Introduction to Meteorology “The Study of our Weather”

Weather is the current state of the atmosphere at a specific time and place.

The atmosphere is made of layers of gases that surround the Earth The gases are primarily: Nitrogen Oxygen Argon

Bottom of Page 1 in ESRT Other includes argon (.91%), carbon dioxide, etc. Water vapor (1-4%) not included

Top of Page 14 in ESRT

The weather is determined by a combination of many changing factors in the troposphere

Measured with a thermometer in 0C, 0F, and 0K Temperature - is a measure of the average kinetic energy of the gases in the air. Air molecules are moving Measured with a thermometer in 0C, 0F, and 0K

Temperature conversions Simply read across the lines. For example room temp. = 680 F 200 C 2930 K Please note: 0F goes by 2’s, 0C and 0K go by 1’s.

Air Pressure – the measure of the weight of air. = density of air About 14.7 lbs/in2 Measured with a barometer in: in. of Hg, mb (millibars) atmospheres

Simply read across the lines. Pressure conversions Simply read across the lines. For example one atm. = 1013.2 mb & 29.92 in of Hg Please note: mb goes by 1’s, and in of Hg go by .01’s.

Measured with sling psychrometers and hygrometers in: Dew Point and Relative Humidity – measure the amount of moisture in the air. Measured with sling psychrometers and hygrometers in: Degrees Percent %

Caused by a difference in air pressure between two locations Wind – the horizontal movement of air Caused by a difference in air pressure between two locations

Measured with a wind vane and anemometer in MPH and knots

Precipitation – liquid or solid water falling from clouds Rain Snow Sleet Hail Freezing rain Measured with a rain gauge in inches

Clouds – tiny suspended water droplets or ice crystals. Cloud cover measured as a % using your vision

Weather maps – are used to represent weather variables

Station models – abbreviations of weather variables plotted on maps pg Station models – abbreviations of weather variables plotted on maps pg. 13 in ESRT

Important highlights Temp always in 0F but.. NO WRITTEN UNITS Pressure abbreviated by omitting decimal and “9” or “10”. So 989.3 = 893 Wind is named after where it comes from.