irrigation but once fertile fields of wheat in the Middle East are now salt-caked desert. Places like the Imperial Valley in California also have the same problem. (What cradle of civilization in the Middle East partly failed because of salt build-up in their soil?)
VIII STEPPE CLIMATES
DIFFERENCES BETWEEN TRUE DESERTS AND STEPPES
A. The difference between desert and steppes are matters of degree. Deserts are arid; steppes are semiarid, eastern Colorado is classed as a semiarid midlatitude steppe, BSk. (You might call the people of eastern Colorado steppe children.) The general pattern is deserts are encircled by steppes.
SAHEL SOUTH OF THE SAHARA
B. There are two type of steppes those which are near low-latitude deserts like the Sahel which is south of the the Sahara. In recent years the Sahara has been expanding and causing severe drought conditions at great deal suffering for both human and animal populations in this region.(Take a look at Table 10.3 on p. 263. Take a look at Figure 10.20 on p. 268 for typical Midlatitude steppe climates.)
MIDLATITUDE STEPPE CLIMATE--BSk
C. To translate from German code to English is BSk; S = steppe, and k = cold. These are a midway point between desert and humid climates. I could describe in great detail the BSk climate, but all you have to do is look out the window any time of the year in Pueblo Colorado, (Do not miss this one on the test or I'll wonder about you steppe children ) Some details might be added to the BSk climate. It has more precipitation than midlatitude deserts and has less temperature extremes. The western part of North America is much larger than the desert areas of North America, and the desert-core and-steppe fringe model is off just a little. It is semiarid in most areas, with only the interior southwest of the United States arid enough to be classified as desert. (Just a question to think about, does all of Colorado fit this model, or is there a major exception?)
HUMAN PROBLEMS WITH MIDLATITUDE STEPPES
D. The part of the area of steppe in the United States is the Great Plains where agriculture is a crap shoot during the best of time, but factor in several years of drought and intensive agriculture which stripped the land of sod and created the "Dust Bowl" of the 1930s. Where drought conditions are most intense is roughly the land west of 100th meridian to the Rockies. (What were the Great Plains called in the early 19th century?)
NOW WE ARE IN CHAPTER 11
MOST OF THIS INFORMATION IS ON 275 TO 304IX MILD MIDLATITUDE CLIMATES--ZONE C
I've used these terms in passing Mesothermal and Microthermal. They are terms used to describe midlatitude climates. I'll define Microthermal a little later.
Mesothermal means means midlatitude climates with moderate temperatures during the year. Summers are long and winters are mild. Some seasons tend to blend.
MOST OF THE PEOPLE ON EARTH LIVE IN MIDLATITUDE LOCATIONS
A. By now we should know that the middle latitudes which approximately are 30š to 60š North and South, is where the action is as far as weather. They are called Zone C climates, and like others are broken down into types and subtypes. Two-thirds of the total population of Earth live between 20š and 60š North, which only excludes the South Asia cluster of population which do not live in midlatitude locations. The greatest day-to-day and seasonal contrasts of climate are found in the middle latitude climates. It is in the midlatitudes where different air masses, like polar and tropical, meet and clash. The conflicting air masses are one of the factors which create the weather. Some of North America fits the description of Zone C climates, but not all. In places that have a BSk climate there is also conflicting air masses, the geology, the location of the mountains, are the important factor which allows the movement of polar air from Canada and tropical air from the Gulf of Mexico. (Take a look at Figure 11.1 on p. 276 for more details on C climates.)
B. Mild midlatitude climates are located from the equatorward margin of the middle latitudes, but can range into the subtropics under some conditions, and can be stretched out poleward in some western coastal areas. (Take a look at Figure 10.4 on p. 246. Take a look at Table 11.1 on p. 275 for details on temperature, controlling factors, location, characteristics, and related features it can help you get a handle of this type of climate.) They are a transitional area between the warm tropics and severe midlatitude climates.
C. Summers in C climates are long and generally hot, winters are short and comparatively mild. These climates sometimes have winter frosts and do not have a year-round growing season. Precipitation can be variable in amounts and in seasons. Most of the time annual moisture is adequate, but sometimes there are seasonal problems.
D. C climates, have three types and five subtypes. The first type is based on when in the season precipitation is most likely to happen, secondarily on the summer temperate, Csa and Csb--Mediterranean, the second type is humid sub-tropical Cfa and Cwa, the third type is marine west coast, with two sub-types Cfb and Cfc.
X MEDITERRANEAN CLIMATE Csa, Csb
DIFFERENCE BETWEEN THE TWO MEDITERRANEAN CLIMATES
A. Two of the C type climates again have codes s = summer hot and b = summer warm. sometimes they are called subtropical because of the location of subtropical highs but the most used term is Mediterranean.There are two Mediterranean climates Csa, Csb are only different in temperature which can be significant. Csb are on the seacoast while Csa are a little further inland with the factor determining temperature being coastal mountains. (Take a look at Figure 11.2, Climographs on p. 276 on how just a few miles can change the temperatures and precipitations.)
B. These climates are located on the western side of continents usually and are small and are centered around the latitudes 35š north and south, and are confined to coastal areas. The examples are central and southern and central California, central Chile, the southern tip of Africa, and two southwestern corners of Australia. (See Figure 11.1 on p. 276) The exception being what the climate type is named after, the Mediterranean which is the largest of this type of climate.
C. Cs climates have three major features. First, they have moderate yearly precipitation falls in winter, summers are almost rainless. Second, winter temperatures are very mild for most places in the midlatitudes, summers range from hot to warm. Third they have clear skies and abundant sunshine and typical, especially in summer. (What industry moved to this area around one hundred years ago?) Mediterranean climates experience dry summers because of the position of subtropical high pressure STHs. During the winter, the wind and pressure belt shift to the equator, and Mediterranean region are dominated by the westerlies, except for an occasion tropical influences in California. The most noticeable characteristic of the Mediterranean climate is its dry summer.
XI. HUMID SUBTROPICAL CLIMATE Cfa Cwa
A. Most of the time in geography it is location that make the difference. The Mediterranean and humid subtropical climates are good example. These two climates are found at the same latitudes but opposite coasts of each land mass. Mediterranean climates are located on the western fringes of continents, the climate pattern on eastern side, at the same latitude are classified as humid subtropical, Cfa and Cwa. Again German Cwa types f = feucht "moist"; a = summer hot; w = winter dry. (Take a look for the differences between Mediterranean climates and humid subtropical climates at Table 11.1 on p. 275.)
B. Cfa and Cwa climates cover more area, east to west, latitudinally, and north south, longitudinally than other climates. In some places it can reach to approximately 15š to the equator, and range to nearly 40š to the poles. The east-west distance is greatest in North America, Asia, and South America. (Take a look at Figure 11.1 on p. 276, and look for Cfa and Cwa climates on the map, yes We've look at this one before. Also take a look at Figure 11.6 on p. 280 for climographs.)
C. There are important differences between subtropical climates and Mediterranean climates. Summer temperatures in humid subtropical areas are warm to hot, not that much different, but the humid subtropical areas have much higher humidity in summer. Cfa days are hot and sticky, and there is little change during the day. During the winter temperature are generally mild, but there can be period of cold which last for several days. Temperatures can be 10--20š lower in the humid subtropics than in Mediterranean regions. The temperatures might mean little to most people, but the lower temperatures means killing frosts many times. In short certain crops can not be grown in certain areas. The best example of this is citrus production areas in the eastern United States citrus production is limited to southern Florida around 29š N, even then sometimes there can be a killing frost. The furthest north that citrus can be grown in North America is the California Cs climate at 38š N. Yearly precipitation in Cfa climates is plentiful and in some places profuse. Precipitation decreases from east to west,
XII MARINE WEST COAST CLIMATE Cfb, Cfc
A. This one can be figured out easily, the words marine and west coast are dead give a ways. It is its closeness to the sea that makes the difference. The code might be just review at this time but here it is again; f = feucht, German for "moist" and b = summer warm; c = summer cool. We talked about this one in passing before, they are one the windward or western side of continents. The global location is 40š and 65š . In the Southern Hemisphere, where the land areas are much smaller, does the marine climate goes to the eastern coasts.
WESTERN AND CENTRAL EUROPE ARE THE LARGEST AREAS
B. The largest areas influenced by a marine climate, is western and central Europe, where it carries into the heart of the continent, because there are no mountains to stop it. (What ocean current modifies this area?)
MOUNTAINS LIMIT THE MARINE WEST COAST IN NORTH AMERICA
C. North American, as mentioned several times in class, the Cfb, is limited because of the mountains. It is the classic Marine west-coast climate. (Take a look at Figure 11.1 on p. 276 and look for Cfb and Cfc climates on the map, yes We've look at this one before. Take a look at Figure 11.11 pp. 284.) Sometimes these climates have hot days, but these are very rare, as are very cold days. For the latitude, there is a very long growing season, in fact Seattle, a has month longer growing season than Atlanta, which is 14š further south. With coastal Marine climates, Cbf, the isotherms tend to form parallel to the coastline rather than following the "normal" east-west pattern. Temperatures on western coastlines decline less than half as fast as coastlines on the eastern side.
WET, FOGGY, RAIN, CLOUDY
D. In Marine climates it rains a lot, but it is a drizzly frontal type with low intensity and is very cloudy. These areas have high humidity. Anyone who has spent time in places like Seattle or London will attest to this. Marine west coast climates are some of the wettest, foggiest, rainiest, in the middle latitudes, this is very noticeable in upland areas, the slopes of the west facing mountains. This also is reflected in the snow fall.
XIII. SEVERE MIDLATITUDE CLIMATES ZONE D
Microthermal climates are also midlatitude climates but with major differences between winter and summer. Winters tend to be severe. Spring and Fall are usually recognizable. There location as far a latitude is the same but are much further inland.
THE SOUTHERN HEMISPHERE DOES NOT HAVE A ZONE D
CONTINENTALITY IS THE KEY TERMA. The Southern Hemisphere since it has limited land area does not have a Zone D climate. This northern climate Zone D ranges across North America, incorporating the northeastern United States much of Canada and Alaska, and Eurasia from eastern Europe through most of Russia to the Pacific. "Continentality" is the term most closely associated with the Zone D climate type. Type D climates range between 35š N to 75š N. The Zone D has meager maritime influence, because of the westerlies. (Take a look at Table 11.2 on p. 289.)
B. Because of the continental nature of climate, Zone D, has the a large temperature range. Zone D has four seasons, a long, cold winter, a short summer which varies from warm to hot, and transition seasons in spring and fall. ( Figure 10.4 on pp. 246-247 and look for D zone climates and types and sub-types on the map, yes We've look at this one before. For a closeup view Take a look at Figure 11.16 p. 288.)
HUMID CONTINENTAL HOT SUMMER CLIMATE --Dfa, Dwa,
AGRICULTURAL PRODUCTION IN THE MIDWESTC. There are two types of D Zone hot summer climates, Dfa, Dwa,, f = feucht = moist; w = dry winter a = summer hot;The European locations ranges from 35š to 60š in central Europe, then runs through Russia and Siberia, (Take a look at Figure 11.18 on p. 291, the Climograph, remember the name, for typical patterns.) Since the entire region is dominated by the westerlies, there are many weather changes. In this climate zone there are cold snaps, heat waves, blizzards, thunderstorms, tornadoes, and many other vigorous weather patterns. Temperatures are run in the mid-70s in the summer, and are as warm subtropical areas in the south, but the summer is shorter. The dominating air mass in summer in humid continental, hot summer climatic regions is Maritime Tropical, mT. Perhaps you remember this from the last chapter, these things are connected. Weather is not the thing that is connected just look at the agricultural production of the American Midwest. The "Corn, Soybean, Hog and Beef Cattle Belt" climate is more technically know as the humid continental hot summer climate. (Take a look at Figure 11.22 on p. 295.) This is also connected to the vast load of top soil laid down in the last glacial period.
HUMID CONTINENTAL MILD SUMMER CLIMATE --Dfb Dwb
D. There are two types of type D mild summer climates, Dfb Dwb f = feucht = moist: w =dry winter, b = summer warm. The key here is they are closer to the north pole than the humid continental hot summer climates. (Take a look at Figure 11.20 on p. 293 and they are Climographs you might compare them to the Climographs of Figure 11.18.) Winters tend to be more severe and longer than humid continental hot climates and precipitation tends to decrease while summers tend to be shorter.
SUBARCTIC CLIMATE Dfc, Dfd, Dwc, Dwd
E. Dfc, Dfd, Dwc, Dfd = feucht = moist; c = summer cool; d = winter very cold; w = winter dry. The location of these Zone D climates (Take a look again at Figure 11.16 on p. 288 and look for D zone climates and types and sub-types on the map, yes we've look at this one before.) This climate is located 50š and 70š in two continuous expanses across the wide northern landmasses: starting at western Alaska across Canada to Newfoundland across Eurasia from Scandinavia to easternmost Siberia.
THE SUBARCTIC HAS TWO NAMES,
TAKE A LOOK AT VERKHOYASK SIBERIAF. This vast land of cold has two names, in Canada it is called boreal, in Eurasia it is called by its Russian name of taiga, which means forest. The major vegetation is coniferous forests of spruce, fir, and pine. What ever name used it means cold, very cold. The crucial word for the subarctic is winter which is long dark and bitterly cold. Ice forms on the lakes in September or October and only clears in May or June. Winter lasts for six or seven months with below freezing temperatures. Summer is brief, and despite the almost continual sunlight it is low because of the angle of incidence. Temperate ranges are almost incredible, the world's greatest annual average temperature range is in Dfd climate in Verkhoyask Siberia, (---68 to +98š) with and average temperate range of 115š Those are official temperatures unofficially they are much lower.
PERMAFROST
G. Precipitation is light, only about five to twenty inches but in subarctic Dfc, Dfd, Dwc, Dfd climates and the thin snow cover, the evaporation rate is low, as is the evapotranspiration rate, the soil is frozen much of the year in a condition called permafrost. There are rivers and lakes which have never been fished but a multitude of mosquitoes makes sport fishing a stinging situation.
XIV POLAR CLIMATE ZONE E
TWO TYPES OF CLIMATE TUNDRA AND ICE CAP
A. These zones are at the top and bottom of the world and are the farest points from the equator. They have no warming period since the tropics are dull heat and humidly, the polar reaches are dull and cold. There are two type of polar climates, the tundra climate ET and the Ice cap EF. (Take a look at Table 11.3 on p. 299 for differences between the Polar Climates.)
TUNDRA CLIMATE ET
B. Tundra first meant just the low, ground vegetation, but the term has been expanded to all high latitude and high-altitude areas, outside of the polar ice cap. Perhaps more than any other type of climate it is vegetation is the best defines a climate. (Take a look at Figure 11.26 on p. 300 they show typical climographs for a tundra climates.) The tundra has long, cold, dark winter, and short cool summers. Frosts are likely almost every night except for mid summer and freezing temperatures can happen any time.
ICE CAP CLIMATE EF--POLAR DESERTS
C. The harshest climate in the world are the climates of Greenland and Antarctica. Vegetation cannot grow there, and the landscape is a sterile permanent blanket of ice and snow. Both Greenland and Antarctica are ice plateaus, and are high altitude which only adds to the cold. There is little precipitation and can be considered polar deserts. (What is the name of the fierce winds that blow down the ice caps?)
XV HIGHLAND CLIMATE ZONE H
ALTITUDE IS MORE IMPORTANT THAN LATITUDE
EXPOSURE TO THE SUNA. The highland climate is different than all the others, it is located in almost all other climates, and the determining factor is not the latitude but altitude. They have countless variations from one place to another. Variations in latitude can effect the location of timberline in Colorado timberline is about 12,000 feet, in the Alps it is about 8,000 feet, while mountains in equatorial Africa timberline is around 15,000 feet. (What short story by Ernest Hemingway is set on a mountain in East Africa?) It is modern researchers who have modified the Koppen system to include these type of climates. However, highland climates are linked to the surrounding lowlands, in respect to seasonal precipitation, but elevation is still the most important. Another factor in highland climate is the exposure to the Sun and relative elevation.
REMEMBER THE LAPSE RATE
B. All four elements of weather and climate operate, if you remember the lapse rate of 3.6š F per 1000 feet is the most important. Wind systems are brisk and there are many local wind systems. Precipitation is usually more intense, and the mountain can be considered a moist island. Around 1800 it was noticed in the scientific press a journey of just a few hundred feet was about the same as an identical journey of several hundred miles to the poles. Vegetation is zonal based on altitude and is called Vertical climate zonation. This is even more noticeable in tropical mountain regions.
C. Highland climates can change very quickly, and temperature can drop in just a few minutes. Upslope winds and convection can cause swift cloud formation and sudden storms are common.
GUIDED PRACTICE
Questions during the lecture.
INDEPENDENT PRACTICE
Readings at home
Culmination
The variables in climate are many list just a few?How did the Greek classify climates, how close were they?
How does the Koppen System and the Modified Koppen System.work ?
The six major types is not to bad, but the sub-types are very difficult know the little letters.
The Distribution of Major Climatic Types and Subtypes are on a certain map it could help you.
Find the Tropical Climates?
Find the Dry Climates?
Find the Mild Midlatitude Climates?
Find the Severe Midlatitude Climates?
Find the Polar Climates?
Find the Highland Climates?
KNOW SOME OF THE CHARACTERISTICS OF THE CLIMATES