Weather- is the state of the atmosphere at a given tie and place
To try to predict weather you need to observe the clouds, wind, temp,humidity, and pressure and precipitation over a period of time
Heating of the atmosphere- energy from the sun results in changes in the weather. heat moves through the atmosphere in three ways
Conduction- An object receives heat when it comes in contact with a hotter object (Ex. a pan on a hot stove)
radiation- Hot bodies radiate energy in short waves (sun); Cold bodies radiate energy in long waves (earth)
Convection- most effective; the rising of hot air and sinking of cold air results in a steady flow. convection is very important in moving heat through the atmosphere
Insulation
Solar energy- that reaches the earth; we receive one two billions of the sun
Green house effect - Short ultra violet waves from the sun are able to reach the earths surface. then longer infrared waves re-radiated by the earths surface are trapped by green house gasses (CFC's and CO2) Normal lapse rate- the rate of cooling with altitude (1 degree c every 160 meters) Temp inversion- when the air is especially still cooler air, because of its greater density settles close to the ground and the warmer air forms a blanket above it. In a temp inversion pollutants in the air such as smoke and soot are also trapped close to the ground
Specific heat - The amount of heat required to raise the temp of something 1 degree C
water has a very high specific heat compared to soil
Absorption - to take in energy and heat up
Reflection- to bounce back energy
Re-radiation-to absorb short wave energy and give off long wave energy
Good absorbers poor Absorbers
Heating of land and water
Which heats up faster ??
Water warms much more slowly than land
In water the sun's rays go to a depth of many meters. on land only the top few centimeters of soil is heated by the sun
water can spread heat easily because it is a fluid
some solar energy is used in the process of evaporation thus less solar energy
WATER CAN SPREAD HEAT EASILY BECAUSE IT IS A FLUID.
SOME SOLAR ENERGY IS USED IN PROCESS OF EVAPORATION. THUS, LESS SOLAR ENERGY IS AVAILABLE TO RAISE THE TEMPERATURE OF THE WATER.
WATER COOLS MORE SLOWLY THAN THE LAND BECAUSE ITS HEAT IS SPREAD THROUGH A GREATER DEPTH.
TEMPERATURE- TEMPERATURE IS A MEASURE OF THE ENERGRY OF MOLECULES. THE MORE ENERGY THE MOLECULES IN AIR HAVE, THE HOTTER IT FEELS.
TEMPERATURE IS MEASURED IN DEGREES CELSIUS, FAHRENHEIT, KELVIN.
THERMOMETERS ARE THE INSTRUMENTS USED TO MEASURE THE TEMPERATURE.
THE ALCOHOL EXPANDS WHEN HEATED
THERMOGRAPHS ARE SELF-RECORDING THERMOMETERS.
ISOTHERMS- ARE LINES DRAWN ON MAPS CONNECTING PLACES WITH THE SAME TEMPERATURE.
Evaporation
The change from liquid from liquid water to water vapor.
Humidity
The capacity of air for holding water vapor.
As are temperature increases so does the amount of water vapor it can hold.
Specific Humidity- the amount of water vapor actually present in the air.
Relative humidity- compares the actual amount of water vapor in the air. (specific humidity) with the maximum amount of water vapor in the air can hold at that temperature.
Psychrometer- is the instrument used to determine relative humidity.
Condensation- The change from water vapor to a liquid. This occurs when the temperature drops low enough that the capacity for water vapor in the air drops below the specific humidity.
EXAMPLES
Dew- water vapor which condenses on surfaces, such as grass, in the form of a liquid.
DEW POINT- TEMPERATURE AT WHICH SATURATION OCCURS.
Clouds or fogs- form when the water vapor condenses into droplets.
Air may be cooled below its dew point in many ways:
CONTACTING A COLDER SURFACE.
RADIATING HEAT.
MIXING WITH COLDER AIR.
EXPANDING WHEN IT RISES.
Water vapor needs to condense on something!!!!!!!!!!!!!!!!!!
Condensation Nuclei- tiny particles, such as salt, sulfate, or nitrate particles, on which water vapor condenses.
When cooling occurs by contact with a colder surface, the water vapor condenses directly on that surface. >0*C = DEW.
Fog- Surface layers of air a few hundred meters thick which are cooled below the dew point. As water vapor condenses tiny droplets stay suspended in the air by the lightest air movement.
Radiation fogs- at night the ground loses heat rapidly. Light winds mix the cold bottom air with the air a short distance from the distance. When the whole layer of air is cooled below the dew point, a fog forms. (Common in humid valleys and near rivers and lakes)
Advection fogs- result when warm, moist air blows over cool surfaces (ex. Coastal California)
CLOUDS- clouds form when air above the surface cools below the dew point.
Precipitation- Is the falling of any forms of water from the air to the earth's surface.
Occurs when cloud droplets grow into drops heavy enough to fall to earth.
Raindrops- form from tiny droplets and then grow by bumping into and combining with other droplets.
Sleet- forms when raindrops fall through the freezing air and fall to the ground as pellets of ice.
Hailstones- begin as a frozen raindrops and grow by collecting smaller ice particles or liquid cloud droplets.
Acid Rain- forms when water condenses on sulfate and nitrate.
Air Pressure
The weight of the atmosphere per unit area.
Differences in air pressure cause the earth's wind and weather changes.
*Pressure decreases with altitude*
Barometer- Is an instrument used to measure air pressure.
Aneroid barometer- measures pressure with a thing metal can.
Millibar- is a metric unit of pressure.
**Standard sea-level pressure if 1013.2*
Isobar- lines that join points having the same air pressure at a given time.
*Each line is worth 4 mb*
High pressure area (high)- The area of the largest pressure. The pressure in a high greater than the surrounding air.
Low pressure area (low)- this area has lower pressure than the surrounding area.
Pressure Gradient- the rate of change for air pressure between two points.
Rising barometer- greater pressure usually means cooler drier weather (sinking air)
Falling barometer- less pressure because the air i warm and moist and rises. This can be a sign of precipitation.
WIND
The horizontal movement of air from areas of high air pressure to areas of low air pressure.
The closer the spacing between isobars the stronger the winds.
Winds blow across isobars, from high to low air pressure.
Air Masses
An air mass is a huge section of the lower troposphere that has the same kind of weather throughout.
The best source regions for air masses.
Air masses have two characteristics.
Temperature depends on weather if comes from the tropics or polar regions.
The HUMIDITY OF THE AIR MASS depends on whether it comes from land or sea.
Air masses are named from their source region.
C-continental (dry)
M-maritime (moist)
T-tropical
P-polar
A-arctic
Fronts are the boundaries between air masses are called fronts.
Cold Front- When cold air is advancing and replacing warm air.
Cold fronts are steeper and move faster than warm fronts.
The air rises upward rapidly forming cumulonimbus.
Heavy precipitation and thunderstorms which start and end quickly, are associated with cold fronts.
Precipitation covers 75-100 miles and occurs both BEFORE and AFTER a cold front passes at the surface.
Cold fronts travel at speeds between 25-30 MPH.
As soon as the front passes the temperature will decrease and the wind speed may rise.
WARM FRONT
Warm air is advancing and replacing cold air.
Warm fronts move slower; warm are moves up a gentle frontal surface.
Warm air may travel 1000 km before rising 2 or 3 km.
First cirrus and cirrostratus clouds form and then there are altostratus clouds. Finally, steadt rain falls form nimbostratus clouds.
Precipitation can occur for 225-275 miles ahead of where the front touches the ground.
Warm fronts travel at speeds between 20-25 MPH.
Warmer temperatures follow the passing warm front.
OCCLUDED FRONT
A cold front is advancing and combining with a warm front.
Occluded fronts move the slowest of all (20 MPH)
The fronts are associated with cirrus and stratus clouds in front of the nimbostratus and cumulonimbus clouds.
Precipitation occurs for about 400 miles, most of which is in front of the frontal boundary.
Cool air is in front, as warm air is force up by the cold air which follows the passing occluded front.
METEOROLOGY- THE STUDY OF THE ENTIRE ATMOSPHERE, INCLUDING ITS WEATHER.
The Atmosphere- Air is a mixture of many gases in earth's lower atmosphere.
Nitrogen and Oxygen together form about 99% of dry air by volume.
The remaining 1% is mainly Argon and Carbon Dioxide.
Structure of the Atmosphere
Troposphere- is the lowest layer of the atmosphere (0-12 km) in which all of earth's weather occurs.
Gradually decreases in temp. with an increase in altitude.
Contains mostly all water vapor.
The jet stream is located between 6-12 km.
Tropopause- the top of the troposphere where the decrease in temp. stops.
Stratosphere- reaches from the troposphere to about 50 km above earth.
Steady winds and few weather changed (planes fly here!!!)
Steady increase of altitude, which is caused by absorption from the ozone.
Ozone- Ultraviolet rays make oxygen 03. The ozone layer absorbs sun's UV rays and protects us from burning.
Stratosphere- the to of the stratosphere where the temp. stops rising.
Mesosphere- The temperature drops again.
Thermosphere- Temperature rises again about 500 km from the earth
.
What is the weather like outside?
Weather- is the state of the atmosphere at a given tie and place
To try to predict weather you need to observe the clouds, wind, temp,humidity, and pressure and precipitation over a period of time
Heating of the atmosphere- energy from the sun results in changes in the weather. heat moves through the atmosphere in three ways
Insulation
Solar energy- that reaches the earth; we receive one two billions of the sun
Green house effect - Short ultra violet waves from the sun are able to reach the earths surface. then longer infrared waves re-radiated by the earths surface are trapped by green house gasses (CFC's and CO2) Normal lapse rate- the rate of cooling with altitude (1 degree c every 160 meters) Temp inversion- when the air is especially still cooler air, because of its greater density settles close to the ground and the warmer air forms a blanket above it. In a temp inversion pollutants in the air such as smoke and soot are also trapped close to the ground
Specific heat - The amount of heat required to raise the temp of something 1 degree C
water has a very high specific heat compared to soil
Absorption - to take in energy and heat up
Reflection- to bounce back energy
Re-radiation-to absorb short wave energy and give off long wave energy
Good absorbers poor Absorbers
Heating of land and water
Which heats up faster ??
Water warms much more slowly than land
WATER CAN SPREAD HEAT EASILY BECAUSE IT IS A FLUID.
SOME SOLAR ENERGY IS USED IN PROCESS OF EVAPORATION. THUS, LESS SOLAR ENERGY IS AVAILABLE TO RAISE THE TEMPERATURE OF THE WATER.
WATER COOLS MORE SLOWLY THAN THE LAND BECAUSE ITS HEAT IS SPREAD THROUGH A GREATER DEPTH.
TEMPERATURE- TEMPERATURE IS A MEASURE OF THE ENERGRY OF MOLECULES. THE MORE ENERGY THE MOLECULES IN AIR HAVE, THE HOTTER IT FEELS.
TEMPERATURE IS MEASURED IN DEGREES CELSIUS, FAHRENHEIT, KELVIN.
THERMOMETERS ARE THE INSTRUMENTS USED TO MEASURE THE TEMPERATURE.
THE ALCOHOL EXPANDS WHEN HEATED
THERMOGRAPHS ARE SELF-RECORDING THERMOMETERS.
ISOTHERMS- ARE LINES DRAWN ON MAPS CONNECTING PLACES WITH THE SAME TEMPERATURE.
Evaporation
The change from liquid from liquid water to water vapor.
Humidity
The capacity of air for holding water vapor.
As are temperature increases so does the amount of water vapor it can hold.
Specific Humidity- the amount of water vapor actually present in the air.
Relative humidity- compares the actual amount of water vapor in the air. (specific humidity) with the maximum amount of water vapor in the air can hold at that temperature.
Psychrometer- is the instrument used to determine relative humidity.
Condensation- The change from water vapor to a liquid. This occurs when the temperature drops low enough that the capacity for water vapor in the air drops below the specific humidity.
EXAMPLES
Dew- water vapor which condenses on surfaces, such as grass, in the form of a liquid.
DEW POINT- TEMPERATURE AT WHICH SATURATION OCCURS.
Clouds or fogs- form when the water vapor condenses into droplets.
Air may be cooled below its dew point in many ways:
CONTACTING A COLDER SURFACE.
RADIATING HEAT.
MIXING WITH COLDER AIR.
EXPANDING WHEN IT RISES.
Water vapor needs to condense on something!!!!!!!!!!!!!!!!!!
Condensation Nuclei- tiny particles, such as salt, sulfate, or nitrate particles, on which water vapor condenses.
When cooling occurs by contact with a colder surface, the water vapor condenses directly on that surface. >0*C = DEW.
Fog- Surface layers of air a few hundred meters thick which are cooled below the dew point. As water vapor condenses tiny droplets stay suspended in the air by the lightest air movement.
Radiation fogs- at night the ground loses heat rapidly. Light winds mix the cold bottom air with the air a short distance from the distance. When the whole layer of air is cooled below the dew point, a fog forms. (Common in humid valleys and near rivers and lakes)
Advection fogs- result when warm, moist air blows over cool surfaces (ex. Coastal California)
CLOUDS- clouds form when air above the surface cools below the dew point.
Precipitation- Is the falling of any forms of water from the air to the earth's surface.
Occurs when cloud droplets grow into drops heavy enough to fall to earth.
Raindrops- form from tiny droplets and then grow by bumping into and combining with other droplets.
Sleet- forms when raindrops fall through the freezing air and fall to the ground as pellets of ice.
Hailstones- begin as a frozen raindrops and grow by collecting smaller ice particles or liquid cloud droplets.
Acid Rain- forms when water condenses on sulfate and nitrate.
Air Pressure
The weight of the atmosphere per unit area.
Differences in air pressure cause the earth's wind and weather changes.
*Pressure decreases with altitude*
Barometer- Is an instrument used to measure air pressure.
Aneroid barometer- measures pressure with a thing metal can.
Millibar- is a metric unit of pressure.
**Standard sea-level pressure if 1013.2*
Isobar- lines that join points having the same air pressure at a given time.
*Each line is worth 4 mb*
High pressure area (high)- The area of the largest pressure. The pressure in a high greater than the surrounding air.
Low pressure area (low)- this area has lower pressure than the surrounding area.
Pressure Gradient- the rate of change for air pressure between two points.
Rising barometer- greater pressure usually means cooler drier weather (sinking air)
Falling barometer- less pressure because the air i warm and moist and rises. This can be a sign of precipitation.
WIND
The horizontal movement of air from areas of high air pressure to areas of low air pressure.The closer the spacing between isobars the stronger the winds.
Winds blow across isobars, from high to low air pressure.
Global Wind Belts
Wind flowing from high pressure at the poles to low pressure at the equator.
The wind is deflected by the earth's rotation, called the coriolus effect.
Air Masses
An air mass is a huge section of the lower troposphere that has the same kind of weather throughout.
The best source regions for air masses.
Air masses have two characteristics.
Temperature depends on weather if comes from the tropics or polar regions.
The HUMIDITY OF THE AIR MASS depends on whether it comes from land or sea.
Air masses are named from their source region.
C-continental (dry)
M-maritime (moist)
T-tropical
P-polar
A-arctic
Fronts are the boundaries between air masses are called fronts.
Cold Front- When cold air is advancing and replacing warm air.
Cold fronts are steeper and move faster than warm fronts.
The air rises upward rapidly forming cumulonimbus.
Heavy precipitation and thunderstorms which start and end quickly, are associated with cold fronts.
Precipitation covers 75-100 miles and occurs both BEFORE and AFTER a cold front passes at the surface.
Cold fronts travel at speeds between 25-30 MPH.
As soon as the front passes the temperature will decrease and the wind speed may rise.
WARM FRONT
Warm air is advancing and replacing cold air.
Warm fronts move slower; warm are moves up a gentle frontal surface.
Warm air may travel 1000 km before rising 2 or 3 km.
First cirrus and cirrostratus clouds form and then there are altostratus clouds. Finally, steadt rain falls form nimbostratus clouds.
Precipitation can occur for 225-275 miles ahead of where the front touches the ground.
Warm fronts travel at speeds between 20-25 MPH.
Warmer temperatures follow the passing warm front.
OCCLUDED FRONT
A cold front is advancing and combining with a warm front.
Occluded fronts move the slowest of all (20 MPH)
The fronts are associated with cirrus and stratus clouds in front of the nimbostratus and cumulonimbus clouds.
Precipitation occurs for about 400 miles, most of which is in front of the frontal boundary.
Cool air is in front, as warm air is force up by the cold air which follows the passing occluded front.