Geology 1350 Lecture 15 Outline of Last Lecture I. Global windsOutline of Current Lecture I. SymbolsII. FrontsIII. Air mass frontsCurrent LectureSurface station model- shows how much clouds there areSea level pressure- shows 149 (add an initial 9 or 10 and put decimal to left of last number > 1014.9)You need instrumentation to define clouds- eyesHurricane starts around 70 miles per hour wind=one triangleCold fronts are blue with triangles- cold air replaces warm, northwest to southwest, airbehind the front is colder and drier that air ahead triangles are oriented the direction in which they are pointed to; transition of cold front- front rises steeply and pushes warm air to rise cools down and produces rain and thunderstorms, cold fronts show upalong cold fronts and are associated with them, cirrus and cirrostratus clouds, pressurereaches min then rises ,Front- boundary b/n air masses normally refers to where this interface intersects the groundWarm front is red circles- southwest to northeast, warm replace cold, transition- cold air mass is heavier and sticks to ground and warm is lighter and goes aloft at angle, creates sleet, unique clouds and precipitation patterns, no thunderstorms but nimbostratus heavy drizzle long rain, rain occurs in front of the frontStationary- is cold and warm front mixed, front that doesn’t move, occurs when temp differences are not that hugeOccluded is purple circles and triangles- puts together warm and cold front together, cold air mass moves faster than warm air mass, cold will catch up to warm on surface, front is uplifted full occlusion then low pressure vanishes; Mid-lat cyclone- occluded fronts are common along mid lat cyclones or deep low pressure and cold and warm These 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.fronts pivot, spiral on satellite shows low pressure, these storms appear mostly in mid latsAir mass- is a huge region that stays around for a few days (homogenous), contains similar temp and moisture, geographical characteristics: tropical, polar, arctic; surface: maritime, continental(dry); they combine mt-warm and humid, mp-cold and humid, cp-less humid and cold, ct- only in summer hot in land and dryDepending where you are the temp and humidity can change, also if its summer or winterModification of cp air mass-you see clouds over the sea because it is warmerTropical air coming in off the west coast mt – causes unstability and thunderstormsGulf and Caribbean tropical air – hot and humidMexican origin of ct air- can be very hot and dryAir mass fronts Front identification- temp, dew point, wind direction, pressure, cloud/precipitation patternsStrengthening front- shows temporal transition b/n a weak front and its frontogenesis or strengthening as it moves offshore over warmer