GEO 203 Key Terms and Concepts (1,2,3)

Spatial Statistics

A variety of statistical techniques can be used to study entities using their topological, geometric, or geographic properties.

Geographic Information Systems GIS

A Geographic Information System is a system (usually a computer software program, such as ArcGIS) that allows users to store, manipulate, analyze, and display geographic information (such as the information from GPS and remote sensing that we have just discussed). Since this system is only as useful as people's ability to apply it to problem-solving, a GIS also can also refer to the people and organizations that design the program and apply it to issues as diverse as natural-resource management, regional planning, natural-hazards analysis, et cetera.

Global Positioning Systems (GPS)

A Global Positioning System, better known as GPS, is an intricate system of satellites (roughly 30, at present) that orbit the earth on regular cycles. By definition, GPS also includes receivers that detect signals transmitted by these satellites in order to determine geographic location. GPS units are used for many applications, including locating the best route to a local restaurant, surveying terrain, and identifying targets for military operations, to name a few.

Volunteered Geographic Information (VGI)

Creation and dissemination of geographic data contributed voluntarily and for free by individuals.

Exosphere

Finally, approximately 500 kilometers above the earth's surface, atoms and molecules can escape into outer space—this region is known as the exosphere, and it is the upper limit of the atmosphere. "The exosphere is the outermost region of the earth's atmosphere. Within the exosphere, atoms follow ballistic trajectories and rarely undergo collisions because the density of atoms in this region is so low. The exosphere begins at approximately 500 kilometer and extends outward until it transitions with interplanetary space (at roughly 10,000 kilometer)."

Surface Weather Stations

Stations that take observations near the earth's surface The ASOS system is the United States' primary network for observing weather from the earth's surface. Can give a lot of information such as sky conditions air and dew point temps but it can only report what it sees.

Hydrologic cycle

The hydrologic cycle is a model of the pathways for water movement in the environment. Water not only exists in three states (phases), but it also moves from one state to another in a cyclical manner. The main pathways of movement are: (1) precipitation, (2) evaporation (and transpiration), and (3) runoff.

How to calculate UTC

Let us imagine we are converting the time in East Lansing, Michigan, to UTC, and it is currently 5 PM. First, convert 5 PM to the 24-hour clock: 5 PM = 1700 hours (1200 + 500). Second, use the chart below to convert to UTC. Chart: + 5 hours 1700 + 5 hours (or, 0500 since East Lansing is in the Eastern Standard Time) = 2200 UTC. From 24-hour Local Time to UTC. UTC = Eastern Standard Time (EST) + 5 hours UTC = Central Standard Time (CST) + 6 hours UTC = Mountain Standard Time (MST) + 7 hours UTC = Pacific Standard Time (PST) + 8 hoursor, written another way: UTC = EST + 0500 UTC = CST + 0600 UTC = MST + 0700 UTC = PST + 0800

Prime Meridian

The reference line for longitude or 0° longitude, as noted in the caption above, is the Prime Meridian, located in Greenwich, England. It divides Earth into Eastern and Western Hemispheres. Longitude is measured from zero to 180° east and 180° west (or -180°) of the Prime Meridian. 180° east and west is the same line, located in the middle of the Pacific Ocean.

Wind barb

The wind barb indicates the wind direction and wind speed.

Surface chart

Type of weather chart. A surface chart is a map that shows the distribution of weather parameters and phenomena such as sea-level pressure systems (shown using isobars). These maps describe the locations of high and low pressure systems, their associated warm and cold fronts, and also the winds and weather associated with such systems.

Station models

diagram that displays data from many different weather measurements for a particular location. You will notice that the following two surface weather charts are covered by circles and numbers. These symbols are called station models, and although small, they are full of information observed at a weather station.

Permanent gases

gases that remain at stable concentrations Nitrogen and oxygen are both permanent gases, which make up most of Earth's atmosphere. However, the 1% of trace gases are important to weather and climate. The most significant trace gases are water vapor, carbon dioxide, and ozone.

Radiosonde rawinsonde

is a balloon-borne instrument used to simultaneously measure and transmit meteorological data while ascending through the atmosphere. Observations where wind information is also obtained are called "rawinsonde" observations.

Geomatics

is a scientific term for gathering, storing, processing, and delivering geographic information. In addition, it is an umbrella term for every method and tool from data acquisition to distribution including math, computers and Earth science (online)

Environmental Geography

is the branch of geography that describes and explains the spatial aspects of interactions between human individuals or societies and their natural environment (wiki)

Space

is the expanse in which things exist. The earth's surface is the space that geography studies

Air density

is the number of air molecules in a certain space (volume). Greater density near the the surface of the Earth temp, pressure, and water vapor all affect density as air pressures increases, air density increases as well.

Meteorology, weather, climate

is the scientific discipline that focuses on studying the atmosphere—its composition, events that occur in the atmosphere, how it changes over time and space, and other related phenomena. Weather- day to day condition of the atmosphere climate- the averages of the day to day weather

Meteorology

is the study of the earth's atmosphere and atmospheric phenomena, and how the atmosphere interacts with the earth's surface.

Outgassing

the process of releasing gases from a planetary interior, usually through volcanic eruptions Most of the water on our planet is believed to have come from the earth's hot interior through outgassing.

Human Geography

the branch of geography dealing with how human activity affects or is influenced by the earth's surface. (online)

Physical Geography

the study of physical features of the earth's surface.

Geography

the study of spatial relationships (the interactions, connections, and processes) between an object/phenomenon and its location. Is naturally multi-disciplinary, as it straddles the natural and social sciences. The word geography means to write about the earth (geo - earth, graphus - write) and the discipline of geography is fundamentally about places, the people who live in those places, and how places affect people.

Above Air Stations

those that take observations above the earth's surface

UTC (Universal Time Coordinated)

universal time is the notation used in all weather maps. To understand UTC, it is helpful to know the system used to describe a location on the earth's surface, specifically, latitude and longitude. UTC is centered on the Prime Meridian UTC can also be denoted as GMT (Greenwich Meridian Time). basically UTC is the same time as in Greenwich England.

Ionosphere

Additionally, we can also consider the portion of the atmosphere that is electrically charged, that is, where a fair amount of ions and free electrons are located. This region is called the ionosphere, and it begins approximately 60 kilometers above the earth's surface. The ionosphere is important to AM radio communications, as radio waves travel different lengths according to the electrical characteristics of this zone. "This absorption of radiation is also responsible for the Ionosphere. Located within the thermosphere, the ionosphere is made of electrically charged gas particles (ionized). The ionosphere extends from 37 to 190 miles (60-300 kilometers) above the earth's surface. It is divided into three regions or layers; the F-Region, E-Layer and D-layer. As seen around the 1900s, the ionosphere has the important quality of bouncing radio signals transmitted from the Earth. Its existence is why places all over the world can be reached via radio. As seen around the 1900s, the ionosphere has the important quality of bouncing radio signals transmitted from the Earth. The remaining waves (red and blue arrows) are called skywaves. These waves bounce off the ionosphere and can bounce for many thousands of miles depending upon the atmospheric conditions."

Air pressure

Because gravity is acting on the molecules of air, air has weight. The amount of force over a given surface area is called air pressure. Near the surface, the number of air molecules and, therefore, weight of the air is much greater than it is higher in the atmosphere. Air pressure, then, is increases near the surface and decreases as you move into the upper levels of the atmosphere. For reference, air pressure near sea level is about 1013 millibars, on Mt. Everest it is closer to 337 millibars. Pressure decreases exponentially with height (meaning decreases rapidly at first and then at a slower rate as you move higher in the atmosphere) by approximately 10 millibars per 100 meters. Additionally, approximately 99.9% of the atmosphere in with 30 kilometers of altitude.

Remote Sensing

In this course, you will see examples of images of the earth taken from the air - either by a plane or satellite. These are called remote-sensing images. Remote sensing refers to the collection of data (for example, identification, measurement, and observation) without direct contact with the object. In geography and in other earth-related disciplines, the term usually refers to measurements taken from an airplane or satellite that results in data (such as aerial photographs or satellite images). Contrast this with the previous discussion of GPS - when using GPS, one is on the ground, taking information (the location) of a feature at that particular site. In remote sensing, we are gathering information about those features from the air

atmosphere

It is the thin envelope of gases that surround Earth, held near by its gravitational pull. Started out as mostly hydrogen and helium but eventually became what it is today through outgassing, where water vapor was introduced the sun rays split the water to increase the hydrogen and oxygen content.

Latitude and Longitude

Latitude lines give the location of points north or south of an origin (or imaginary reference line), which on Earth is the Equator. Are also known as parallels. Described in degrees. Longitude lines (also known as meridians) give the location of points east or west of an origin line; they run from north to south and meet at the poles. Facts should know: Parallels (another name for latitude lines) are true east-west lines: If you follow a line of latitude, you will be traveling due east or due west (whichever direction you decided to follow). Parallels are equally spaced between the Equator and the poles. Meridians (another name for longitude lines) are spaced farthest apart at the equator and converge to a single point at the poles—take a look at a globe and see how that works. Parallels and meridians cross at right angles (90°).

Cartography/Visualization

Once geographic information is collected, stored, and analyzed, a geographer's job is to effectively represent and display the new geographic insights/findings. We do this using cartography, and we present our spatial information most effective using maps (and you will see many in this class!

polar mesospheric clouds

Polar mesospheric clouds are also known as noctilucent or night-shining clouds—a property that is clearly visible in this astronaut photograph. The clouds exhibit thin, wispy light blue forms that contrast with the darkness of space (image upper right). Lower levels of the clouds are more strongly illuminated by the Sun and appear light orange to white. Clouds closest to the earth's surface are reddish-orange (image center)."

Stratosphere

Temperature increases gradually in the stratosphere, which is caused by trace gases (mostly ozone) absorbing solar radiation. This temperature increase with height is called a temperature inversion. "The stratosphere is the second major strata of the atmosphere. It resides between 10 and 50 kilometers above the planet's surface. The air temperature in the stratosphere remains relatively constant up to an altitude of 25 kilometers. Then it increases gradually to 200-220 Kelvin at the lower boundary of the stratopause (~50 kilometers), which is marked by a decrease in temperature. Because the air temperature in the stratosphere increases with altitude, it does not cause convection and has a stabilizing effect on atmospheric conditions in the region. Ozone plays the major role in regulating the thermal regime of the stratosphere, as water vapor content within the layer is very low. Temperature increases with ozone concentration. Solar energy is converted to kinetic energy when ozone molecules absorb ultraviolet radiation, resulting in heating of the stratosphere."

Thermosphere

Temperature increases rapidly again in the thermosphere, due to the absorption of solar rays by oxygen molecules. As you might tell from its name, the thermosphere is the warmest layer of the atmosphere. However, air density in the thermosphere is extremely low—conventional thermometers for temperature will not even work because too few particles would strike the thermometer to heat it! Oxygen molecules are widely scattered in this portion of the atmosphere, which is probably best known because ionization within this layer often results in the colored glowing lights, known as Aurora Borealis (northern lights, in the Northern Hemisphere) or Aurora Australis (southern lights, in the Southern Hemisphere). "The thermosphere is located above the mesosphere and is separated from it by the mesopause transition layer. The temperature in the thermosphere generally increases with altitude up to 1000-1500 Kelvin. This increase in temperature is due to the absorption of intense solar radiation by the limited amount of remaining molecular oxygen. At an altitude of 100-200 kilometer, the major atmospheric components are still nitrogen and oxygen. At this extreme altitude gas molecules are widely separated."

Mesosphere

The mesosphere lies above the stratosphere, and there is little heat input from the Sun in this atmosphere layer and it is far from the earth (a source of re-radiated heat). It is the coldest layer, with an average temperature of approximately -86 degrees Celsius. The top of the mesosphere is approximately 85 kilometers above the earth's surface, and it is called the mesopause. "The mesosphere a layer extending from approximately 50 to 80 kilometers, is characterized by decreasing temperatures, which reach 190-180 Kelvin at an altitude of 80 kilometers. In this region, concentrations of ozone and water vapor are negligible. Hence the temperature is lower than that of the troposphere or stratosphere. With increasing distance from earth's surface the chemical composition of air becomes strongly dependent on altitude and the atmosphere becomes enriched with lighter gases. At very high altitudes, the residual gases begin to stratify according to molecular mass, because of gravitational separation."

Upper-level chart

Type of weather chart. (also called an upper-air) chart -- Weather in the upper levels of the atmosphere is quite important to how the weather behaves at the surface. As you learned earlier, radiosondes are launched from many different sites, twice per day, and they give us detailed information about the winds, temperature, pressure, and humidity in the atmosphere above. This information is then plotted on upper level maps, or upper air charts. Such information is typically plotted at standard pressure levels (250 millibars, 500 millibars, 700 millibars, 850 millibars, 1000 millibars) and demonstrates the varying heights associated with those constant pressure readings. For example higher pressure over Colorado will show higher heights on these charts, while lower pressure over Michigan will show lower heights on these charts. An upper-level chart shows height variations at a constant pressure surface, usually at 850 millibars, 700 millibars, 500 millibars, 300 millibars, and 200 millibars. Compared to a surface chart, an upper-air chart is simpler. It contains three main elements (illustrated in the image below): isoheights (contour lines along which height values are constant, gray); isotherms (contour lines along which temperature values are constant, yellow); and station models (which, as you know, temperature, dew point, height, height tendency, wind speed and direction).

Carbon cycle

also illustrates the movement of a gas in and out of the atmosphere. Sources of carbon dioxide to the atmosphere include the decay of plants and animals and burning of fossil fuels, among others. All types of vegetation (including forests) contain carbon, and they release carbon dioxide when they decay or burn. Fossil fuels are also formed from the remains of plants and animals that lived (and died) millions of years ago through complex geologic processes—therefore, carbon is also released when these fossil fuels are burned for energy. Sinks for carbon dioxide include vegetation, which absorbs gas during the photosynthesis process, and the world's oceans.

Weather Charts

are images, often maps, showing the principal meteorological elements (or observations) at a given time, over an extended region.

Variable gases

atmospheric gases such as carbon dioxide, water vapor, and ozone that vary in concentration in space and time

Troposphere

comes from the Greek word tropein, which means to turn or change. This makes sense because the troposphere is the layer of the atmosphere that contains the active and changing weather we experience on a daily basis. The troposphere contains about 78% of the atmosphere's total mass, and all of the earth's living things are contained within the troposphere.The troposphere is the atmospheric layer closest to the planet and contains the largest percentage of the mass of the total atmosphere. It is characterized by the density of its air and an average vertical temperature change of 6 degrees Celsius per kilometer. Temperature and water vapor content in the troposphere decrease rapidly with altitude. Water vapor plays a major role in regulating air temperature because it absorbs solar energy and thermal radiation from the planet's surface. The troposphere contains 99 % of the water vapor in the atmosphere. Water vapor concentrations vary with latitudinal position. They are greatest above the tropics, where they may be as high as 3%, and decrease toward the polar regions. All weather phenomena occur within the troposphere, although turbulence may extend into the lower portion of the stratosphere. Troposphere means "region of mixing" and is so named because of vigorous convective air currents within the layer."

Spatial

means related to the space around us, in which we live and function