hurricanes and tornadoes

Tornadoes:

• they are often reffered as a twister or cyclone
• a dangerous, violent rotataing column of air that is in contact with both the surface of the earth and a cumulonimbus cloud

• tornadoes come in many shapes and sizes but are typically in the form of a visible condensation funnel whose narrow end touches the ground destroying everything in its path
• is often encircled by debris and dust
• the most extreme tornadoes can attain wind speeds of more than 300mph
• some types of tornadoes includes landspouts, waterspouts, multiple vortex tornado

multiple vortex tornado





waterspout





landspout


• less common in high lattitudes, frequently developed in tropical areas close to the equator
• tornadoes have been observed in every continent except Antartica

Hurricanes:

• a storm system characterized by a low-pressure center and numerous thunderstorms that produce strong winds and heavy rain

Earth Science per. 7

• water vapor is the most important gas in the atmosphere for understanding atmospheric processes
• the process of  changing state requires that energy is transferred in the form of heat
• when saturated, warm air contains more water vapor than cold air
• relative humidity is a ratio of the air's actual water vapor content compared with the amount of water vapor needed for saturation  at that temperature and pressure
• when the water vapor content of air remains constant, lowering air temperature causes an increase in relative humidity, and raising air temperature causes a decrease in relative humidity
• when air is allowed to expand, it cools, and when it is compressed, it warms
• four mechanisms that can cause air to rise: Orographic Lifting (mountain)      Frontal Wedging   Convergence   Localized Convective Lifting
• stable air tends to remain in its original position, while unstable air tends to rise
• for condensation or water to occur, the air must be saturated
• clouds are  classified on the basis of their form and height
• fog is a cloud with its base near the ground
• in order for precipitation to form, cloud droplets must grow in volume by roughly one million times
• the type of  precipitation that reaches earth's surface depends on the temperature profile in the lowest few kilometers of the atmosphere
• the Coriolis effect describes how earth's rotation affects moving objects. All free moving objects or fluids, including the wind, are deflected to the right of their path of motion in the Northern Hemisphere. In the Southern Hemisphere, they are deflected to the left.
• wind is the result of horizontal differences in the air pressure. Air flows from areas of higher pressure to areas of lower pressure
• solar radiation is the ultimate energy source for most wind
• three factors combine to control wind : pressure differences, the Coriolis Effect, and the friction
• cyclones : pressure decreases from outer isobars toward the center (from out to in)
• anticyclones are from in to out