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Weather and Climate. The atmosphere’s condition makes up the six components of Weather. temperature cloud cover wind speed wind direction humidity air pressure . Temperature. is a measure of how fast air molecules are moving.
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The atmosphere’s condition makes up the six components of Weather • temperature • cloud cover • wind speed • wind direction • humidity • air pressure
Temperature • is a measure of how fast air molecules are moving. • When the molecules are moving rapidly temperature is high and when they are moving slowly, the temperature is low.
Transfer of Energy • Energy is transferred between fast-moving molecules and slower moving molecules. • Conduction is the transfer of energy when molecules collide. • Convection is the process that occurs when the warm air rises and cool air sinks.
Cloud Cover Clouds form when air rises, cools to its dew point, and becomes saturated! Then they start to fall back to ground as precipitation!
Dew and Dew Point • Dew point is: the temperature which water vapor molecules start to form liquid water. • Dew point can be defined another way: It is when the air is holding as much water vapor as it can.
Wind • air moving from one temperature or pressure area to another • Meteorologists measure wind speed with an anemometer and wind direction as part of the weather
Important facts about the wind • Coriolis Effect occurs when deflected air moves to the right in the northern hemisphere and to the left in the southern hemisphere • Surface winds include: • the trade winds near the equator • The prevailing westerlies from about 30 degrees latitude north and south of the equator, and the polar easterlies near the poles.
Jet Stream Jet streams are bands of strong winds near the top of the troposphere at the northern and southern boundaries of the prevailing westerlies.
Humidity • is the amount of water vapor in the air. • Temperature affects how much moisture is in the air. • The relative humidity is the measure of the amount of water vapor present compared to the amount that could be held at a specific temperature.
Barometric Pressure • Air pressure is the air weight (gravity) that varies over the Earth’s surface. • Air pressure and temperature are related. • Warmer air is less dense (why heated air moves expands & moves upward and creating a lower pressure.) • Cooler air sinks and is denser which creates more pressure.
Pressure SystemsEither a high pressure or low pressure!!! • High-pressure systems happen when air sinks and spreads away from the high-pressure center • moisture cannot rise and condense • usually dry with a few clouds
Pressure Systems • Low-pressure systems happen when air rises and cools forming clouds • Usually has precipitation with this system
Fronts the term used to determine a boundary between different air masses.
Fronts • Cold fronts are cold air masses that push under a warm front possibly causing a narrow band of violent storms and the temperatures to drop. • Warm fronts happen when warm air masses slide up over a cold air mass and wide-spread precipitation develops.
Fronts • Stationary fronts occur when warm air mass and cold air mass meet but neither advance; they just sit in place or move very slowly!!! The result is cloudiness and precipitation. • Occluded fronts are fast moving cold fronts that overtake a slower moving warm front or vice versa; cloudy weather with precipitation is the result.
Severe Weather • Thunderstorms that develop from cumulonimbus clouds that form along cold fronts and can have strong wind, dangerous hail, lightning and thunder
Severe Weather • Tornados are violent, whirling wind that moves in a narrow path over land. • Hurricanes are large storms that begin as an area of low pressure over tropical oceans; heat energy from moist air is converted to wind that can reach speeds of 250 km/h
Weather • The National Weather Service monitors weather and issues watches when severe weather is a potential threat and warnings when severe weather is an actual threat. • Remember!!! Watches are when the weather conditions may produce severe weather. Warnings mean that the severe weather is here!!! Take Cover!!!
Occluded Frontfast moving cold air mass overtakes a slower warm air mass
Stationary Frontwarm and cold air masses meet, but neither advances
Answers to quiz 1. Cold Front 2.Warm Front 3.Stationary Front 4.Occluded Front 5.Trough 5.Squall 7.Dry Line 8.Tropical Wave