Download Weather Review Sheet High pressure (no clouds, good weather) vs

Weather Review Sheet
➢ High pressure (no clouds, good weather) vs. Low pressure (clouds, storms)
➢ Fronts! As they cross a location…
o Cold-temperature drops, pressure drops, violent storms possible
o Warm-temperature & humidity rise, clouds, precipitation possible
o Stationary-fluctuating temps, clouds, storms possible
o Occluded-temperature cools, clouds & precipitation likely
➢ 5 Types of Air Masses
o Continental polar (Cp)-forms over land and is cold & dry
o Maritime polar (Mp)-forms over the ocean and is cold & moist
o Continental tropical (Ct)-forms over land and is warm & dry
o Maritime tropical (Mt)-forms over the ocean and is warm & moist
o Continental arctic (Ca)-forms over polar regions; is very cold & dry
➢ The Atmosphere
o Layers
▪ Troposphere (0-10 km)-all of Earth's weather occurs here, 99% of all
pressure molecules here, both temperature & pressure decrease as
you ascend vertically through this layer
▪ Stratosphere (10-50 km)-ozone layer is located here, which causes
temperature to increase as you ascend vertically through this layer;
pressure continues to decrease exponentially as you go up
▪ Mesosphere (50-85 km)-both temperature & pressure decrease as you
ascend vertically through this layer; the ionosphere (what radio
signals reflect off of) is located in this layer
▪ Thermosphere (85-500 km)-pressure continues to decrease as you
ascend through this layer, while temperature begins to increase due
to influences from the sun
▪ Exosphere (>500 km)-outer "skin" of Earth's atmosphere; pressure
decreases and temperature increases as you ascend vertically
o Composition is 78% Nitrogen, 21% Oxygen, ~1% Argon, and other trace gases
such as Water Vapor, Carbon Dioxide, and Methane
o Increase in CO2 leads to "global warming" or "climate change" because CO2
traps heat reflected from Earth's surface
➢ Water Cycle
o Evaporation-sun heats liquid water until it turns into water vapor
o Condensation-water vapor cools until it condenses into liquid water (clouds
form)
o Transpiration-evaporation of water from plants
o Precipitation-liquid water build-up in clouds falls to Earth
➢ Convection is the rising of warm air and sinking of more dense, cooler air (helps form
clouds and storms from heating of the Earth's surface)
➢ Advection is the movement of air masses horizontally (north, south, east, west)
➢ Jet stream (fast stream of winds in the atmosphere) separates colder air to the north
from warmer air to the south; its movement determines where fronts may move and
where storms may form
➢ Air pollution in other nations should be monitored by the U.S. because other
countries' pollution can travel through the atmosphere and affect us
➢ Clouds
o Cirro-high level, wispy clouds formed by ice crystals
o Alto-middle level clouds
o Strato-low level clouds where fog or precipitation most often result