BIOLOGICAL PATCHINESS IN RELATION TO SATELLITE THERMAL IMAGERY AND ASSOCIATED CHEMICAL MESOSCALE FEATURES Ronald Wayne Phoebus NAVAL POSTGRADUATE SCHOOL Monterey, California THESIS Biological Patchiness in Relation to Satellite Thermal Imagery and Associated Chemical Mesoscale Features by Ronald Wayne Phoebus June 1981 Thesis Advisor Eugene D. Traganza Approved for public release; distribution unlimited, TP.00659 UNCLASSIFIED SeCU»lTY CLASSIFICATION 3f THIS »4(il (■•*•« Oat* !ni«r.<) REPORT D0OJMCHT4TI0M PAO* rI^ORI- «uMBf * 1 'IV' j oovt *ecys|iOM tip; READ INSTRUCTIONS BEFORE COMPLETING FORM V»iO*lENT^ CATALOG MUMH< -W 4 title r#m *v*»i«/»j Biological Patchiness in Relation to Satellite Thermal Imagery and Associated Chemical Mesoscale Features 1 TYPC 0* HfRORT A RER100 COUCRfD Master's Thesis; June 1981 • *t*rQ*mHG,~6n'G;~nkmomT «umii* • . CONTRACT OR SKANT NbMKKMJ 7. AuTHORf»> Ronald Wayne Phoebus • ~>ER*ORMIn6 ORGANIZATION MAmE'ahD' A'tiOMCM Naval Postgraduate School Monterey, California 93940 10. PROGRAM ELtUttif. RROJECT. I* AREA A WORK UMlT NUMII RS SK Ta.'Re^owT oatc June 1981 tt CONTROLLING O'^lSf NAME ANO ADDRESS Naval Postgraduate School Monterey, California 93940 1*. NUMBER. Of RASES 14' MONITORING AGENCY NAME A AOORESaTli ittiimrmtHwm Co«»ro/iln| OfHCRJ SlL '••." DISTRIBUTION STATEMENT fol ittlt Raparl) Approved for public release; distribution unlimited. If. SECURITY CLASS. (of <«»« « Unclassified i*a. QfCLAlSl'lCATtQN/'OORtlGRAOlMG SCHEDULE 7 • 7. Distribution STATEMENT (at ih. <«n-»f «-'»r.d la *V»e* JO, (/ '• *•<•••«»» Biological patchiness Thermal fronts Chemical fronts Sea surface temperature Satellite infrared imagery and ismmtlty At a/ae* nia»a«r) Upwelling Nutrients Chlorophyll a Phosphate 10 ABSTRACT (Continue an tmvmmm • !<*• .'f naeaaaavr aw 4 i4*ntlfr a? AlaeJt m#lw) The presence of biological patches, or communities, can have a direct effect on Naval operations, scientific research, and fisheries. It is shown that remote infrared satellite sensing may be used as a real-time tool to accurately locate thermally and biologically significant features. Several physical, chemical, and biological variables were sampled in the surface layer of DO \ :°AZr 147} (Page 1) ■ ' ! ■ ■■ iii EDITION OR < MOV »» IS OBSOLETE S/N 0 103-0 14- AA0 I 1 UNCLASSIFIED SECURITY CLASSIFICATION Q» TMlS RAO* (V*mn Omi» K*ff4) UNCLASSIFIED fuCuWtTv Ct AS»I*'C ATlON OW THIS <»»OEC>o>«« n*im Enfrad mesoscale thermal features which were located using satellite imagery. The bio-chemical sampling produced replicate results from which the distribution of biomass could be inferred. Possible explanations are advanced for patch forming mechanisms and biomass distribution. DD Form 1473 „„„,. 1 Jan 73 2 UNCLASSIFIED ~/N 0102-014-6601 secuairv claisiucation or this PAcer***" o««« £«»•»•* Approved for public release; distribution unlimited Biological Patchiness in Relation to Satellite Thermal Imagery and Associated Chemical Mesoscale Features by Commander Ronald Wayne Phoebus United States Navy B.S., United States Merchant Marine Academy, 1967 Submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE IN METEOROLOGY AND OCEANOGRAPHY from the NAVAL POSTGRADUATE SCHOOL June\ 19|81 ABSTRACT The presence of biological patches, or communities, can have a direct effect on Naval operations, scientific research, and fisheries. It is shown that remote infrared satellite sensing may be used as a real-time tool to accurately locate thermally and biologically significant features. Several physical, chemical, and biological variables were sampled in the surface layer of mesoscale thermal features which were located using satellite imagery. The bio-chemical sampling produced replicate results from which the distribution of biomass could be inferred. Possible explanations are advanced for patch forming mechanisms and biomass distribution. TABLE OF CONTENTS I. INTRODUCTION 9 II. METHODS AND MATERIALS 14 A. CHLOROPHYLL 15 B. NUTRIENTS 18 C. ATP 18 D. TEMPERATURE 19 III. RESULTS 20 A. APRIL '79 CRUISE 20 B. JUNE '79 CRUISE 21 C. AUGUST '79 CRUISE 22 D. SEPTEMBER '79 CRUISE 23 IV. DISCUSSION 25 V. CONCLUSIONS 29 LIST OF REFERENCES 57 INITIAL DISTRIBUTION LIST 60 LIST OF PHOTOGRAPHIC PLATES 1. TIROS-N Satellite IR Image of the California Coast, 10 April 1979 31 2. TIROS-N Satellite IR Image of the California Coast, 17 April 1979 32 3. TIROS-N Satellite IR Image of the California Coast, 18 April 1979 33 4. TIROS-N Satellite IR Image of the California Coast, 19 April 1979 34 5. TIROS-N Satellite IR Image of the California Coast, 29 April 1979 35 6. TIROS-N Satellite IR Image of the California Coast, 13 June 1979 36 7. TIROS-N Satellite IR Image of the California Coast, 30 July 1979 37 8. TIROS-N Satellite IR Image of the California Coast, 05 August 1979 38 9. TIROS-N Satellite IR Image of the California Coast, 23 September 1979 39 10. TIROS-N Satellite IR Image of the California Coast, 24 September 1979 40 11. TIROS-N Satellite IR Image of the California Coast, 25 September 1979 41 12. TIROS-N Satellite IR Image of the California Coast, 26 September 1979 42 LIST OF FIGURES 1. Track of the April '79 Cruise and outline of the upwelling feature based on satellite IR imagery 43 2. Nitrate, phosphate , and sea surface temperature versus elapsed distance along the track of the April '79 Cruise 44 3. ATP, chlorophyll a, and sea surface temperature versus elapsed distance along the track of the April '79 Cruise 45 4. Track of the June '79 Cruise and outline of upwelling feature based on satellite imagery 46 5. Nitrate, phosphate, nutrient ratio, ATP, chlorophyll a, and sea surface temperature versus elapsed distance along the track of the June '79 Cruise 47 6. Track of the August '79 Cruise and outline of the upwelling feature based on satellite imagery 4 8 7. Nitrate, phosphate, and sea surface temperature versus elapsed distance along the track of the August '79 Cruise 49 8. ATP, chlorophyll a, and sea surface temperature versus elapsed distance along the track of the August '79 Cruise 50 9. Track of September '79 Cruise and outline of the upwelling feature based on satellite imagery 51 10. Nitrate, phosphate, and sea surface temperature versus elapsed distance along the cruise track of the September '79 Cruise 52 11. ATP, chlorophyll a, and sea surface temperature versus elapsed distance along the track of the September '79 Cruise 54 12. Tongues of cool and warm water alternating away from and towards the coast 56 ACKNOWLEDGEMENTS The author gratefully acknowledges the assistance and constructive criticism offered by Dr. Eugene D. Traganza who is the principal investigator for the "Chemical Mesoscale Project" under the auspices of the Office of Naval Research (Code 482). Dr. Traganza's unfaltering interest and guidance provided the impetus which led to the ultimate completion of this study. The friendship, kindness, and technical assist- ance provided by Ms. Andrea McDonald will always be remembered warmly. I extend my very sincere personal regards to Dr. Eugene C. Haderlie — a professional educator and gentleman. My memories of Dr. Haderlie will keep alive my interest in the sea and its "critters." I owe loving thanks to my wife, Patricia, who provided encouragement when the well of motiva- tion was running dry. Finally, I dedicate this work to my Dad, whose interest in education and his insistence on striving to better oneself was meaningless until I, too, became a father . I. INTRODUCTION Biological patchiness, or spatial heterogeneity, can occur on nearly every scale. The presence of biological patches, or communities, can have a direct effect on Naval operations, scientific research, and fisheries. The impact on Naval operations is apparent in the negative effects randomly distributed populations may have on sonar operations due to varying degrees of sound scattering and reverberation. Patchy distributions of plankton populations may hamper research efforts through the introduction of sampling errors into collecting efforts (Wiebe, 1971). The presence of phyto- plankton populations provides pasture for herbivorous zoo- plankton which lure larger carnivores sought by the fisheries. A better knowledge of the cause and effects of plankton patchiness may aid man in exploiting, or perhaps avoiding, its far-reaching effects. Prior to the turn of the century, scientists had already observed a spatial heterogeneity, or patchiness, in oceanic plankton populations. In the few decades leading up to the 1930' s, the general opinion was that patchiness was attribu- table to heavy differential grazing of herbivorous zooplankton, thereby establishing the frequently observed negative correla- tion between zooplankton and phytoplankton populations. Hardy and Gunther C193 5) advanced the theory that diel migrations of zooplankton through vertical current strata could account for separation and redistribution of planktonic populations. A little more than a decade later, the now familiar negative correlation in populations was observed after only a few days of moderate grazing (Riley and Bumpus , 1946). The end of the decade found physical oceanographers attempting to explain the phenomena whose evolution had eluded biologists for more than half a century. Stommel (1949) pro- posed a hydrodynamic model of plankton distribution based on Langmuir spirals in the surface waters which caused an aggre- gation of plankton within alternating regions of convergence and divergence. The classical work of Kierstead and Slobodkin (1953) addressed the influence of physio-chemical characteris- tics of the water mass, such as temperature, salinity, dissolved oxygen, and dissolved nutrients. Cassie (1959, 1960) related abundance and distribution in terms of gradients of physical factors and suggested that these factors could influ- ence distribution patterns as much as biological interactions. Others stressed biological interaction and association as the dominant factors involved (Bernhard and Rampii, 1965) . Wiebe (1970) defined patchiness as any concentration of individuals exceeding the central value in a given data set. He further subscribes to the theory of temperature, salinity, and light concentrations as primary causal factors in determining distri- bution. Perhaps one of the most significant contributions 10 was his forthright admission that patch-forming mechanisms are not well known. The literature of the 1970' s found oceanographers and biologists presenting varying hypotheses to explain spatial heterogeneity of plankton. Piatt (1972) suggested distribu- tion was largely controlled by turbulence and not the dynamic attributes of the organisms. Other scientists indicated that distribution might be attributable to local variations in the physio-chemical characteristics of the medium, or to differences in the social behavior of organisms (Piatt and Filion, 1973) . Kamykowski (1974) suggested observed distri- butions were caused by internal waves of tidal period impinging on continental shelves. These internal waves, combined with the diel migrations through levels of varying currents, could produce a horizontal separation and an inverse relationship between zooplankton and phytoplankton. Reasoning has now completed a full cycle since Hardy and Gunther proffered their hypothesis in 1935. Riley (.1976), referring to the work of Kamykowski, calls it the first and only creditable theory to explain plankton patchiness on the basis of physical forcing mechanisms. Riley, however, states that Kamykowski 's theories are applicable only in waters of sufficiently shallow depth to be affected by these waves. The theory leaves unexplained the distributions observed in deeper oceanic waters. Piatt and Denman (1975) offer horizontal diffusion rates and net rate of biological 11 change as the forcing mechanisms in these waters. Migrations of organisms combined with differential currents in the verti- cal as additive and subtractive quantities to tidal currents were offered to fill the voids left by Kamykowski's theory (Riley, 1976). According to Therrault et al (1978), the spatial patterns are a function of physical processes and differential algal growth rates under varying local physical conditions . The author believes that Stavn (1971) summarized the hypotheses of nearly a century of researchers in an admirable way. He states that the principal factors determining non- random distributions of planktonic organisms may be summarized as follows : 1. Physical/chemical boundary conditions, including light, temperature, and salinity gradients. 2. Advective effects as in wind and water transport, including small scale variations due to turbulence. 3. Reproduction rates within the populations. 4. Social behavior within the populations of the same species . 5. Coactive factors determined by competition between species . The physio-chemical and behavioral factors listed above are presumed to be continually present within a community. Large scale water mass transport may account for large scale distributions such as those found in more productive regions 12 of upwelling on the western coasts of continents. Spatial distribution of plankton patches are, however, frequently many orders of magnitude smaller than the oceanic gyres associ- ated with these regions. The purpose of this study was to show, firstly, that chemical mesoscale features innoculate surrounding oceanic waters with properties sufficient, and necessary, to support biological communities, thereby estab- lishing biological patchiness. Secondly, these mesoscale features can be observed, tracked, and geographically located through the use of high-resolution visual and infrared satel- lite images. 13 II. METHODS AND MATERIALS Four cruises were conducted aboard the R/V Acania of the Naval Postgraduate School between April and September, 1979. The areas of interest were located in the oceanic waters off Point Sur, California. Very high resolution (1.1 km, 0.5°C) infrared and visual satellite images provided by Mr. Larry Breaker, National Environmental Satellite Service (NESS) , Redwood City, California, were used to initially detect the presence of mesoscale (10 to 100 km) thermal features. When the image revealed the existence of an oceanic thermal feature, direct telephone contact was made with Mr. Breaker who pro- vided up-to-date information relative to geographic location, intensity, and persistence of the feature as inferred by image analysis. Once a significant feature was evident, cruise preparations began and the feature was monitored by NESS. A final update with respect to geographic location was obtained just prior to the Acania' s departure from Monterey. Time enroute was spent in equipment checkout and in planning the ship track. Nearing the last reported location, a constant watch was kept on sea surface temperature in order to identify thermal gradients characteristic of these features. Once detected, an appropriate search pattern was initiated to obtain maximum data density while attempting to define the boundaries of the features. 14 To effectively describe the relationship between chemical mesoscale and microplankton in the surface layer of the feature, it was decided to sample several significant physical, chemical, and biological parameters. To this end, continuous measure- ments of sea surface temperature (injection temperature, expend- able bathythermographs, and bucket temperatures) , dissolved nutrient (nitrate and phosphate) , and biomass (adenosine triphosphate and chlorophyll fluorescence) were made. A. CHLOROPHYLL The relatively low concentrations of chlorophyll encountered in the surface layer (<1 yg/1) and the size of the features being investigated required a method of chlorophyll determina- tion which was rapid, sensitive, and continuous (Yentsch and Menzel, 196 3) . Early investigators (Richards and Thompson, 1952) used spectrophotometric measurements of algal extracts to determine chlorophyll concentrations. More recent studies have shown that the measurement of fluorescence of chlorophyll is more sensitive than previously used methods and can be adapted to continuous in situ analysis (Lorenzen, 1966) . The lower limit for detection of chlorophyll by fluorescence methods is about 0.1 yg/1 chlorophyll a, which is about 5% that required by spectrophotometric methods (Holm-Hansen, et al, 1965) . Seawater for all shipboard analysis was initially pumped from a through-the-hull fitting, utilized for engine cooling (depth of 2.5 m) , directly to the vessel's dry laboratory. The seawater was directed into a Turner Model III fluorometer 15 fitted with a flow-through cuvette. The cuvette was acid washed (IN HC1) and thoroughly rinsed with distilled water prior to each cruise, although no evidence of algal growth was ever seen. Bubble contamination, due to rough seas on some cruises (August and September) required subsequent incorporation of a bubble trap into the intake system prior to the introduction of seawater into the fluorometer. Continu- ous in situ chlorophyll fluorescence was recorded by connecting the 0 to 10 mv output terminal of the fluorometer to a suit- able continuous feeding strip chart recorder. Fluorescence was calibrated by the analysis of discrete chlorophyll samples (three replicate samples) withdrawn from the fluorometer dis- charge outlet at one-half hour intervals throughout the cruise tracks. Additional discrete samples were drawn when signifi- cant gradients of thermal or nutrient properties were observed. Phytoplankton was harvested by filtering the replicate samples of fluorometer discharge through glass fiber filters (Whatman GF/C, 4.25 cm dia., pore size 0.45 urn) which had been moistened with a 1% solution of MgCCU to prevent premature acidification. Filters were then folded in half and placed in sterile plastic bags which were properly identified and indexed with the strip chart. The filters were immediately placed in a shipbpard freezer to await extraction in a shore laboratory facility. Holm-Hansen C19 78) reported no detectable loss of chlorophyll after frozen storage for periods up to three weeks duration. 16 In every case reported in this study, the extraction process was completed within that period. The chlorophyll extraction was accomplished by introducing the frozen unground filters into 15 ml screw-top centrifuge tubes containing approximately 10 ml of 90% spectral quality acetone. The tubes were vigorously shaken and placed in a darkened refrigerator for twenty-four hours. When extraction time exceeds a few hours, there is no difference between samples which have been extracted with or without grinding (Holm-Hansen, 1978). Prior to fluorometric determinations, the samples were removed from the refrigerator and brought to room temperature inside a darkened cabinet. Acetone volume was then brought to exactly 10 ml. Samples were again shaken and centrifuged at 15,000 X g for about five minutes. The fluorometer was zeroed by placing a disposable culture tube containing only 90% acetone into the light path of the fluor- ometer. The extractant was carefully decanted into similar culture tubes and placed in the fluorometer. Only door "slit width" settings 3 and 10 were utilized due to the non-linearity of response associated with the larger "slit" setting of 1. Each sample was removed from the fluorometer and injected with two drops IN HC1, gently mixed and allowed to stand for one minute prior to being replaced in the fluorometer. Fluorometer readings were carefully recorded before and after acidification Chlorophyll concentration for strip chart calibration was cal- culated in the manner of Strickland and Parsons (1972) . 17 The author acknowledges more recent advances in methodology associated with chlorophyll determination. The use of pure methanol as an extraction fluid (Holm-Hansen and Rieman, 1978) and injection of DCMU (3-(3,4 dichlorophenyl) -1, 1-dimethylurea) , a herbicide, to block photosynthetic electron transport and thereby maximize fluorescence (Slovacek and Hannan, 19 77) should be considered by future investigators. For the purpose of maintaining continuity, the procedures previously described were utilized in the determination of chlorophyll fluorescence throughout the course of this study. B. NUTRIENTS A Technicon Autoanalyzer II was used to measure reactive dissolved nutrients as described by Nestor (1979) . Data collection was accomplished by fellow students (Conrad, 19 80) involved in the Chemical Mesoscale Project at the Naval Post- graduate School. C. ATP A determination of adenosine triphosphate (ATP) in the particulate matter of seawater is of value as an indication of the quantity of living material (Strickland and Parsons, 1972) . Seawater samples for analysis were obtained every ten minutes (ca 3 km) along the cruise tracks. Analysis techniques were those of Holm-Hansen (1972) . 18 D. TEMPERATURE Sea surface temperature was sensed by a thermistor located in the engine cooling water intake at the same depth, and in line with, tubing supplying seawater for all onboard analysis. Temperature was continuously recorded on a strip chart which provided a real-time visual signal of thermal gradients. Strip chart calibration was provided by periodic comparison to mercury thermometer reading and frequent expendable bathy- thermograph (XBT) launches. 19 III. RESULTS Data presented in this study were collected between April and September 1979, during cruises of the R/V Acania. Data traces of temperature, dissolved nutrients, and biomass indi- cators (ATP and Chlorophyll) are plotted against elapsed dis- tance (in km) along the respective cruise tracks. ATP and Chlorophyll a have been converted to carbon units to facili- tate comparison (Conrad, 19 80) . A. APRIL CRUISE On 10 April 1979, satellite imagery showed a wave-like perturbation on a narrow band of cooler coastal water near Point Sur, California (Plate 1) . On 17 April, the feature had grown, extending nearly 100 km to seaward, and had devel- oped a noticeable cyclonic swirl (Plate 2) . The following day (April 18), growth continued and the cyclonic pattern persisted with noticeable thermal banding present (Plate 3) . At the same time, a similar perturbation which spawned the feature under investigation became evident in the waters north of Monterey Bay. Images received on 19 April showed little change in the feature's basic structure. The feature was persisting with, perhaps, a somewhat tighter curvature indicated (Plate 4) . The perturbation north of Monterey seemed to be following the same developmental pattern of growth, cyclonic swirling, and thermal banding. 20 Vessel scheduling did not allow getting underway while the characteristics of these features appeared to be so well delineated. Satellite images were not available during the next several days due to cloud cover over the coastal regions of Central California. On 29 April (the first day of the cruise) images received indicated a relaxation of the previ- ously observed swirling which appeared to recede into coastal waters with a southwesterly excursion of cooler waters (Plate 5) . The Acania got underway on 29 April to investigate the remnants of the feature which had been first observed on 10 April and whose development had been monitored for more than two weeks. Figure 1 depicts the cruise track. ATP, chloro- phyll a, and sea surface temperature were collected and dis- played in Figures 2 and 3. Excellent agreement between thermal structure inferred from satellite imagery (0.5 cm) and sea surface temperature measurements (2.5 m) was evident. Figure 2 shows a strong inverse relationship between dissolved nutri- ents and temperature, presumably attributable to upwelling origins of the water mass. Peaks in biomass indicators (ATP and chlorophyll a) occurred adjacent to increases in dissolved nutrients and in regions of increasing temperature (Figure 3) . B. JUNE CRUISE The June Cruise was of short duration to investigate a "feature of opportunity" which became visible on images received after an extended period of cloud cover that had pre- cluded earlier reception of satellite images. Infrared images 21 received on 13 June revealed an intense protrusion of coastal upwelling off Point Sur (Plate 6) . The R/V Acania departed Monterey to locate the feature at approximately 1800 LST and followed the track depicted in Figure 4 . Figure 5 further substantiates previous findings. Nutrients and temperature again showed a strong inverse relationship, while biomass indicators peaked in areas adjacent to these maxima in warmer temperature gradients on the equatorward side of the feature. Although short in duration, the cruise provided excellent data from which to investigate the characteristics of the feature. C. AUGUST CRUISE Satellite images of 30 July (Plate 7) revealed a large area of apparent upwelling southwest of Point Sur. Subsequent images (5 August, Plate 8), although somewhat contaminated with cloudiness over the coastal region, showed an elongated extension of cold water projecting nearly 150 km in a south- westerly direction. Additional imagery was not available. The cruise began on 7 August and endeavored to locate and study the feature last observed on 5 August. The cruise track followed over the next two days is shown in Figure 6. Concen- trations of all sampled variables were, for the most part, quite low. The data presented in Figures 7 and 8, although sporadic, were consistent with that previously observed , Chlorophyll data became increasingly unreliable due to bubble contamination resulting from air ingestion during roughing 22 seas. Despite difficulties, biomass data (Figure 8) supports distributions found during previous cruises. Except for two peaks in ATP (ca 3 20 km and 3 80 km) which occur in areas of decreasing temperature, the biomass indicators were again found adjacent to nutrient maxima and in regions of increasing temperature, thereby supporting previous findings. D. SEPTEMBER CRUISE The satellite images of 23 September (Plate 9) showed a narrow coastal band of upwelled water extending nearly 20 0 km south from Monterey Bay. More intense upwelling, indicated by lighter grey shades, appeared due west of Point Sur. The next day (24 September) the upwelling previously noted west of Point Sur appeared to be more diffuse and widespread, extending approximately 70 km seaward (Plate 10) . Although imagery was badly contaminated, there appeared to be a slight anticyclonic (northward) curvature associated with the feature. On 25 September, the diffuse nature and northward turning of the sea- ward extremity were again apparent (Plate 11) . Also visible was a new, intense upwelling event positioned between Point Sur and Point Pinos. Clear images on 26 September (Plate 12) showed continued development of the latter feature within the confines of the original feature observed in earlier images. A pronounced cyclonic "hook" was developed at a position approximately 22 km off Point Sur. The cruise began on 26 September and followed the track of Figure 9. Data presented in Figures 10 and 11 consistently 23 revealed the expected inverse relationship between tempera- ture and nutrients. Biomass indicators were consistently low. The near absence of chlorophyll a in the presence of nutrient concentrations was somewhat disquieting. The only peak of consequence occurred at approximately 220 km elapsed distance in a region of relatively high nutrients and of little thermal gradient. The absence of notable chlorophyll concentrations suggested a malfunction of sampling equipment Post cruise analysis, however, disproved this possibility. Of particular interest was the absence of biomass peaks here- tofore found in the warm water gradients following nutrient increases . 24 IV. DISCUSSION If one accepts Wiebe's definition of patchiness (i.e., any concentration of individuals exceeding the central value in a data set) , then the results of this study stand alone as evidence that biological patchiness occurs in association with chemical mesoscale features. Kamykowski (1974) attributed patchiness to the transport of plankters and nutrients by internal waves. Water particle trajectories in his mathematical model described ellipses of varying proportions, oriented perpendicular to the coast. Such motion in an area of intense upwelling and high produc- tivity would allow for the wholesale transport of chemical properties and planktonic communities on a grand scale. A nutrient-rich, highly productive "blanket" of surface water would extend seaward from areas of intense upwelling. Such a large-scale transport would require a redefining of patchi- ness; viz., any area where concentration is significantly less than the central value of a data set. Patchiness would be indicated by voids or "holes" in the "blanket," presumably a result of grazing or other physical processes working on a smaller scale. This clearly is not the case, as further evidenced by the data traces of variables samples during this study. Large-scale water and wind transport can be similarly discounted by applying the same arguments. 25 It is necessary to be acquainted with the physical charac- teristics of the region under investigation prior to offering an alternative hypothesis. The oceanic environment off the Central California coast is largely under the influence of the California Current which marks the eastern extremity of the North Pacific Gyre. It is characterized by a general southerly flow of Subarctic Water. The current is wide (ca 700 km) with a mass transport of approximately 10 sverdrups. This transport, when considered in conjunction with the enormous width, pro- vides for relatively slow currents as it moves sluggishly to the southeast. The waters are characteristically low in salin- ity and dissolved nutrients. In the spring and early summer (March to July) north-northwest winds prevail off the California coast, giving rise to upwelling that is more or less continuous throughout the period. Sverdrup (1942), in citing the work of Scripps Institution of Oceanography, shows that from areas of intense upwelling, tongues of water of low temperature extend in a southward direction away from the coast. These tongues are separated from each other by similar tongues of higher temperature water extending towards the coast. Within the tongues, the flow of warm water is directed to the north, whereas the flow of the cooler water is soughward (Figure 12) . The shear due to the opposing flow may impart positive (cyclonic) vorticity to the waters creating "swirls" and meso- scale features possessing the cyclonic curvature and thermal 26 banding evidenced in this study. The cold water, presumably of upwelling origin, is rich in nutrients and may carry a biological "seed" population. Once formed, the feature may be advected by the mechanism of Kamykowski or others. As advection continues, the longevity of the feature, and indeed its populations, are further modified by chemical, physical, and physiological processes. Nutrient-rich surface waters are depleted by mixing, further advection, and assimi- lation by the exponentially growing phytoplankton population. Phytoplankters are lost due to turbulence , herbivorous grazing, natural aging and sinking of senescent cells. The tendency of the biomass indicators sampled in this study to be distributed adjacent to increased nutrient concen- trations but in regions of warmer temperature gradients is unexplained. The author suggests the distribution may be attributed to physiological adaptation of the plankters. Since extensive quantitative biological sampling was not undertaken, the hypothesis cannot be substantiated. The theory is plausible, as reported by Hand et al (1965) . Their data suggests that with Gonyaulax polyedra (a dinof lagellate producing "red tides"), cells exposed to a 2° temperature change over a 30 minute period do not lose motility, but steeper gradients do lead to paralysis. The low chlorophyll a_ concentrations in the presence of nutrients during the Sep- tember cruise may be indicative of a new upwelling event which 27 was either devoid of a "seed" population, or contained a population that had inadequate time for growth, or one in which some other limiting factor was operating. Alternately, a subsurface chlorophyll concentration may have been present and undetected. Hobson and Lorenzen (19 72) showed that chlorophyll maxima were associated with pycnoclines at various depths and that increased concentrations of micro- zooplankton were associated with these maxima. Subsurface maxima may also be attributed to photosynthetically active cells which are apparently adapted to low-light intensity (Andersen, 1969) . Organisms may be further stressed or limited by chemical properties such as pH and dissolved oxygen. The limited variables sampled in the surface (2.5m) layer and the absence of quantitative biological sampling again precludes substantiation in this study. These possibili- ties, however, should not be excluded in future research efforts. 28 V. CONCLUSIONS The great impact of upwelling on the physical and econmi- cal endeavors of man has led to extensive investigation of this phenomenon with the objective of predicting the occur- rence or intensity of upwelling events. Owing to their complexity, it is doubtful that accurate prediction equations will evolve in the near future. This study has shown, in part, that remote infrared satellite sensing may be used as a real-time tool to accurately locate thermally and biologi- cally significant features. It is possible to observe, track, geographically locate and study upwelling pulses depic- ted in infrared satellite images, thereby eliminating the expense of multiple ship operations in research efforts — efforts whose potential value was realized by Armstrong et al (1967). Several signifcant physical, chemical, and biological parameters were sampled in the surface layer of the mesoscale thermal features which were located using satellite imagery. The results of biochemical sampling produced replicate results from which the distribution of biomass within the chemical mesoscale feature could be inferred. As for the causes of the observed distribution, it would be a gross simplification to segregate a single variable as the primary causal factor. This is especially valid when one deals with two media (air- sea) that are so dynamically interrelated. Theories were 29 advanced which most closely support the findings of Barnes and Marshall (1951) , who suggested that population changes were associated with different water masses that maintained their identity while the populations developed, and the association is maintained. The biological significance of the observed spatial structure is not readily apparent and probably will not become so until patch forming mechanisms are better known (Wiebe, 1970). As research is continued, a more explicit relationship between the physical, chemical, and biological processes will no doubt emerge. 30 Plate 1. TIROS-N Satellite IR Image of the California Coast, 10 April 1979. 31 Plate 2. TIROS-N Satellite IR Image of the California Coast, 17 April 1979. 32 3&5Ss35S£s»sSk2&S^ Plate 3. TIROS-N Satellite IR Image of the California Coast, 18 April 1979. 33 93£&S39fiS&B&9SS£3£SB&fi8SB8SBBB38S8BSI ,.;:;::,=, Plate 4. TIROS-N Satellite IR Image of the California Coast, 19 April 1979. 34 ' ■■' t. Plate 5. TIROS-N Satellite IR Image of the California Coast, 29 April 1979. 35 1 Plate 6. TIROS -N Satellite IR Image of the California Coast, 13 June 1979. 36 Plate 7. TIROS-N Satellite IR Image of the California Coast, 30 July 1979. 37 Plate 8. TIROS-N Satellite IR Image of the California Coast, 5 August 197 9. 38 Plate 9. TIROS-N Satellite IR Image of the California Coast, 23 September 1979. 39 Plate 10. TIROS -N Satellite IR Image of the California Coast, 24 September 1979. 40 Plate 11. TIROS -N Satellite IR Image of the California Coast, 25 September 1979. 41 Plate 12. TIROS-N Satellite IR Image of the California Coast, 26 September 1979. 42 124° CRUISE TRACK 30 APRIL to 1 MAY, ©0200 CAMBRIA Figure 1. Track of the April '79 Cruise and outline of the upwelling feature based on satellite IR imagery. 43 o 16' TEMPERATURE NITRATE PHOSPHATE LEG I 25 50 75 ELAPSEO DISTANCE, km 125 225 ELAPSEO DISTANCE, km 275 18t £ 14- TEMPERATURE NITRATE PHOSPHATE 300 325 350 375 ELPAPSED DISTANCE, km 400 425 P04 N03 3 + 30 LEG 2 20 * ■10 150 300 P0„ NO, 3T30 2f20 5 K 10 z 450 Figure 2. Nitrate, phosphate, and sea surface temperature versus elapsed distance along the track of the April '79 Cruise. 44 o 16-- 10-- 20 75 100 ELAPSEO DISTANCE. »m 225 250 ELAPSED DISTANCE, Km TEMPERATURE ATP CHLOROPHYLL LEG 3 uj |2-. 300 325 350 375 400 ELAPSED DISTANCE, km 4 25 00 300 ■•I 8 ••16 •I 4 f 1.2 e 10 1 • 8 6 ■ 4 • 2 0 4 50 Figure 3. ATP, chlorophyll a_, and sea surface temperature versus elapsed distance along the track of the April '79 Cruise. 45 -Santa Cruz 124' Nc— ■37 122' 0200 0132 V0100 2T400T 2350 2300 23-18' 36' CRUISE YL 13 JUNE, 1979 LEG 1 2100-2318 GMT LEG 2 2318-2350 GMT LEG 3 2350-0132 GMT Figure 4. Track of the June '79 Cruise and outline of the upwelling feature based on satellite IR imagery, 46 o 16 - ELAPSED OISTANCE. km , LEG 2 Figure 5. Nitrate, phosphate, nutrient ratio, ATP, chlorophyll a and sea surface temperature versus elapsed distance along track of the June '79 Cruise. 47 7 to 9 AUG. 1979 TO 1452 GMT 700 GMT 900 GMT 2128 GMT 2230 GMT 0934 GMT 124' 123" 122' Figure 6. Track, of the August '79 Cruise and outline of the upwelling feature based on satellite IR imagery. 48 375 400 ELAPSEO OISTANCE. »m < 14 X 0. 2 TEVPERATURE NITRATE PHOSPHATE \~-- 525 ELAPSED OISTANCE Figure 7. Nitrate, phosphate, and sea surface temperature versus elapsed distance along the track of the August f79 Cruise. 49 225 ElaPSEO DISTANCE, urn 275 300 375 400 ELAPSED DISTANCE. «ti TEMPERATURE CHLOROPHYLL 12 - I 8 ■•I 6 ••I 4 ■■I 2 ■10 ■•8 6 4 ■2 0 * — 450 325 ELAPSED OISTANCE. km 600 Figure 8. ATP, chlorophyll a and sea surface temperature versus elapsed distance along the track of the August '79 Cruise. 50 26-29 September CRUISE i:i3w 122W 35 N Figure 9. Track, of the September '79 Cruise and outline of the upwelling feature based on satellite IR imagery. 51 (itPStO OlSTAMCC . - lL*»*tO OilUME . riBPfnatum ■ NiT»*r« , »mOSPH*TE '-i»»»(0 OiSTMCC ■- Figure 10. Nitrate, phosphate and sea surface temperature versus elapsed distance along the track of the September '79 Cruise. 52 ISO J LEO a •Q." Lia LEGS N r * t' ' n^ V-— -— -^-"*- y — '(■»«s*ru«f 1 1 ■ ■ITRATI '"'■ ■-Oi<"-i'i 1 _^~—- — A X — -— "~ ■* •». ^ ^— *" ^ / -*■ .- *" ^f • N-. , h.»»C 0iST4MCC . Lta > lCG 1 __^^ , / , rtapcRATum — . A 1 * . -*^* ^W\ **— K— T 1 CLAVStO OISTAWCC Figure 10. Continued. 53 II 1fl ^ / ■> ^~ LEG 1 [ tea 2 , u a 3 — — — TEMPERATURE CMLOOOPMYLl z 1 X '2 ■ £L»PSEO OiSTANCE 11 Lea 2 LEO 3 ■ ,. . -— _— -~ S - u tewpe«*tupe r" '* ■'■■■" «IP 3 CMLOflOPMrCL * | >• to " . ^7" I_ ~~" ' - __- "- ~ -'-' ~~~^ f'.-PSEO OISTANCE II LEO J LEO « ' 'a '"--•---^ -„ ^ .- -*-*-^* -~ ' "~— " TEMP6R4TUOE u MM. .IP 5 CMLOPOPMVLL I n i0 ~~~*~-~. • - --=*■ • - _^— -_ -— " --* ._ - ^ — ^-, • pseo DtsiANce Figure 11. ATP, chlorophyll a and sea surface temperature versus elapsed distance along the track of tne September l 79 Cruise. 54 / TEMPERATURE CHLOROPHYLL ELAPSED OiSIAWCE km II LEG 5 LCO 1 It y "~"*"- ■ — • ~v_.. _,^.- — '"^ ""•—-.." - ? • X 3 < X i « * ,, * a ^ — ~ - - • • • - " - _^_ - - • '" -— - ELAPSED OlSTAWCE Figure 11. Continued. 55 Figure 12. Tongues of cool and warm water alternating away from and towards the coast. CAfter Sverdrup et al, 1942) 56 LIST OF REFERENCES Anderson, G. C, "The Seasonal and Geographic Distribution of Primary Productivity Off the Washington and Oregon Coasts," Limnology and Oceanography, v. 9, p. 284-302, 1964. Armstrong, F. A. J., C. R. Stearns and J. D. H. Strickland, "The Measurement of Upwelling and Subsequent Biological Processes by Means of the Technicon Autonanalyzer and Associated Equipment," Deep-Sea Research, v. 14, p. 381- 389, 196 7. Barnes, H. and S. M. Marshal, "On the Variability of Replicate Plankton Samples and Some Application of "Contagious" Series to the Distribution of Catches Over Restricted Periods," Journal of the Marine Biological Association of the United Kingdom, v. 30, p. 233-263, 1951. Bernhard, M. and L. Rampi, "Horizontal Microdistribution of Marine Phytoplankton in the Ligurian Sea," Botan. Gothoburgensia , v. 3, p. 13-24, 1965. Cassie, R. M. , "An Experimental Study of Factors Inducing Aggregation in Marine Plankton," New Zealand Journal of Science, v. 2, p. 339-365, 1959. Cassie, R. M., "Factors Influencing the Distribution of Plankton in the Mixing Zone Between Oceanic and Harbour Waters," New Zealand Journal of Science, v. 3, p. 26-50, 1960. Conrad, J. W, , "Relationships Between Sea Surface Temperature and Nutrients in Satellite Detected Oceanic Fronts," M. S. Thesis, U. S. Naval Postgraduate School, 1980. Hand, W. G. , P. A. Collard and D. Davenport, "The Effects of Temperature and Salinity Changes on the Swimming Rates of Dinof lagellates Gonyaulax ans Gymnodinium, " Biological Bulletin, v. 128, p. 90-101, 1965. Hardy, A. C. and E. R. Gunther, "The Plankton of South Georgia Whaling Grounds and Adjacent Waters," Discovery Rep, v. 11, p. 1-456, 1935. Hobson, L. A. and C. J. Lorenzen, "Relationships of Chlorophyll Maxima to Density Structure in the Atlantic Ocean and Gulf of Mexico," Deep-Sea Research, v. 19, p. 297-306, 1972. 57 Holm-Han sen, 0. with C. J. Lorenzen, R. W. Holmes, J. D. H. Strickland, "Fluorometric Determinations of Chlorophyll," Journal Du Conseil, v. 30, no. 1, p. 1-15, 1965. Holm-Hansen, 0. and H. W. Paerl, "The Applicability of ATP Determinations for Estimation of Microbial Biomass and Metabolic Activity," Mem. 1st Ital. Idrobiol, v. 29, suppl., p. 149-168, 1972. Holm-Hansen, 0. and B. Riemann, "Chlorophyll a Determinations: Improvements in Methodology," Oikos, v. 3U, p. 438-447, 1978. Kamykowski, D., "Possible Interactions Between Phytoplankton and Semi-Diurnal Internal Tides," Journal of Marine Research, v. 32, p. 65-87, 1974. Kierstead, H. and L. B. Slobodkin, "The Size of Water Masses Containing Plankton Blooms," Journal of Marine Research, v. 12, p. 141-147, 1953. Lorenzen, C. J., "A Method for the Continuous Measurement of in vivo Chlorophyll Concentration," Deep-Sea Research, v. 13, p. 223-227, 1966. s Nestor, D. A. , "A Study of the Relationship Between Oceanic Chemical Mesoscale and Sea Surface Thermal Structure as Detected by Satellite Infrared Imagery," M. S. Thesis, U. S. Naval Postgraduate School, 1979. Piatt, T., "Local Phytoplankton Abundance and Turbulence," Deep-Sea Research, v. 12, p. 183-187, 1972. Piatt, T. and C. Filion, "Spatial Variability of the Produc- tivity: Biomass Ratio for Phytoplankton in a Small Marine Basin," Limnology and Oceanography, v. 18, p. 743-749, 1973. Piatt, T. and K. L. Denman, "A General Equation for the Meso- scale Distribution of Phytoplankton in the Sea," Mem. Soc . R. Sci. Liege, ser. 67, p. 31-42, 1975. Richards, F. A. and T. G. Thompson, "The Estimation and Characterization of Plankton Populations by Pigment Analysis. II. A Spectrophotometric Method for the Estimation of Plankton Pigments," Journal of Marine Research, v. 11, p. 156-172, 1952. Riley, G. A. and D. F. Bumpus, "Phytoplankton-zooplankton Relationships on Georges Bank," Journal of Marine Research, v. 6, p. 33-47, 1946. 58 Riley, G. A., "A Model of Plankton Patchiness," Limnology and Oceanography , v. 21, p. 873-880, 1976. Slovacek, R. E. and P. J. Hannan, "In Vivo Fluorescence Deter- minations of Phytoplankton Chlorophyll a," Limnology and Oceanography, v. 22, p. 919-925, 1977. Stavn, R. H., "The Horizontal-Vertical Distribution Hypothesis Langmuir Circulations and Daphnia Distributions," Limnology and Oceanography, v. 16, p. 453-466, 1971. Stommel, H., "Trajectories of Small Bodies Sinking Slowly Through Convection Cells," Journal of Marine Research, v. 8, p. 24-29, 1949. Strickland, J. D. H. and T. R. Parsons, A Practical Handbook of Seawater Analysis, Fisheries Research Board of Canada, 1972. Sverdrup, H. U. with M. W. Johnson and R. H. Fleming, The Oceans, Prentice Hall, p. 724-727, 1942. Therriault, J. and D. J. Lawrence, "Spatial Variability of Phytoplankton Turnover in Relation to Physical Processes in a Coastal Environment," Limnology and Oceanography, v. 23, p. 900-911, 1978. Wiebe, P. H., "Small Scale Spatial Distribution in Oceanic Zooplankton, " Limnology and Oceanography, v. 15, p. 205- 217, 1970. Wiebe, P. H. , "A Computer Model Study of Zooplankton Patchi- ness and Its Effects on Sampling Error," Limnology and Oceanography, v. 16, p. 29-38, 1971. Yentsch, C. S. and D. W. Menzel, "A Method for the Determina- tion of Phytoplankton Chlorophyll and Phaeophytin by Fluorescence," Deep-Sea Research, v. 10, p. 221-231, 1963. 59 INITIAL DISTRIBUTION LIST No. Copies 1. Defense Technical Information Center 2 Cameron Station Alexandria, Virginia 22314 2. Library, Code 0142 2 Naval Postgraduate School Monterey, California 93940 3. Chairman (Code 6 8Mr) 1 Department of Oceanography Naval Postgraduate School Monterey, California 939 4 0 4. Chairman (Code 6 3Rd) 1 Department of Meteorology Naval Postgraduate School Monterey, California 9 394 0 5. Dr. Eugene D. Traganza (Code 6 8Tg) 5 Department of Oceanography Naval Postgraduate School Monterey, California 93940 6. CDR R. W. Phoebus (Code 001) 2 Fleet Numerical Oceanography Center Monterey, California 93940 7. Director 1 Naval Oceanography Division Naval Observatory 34th and Massachusetts Avenu NW Washington, DC 20 390 8 . Commander 1 Naval Oceanography Command NSTL Station Bay St. Louis, Mississippi 39522 9. Commanding Officer 1 Naval Oceanographic Office NSTL Station Bay St. Louis, Mississippi 39522 60 10. Commanding Officer Fleet Numerical Oceanography Center Monterey, California 93940 11. Commanding Officer Naval Ocean Research and Development Activity NSTL Station Bay St. Louis, Mississippi 39522 12. Commanding Officer Naval Environmental Prediction Research Facility Monterey, California 93940 13. Chairman, Oceanography Department U. S. Naval Academy Annapolis, Maryland 21402 14. Chief of Naval Research 800 N. Quincy Street Arlington, Virginia 22217 15. Office of Naval Research (Code 480) Naval Ocean Research and Development Activity NSTL Station Bay St. Louis, Mississippi 39522 16. Office of Naval Research (Code 482) Naval Ocean Research and Development Activity NSTL Station Bay St. Louis, Mississippi 39522 17. Scientific Liaison Office Office of Naval Research Scripps Institution of Oceanography La Jolla, California 92037 18. Library Scripps Institution of Oceanography P. 0. Box 2367 La Jolla, California 92037 19 . Library Department of Oceanography University of Washington Seattle, Washington 98105 20. Library CICESE P. 0. Box 4803 San Ysidro, California 92073 61 21. Library School of Oceanography Oregon State University Corvallis, Oregon 97331 22. Commander Oceanographic Systems Pacific Box 1390 Pearl Harbor, Hawaii 96860 62 Thesis P48625 c.l 193791 Phoebus Biological patchi- ness in relation to satellite thermal imagery and asso- ciated chemical mesoscale features. Thesis P48625 c.l Phoebus 193791 Biological patchi- ness in relation to satellite thermal imagery and asso- ciated chemical mesoscale features. thesP48625 Biological patchiness in relation to sat 3 2768 001 97891 9 DUDLEY KNOX LIBRARY