Greetings and welcome to course one of Arctic Climate Environment and the Geographies of the Changing North. I'm your host, Mark Serreze. I'm with the geography Department at the University of Colorado Boulder. And I'm also part of the Cooperative Institute for Research in Environmental Sciences. Well, what's course one all about? It's about the Arctic as a system. If we're going to understand the Arctic, we have to have this basic knowledge about the Arctic. What's it all about? Now, this course will have five modules. The first is really just an introduction to the Arctic. The Arctic as a region. How do we actually define the arctic? That's a pretty basic question, right? But then I'll give you a little taste of the rapidly changing Arctic. We'll go full bore on this during course too, but we can't really even talk about the Arctic anymore without talking about some of the big changes that we've seen. So I'll give you a little taste here, but we'll be touching on this all through this course. Building our knowledge. Early exploration and events. And what was happening from the Cold War through the modern era. But we're going to go even back further than that. How did North America, for example, first even get peopled? And who are the peoples in the Arctic? How many people live in the Arctic? We're going to cover some of those basic issues. Well, once we do that, we're going to jump right into the climate issues and talk about Arctic climate basics. We need to talk about solar energy. Because the Arctic has an extreme seasonality in how much solar energy we get, that's energy from the sun. We have polar darkness, where the sun never rises above the horizon. But also the midnight sun, where the sun never sets. We need to understand how that all works. Then we'll start to talk about temperature and precipitation. And what we'll learn is that, well, yeah, we think of the Arctic as a cold place. Well, there's some places which are really cold, but some areas which are surprisingly warm. When we talk about precipitation, we'll learn that precipitation patterns across the Arctic vary widely. It might surprise you, we'll understand this later, that parts of the Arctic actually qualify as desert. They're basically bone dry. Other areas are fairly well watered. We have to talk about cloudiness. The Arctic is generally a pretty cloudy place, but clouds are so important in the Arctic because they have such a big impact on what we call surface energy exchanges. So the cloudiness is shaped by the climate and also shapes the climate as well. When we move into module 3, we're going to turn to the Arctic Ocean. Basic features of the Arctic Ocean. We need to understand the vertical structure of the ocean, temperature, and salinity. We have to understand that the Arctic Ocean is a floating sea ice cover. And we need to understand the processes of how sea ice grows, how it melts, and how it deforms, that is, for example, floes of ice coming together and crunching together and causing ridges. Leads developing, that is, openings in the ice cover developing. And we need to understand also the sea ice and basic circulation of the Arctic Ocean. Then we're going to move, as you might expect, to the Arctic lands. We've got to talk about the Greenland ice sheet. Now, the Greenland ice sheet's one of our planet's two ice sheets, the other's the Antarctic ice sheet. But the Greenland ice sheet is shrinking, as I think most of us know, and contributing to sea level. Tundra and the boreal forest. Vast Arctic land areas, some of it is Tundra, but it may come to a surprise to some that a lot of the Arctic lands is actually forest, boreal forest. River systems. A number of extremely large rivers that drain into the Arctic Ocean. And they have very pronounced effects. The runoff, the discharge from these rivers, it has very pronounced effects on the Arctic Ocean, and impacts for example, on the sea ice cover. A great example of how what happens in the ocean is connected to what happens over the land. And then permafrost, characteristics and distribution. What is permafrost? Perennially frozen ground that underlies much of the Arctic land. Also, you find it under the sea floor in places. But it has very, very strong impacts on, for example, on land, the types of plants that can grow. One thing we'll learn, and we'll look at it more thoroughly in the next class, is how the permafrost is thawing and the permafrost is melting. Finally, module 5, the Arctic atmosphere and energy budget. A little taste of Arctic weather. What are the types of weather systems that we get in the Arctic? The Arctic and the large scale circulation. What we have, of course, what drives weather in the first place, a lot of weather, is that there's more solar energy coming in at lower latitudes than at higher latitudes. That's, for example, the Arctic or the Antarctic. And that temperature, that difference in solar heating, drive a temperature gradient. And that's what really drives the weather. And of course, the Arctic as kind of the northern heat sink plays a huge role in that. We have to understand how that work. Atmospheric teleconnections, these are connections between climate patterns in widely separated regions. And a lot of number of teleconnections have very big impact in the Arctic. And then the Arctic energy budget. We've got to get into a little bit of the nitty gritty here of energy flows in the Arctic, energy flows into the region, energy flows out of the region, and how these flows of energy so very much shape the environment. So that's a little brief overview of the first class of Arctic Climate Environment and the Geographies of the Changing North. I hope you enjoy it. Thank you.