 You are clear for launch. And with that, shut down your visors, O2 on, and prepare for ignition to O2. You can copy that and, um... Hey guys, Mr. Rochop here. All right, this is the last lesson in our physical geography unit. Together, what we've done, we've looked at the landforms and the process that create them, and then we've been looking at the factors that create our climate and how climate impacts our ecosystems or our biomes. In this lesson, we're going to examine the major climate types of the Earth using something known as the Copen classification system. At the end of this lesson, our objective is that you can look at the map of the world and together what we've learned about the five factors of climate, identify what type of climate there would be and any region of the world. As we have earlier covered, climate is the average seasonal weather for an entire area, usually described in monthly averages of temperature and precipitation. We can chart a climate using a special type of graph called the climograph. This type of graph shows the entire year's average precipitation and temperature. While colors can change, precipitation is always going to be graph using a bar graph and temperature is going to be using a line graph. From looking at the climograph of each region, we can determine the type of climate that is found there. And what are those types of climates? Well, today we're going to use this classification system that was created by Vladimir Copen. And here's an interesting fact. Remember, Albert Wegener, who brought us the idea of continental drift, was so happens that Wegener was Copen's son-in-law. Small world, right? Anyway, Copen gave us a system that classifies the world's climate based upon the patterns of temperature and precipitation. Comparing these two characteristics, 12 climate zones are identified. At first, this sounds balancing to learn all 12, but it's really not that hard. Fortunately, nine of these climate zones can be remembered by their location and latitude and which side of a continent they follow on. In the low latitudes, we find tropical wet and tropical wet dry. As we go into the middle latitudes, we find five climates, the Mediterranean and the marine west coast and the west side of a continent. And then on the east coast of a continent, we find human subtropical and human continental. And at the top of the temperate latitudes, we find the subarctic climates. And as we approach the poles into the high latitudes, we find two climates, the Arctic and then the polar climates. So those are the nine that we can classify based upon latitude. There are three other climate zones which are the semi-arid, arid and highland climates that can be found at any latitude. Now, to help us understand these climate zones, we'll be using this graphic organizer to make it easy for you. So let's begin at the equator and make our way towards the poles and talk about each climate and their related biomes. Below latitudes, remember, those are called the tropics is where we find the tropical wet and tropical wet dry climates. Now, both of these climates are warm all year long. Tropical wet climates are often found in the islands and the tropics and where the itch doesn't really move very much throughout the year. This creates rains all year long. So a tropical wet climate really only has one warm rainy season throughout the year. Now, you can see by this climate graph how both the temperature and the amount of precipitation is high throughout the year for a tropical wet climate. Now, compare that graph with this one, which shows a climate that has still a warm weather all throughout the year, but now there is a distinct wet season and a dry season. We call this climate tropical wet dry. Tropical wet dry is generally found where the itch will move much more north and south throughout the year in creating those dry wet seasons. Eastern Africa and South Asia are places where you can find this type of climate. So let's talk about biomes. The biome found in the tropical wet climate is the tropical rainforest, such as the Amazon or the Congo rainforest in South America and Africa. Most tropical wet climate areas will receive more than 100 inches of per rain every year and some have received as much as 300 inches over the year. Now, a tropical wet dry climate receives much less rainfall, usually less than 50 inches per year. Therefore, the climate cannot support a rainforest like its tropical wet neighbor. Instead, in a tropical wet dry climate, we find a savanna biome. If you think of zebras and giraffes in the wild, like the pictures I took here in Tanzania, you're thinking about savanna. So that is our two tropical climates, tropical wet with the tropical rainforest biome and tropical wet dry with the savanna biome. Now we move into our middle or our temperate latitudes. Now the term temperate means it has a mild climate where it is not very warm or very cold all year long. Now there are five climates in the temperate latitudes with two in the west coast and two on the east coast. And then we have our fifth climate that stretches across the continent just short of the high latitudes. Now remember that the ocean currents on the east coast of the continent are warm, creating more humidity. This explains why on the east coast of the continent, we have a humid subtropical and a humid continental climates. Humid subtropical climates should be easy for you to remember as it is actually the climate that we have here in Bryan, Texas. Now this climate usually can be found as close as the equator's 20 degrees and extends as far as 40 degrees latitude. And as we look at the climate graph for the humid subtropical climate, we can see the beginning of four seasons with the temperatures being cool in the winter and warmer in the summer. We also see precipitation throughout the year. Now a humid subtropical climate supports temperate grasslands and mixed forests. Remember mixed forest means that you'll have forests with both broadleaf and needleleaf trees. Now the second east coast climate is the humid continental climate, which lies further away from the equator than the humid subtropical climate. Usually we find it between 37 and 60 degrees latitude. Now by looking at the climber grass of each of these climates, we find that the humid continental climate has a much stronger seasonal pattern of temperature and precipitation than we find are a humid subtropical climate. The winters tend to be much drier and colder than its summers. Now the major climate factors that form these two climates are once again latitude, but also I think we have the warm ocean currents for the humid subtropical climate and the effect of cold wind currents coming from the poles for the humid continental climate. Another factor that helps form the humid continental climate is something called continentality. Remember continentality is the function of a region being further separated from the ocean currents. The farther an area is from the ocean, the less of an effect that the ocean's currents will have on that region. So these are two temperate east coast climates. Now let's look at our two west coast climates in the middle or the temperate latitudes. These are the Mediterranean and the marine west coast climates. The Mediterranean climate is usually found on the west coast of the continent between about 30 degrees and 35 degrees latitude. It is named for the same type of climate that we find in Europe around the Mediterranean Sea. Now this has four seasons that are marked by a short rainy summers and very long dry summers. For example, here's a climate graph for Rome, Italy. This climate is formed due to latitude, the cool ocean currents off the west coast of the continent, and the high pressure system caused by the Hadley cell pushing down dry air around 30 degrees latitude. For the United States, the Mediterranean climate was instrumental in determining where we get our movies from. See, it costs a lot of money for movies to be made and most movies don't actually want to be filmed in the rain, but Southern California has a Mediterranean climate which has long dry summers, which gave movie makers more time in the summer to be able to film their movies. This is why movie makers actually moved to Southern California and established what we now know as Hollywood. This is just one of the many examples how climate has influenced the settlement patterns of people around the world. Now the biome of the Mediterranean climate is the Chaperral biome which is shrubs and bushes. Now lying closer to the poles between about 35 degrees and 60 degrees latitude is the Marine West Coast climate. This climate usually doesn't stretch too far inland as it's largely influenced by the oceans. In fact, this is sometimes known as an oceanic climate. As with all of our temperate climates, it has four seasons. The temperature will remain mild throughout the year, however it will receive a large amount of precipitation throughout the year, especially in the winter. Now in the Marine West Coast climate we find mixed forests. Now due to the high amount of precipitation that Hadley is caused by rain, but also fog that rolls in off of the cool oceans, we find temperate rainforests such as the redwoods in California. In the redwoods we find the tallest living things on earth. Redwood trees can reach more than 360 feet tall and to support such tall trees, the redwoods are actually really big along as big as having a diameter of 24 feet. Now as usual, latitudes are contributing factor to creating the Marine West Coast climate, but the North Atlantic Drip also helps bring the Marine West Coast climate to Northwestern Europe. So our West Coast climates are the Mediterranean and the Marine West Coast climates. Our last temperate climate is the sub-arctic climate. Now a sub-arctic climate will stretch across the entire continent between 50 and 70 degrees latitude. It's defined by long, barely cold winters with short clear days and little precipitation, which is usually in the form of snow. It receives more precipitation in the summers, but it still remains rather cool ravaging only about 60 degrees Fahrenheit. Now the dominant climate factor here is latitude and the bind we find in the sub-arctic is the boreal forest, which you remember consists of trees specially adapted to deal with the sub-arctic's cold temperatures. So the sub-arctic climate is our last of our five temperate climates. As we move even closer to the poles, we enter the high latitudes and the temperature become even more cold. It is here we find the polar and the ice cap climates. The overriding climate factor here of both of these climates is latitude. The polar climate is found between 60 and 75 degrees latitude and the ice cap climate is found between 75 degrees and the north or south pole. Both of these climates really only have two seasons, polar day and polar night. And the polar climate is short summer and lasts only a few weeks and never gets warmer than 45 or 50 degrees Fahrenheit. But its winter temperatures are truly cold, never rising above 20 degrees Fahrenheit and has low temperatures are down to 40 degrees below zero. Here the associated biome is the tundra as it's quite frankly just too cold to support trees. As cold as the polar climate seems, the ice cap climate is even more unforgiving. Here the temperature never rises above freezing in winter or the summer. In fact the record low temperature is 128 degrees below zero. Now because of such cold temperatures, there is almost no precipitation at all in the ice cap climate. There also is no associated biome because with the exception of bacteria, no life can actually naturally survive these conditions. So on our graphic organizer, we finally can easily divide these nine climates of by latitude. But there are three climates that can exist at any latitude. These are the arid, semi arid and the highland climates. The word arid literally means dry and that's exactly what arid or semi arid means, they are dry. In fact these two climate types are classified due to the amount of precipitation they receive. The arid climate describes any region that receives less than 10 inches of rain per year and the temperature doesn't matter. An arid climate can be warm or they can be cold. Now an arid climate is also known as a desert climate which is the biome that exists here. There are three major factors that creates an arid or a desert climate. The first is the rain shuttle effect which is when mountains will block the precipitation from moving into a region. The second reason for deserts is the dry air of the Hadley cell which comes down to the Earth's surface around 30 degrees latitude north or south. This all by the way explains why so many of the world's deserts are found around 30 degrees latitude. And the last factor is being located near cold ocean currents. Both the Atacama Desert in South America and then the Mid Desert in Africa are located right next to oceans. Yet because they are located on the west coast of their continents the water is cold and receives no humidity for precipitation. The semi arid climate is the other dry climate. The word semi actually means half so essentially the semi arid climate is half as dry as the arid or desert climate. So if the air climate is a region that receives less than 10 inches of precipitation throughout the year, the semi arid climate receives between 10 and 20 inches of precipitation in the year. The factors that make us arid climate also create semi arid climates. This is the reason why we find semi arid regions around deserts where the factors are there but they're just not as strong as they are for the desert or the arid climates. We also find semi arid climates in the middle of continents due to continentality. Now the associated biome for a semi arid climate is the steppe. The steppe is a rolling grassland that is scattered with shrubs and isolated trees. This is also known as a semi arid desert. In fact the largest semi arid region in the United States is found in the Great Plains and early explorers used to call the Great Plains the Great American Desert. Now it is one of the most productive agricultural regions in the world. So those are our two dry climates. The last type of climate is the one that has been added actually after Copen created his classification guide. This climate is the Highland climate. The Highland climate is found in the world's mountains but really it isn't one climate but it can be several depending upon how high it is in elevation. The climate conditions change based upon the elevation of the mountain but generally are wetter cooler versions of those found at lower elevations. Now because the climate conditions change as you increase in elevation the biomes look very as well. This is known as altitudinal zonation. This means that on the slopes of one single mountain you can have many different zones of different biomes creating different vegetation and different crops. So those are the 12 major climate types of the earth. This also concludes our last lesson on the essentials of physical geography. In our next lesson we'll start putting people on the ground and start talking about human geography but until then keep on learning.