GEO 203 Notes – 9/7/10UTC – Universal Time CoordinatedGreek letter phi denotes latitude: angular distance on Earth N/S of EquatorEL latitude: 42.736 NPrime Meridian: longitude = 0East of PM: positive; west: negativeEL longitude: 84.483 WPrime Meridian: Greenwich, England2:14 am = 0214 in 24-hr. military time11:55 pm = 2355Four time zones in contiguous US: Eastern, Central, Mountain, PacificPrime Meridian also known as Greenwich Meridian: UTC = GMT (Greenwich Meridian Time)Z = Zulu (military/aviation time)Local time is one hour behind/ahead for every 15 degrees west/east of the PMDiff. between MI (EST) and UTC (GMT):MI longitude: 84.483 W84.483/15 = 5.63MI is five hours behind GMTEST = UTC – 0500Not all states use Daylight Savings TimeConversion to UTC:Convert AM/PM to 24hrEST + 5h = UTCCST + 6h = UTCMST + 7h = UTCPST + 8h = UTC10:20am in Michigan = 1020 EST1020 EST + 0500 = 1520 UTC (3:20pm)11:40am in Michigan = 1140 EST1140 EST + 0500 = 1640 UTC (4:40pm)3pm in California = 1500 PST1500 PST + 0800 = 2300 UTC (11:00pm)QUIZ THURSDAY: TIME CONVERSIONMore than 10,000 surface observation stations around the world; collects hourly data for as many as 18 variablesSatellites used to measure conditions at seaRadiosondes launched twice per day at 1200 UTC (7am EST) and 0000 UTC (7pm EST) around the worldVariables measured: pressure, temperature, humidityRawinsonde: instrument name when winds are measured by tracking the movement of the balloon using a GPS systemCan ascend up to 30km into atmosphereEach balloon launch costs $250-300Two locations in MI where balloons are launched: Detroit, GaylordMeteorological data sent to:Melbourne, AustraliaMoscow, RussiaWashington, DC, United StatesData disseminated at centers to nat’l meteorological center in each country, where weather charts are generatedSurface chart: sea-level pressure chart, constant height chart, represent atmospheric pressure at constant height level, in this case, the sea levelUpper-level chart: constant pressure chart, usually at 850mb, 700mb, 500mb, 300mb, and 200mb – show height variations at a constant pressure surfaceMb = millibarLow pressure center denoted by red L on weather chart: more opportunity for severe weatherHigh pressure center denoted by blue H on weather chartStation models (temp, dew point, pressure, pressure tendency, current wx, cloud cover/type, wind speed, precip)Isobars: contour lines that denote pressure (mb) on map; pressure is constant along lineLow pressure found in tropical stormsPurple line: occluded front (most intense precipitation)Red/blue (alternating) line: stationary front (nonmoving—can cause flooding, drought, etc.)SURFACE STATION MODELCircle: cloud cover (percentage of circle covered = cloud cover percentage)Line with barbs: wind speed and directionSoutherly wind: wind is coming *from* southLine on model shows direction wind is coming from; line points inward toward station, going away from the windBarbs show wind speedShort barb = low speedAdditional bars, triangles added at higher speedNumber in top-left: temperature in FahrenheitNumber in bottom-left: Dew pointSymbol between two left-hand numbers: present weatherNumber on top-right: Sea level pressure (add an initial 9 or 10 and put decimal to left of last number:)If first number is greater than or equal to 5: add 9 to front949 = 994.9mbIf first number is less than 5: add 10 to front149 = 1014.9mbNumber on bottom-right: pressure chg in past 3hrs. (25 = 2.5mb)Symbol on bottom-right: pressure tendencyThicker cloud = brighter colorColor coded satellite image to enhance deep cloudsRadar shows area of