unit 7, exam 2 Flashcards
speed and direction of ocean currents
surface wind speed and direction
coriolis force
ekman spiral transport
shape of ocean basin
ekman transport
piles ocean water up in the middle of the ocean basin causing differences in sea level that yields a pressure gradient, and then eventually geostrophic circulation
deep ocean convection
mechanism for sinking ocean water in higher latitudes. The surface temperatures cool the water which then sinks
Brine Rejection
mechanism for sinking water in the southern latitudes. surface water freezes the salt is left behind causing both the salinity and density of the water to increase
coastal upwelling
ekman transport moves surface waters away from the coast and surface waters are replaced by water that wells up from below-cold-nutrients from depths
coastal downwelling
occurs where ekman transport moves surface waters towards the coast the water piles up and sinks-warm-not a lot of nutrients
equatorial upwelling
strong tradewinds cause water to diverge, causing upwelling. when lesser winds not as much divergence and waters warmer than normal.
walker
trying to predict indian monsoon. discovered an inverse sea saw ossillation of surface P between darwin and Tahiti.
walker circulation
the effect of orientaiton of tropical SSTs featuring warm (W) and cold (E) characteristics. shapes a E-W closed cell fo winds similar to N-S hadley cells
El NIno
weak trade winds and weak equatorial upwelling. warm phase of pacific ocean T
La Nina
strong trade winds and strong equatorial upwelling. cold phase of pacific ocean T
temperature threshold for El Nino and La Nina events
5 degrees C
ENSO
the net effect between the coupled atmospheric and oceanic pressures associated with teh souther oscillation (walker circulation, el nino, la nina)
ENSO variable index
sea level air P zonal component of surface wind meridional component of surface wind surface air T sky cloud cover SST
El Nino in N. America
reduction of amplitude in pacific jet stream
guides storm track further south
creating wet cool conditions which dry conditions in the north.
La Nina in N. America
High amplitude polar jet stream that combines with pacific for strong blocking patterns.
Drives storm track further North
net cool conditions across N and higher lats with dry warm or even wet extend across S and E states.
Oscillations
arctic
N. atlantic
pacific decadal
madden-julian
arctic oscillation
seasaw variation in air P between N pole and middle lats that change the speed of the polar vortex
N. Atlantic oscillation
seasaw variation in air P between iceland and somewhere that influence precipitaiton and T primarily in winter over E N.America and much of europe and N. africa
Pacific decadal oscillation (PDO)
long lined variation in climate over the N. pacific ocean and N.A with SST fluctuations between the N central pacific ocean dan the west coast of N.A
PDO warm phase
negative index
aleutian low is well developed with strong counter clockwise winds steering mild and drier air masses into the Pacficic NW
PDO cool phase
positive index
aleutian cyclone is weaker so cold moist air masses more frequently invade pacific NW.
Madden Julian Oscillation
clusters fo conventive thunderstorms develop in the indian and tropical pacific oceans and migrate E across the globe every 30-6- days
- affected by changing SST-prevelant in warm pacific oceans
- can influence enso
evidence of warming oceans
coral bleaching
acidification
rising sea level over last century
