What is the difference between satellites and radars Satellite view of the clouds from space Radar views precipitation from the ground How is wind direction defined it is defined by the direction that the wind is coming from How do winds blow about high and low pressure systems in the Northern Hemisphere High winds blow clockwise and outward Low winds blow counterclockwise and inward What is pressure and how does it change with height Pressure is force area Atmospheric pressure ALWAYS decreases with height 1 mb with every 10 m What is an inversion Layer in which the temperature increases with height What is latent heat energy absorbed or released during a phase change hidden energy What is advection transfer of heat or moisture through horizontal movements of air What is saturation What mathematical relationships are true at saturation evaporation rate condensation rate vapor pressure saturated vapor pressure relative humidity 100 What is relative humidity How can it be changed Ratio of water vapor in the air to that required for saturation vp svp x 100 A higher relative humidity means closer to saturation To increase relative humidity add moisture to the air increase vp cool the air decrease SVP To decrease relative humidity remove moisture from the air decrease VP warm the air increase SVP What is dewpoint Why is it useful The dewpoint temperature is the temperature at which saturation occurs The higher the dew point means always there is more moisture in the air How do clouds form First we need rising air either from surface heating convection uplifting by mountains surface convergence or fronts Second the amount of water vapor in the air does not change as the air rises The relative humidity increases air eventually rises high enough cools enough to become saturated RH 100 and a cloud forms How do you read a station model See example on labs What is a constant pressure surface assume uniform surface pressure and temperature Constant pressure surfaces are parallel to constant height surfaces How are low and high heights related to temperature and weather High Heights warm air below pressure surface analogous to high pressure on constant height surfaces a high is high Low Heights cold air below pressure surface analogous to low pressure on constant height surface a low is a low How do you identify ridges and troughs Ridge an area of higher heights or pressures Trough an area of lower heights or pressures can not only look at the shapes of contours but the values What is the pressure gradient force In what direction does it act PGF is the change in pressure distance Tightly packed isobars mean strong pressure PGF is directed from areas of high pressure to low pressure or higher heights to lower heights on constant pressure surface Acts perpendicular to isobars height contours How does the pressure gradient force influence the wind speed Causes the wind to blow The stronger the PGF the faster the wind blows What is a cyclone An area of low pressure center of a cyclone is the center of a low What is an anticyclone a large atmospheric circulation system around a high with winds flowing clockwise in northern hemisphere Forms from air masses cooling more then their surroundings How do you determine the surface wind direction from isobars wind direction crosses isobars at an angle they do NOT flow parallel because of friction Surface wind direction is a right angle with CF Coriolis force is to the right of wind direction What is convergence Divergence Convergence when air flows together wind converges into low pressure systems at the surface counter clockwise in NH air rises cools water vapor condenses forms clouds and precipitation air diverges aloft Divergence when air flows apart clockwise air sinks dries out inhibiting cloud formation air converges aloft How are convergence and divergence related to the development of surface highs and lows Divergence decreases surface pressure subtract molecues from air column Convergence increases surface pressure adds weight to column Why is vertical motion important faster rising air caues clouds and can cause more interesting weather What is a jet stream Where are jet streams found What causes jet streams The jet stream is a river of fast moving air in the upper atmosphere It exists near the tropopause level about 10 km and its flow is parallel to height contours Flow is not the same speed everywhere What is an air mass How are they classified A large body of air with similar temperature and moisture concentrations Horizontal only Air masses form over flat homogeneous regions of the earth s surface Boundaires are around low pressure called fronts centers are high pressure systems They are classified based on moisture and temperature two letters Moisture Continental c Dry Maritime m moist Temperature Tropical T warm hot Polar P cool cold Arctic A frigid What is a front It is the boundary between air masses of different densities warm air is less dense than cold air moist air is less dense then dry air FRONTS are NOT airmasses fronts strongest at the surface How are fronts represented on weather maps Lines with symbols pointing in direction front is moving cold front blue with triangles warm front red with half circles stationary front combination cold warm occluded front purple What is a dryline seperates the mT air to the east from the cT air to the west Typically found in KS OK TX during spring What is a mid latitude cyclone also called an extratropical cyclone It is an are of low pressure where the center of cyclone is center of low It usually lasts several days to a week and can be as large as 1000 miles across Weather includes thunderstorms and tornadoes blizzards and ice storms widespread snow and rain Where is warm air and cold air found with respect to a surface low Warm air is usually east and cold is usually south How do Mid Latitude cyclones influence the weather brings cold air southward and warm air northward provides precipitation to many regions in world and can produce severe weather What is the Gulf Stream a strong fast moving warm ocean current that originates in the gulf of mexico and moves to the atlantic ocean What is the thermocline the rapid temperature decrease with depth a few hundred meters below the surface How does oceanic temperature vary with depth the temperature decreases with depth What is upwelling How does it affect oceanic temperature upwelling is the vertical transport of deep ocean waters upward