GEOPHYSICAL FLUID DYNAMICS FOR OCEANOGRAPHERS-Von Schwind(1980)
Geophysical Fluid Dynamics
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Geophysical Fluid Dynamics “… study of naturally occuring, large-scale flows on earth and elsewhere …” Definition Large-Scale: Time Scale of Motion > Rotational Period
description
Geophysical Fluid Dynamics. “ … study of naturally occuring, large-scale flows on earth and elsewhere … ”. Definition Large-Scale: Time Scale of Motion > Rotational Period. L~10-m. Condensation cloud as an F/A-18 Hornet flies at or near the speed of sound. Photo by John Gay. - PowerPoint PPT Presentation
Transcript of Geophysical Fluid Dynamics
Geophysical Fluid Dynamics
“… study of naturally occuring,
large-scale flows on earth and
elsewhere …”
Definition Large-Scale:
Time Scale of Motion > Rotational Period
Condensation cloud as an F/A-18 Hornet flies at or near the speed of sound. Photo by John Gay
L~10-m
Geophysical Fluid Dynamics on Jupiter
NASA
L
L~10,000-km U~100-m/s L/U~27-days
Jet-on-Earth: L/U ~ 10/300 s = 33-ms
Wave-on-Jupiter: L/U ~ 107/100 s = 27-days
Compare time scale to the rate of rotation ?
Earth: ~ 2 / (24 hrs)Jupiter: ~ 2 / (10 hrs)
Rossby Number Ro=(U/L)/ >>1 for Jet-on-Earth <<1 for Wave-on-Jupiter{
“Katrina” Aug.-2005
L~1000-km U~30 m/s L/U~9-hrs Ro~0.4
Sea Surface
Temperature
Gulf Stream
Eddies
1997
Arctic Sea Ice off Alaska
Summer 2001
from MODIS
Optical Remote Sensing
Mixing without rotation
Mixing with rotation
http://paoc.mit.edu/labweb/GFDlab.htm
The waves have a period of about 3 or 4 days and a wavelength of 2000 to 2500 km [1200 to 1500 mi], typically (Burpee 1974).
High Pressure
High Pressure
Atmospheric Jet Stream : http://squall.sfsu.edu/scripts/nhemjetstream_model.html
1 Jetstream passing north of the UK bringing settled, dry and warm weather2 Jetstream passing further south, causing weather that is unsettled and cool for the time of year
x
y
y
z
National Weather Service
Planetary “Rossby”Wave Dynamics
