1. Major Geographic Zones of the United States Geography Section 3

2. Climate Zone Snow and rain, heat and cold, and seasonal variations are characteristics of climate, the year-to-year weather conditions that prevail over long periods of time. Snow and rain, heat and cold, and seasonal variations are characteristics of climate, the year-to-year weather conditions that prevail over long periods of time.

3. Climate greatly affects our environment and, therefore, our way of life. Climate greatly affects our environment and, therefore, our way of life.

4. What determines Climate? The Climate that people in a particular location enjoy or endure depends on a number of factors: The Climate that people in a particular location enjoy or endure depends on a number of factors:

5. Latitude is the measure of how far a place is from the equator and from the Earth’s poles. Latitude is the measure of how far a place is from the equator and from the Earth’s poles. The United States is entirely north of the equator, in the Northern Hemisphere. The United States is entirely north of the equator, in the Northern Hemisphere. The closer a place is to the equator, the more directly the sun’s rays strike it and, therefore, the more its surface is heated. The closer a place is to the equator, the more directly the sun’s rays strike it and, therefore, the more its surface is heated.

6. Altitude, the distance above sea level or the ocean floor, also affects climate, since high attitudes are colder than low altitudes. Altitude, the distance above sea level or the ocean floor, also affects climate, since high attitudes are colder than low altitudes. Mountains are a good example of this top is cold bottom is hot. Mountains are a good example of this top is cold bottom is hot.

8. A third influence on climate is the direction of prevailing winds the normal direction from which high-altitude winds blow. A third influence on climate is the direction of prevailing winds the normal direction from which high-altitude winds blow.

10. Landforms such as mountains interact with the prevailing winds to help determine climate. Landforms such as mountains interact with the prevailing winds to help determine climate. As storm systems gain altitude to cross over mountains and other high place, they generally release their moisture. As storm systems gain altitude to cross over mountains and other high place, they generally release their moisture.

11. Seacoasts are also landforms that influence climate. Seacoasts are also landforms that influence climate. Generally, the closer to an ocean a place is the more rain or snow it will receive. Generally, the closer to an ocean a place is the more rain or snow it will receive.

12. Oceans and lakes have a moderating effect on temperature. Oceans and lakes have a moderating effect on temperature. Such large bodies of water lose or gain heat only slowly, so they often hold their heat into the early winter and remain cool even in early summer. Such large bodies of water lose or gain heat only slowly, so they often hold their heat into the early winter and remain cool even in early summer. That is why people cool off in summer by going to the shore. That is why people cool off in summer by going to the shore.

13. Oceans are not static; they having moving currents that circulate their water from one area to another. Oceans are not static; they having moving currents that circulate their water from one area to another. The Gulf Stream, an important feature of the Atlantic Ocean, carries warm waters from the Gulf of Mexico north along the east coast of the United States and then eastward toward northern Europe. The Gulf Stream, an important feature of the Atlantic Ocean, carries warm waters from the Gulf of Mexico north along the east coast of the United States and then eastward toward northern Europe.

14. The Gulf Stream keeps the eastern United States and much of Europe warmer than most other places at the same latitudes. The Gulf Stream keeps the eastern United States and much of Europe warmer than most other places at the same latitudes.

15. Ocean currents in the Pacific also affect U.S. climate. Ocean currents in the Pacific also affect U.S. climate. The waters of the tropical Pacific are periodically warm or cool. The waters of the tropical Pacific are periodically warm or cool.

16. When the waters are warm, a condition known as El Nino contributes to strong storms and bitterly cold winters in the United States. When the waters are warm, a condition known as El Nino contributes to strong storms and bitterly cold winters in the United States. When the waters of the tropical Pacific are cool, another condition, known as La Nina, tends to bring warm winters to the nation’s Southwest, cool winters to the northern central regions, and mild winters to the East. When the waters of the tropical Pacific are cool, another condition, known as La Nina, tends to bring warm winters to the nation’s Southwest, cool winters to the northern central regions, and mild winters to the East.

17. I am El Nino

18. Temperature Variations Temperatures in the United States vary widely from day to day and season to season. Temperatures in the United States vary widely from day to day and season to season. Temperatures also influence the kinds of homes people live in. Temperatures also influence the kinds of homes people live in.

19. Moisture Variations The amount of moisture that falls on an area helps to determine what kinds of crops can be grown there. The amount of moisture that falls on an area helps to determine what kinds of crops can be grown there. Rain, snow, sleet, and hail are all forms of precipitation. Rain, snow, sleet, and hail are all forms of precipitation.

21. Key Climate Regions The United States has ten major climate regions, each with its own distinct features: The United States has ten major climate regions, each with its own distinct features: The north coast of Alaska along the Arctic Ocean has an ocean arctic climate. The north coast of Alaska along the Arctic Ocean has an ocean arctic climate.

22. From its western coast to its interior, Alaska has a subarctic climate. From its western coast to its interior, Alaska has a subarctic climate. From southern Alaska to northern California, a marine West Coast climate prevails. From southern Alaska to northern California, a marine West Coast climate prevails.

23. A good portion of California, including all but the northern coast and much of the interior lowlands, has a Mediterranean climate. A good portion of California, including all but the northern coast and much of the interior lowlands, has a Mediterranean climate.

24. The interior mountain ranges of the western states (New Mexico, Arizona, Nevada, Utah, Colorado, Wyoming, Idaho, and parts of California, Oregon and Washington) have a highland climate. The interior mountain ranges of the western states (New Mexico, Arizona, Nevada, Utah, Colorado, Wyoming, Idaho, and parts of California, Oregon and Washington) have a highland climate. Characterized by cool to cold temperatures. Characterized by cool to cold temperatures.

25. The western Great Plains and the lowlands between the mountains of the West generally have a steppe climate, with lots of sunshine and not much rain. The western Great Plains and the lowlands between the mountains of the West generally have a steppe climate, with lots of sunshine and not much rain. A steppe is an area that receives less than 20 inches of precipitation a year which is enough to support grass but not trees. A steppe is an area that receives less than 20 inches of precipitation a year which is enough to support grass but not trees.

26. The northeastern quarter of the continental United States, from the edge of the Great Plains to the Atlantic, has a humid continental climate. The northeastern quarter of the continental United States, from the edge of the Great Plains to the Atlantic, has a humid continental climate. Humid- Moist. Humid- Moist.

27. The southeastern United States, as far inland as Texas and Oklahoma generally has a humid subtropical climate. The southeastern United States, as far inland as Texas and Oklahoma generally has a humid subtropical climate.

28. The tips of Florida, the Florida Keys, and Hawaii all have a mild tropical climate. The tips of Florida, the Florida Keys, and Hawaii all have a mild tropical climate. Because of Hawaii’s location in the lower northern latitudes, prevailing winds, known in the tropics as trade winds, come from the northeast. Because of Hawaii’s location in the lower northern latitudes, prevailing winds, known in the tropics as trade winds, come from the northeast.

30. Natural Vegetation Zones Latitude, altitude, landforms, and climate combine to influence the natural vegetation that a place supports. Latitude, altitude, landforms, and climate combine to influence the natural vegetation that a place supports.

31. Natural vegetation zones are bands of territory in which climate and other natural conditions produce certain characteristics mixtures or communities of plants. Natural vegetation zones are bands of territory in which climate and other natural conditions produce certain characteristics mixtures or communities of plants.

32. Major U.S. Natural Vegetation Zones Alaska and the 48 contiguous United States have eight major natural vegetation zones: Alaska and the 48 contiguous United States have eight major natural vegetation zones: The tundra zone is a bleak, dry lowland stretching inland from Alaska’s coasts. The tundra zone is a bleak, dry lowland stretching inland from Alaska’s coasts.

33. The coniferous forest zone stretches south from inland Alaska through western Washington and Oregon to northern California and also includes northern Minnesota, Wisconsin, and Michigan. The coniferous forest zone stretches south from inland Alaska through western Washington and Oregon to northern California and also includes northern Minnesota, Wisconsin, and Michigan.

34. Coniferous forest is dominated by evergreens. Coniferous forest is dominated by evergreens.

35. The broadleaf forest zone reaches from the central Midwest to the southern Appalachians into the mid- Atlantic states. The broadleaf forest zone reaches from the central Midwest to the southern Appalachians into the mid- Atlantic states. Its dominate trees are oaks, maples, and other deciduous trees (those that lose their leaves seasonally), with flat, broad leaves. Its dominate trees are oaks, maples, and other deciduous trees (those that lose their leaves seasonally), with flat, broad leaves.

36. The mixed forest zone comprises coniferous and broadleaf trees and covers much of the northern and eastern United States. The mixed forest zone comprises coniferous and broadleaf trees and covers much of the northern and eastern United States. The Mediterranean scrub zone includes California’s coastal terrain from the San Francisco region southward and the lowland interiors to the east. The Mediterranean scrub zone includes California’s coastal terrain from the San Francisco region southward and the lowland interiors to the east.

37. The grassland zone covers most of the Great Plains. The grassland zone covers most of the Great Plains. With relatively low rainfall (10 to 20 inches a year), this zone will not support forests. Excellent for growing wheat. With relatively low rainfall (10 to 20 inches a year), this zone will not support forests. Excellent for growing wheat.

38. The steppe zone occupies nonmountainous areas in northern New Mexico and western Colorado and parts of Utah, Nevada, Oregon, Washington, Idaho, Montana, and Wyoming. The steppe zone occupies nonmountainous areas in northern New Mexico and western Colorado and parts of Utah, Nevada, Oregon, Washington, Idaho, Montana, and Wyoming.

39. The desert zone lies in a board band from northern Nevada to the south western corner of Texas. The desert zone lies in a board band from northern Nevada to the south western corner of Texas. Conditions on the Hawaiian islands create two additional zones that occur no where else in the United States. Conditions on the Hawaiian islands create two additional zones that occur no where else in the United States.

40. A tropical rain forest zone predominates in the mountains, where year around warmth and plentiful rain sustain many kinds of trees. A tropical rain forest zone predominates in the mountains, where year around warmth and plentiful rain sustain many kinds of trees. Neighboring lowlands experience several short dry seasons every year, which create a tropical grassland zone characterized by scrubby shrubs and scattered trees. Neighboring lowlands experience several short dry seasons every year, which create a tropical grassland zone characterized by scrubby shrubs and scattered trees.

41. Agriculture and Industry Nature + Culture + Technology Nature + Culture + Technology Each region of the United States has its own agricultural products depending on the environment and climate. Each region of the United States has its own agricultural products depending on the environment and climate.

43. Many industries depend on mineral or energy resources and tend to be located near necessary raw materials. Many industries depend on mineral or energy resources and tend to be located near necessary raw materials. Other industries use agricultural products (tobacco for cigarettes) and tend to be located where such products are grown or stored. Other industries use agricultural products (tobacco for cigarettes) and tend to be located where such products are grown or stored.