Transcript Chapter 6
Oceanic Influences on Climate Ocean currents redistribute heat Large scale currents are called gyres QuickTime™ and a Sorenson Video decompressor are needed to see this picture. QuickTime™ and a Sorenson Video decompressor are needed to see this picture. North Atlantic Gyre Includes the Gulf Stream SST in Gulf Stream- July Influence of Gulf stream SST on air temp Walker cell circulation El Nino and La Nina years since 1950. El Nino years produce weird weather in North America La Nina years are more “normal” Prevailing wind flow along the ITCZ pushes warm water eastward Position of ITCZ shifts North with Northern Hemisphere summer and south with the Southern Hemisphere summer SST July- Illustrating El Nino Southern Oscillation (ENSO) SST- Equatorial Pacific July SST January- El Nino Southern Oscillation El Nino circulation La Nina circulation Fronts (1:2) ･ Transition zone between air masses - described according to air mass which is approaching and relative motion ･ Cold Front (can move very fast) - colder air mass moving faster than warmer air - lifts warm air up in front of it - may form something called a "dry line" > associated with strong thunderstorm development Fronts (2:2) ･ Warm Front (typically moves more slowly) - warmer air mass moving faster than cooler air - warm air rides up over cold dense air - usually a wider band of "active" weather Cyclonic storms ･ Associated with Low pressure systems ･ Lows moved by Upper level high velocity winds - Jetstream ･ usually involve air masses with different properties - one warm the other cold - one humid the other dry