Transcript Wind
Wind Measuring Wind Instruments –Anemometer (speed) Wind Vane (direction) And Units: Knots (kts) or mi/hr Named for the direction from which the wind comes Ex. SE wind – comes from the southeast and blows toward the northwest The aerovane (skyvane). Definition Horizontal movement of air due to differences in air pressure due to the unequal heating of the earth Wind flows from High to low pressure Size of the pressure gradient dictates the force of the wind. The higher the gradient, the stronger the winds. Global Winds • What is the name we give motion due to earth’s rotation? ________________________ Coriolis Effect Because Earth is spinning, wind curves to right the ________ in the northern hemisphere and to the left in the southern hemisphere Global Winds If earth did not spin, the air movement would look like this. Air would rise at the equator and sink at the poles due to differences in temperature Global Winds But the earth does spin, so winds get deflected to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. Creates three Giant circulation cells in each Hemisphere ESRT Page 14 Will do more with this in the climate unit As air moves from high to low pressure in the northern hemisphere, it is deflected to the right by the Coriolis force • http://eram.k12.ny.us/education/page/dow nload.php?fileinfo=YWlyaW50b2xvdy5na WY6Ojovd3d3L3NjaG9vbHMvc2MvcmVtb 3RlL2ltYWdlcy9kb2NtZ3IvNDQ0ZmlsZTg wMjAuZ2lm§iondetailid=17511 • http://eram.k12.ny.us/education/page/dow nload.php?fileinfo=YWlyb3V0b2ZoaWdoL mdpZjo6Oi93d3cvc2Nob29scy9zYy9yZW 1vdGUvaW1hZ2VzL2RvY21nci80NDRma WxlODAyMS5naWY=§iondetailid=175 11 Low and High Pressure Systems Low Pressure System = Cyclone Winds are counterclockwise and inward Winds converge or go into the center Air is forced up, expands, cools to dew point, condenses and clouds form Jet Stream • Area of high wind speeds in the upper troposphere. The jet stream generally moves __________ WEST to __________ EAST • Jet Streams steer storms Most low pressure systems move from the SOUTHWEST TO NORTHEAST IN NEW YORK STATE, ESRT p14 High Pressure = Anticyclone Winds are clockwise and outward High pressure is more dense so air sinks Winds diverge or move away from the center High Pressure is associated with fair/nice weather LOCAL BREEZES • Sea/Land Breezes – caused by the unequal heating of land and water • Water heats up longer because of its high specific heat • Land heats up quicker due to its lower specific heat Sun heats the land Air is cooler over ocean Warm air rises b/c less dense Air is more dense wind High pressure Low pressure Sea Breeze Sun is down Air is warmer over ocean Land cools down quicker Air is less dense wind Air is more dense Low Pressure High Pressure Land Breeze • http://www.youtube.com/watch?v=uBqohR u2RRk • http://www.youtube.com/watch?v=9DNbkq Vu2CE&feature=related Do not play • http://www.youtube.com/watch?v=_36MiC US1ro • More coriolis on utube • http://ww2010.atmos.uiuc.edu/(Gh)/guides /mtr/fw/crls.rxml