JPL M/S 300-323
4800 Oak Grove Drive
Pasadena CA, 91109 - USA
Satellite altimeters provide data that are helpful for understanding both the ocean circulation
(which varies in time) and the geophysical characteristics of the sea floor (which are invariant).
The influence of sea floor bathymetry on ocean circulation is examined by jointly studying the
time-varying and time-invariant components of altimeter measurements.
Our research includes theoretical efforts, statistical analysis of satellite altimeter data and
of ocean color images, and modeling. In figure 1, we illustrate characteristic amplitude of sea
surface height variations, s (cm), due to baroclinic inertia-gravity (BIG) waves. Particularly
large values of s are observed near strong ocean current regions, thus identifying current-wave
interactions as a likely mechanism of energy transfer to BIG waves. Our plans include a study of
these interactions on a global scale, an investigation of long-term variability of the wave
properties and their relationship to relevant factors of ocean dynamics. Our tracer transport
study recently produced a rigorous theoretical description of the underlying mechanisms [Weichman
et al., 1999, Weichman et al., 2000]. This description will serve as a basis for our planned
efforts on predicting and modeling the BIG wave effects. In figure 2 we illustrate a spectrum
of Chlorophyll-a variations in a 10° x 10° ocean region in the NW Pacific where BIG waves are
well manifested in ocean dynamics. This spectrum confirms our theoretical predictions, and it
displays a peak at the wavenumber scale corresponding to the semi-diurnal internal tides-a new
phenomenon discovered for the first time by our analysis.
Glazman R.E., B. Cheng, 1999: Altimeter observations of baroclinic oceanic inertia-gravity wave turbulence. Proc. Roy. Soc. Ser. A, 455, 91-123.
Weichman P.B., R.E. Glazman, 1999: Turbulent fluctuation and transport of passive scalars by random wave fields. Phys. Rev. Lett. 83, 5011-5014.
Weichman P.B., R.E. Glazman, 2000: Passive scalar transport by traveling wave fields. J. Fluid Mech. 420, 147-200.