Graphic scale
The use of a line marked off in graduated distances as a map scale.
Fractional scale
-Representative fraction describing the ratio b/w distance on the map and the actual distance on earth's surface it represents.
-assumes that the same units of measurement (e.g. 1map in=200,000 earth in
Large-scale map
A map with a scale that is relatively large representative fraction and therefore portrays only a small portion of the earths surface.
Small-scale map
A map whose scale is a relatively small representative fraction and therefore shows a large portion of earths surface in limited detail
Isoline
A line on a map connecting points that have the same quality or intensity of a given phenomenon.
Contour line
a line joining two points of equal elevation
Contour interval
The difference in elevation between two elevation contour lines.
Depression contour
Elevation contour line with hachure marks pointing downslope into a depression
Relief
The difference in elevation between the highest and lowest points in an area; the vertical variation from mountain top to valley bottom.
Index contour
Every fourth or fifth contour line on most contour line maps; thicker than regular contour lines; usually marked with elevation.
Isotherm
A line on a map joining points of equal temperature.
Isobar
A line on a map joining points of equal atmospheric pressure.
Insolation
incoming solar raidation
Angle of incidence
The angle at which the sun's rays strike the earths surface.
Station model
Standardized system of data presentation used on a weather map to convey conditions at a weather station.
Friction
The force that impedes the relative motion of two objects in contact
Coriolis effect
The apparent deflection of free moving objects to the right in the northern hemisphere and to the left in the southern hemisphere, in response to the rotation of the earth
Humidity
Water vapor in the air
Mixing ratio
Description of the water vapor content of the air expressed as the mass of water in a given mass of dry air; usually as grams of water vapor per kilogram of dry air.
Saturation mixing ratio (SMR)
The water vapor capacity of air at a given temperature.
Saturation
Circumstances in which the air contains the maximum amount of water vapor for a given temperature;
Relative humidity
MR/SMR; an expression of the amount of water vapor in the air in comparison with the total amount there could be if the air were saturated. This ratio is expressed as a percentage.
Dew point
The critical air temperature at which water vapor saturation is reached.
Warm front
The leading edge of an advancing warm air mass
Cold front
The leading edge of an advancing cool air mass actively displacing warm air.
The 5 factors that control temperature
1. Latitude
2. Land-and-Water Contrast
3. Ocean Currents
4. Wind Patterns
5. Altitude
The 3 factors that affect daily insolation
1. Angle of Incidence
2. Length of Day
3. Atmospheric Obstruction.
Temperature change with altitude change
In general, temperature decreases with increased altitude.
Rate of temperature change (average lapse rate)
3.6�F per 1000 ft
6.5�C per 1000 m
Descending air in terms of pressure
Produces High Pressure near the earths surface
Ascending air in terms of pressure
Produces low pressure near the earths surface
Wind direction in upper atmosphere
In the northern hemisphere, the air encounters little friction. The balance of the pressure gradient force and the Coriolis effect result in winds that blow parallel to isobars (geostrophic winds), clockwise around highs, and counterclockwise around lows.
Wind direction at the surface
In the northern hemisphere, Friction is increased so the Coriolis effect deflection is reduced. Near the surface, the balance of the pressure gradient force, Coriolis effect, and friction results in winds that diverge clockwise out of highs (anticyclones)
Air movement around low pressure systems
In the northern hemisphere, air moves in a counter clockwise direction.
Air movement around high pressure systems
In the northern hemisphere, air moves in a clockwise direction.
Relationship among temperature, SMR, mixing ratio, dew point, and relative humidity
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