Mid-latitudinal CyclonesClimate ClassificationKoppen’s SystemGEO 155 1st Edition Lecture 12Outline of Last Lecture Air Masses and FrontsOutline of Current Lecture I. Mid-latitudinal Cyclonesa. How they Developb. “Steering” by the Jet Streamc. Latitudinal Energy TransportII. Climate Classificationa. About Climateb. Koppen’s SystemCurrent LectureMid-latitudinal CyclonesBetween the polar easterlies and mid-latitude westerlies, there is a stationary front with a center of low pressure- At this center, winds from the easterlies and westerlies converge and create a cold front (in the mid-latitude westerlies) and a warm front (in the easterlies)- Cyclonic wind patternsUp above this is the Jet Stream- Meridional pattern – gives the phenomenon of vorticityo When the Jet blows at higher latitudes, winds accelerateo When the Jet blows towards lower latitudes, winds decelerate- Divergence aloft – example of dynamic uplifto Creates a void, pulls air up from the surface to fill the Jet StreamCenter of low pressure at the Jet Stream remains below the Jet Stream, even though the Jet Stream can move- Cold front at the decelerating windsThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.o Center of high pressure feeds air into the center of low pressure in between the deceleratingand accelerating winds- Warm front at the accelerating winds- Cold front catches up to warm front as the Jet movesEarth sun relationship gives an energy difference between latitudes; this leads to latitudinal temperature differences, which brings a pressure gradient aloft. PGF brings about Coriolis, which contributes to the Jet Stream that gives dynamic uplift. From there, surface low pressures lead to mid-latitudinal cyclones, which create a massive energy distribution- Moves cold air to a place of more energy and moves warm air to a place of less energyClimate ClassificationLong-term patterns of weatherKoppen’s SystemA. Tropical B. DryC. Mild WinterD. Cold WinterE. PolarEnergy from Jet Stream Land and water do not affect themHave frontsRising air at the centerMid-latitudinal CyclonesEnergy from warm ocean waterAlways weaken over landNo frontsSinking air at the center - "eye"Tropical
View Full Document