CalCOFI Reports, Vol. 23, 1982 - California Cooperative Oceanic ...

REID: AN OCEANOGRAPHER’S PERSPECTIVECalCOFI Rep., Vol. XXIII, 1982Nansen in 1909. They had gone to sea making traditionalhydrographic casts, measuring what they could,and when they analyzed their data, they found notlarge-scale smooth fields but rather wobbly ones.There would be a station-to-station variation of thedepth of various isotherms. Of course, they didn’t getto sea very often, and they couldn’t repeat their measurementsas much as they liked, but they at leastthought about them and wrote about the patterns. Theydidn’t know whether the patterns represented meanflows on a smaller scale than people had supposed, orwere waves of some kind, huge solitary waves, orwere little anticyclonic and cyclonic gyres. They wereable to repeat a few of their lines here and there andfound that things changed in time as well as in space.Their work was limited by the facilities at hand, butthey did say such things as, “Gee, it looks differentfrom time to time. We really should try to augment ourwork and repeat lines whenever we can, make ourobservations as close together as possible to avoidaliasing, and whenever possible, stay in one place fora while, repeating the observation to get some feelingfor the time variation.” That was 1909. Now, thatwould have been a perfect prospectus for the AtlanticMODE operation if anyone in the MODE group hadever read the paper, but I don’t think they had.That was the background in which we were working.Some notions of the general circulation were athand in 1948 when the cruises were planned, but wehad little feeling for the kind of spacing required todefine the field of flow and patterns of the othercharacteristics, and at what intervals we would have tooccupy these stations to follow their time-fluctuations.Cruise I of MLR and CalCOFI went out in March of1949, and I was on the Horizon (the old Horizon, notthe New Horizon). We also had in that early periodsuch ships as the Paolina-T and the Crest. May I havea show of hands of people in this group who were everat sea on the Paolina-T? Bravo. Well, I don’t have totell you what she was like. She was a perfectly seaworthyvessel. She would never sink-though we kepthoping! She just didn’t care which end was up.You remember perhaps what our 1949 pattern waslike. We had about twelve lines spaced 120 miles apartgoing offshore from the west coast of North America,and the stations were spaced about forty to sixty milesapart along each line. We found out from the first fewcruises that we hadn’t done it quite right. We discoveredby our own examination, not from anyone else’ssage advice, that we would have to tighten this line ofstations and spacing in order to get what we wereafter. I think I’m talking mostly about the physicaloceanographic aspects of it, but it certainly proved tobe true, and perhaps might have been noticed evenearlier, in the egg and larva work. I’m not going tocriticize the biologists at this stage; I am sure there areenough of them to do it for each other.But this was a primitive period of physical oceanography.Out in the California Current we foundstrange shapes that did not fit any of the concepts wehad in mind. There were unexpected loops and whorlsin the temperature field on various scales. We calculatedthat the topography of this sea surface had undulationson a scale that we hadn’t anticipated. And whatwere these?At that time, someone decided they must be internalwaves of a semidiurnal period, and we invited a verydistinguished Austrian oceanographer, Albert Defant,to come and work on it. He came for a year or so andtried to make some accounting in terms of the conceptof semidiurnal internal waves, but that wasn’t the rightanswer. In fact, when he left, I was assigned to carryout, on the later cruises, the same kind of calculationsthat he had made for the earlier ones. But it seemedobvious to me that this was wrong, and I was able bythat time-believe it or not, with Frances’s encouragementand Roger Revelle’s education-to approachpeople in the right way and say that we should not dothis sort of smoothing any more.The program, of course, was not just physicaloceanography, but was intended to include biologyand chemistry as well. Warren Wooster was a chemicaloceanographer in those days before he moved moreinto the physical end. We did try to measure oxygen,which we did successfully. We were not so successfulwith nutrients at that time. We tried in the first year orso, in fact, to measure chlorophyll, but our primitivetechniques were not good enough. Finally, thechlorophyll program was dropped and only recentlyreinstituted.We did, on the basis of, say, the first ten years ofdata, begin to find some reasonable patterns relatingsome variables to others. As you recall from readingthe proceedings of the 1958 Rancho Santa Fe Symposium(CalCOFZ Reports, Vol. VZZ), people such asJohn Radovich had even then been able to establishrelations between some patterns of fish distributionsand the sea surface temperature anomalies. There wererelations between those two and various kinds of fishthat were taken both commercially and by the sportsfishermen; that is, there were nonseasonal northwardand southward movements of various species that tiedin rather well with variations in the physical characteristicsof the ocean.Also, even at that period, the data showed an inverserelation between the temperature and the zooplanktonvolume. With only seven or eight years ofdata, the statistics were not as convincing as one40