GALILEO DOPPLER MEASUREMENTS OF THE DEEP ZONAL WINDS AT JUPITER

Changes in the speed of the Galileo probe caused by zonal winds create d a small but measurable Doppler effect in the probe relay carrier fre quency. Analysis of the probe relay link frequency allows direct measu rements of the speed of Jupiter's zonal winds beneath the cloud tops, The deep winds were prograde and strong, reaching a sustained 190 to 2 00 meters per second at an altitude marked by a pressure of 24 bars. T he depth and strength of the zonal winds severely constrain dynamic mo deling of the deeper layers and begin to rule out many shallow weather theories.