Digitalcracy

Wladimir Koeppen provided his scheme of classification in 1900 which was modified later multiple times. BASIS OF CLASSIFICATION He used french plant physiologist Candolle classification of major global vegetation types to classify major climatic types as he believed vegetation is holistic expression of climate of a place Koppen used annual temperature and precipitation data and seasonal variations to delineate different climatic zones. He used alphabets as symbols of these climates.Capital letters for major types and small letter for subtypes of climate. Vegetation zones by Candolle Major climate types(symbols) Temperature and precipitation criteria Megatherms Tropical,A Average temperature of all months is greater than 18 °C Xerophytes Dry,B Evaporation exceeds precipitation Mesotherms Warm Temperates,C Temperature of coldest month less than 18 °C but greater than -3;Temperature of warmest month greater  than 10 °C Microtherms...

Q.Write short note on Rossby waves and Jet stream. (12/11) Jet Streams are fast flowing narrow stream of Geostrophic westerly winds found in upper troposphere near tropopause which encircles globe at respective latitudes.           Peterson has defined jet streams as thermal winds produced by great temperature contrast found between meridional cells which produces intense pressure gradient. CHARACTERISTICS Genesis: They are product of high pressure gradient, strong coriolis and negligible friction which is ideal for geostrophy. Speed : varies from 120 Km/hr to 900 Km/hr Seasonal Migration : During winter, they are poleward while in summer they shift equatorward.This is associated directly to the shifting of meridional cells with seasons. Rossby Waves : Associated with polar front jet stream .They follow meandering path which appears like waves with crest and trough.Crest and trough have north-south alignmen...

Air Masses DEFINITION An air mass may be defined as a large body of air whose physical properties, especially temperature,moisture content, and lapse rate, are more or less uniform  horizontally for hundred of kilometers. Can be large enough to cover large section of a continent and vertical extent can reach up to tropopause. These are secondary circulation embedded in planetary wind system. CONDITIONS OF FORMATION          1.Homogenous and Extensive earth's surface.          2.Anticyclonic conditions          3.Stable weather conditions.          4 Stagnation for 7-8 days CLASSIFICATIONS Two Fold Classifications Geographical Classification(Trewartha) Based on location of source: Polar(P), includes arctic Tropical(T), include equatorial. Based ...