Week 3 Notes- Atmospheric Pressure, Wind, Circulation/Ch.-Lec. 3 Flashcards
Adiabatic Heating and Cooling: Cold air sinks to Earth’s surface (and then warms), and warm air rises (and then cools). Cold air sinking results in ________ density and pressure than warm air at Earth’s surface.
Higher
Air always moves from areas of high pressure to areas of low pressure. What do we commonly call this movement of air?
Pressure Gradient
What is the unit of measurement for air pressure?
millibars
The Coriolis effect (Earth’s rotation) causes winds to deflect in which direction on the Northern and Southern hemispheres.
Wind deflects to the right in the Northern
Hemisphere, and to the left in the Southern
Hemisphere
Cyclones and Anticyclones. Review the illustrations! What air temperature (cold, warm) and pressure (high, low) is at work to produce each of these, and what vertical direction does the air travel (up or down)? Does air “converge” (spiral together) or “diverge” (flow apart) during a cyclone or anticyclone.
slides 13-14
What are the three primary global wind systems, starting at the tropics and moving toward the poles?
trade winds, the prevailing westerlies, and the polar easterlies
In what general latitude and “wind zone” do cyclones and anticyclones occur, and in which direction do they generally travel?
mid-latitudes
west to east
Local Wind Systems-Land & Sea Breezes: In tropical and mid-latitude zones (such as the Bay Area), during the day cool breezes flow from where to where, and at night, warm air flows from where to where (direction).
During the day, the wind blows from the sea to the land. At night, breezes flow from the land to the sea.
cool/high-pressure air moves to warmer/low-pressure areas
Valley & Mountain Breezes: During the day, cool air flows from where to where, and at night, cool air reverses course and flows from where to where.
day: valley to the mountain
night: mountain to the valley
El Nino: is caused by a weakening in the strength of Trade winds, which then allows an expansion of the Pacific Ocean _________ towards which area. (The reverse happens in the case of La Nina).
Warm pool
What does humidity measure? What is relative humidity versus absolute humidity?
Humidity measures water vapor in the air.
Absolute humidity measures the actual water vapor content in a given volume of air
Relative humidity water vapor capacity of air
What is the common term for when 100% relative humidity is reached, and water molecules condense to form water?
Dewpoint Temperature
m. What are the four ways clouds can form and bring precipitation (see page 23, Chapter-Lecture 3).
Convective
Frontal
Orographic
Convergent
What are the three basic types of cloud formations – be able to identify them from photos.
Cumuli form (cumulus clouds)- massive and rounded + stereotypical cloud shape
Stratiform (stratus clouds)- grey sheets + ones that take over the whole sky
Cirriform (cirrus clouds)- thin and wispy + the ones that barely look there and thin
What is Fog?
A cloud on the ground; can be formed when 1) air on the surface cools to below dew point temperature or 2) enough water vapor is added to the air to saturate it.
