126
Walter Munk
defended the view that coordinates should be to the precision required for the scientific
interpretation of the results. There is no simple answer here.
It is prudent to monitor source performance in real time, as has been demonstrated on a number of occasions. It is difficult to convey the satisfaction of hearing
the signal arrive at a remote site at the expected moment. It is also difficult to convey
the sense of disappointment when it does not.
15 Most of us have clearances to visit the
facilities, and the monitoring in real time was arranged on a personal basis and initially did not involve our institutions. We are pleased to report that these arrangements
(with some modifications) have worked satisfactorily. The tomographic community
is greatly indebted to the U.S. Navy for having permitted the use of these remarkable
facilities.
We are still, today, depending on the SOSUS arrays (as will be seen). But the situation has changed, and the Navy and the oceanographic community find themselves
under a common siege by the environmental community.
A DECADE OF EXPERIMENTS (1981–1990)
The decade
16 started with the 1981 “Demonstration Experiment” (Figure 8.5a). Bruce
Cornuelle, a Wunsch Ph.D., applied Gauss–Markov estimation theory to generate
mesoscale maps for comparison with CTD surveys.
17 Most of the remaining decade
was spent in a struggle to understand the capabilities and limitations of the method
and to develop autonomous instrumentation adequate for megameter ranges. The 12
experiments, 8 in the Atlantic and 4 in the Pacific, are outlined in Table A.1 of MWW.
Among the results were perturbations in travel time across the meandering Gulf
Stream (Figure 8.5b)
18 and measurements of tidal currents and vorticity in a 1000-km
triangle. The progression toward larger ranges culminated in the climate-oriented
4000-km transmissions by Spiesberger and Metzger from Hawaii to the mainland.
19
I will single out the Greenland Sea Project 1988–89 by Worcester, Sutton,
Morawitz, Cornuelle, Lynch, Pawlowicz, and others.
20 A 200-km pentagon array of
transceivers was deployed in summer 1988, then frozen over, and recovered in summer
1989. The measurements yielded time histories of heat content, barotropic currents,
and tides in an arctic environment and documented the formation and evolution of a
convective chimney. The chimney had a spatial scale of about 50 km and a time scale
of about 10 days, reaching depths of 1500 m.
Prior to the installation, concerns had been raised about the security of acoustic
moorings in a strategic sea lane. (Moorings had mysteriously disappeared in the 1970
MODE experiment.) I telephoned Brekhovskikh in Moscow and arranged for a visit.
My wife insisted on coming along (this was at the height of the Cold War). When we
entered Brekhovskikh’s office he held up his hand: “Let me tell you why you are here.
You are here to make sure no one interferes with your moorings.” I replied: “Yes.”
He said, “I will see what I can do, but I do not command the Soviet Navy.” There
was no interference. Some years later Brekhovskikh telephoned from Washington,
Walter Munk
defended the view that coordinates should be to the precision required for the scientific
interpretation of the results. There is no simple answer here.
It is prudent to monitor source performance in real time, as has been demonstrated on a number of occasions. It is difficult to convey the satisfaction of hearing
the signal arrive at a remote site at the expected moment. It is also difficult to convey
the sense of disappointment when it does not.
15 Most of us have clearances to visit the
facilities, and the monitoring in real time was arranged on a personal basis and initially did not involve our institutions. We are pleased to report that these arrangements
(with some modifications) have worked satisfactorily. The tomographic community
is greatly indebted to the U.S. Navy for having permitted the use of these remarkable
facilities.
We are still, today, depending on the SOSUS arrays (as will be seen). But the situation has changed, and the Navy and the oceanographic community find themselves
under a common siege by the environmental community.
A DECADE OF EXPERIMENTS (1981–1990)
The decade
16 started with the 1981 “Demonstration Experiment” (Figure 8.5a). Bruce
Cornuelle, a Wunsch Ph.D., applied Gauss–Markov estimation theory to generate
mesoscale maps for comparison with CTD surveys.
17 Most of the remaining decade
was spent in a struggle to understand the capabilities and limitations of the method
and to develop autonomous instrumentation adequate for megameter ranges. The 12
experiments, 8 in the Atlantic and 4 in the Pacific, are outlined in Table A.1 of MWW.
Among the results were perturbations in travel time across the meandering Gulf
Stream (Figure 8.5b)
18 and measurements of tidal currents and vorticity in a 1000-km
triangle. The progression toward larger ranges culminated in the climate-oriented
4000-km transmissions by Spiesberger and Metzger from Hawaii to the mainland.
19
I will single out the Greenland Sea Project 1988–89 by Worcester, Sutton,
Morawitz, Cornuelle, Lynch, Pawlowicz, and others.
20 A 200-km pentagon array of
transceivers was deployed in summer 1988, then frozen over, and recovered in summer
1989. The measurements yielded time histories of heat content, barotropic currents,
and tides in an arctic environment and documented the formation and evolution of a
convective chimney. The chimney had a spatial scale of about 50 km and a time scale
of about 10 days, reaching depths of 1500 m.
Prior to the installation, concerns had been raised about the security of acoustic
moorings in a strategic sea lane. (Moorings had mysteriously disappeared in the 1970
MODE experiment.) I telephoned Brekhovskikh in Moscow and arranged for a visit.
My wife insisted on coming along (this was at the height of the Cold War). When we
entered Brekhovskikh’s office he held up his hand: “Let me tell you why you are here.
You are here to make sure no one interferes with your moorings.” I replied: “Yes.”
He said, “I will see what I can do, but I do not command the Soviet Navy.” There
was no interference. Some years later Brekhovskikh telephoned from Washington,