Arrange this isoelectronic series in order of decreasing radius: F- , Ne, O2- , Mg2+ , Na+ .
Physical Geography Lecture 11 Tropical and Humid Subtropical Climates and Weather Tropical weather involves only one air mass Subtropical weather involves two air masses especially in winter Thunderstorms occur frequently in the tropics and humid subtropics Tornadoes occur frequently in the subtropics Tropical Cyclones Powerful regional scale storms that form over warm tropical ocean surfaces Hurricanes, Typhoons, Cyclones High winds and associated storm surges, heavy rains, landslides and riverine flooding are hazardous Transfer surplus heat and moisture to the higher latitudes Help to redress global energy imbalances Replenish freshwater supply Stages of a thunderstorm 1. Early 2. Mature 3. Dissipating Tropical Cyclones Form in Trade Wind Zones between 8 degrees to 20 degrees N and S do not form along the equator coriolis effect is too weak Warm tropical Ocean Surfaces Water temperatures at least 27 degrees C ( 80 degrees F) to depth of 200 ft Sources of energy sensible heat from ocean latent heat of condensation degrades once it makes landfall or moves into colder waters cut off from energy supply convergence at surface winds stimulate evaporation adds moisture to the atmosphere Monsoon Term is derived from an Arabic word for a wind that reverses direction seasonally A true monsoon experiences a 180 degree reversal Operates on a regional scale (secondorder circulation) Summer Monsoon associated with RAIN Winter Monsoon is usually DRY in most locations Most well developed in Asia due to large land mass other land masses also experience monsoon like winds and weather patterns Humid Tropical Climates Humid: have annual moisture surpluses precipitation exceeds evapotranspiration Occupy almost all of the land area from 25 degrees N or S of the equator Interrupted by mountains and zones of aridity Temperatures are generally high Annual moisture surplus region of convergence atmosphere is unstable precipitation is convectional in nature General movement of air is from east to west 2 main types of humid tropical climates tropical rain forest climates tropical monsoon climates tropical savanna climates Lecture 12 Conditions Favorable to Development of Dry Climates Locations on leeward side of mountains rainshadows Presence of subsiding air masses Prevailing wind direction from land to water Locations off the path of moisture laden winds Cold currents offshore Characteristics of Dry Climates Evaporation exceeds precipitation Skies are clear with sunshine Daily temperature ranges are excessive due to lack of cloud cover Insolation proceed rapidly during the day causing temperatures to be high Ground radiation proceeds rapidly at night causing temperatures to drop rapidly Most precipitation is convectional Humidity is low Natural vegetation is sparse and scanty Fog is common Distribution and Influence of Topography on Dry Climates Mountains in Deserts Mountains may have relatively moist climates in desert regions due to: orographic lifting and precipitation lower temps leading to lower evapotranspiration rates may contain relict plant and animal populations isolated due to climate change (refugia) ex: dwarf crocodiles in sahara deserts