1	Lecture 1: Properties of Atmosphere
2	Thickness of the Atmosphere The thickness of the atmosphere is only about 2% of Earth’s thickness (Earth’s radius = ~6400km). Most of the atmospheric mass is confined in the lowest 100 km above the sea level.
3	Units of Air Temperature
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5	Variations in Tropopause Height
6	Stratosphere
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11	Units of Atmospheric Pressure Pascal (Pa): a SI (Systeme Internationale) unit for air pressure. 1 Pa = a force of 1 newton acting on a surface of one square meter 1 hectopascal (hPa) = 1 millibar (mb) [hecto = one hundred =100] Bar: a more popular unit for air pressure. 1 bar = a force of 100,000 newtons acting on a surface of one square meter = 100,000 Pa = 1000 hPa = 1000 mb One atmospheric pressure = standard value of atmospheric pressure at lea level = 1013.25 mb = 1013.25 hPa.
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13	Pressure Correction for Elevation Pressure decreases with height. Recording actual pressures may be misleading as a result. All recording stations are reduced to sea level pressure equivalents to facilitate horizontal comparisons. Near the surface, the pressure decreases about 100mb by moving 1km higher in elevation.
14	Pressure and Height
15	Isobar It is useful to examine horizontal pressure differences across space. Pressure maps depict isobars, lines of equal pressure. Through analysis of isobaric charts, pressure gradients are apparent. Steep (weak) pressure gradients are indicated by closely (widely) spaced isobars.
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18	Vapor Pressure The air’s content of moisture can be measured by the pressure exerted by the water vapor in the air. The total pressure inside an air parcel is equal to the sum of pressures of the individual gases. In the left figure, the total pressure of the air parcel is equal to sum of vapor pressure plus the pressures exerted by Nitrogen and Oxygen. High vapor pressure indicates large numbers of water vapor molecules. Unit of vapor pressure is usually in mb.
19	Observed Vapor Pressure
20	Saturation Vapor Pressure Saturation vapor pressure describes how much water vapor is needed to make the air saturated at any given temperature. Saturation vapor pressure depends primarily on the air temperature in the following way: è Saturation pressure increases exponentially with air temperature.
21	Relative Humidity
22	Dew Point Temperature Dew point temperature is another measurement of air moisture. Dew point temperature is defined as the temperature to which moist air must be cool to become saturated without changing the pressure. The close the dew point temperature is to the air temperature, the closer the air is to saturation. Dew points can be only equal or less than air temperatures.
23	Daily Variations of Temperature, Relative Humidity, and Dewpoint Temp.
24	Measuring Winds Wind direction always indicates the direction from which wind blows. An anemometer indicates both wind speed and direction. Official measurements of wind at surface are made at an elevation of 10 meters, which is referred to as the anemometer height. Meteorologists typically measure wind speed in knots. è 1 knot = 1.15mph =0.51 m/sec
25	Wind Direction and Speed
26	Cloud Type Based On Properties
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28	Cloud Types Based On Height
29	Cloud Classifications
30	High Clouds High clouds have low cloud temperature and low water content and consist most of ice crystal.
31	Middle Clouds Middle clouds are usually composite of liquid droplets. They block more sunlight to the surface than the high clouds.
32	Low Clouds Low, thick, layered clouds with large horizontal extends, which can exceed that of several states.
33	Clouds With Vertical Development They are clouds with substantial vertical development and occur when the air is absolute or conditionally unstable.
34	Observation Time for Weather Map
35	Time Zone