U.S. JGOFS: A Component of the U.S. Global Change Research Program U.S. JGOFS NEWS Volume 12, Number 4 November 2004

Do We Now Understand The Ocean’s Biological Pump? by Jorge L. Sarmiento, John Dunne and Robert A. Armstrong

core problem for global carbon- layer or increases in irradiance. It is a measure of its effectiveness in Acycle research is to explain the fundamentally unstable, disappear- reducing surface nutrients relative to role of the oceanic “biological pump” ing rapidly when resources become subsurface values. We defi ne it more in determining levels of dissolved limited, and has a high ef-ratio.-ratio. WWee specifi cally as the average nitrate inorganic carbon (DIC) in surface wa- now think that a large fraction of level at depths in the range of 100 to ters and the exchange of carbon be- oceanic variability in the ef-ratio-ratio dde-e- 200 meters, minus the average in the tween ocean and atmosphere. Surface pends upon whether a given region top 100 meters, divided by the aver- nutrient concentrations are key to supports just the regeneration system age in the 100- to 200-meter range predicting this exchange because un- or the export pathway as well. (Figure 1). We use nitrate observa- used nutrients in the upper ocean al- Is knowledge of the relationship tions in the upper 100 meters from low associated carbon dioxide (CO2) of ef-ratio-ratio ttoo tthehe sstructuretructure ooff pplank-lank- summertime, when surface nutrients to escape into the atmosphere. What tonic food webs either necessary are at a minimum and the effi ciency have we learned during the JGOFS or suffi cient for understanding the is at its maximum. Thus a region in era that can help us understand what biological pump? We would argue which summer surface-layer nutrient controls the strength and effi ciency that it is neither. levels are equal to deep nutrient of the biological pump? A key concept for analyzing the levels has an effi ciency of 0%, and A new paradigm of ecological biological pump is the distinction be- one in which summer surface-layer systems in the surface ocean has tween its strength and its effi ciency. nutrients are totally depleted has an emerged during the last several years, We defi ne the strength of the pump effi ciency of 100%. focused on the relative roles of the as the magnitude of the export of or- Figure 2a shows that the strength regeneration of nutrients versus their ganic matter. For example, a location of the biological pump and its effi - export. The regeneration system such as the Bermuda Atlantic Time ciency are generally inversely related includes the smallest autotrophs, Series (BATS) station in the Sargasso to each other. For example, the picoplankton that are generally Sea where the export of organic mat- high-latitude regions of the Southern only able to utilize ammonium; ter is 4 moles of carbon per square Ocean have a strong but ineffi cient a microbial loop that consists of meter per year (mol C/m2/yr), has a biological pump. Conversely, the heterotrophic bacteria and the dis- stronger biological pump than one low-latitude subtropical gyres have a solved organic matter on which they with an export of 2 mol C/m2/yr, weak but effi cient biological pump. live, and small protists that graze such as the Hawaii Ocean Time-series While the strength of the biologi- on bacteria and picoplankton. This station (HOT) in the north Pacifi c cal pump is important in determin- system is ubiquitous and stable. It oligotrophic gyre (Figure 1b). ing the export of organic matter has a low ef-ratio,-ratio, ddefiefi nneded aass tthehe ffrac-rac- The maximum possible strength and thus the biological activity in tion of productivity that is supported of the biological pump at a given the deep ocean, the effi ciency of the by nutrients supplied from external location is limited by the supply of biological pump is the key factor in sources such as the nutricline or the macronutrients in the upwelling determining the balance of carbon atmosphere. water and the stoichiometric ratio of between the atmosphere and the The export pathway, on the carbon to nitrogen to phosphorus in ocean, at least in regions where other hand, comprises the classical the organic matter exported from the the supply of nutrients and carbon diatom-based food chain, including surface. Nitrogen fi xation and aeo- from below is high. This is because copepods and other large zooplank- lian fi xed nitrogen also contribute, it is ultimately the effi ciency of the ton predators. It is opportunistic, but to a lesser extent. biological pump in stripping out as responding rapidly to injections of In contrast, we defi ne the ef- nutrients, shoaling of the mixed fi ciency of the biological pump as Continued on page 2 much carbon as possible from up- its link to the ef-ratio-ratio ttellell uuss aaboutbout pump effi ciency. welling waters that determines how biological pump effi ciency? Given If the ef-ratio-ratio ddoesoes notnot indicateindicate tthehe much of the excess carbon stored in the relationship between the export effi ciency of the biological pump, the deep ocean can escape back into pathway and high ef-ratios,-ratios, oonene what does? While ocean circulation the atmosphere. In regions such as might expect high ef-ratio-ratio eenviron-nviron- plays an important role, effi ciency is the Southern Ocean where the bio- ments to have an effi cient biological clearly modulated by other factors.

logical pump effi ciency is low, CO2 is pump and vice-versa. In fact, most The regions characterized by low able to escape from the deep waters of the world ocean exhibits the biological pump effi ciency in Figure that upwell there. Thus the average opposite relationship (Figure 2b). For 1d generally correspond to areas atmospheric concentration is higher example, the Southern Ocean has where the supply of nutrients from than it would be if the effi ciency of a high ef-ratio-ratio bbutut a llowow bbiologicaliological upwelling and deep wintertime mix- the pump were high. pump effi ciency; the subtropical ing is high. However, there are areas gyres, on the other hand, have a low of high biological pump effi ciency What Governs Pump Effi ciency? -ratio but a highly effi cient biological that have extremely high nutrient What does the JGOFS-era para- pump. Thus knowledge of the ef-ratio-ratio supply, such as coastal regions. digm of the surface ecosystem and does not help us predict biological As a result of JGOFS-era discover-

A) Primary Production (mmol C m-2 d-1) B) Particle Export Ratio 500 0.65 80°N 80°N 70 0.40 0.35 40°N 60 40°N 0.30 50 0.25 0° 40 0° 0.20 30 0.15 40°S 40°S 20 0.10 10 0.05 80°S 80°S 0 0.00 0° 100°E 160°W 60°W 0° 100°E 160°W 60°W

C)C) Particle Export (mmol C m-2 d-1) D) Biological Pump Efficiency 100 1.0 80°N 80°N 20 0.9 0.8 15 40°N 40°N 0.7 10 0.6 0° 8 0° 0.5 6 0.4 0.3 40°S 4 40°S 0.2 2 0.1 80°S 80°S 0 0.0 0° 100°E 160°W 60°W 0° 100°E 160°W 60°W

Figure 1: (a) Primary production estimated by a combination of empirical models using satellite-based estimates of chlorophyll. (b) Particle export ratio (particle export divided by primary production) estimated from satellite-based chlorophyll estimates and temperature distributions using an empirical model developed by John Dunne. (c) Particle export calculated by taking the product of the particle export ratio times the primary production. (d) Estimate of the effi ciency of the oceanic biological pump calculated from climatic average nitrate observations. Effi ciency is 100% when organisms deplete surface nutrients totally. It is 0% when no biological removal of upwelled nutrients occurs.

2 U.S. JGOFS Newsletter – November 2004 ies, we now generally believe that this hypothesis to the global of the region. Mitchell and his col- iron limitation plays a crucial role context, we fi nd that the overall leagues defi ned light limitation, not in limiting the uptake of nutrients, lower supply of iron to the ocean by the usual Sverdrup criterion of most particularly in the high-nutri- in the Southern Hemisphere may the threshold light supply necessary ent, low-chlorophyll areas that occur explain much of the remarkable to get a bloom started, but rather by predominantly in the Southern difference between the waters of the the light supply that is required to Ocean and the Southern Hemisphere Northern Hemisphere and those of deplete nutrients completely. subtropics (Figure 3a) and in the the Southern Hemisphere in terms of Given deep summertime mixing, North and equatorial Pacifi c (Figure biological pump strength, effi ciency frequent cloudiness, phytoplankton 3b). and ef-ratio-ratio ((FigureFigure 22).). TToo cconfionfi rrmm self-shading and an extremely high What is the role of iron? Because of this hypothesis, we turn to seven nutrient supply, the Southern Ocean the inverse relationship between ef- major mesoscale iron fertilization might never experience total deple- ratio and export effi ciency observed experiments conducted during the tion of nutrients in surface waters in our analysis, we suggest that the JGOFS era. even if the iron supply were ad- critical role of iron is not associated These experiments demonstrate equate. While it is well documented with its enhancement of the export that iron fertilization can stimulate that Southern Ocean phytoplankton pathway component of the ecosys- phytoplankton growth suffi ciently suffer from an insuffi ciency of iron, tem. Our analysis leads us rather to to deplete surface-water nutrients the evidence suggests that adding conclude that iron functions through in both the North and equato- iron might only lead to a relatively Liebig’s Law of the Minimum, where rial Pacifi c. For example, scientists modest drop in nitrate concentra- the ability of the phytoplankton to observed a maximum drawdown tions before light limitation becomes remove macronutrients at a given of 15 mmol/m3 of nitrate at the a major limiting factor. location is determined by the ratio Subarctic Pacifi c Iron Experiment Considering all the above observa- of iron to the macronutrients, as for Ecosystems Dynamics Study tions and experiments, we conclude originally proposed by the late John (SEEDS) site in the northwest Pacifi c that the relative strength of the Martin. and roughly 5 mmol/m3 of nitrate regeneration system versus the The mean deep-ocean iron during the IronEx II experiment in export pathway, as refl ected in the concentration of approximately 0.7 the equatorial Pacifi c. These results relative abundances of small versus micromoles per cubic meter (µmol/ suggest that an increased iron supply large phytoplankton, is not nearly as m3) is about half of what would from airborne dust would make it good a predictor of biological pump be required to deplete the mean possible for phytoplankton growth effi ciency as is the ratio of macro- deep-ocean nitrate concentration of to exhaust surface nutrients in these nutrients to other limiting factors, 30 mmol/m3, given a representative regions. such as iron and, in the case of the iron-to-nitrogen ratio of 40 mmol Fe However, three separate Southern Southern Ocean, light. per mol N in phytoplankton. Model Ocean iron fertilization experiments simulations, such as those performed were unable to stimulate nitrate Ballast In The Export Flux by David Archer of the University of drawdown by more than roughly We have shown that knowing the Chicago and Kenneth Johnson of the 3 mmol/m3. In an article in Nature relative strengths of the regeneration Monterey Bay Aquarium Research in 2004, Kenneth Coale of Moss system and export pathway does not Institute (MBARI) in 2000 and re- Landing Marine Laboratory and col- help us understand the effi ciency of ported in Global Biogeochemical Cycles, leagues provide a compelling expla- the biological pump. But this distinc- suggest that about three-quarters of nation of SOFeX results that ties in tion is important to our understand- the surface biological production is nicely with an hypothesis presented ing of another aspect of the biologi- driven by iron supplied from below, originally by Greg Mitchell of the cal pump. Ocean scientists have long with the remainder coming from Scripps Institution of Oceanography recognized that inclusion of mineral atmospheric dust. and his colleagues in Limnology and material makes particles containing An inadequate supply of iron Oceanography inin 11991.991. TheyThey ppointedointed organic carbon heavy enough to to the high-nutrient North and to light limitation on phytoplankton sink. Only during the JGOFS era, equatorial Pacifi c and the Southern growth as the primary reason why however, did it become evident that Ocean is the most likely reason for nutrients are not depleted in the there is a strong quantitative rela- the low biological pump effi ciency Southern Ocean, linking this fi nding tionship between particulate organic in these regions (Figure 3). Applying in part to the deeper mixed layers carbon (POC) fl ux and the fl ux of

U.S. JGOFS Newsletter – November 2004 3 25 North Atlantic North Pacific Marginal North Indian Sea Ice Tropical Atlantic 20 Tropical Pacific ) Figure 2: Top panel shows particle -1 Tropical Indian export in mmol C/m2/d plotted d South Atlantic -2 versus biological pump effi ciency. South Pacific Lower panel shows the particle ex- NH Trend South Indian 15 port ratio (particle export divided

Low Lat by primary production) versus Upwelling biological pump effi ciency. Each symbol corresponds to the geo- 10 metric mean over each of 33 bio- geographical provinces based on six biome defi nitions: the marginal ice zone, the subpolar gyre region

Particle Export (mmol C m of downwelling, the subtropical 5 gyre region of upwelling, the SH Trend permanently stratifi ed subtropical gyre, the tropics between 5°S and 5°N, and the low-latitude coastal 0 upwelling regions. The data used 0.0 0.2 0.4 0.6 0.8 1.0 to calculate biological pump ef- fi ciency are summertime obser- Biological Pump Efficiency vations in each hemisphere. The particle export ratio is calculated from annual mean satellite chlo- 0.7 rophyll estimates and temperature observations using an empirical model developed by John Dunne 0.6 and colleagues. The SH and NH lines shown in the diagrams il- lustrate the two major trends NH Trend 0.5 that separate primarily Southern Hemisphere observations (open symbols) plus the tropical Pacifi c Marginal (shaded squares) from Northern 0.4 Sea Ice Hemisphere observations (fi lled symbols) plus the tropical Atlantic Marginal Sea Ice and Indian oceans. 0.3 Subpolar Subpola Particle Export Ratio Low Lat 0.2 Subtropical Upwelling Seasonal SH Trend 0.1

0.0 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Biological Pump Efficiency

4 U.S. JGOFS Newsletter – November 2004 mineral ballasts. By fi tting a series of be reconciled if the foraminifera are small phytoplankton, does not ap- models to data from the U.S. JGOFS found to consume sinking diatom pear to explain the strength Equatorial Pacifi c Process Study, aggregates on their way through the of the biological pump. We con- Robert Armstrong of Stony Brook so-called “twilight zone” between clude, however, that it promises to University and his colleagues found 200 and 1000 meters. be very useful in explaining the that using total mineral material as In summary, the relative strength magnitude of POC delivery to the a predictor of POC fl ux greatly in- of the regeneration system versus the deep ocean and sediments and the creased the predictive power of both export pathway, as refl ected in the depth scale of remineralization in exponential and power-law (“Martin relative abundances of large versus the water column.❖ curve”) remineralization profi les. In a related study, Christine Klaas 1.4 and David Archer of the University of Chicago collected global data on 1.2 POC fl ux and the fl uxes of individual Marginal Sea Ice

) 1

mineral ballasts. They then made -3 a regression of POC fl ux versus NH High Latitudes 0.8 fl uxes of silicate minerals, carbonate minerals and dust. They found that Subpolar 0.6 this simple regression explained

85% to 90% of the variance in POC Chlorophyll (mg m 0.4 Southern Ocean at depths greater than 2000 meters, HNLC Trend Subpolar Marginal whereas reliance on a single predic- Sea Ice 0.2 SH Subtropics tor, such as silicate, explained only 50-60% of the variance. In addition, 0 they found that at these depths, 0 5 10 15 20 25 30 silicate transported only 3% to 4% Nitrate (mmol m-3) of POC (by mass), whereas carbonate Atlantic Pacific Indian and dust transported 5% to 6%. If deep-water fl uxes of POC are 0.6 largely determined by their associat- SH LL-U ed mineral ballasts, then the distinc- 0.5 tion between small phytoplankton, ) which do not make mineral ballasts, -3 0.4 and larger phytoplankton, many N. Pacific NH ST-SS NH ST-SS of which do make mineral ballasts, 0.3 is key to predicting the strength of Eq. Pacific HNLC Trend these fl uxes. However, this distinc- 0.2 Eq-U Eq-D tion may not be the whole story. Chlorophyll (mg m NH LLU At a U.S. JGOFS Synthesis and SH ST-PS 0.1 NH ST-PS SH LLU Modeling Project conference on calcifi cation in June 2002, fi eld researchers presented evidence that 0 half or more of the carbonate fl ux 0 1 2 3 4 5 measured in deep traps is associated Nitrate (mmol m-3) with foraminifera tests, not with Atlantic Pacific Indian coccoliths. This result challenges two tightly-held and somewhat contra- Figure 3: Geometric mean chlorophyll from Figure 1a plotted versus mean observed nitrate dictory views: that export from the for each of the biogeographical provinces described in the caption to Figure 2. The lower euphotic zone is largely mediated by panel is a blowup of part of the upper. The HNLC (high-nutrient, low-chlorophyll) trend diatoms, and that export to the deep lines are intended as a guide; they are not fi ts to the observations. The biogeographi- ocean is largely associated with cal- cal provinces that sit on the HNLC trend line have low biological pump effi ciencies and cium carbonate. These views could relatively low particle exports and particle export ratios (see Figure 2).

U.S. JGOFS Newsletter – November 2004 5 Phytoplankton And Heterotrophic Respiration In The Ocean by John Marra

ome two and a half years ago, the conference with the matter un- incubations can estimate both net SRichard Barber of Duke Univer- resolved but agreed to go back to our and gross primary production. sity and I were sitting in a pub in respective labs and think darkly. It was clear from comparisons with Bangor, Wales, puzzling over ocean As part of my contribution to the the oxygen methods that 14C uptake productivity data based on carbon-14 Bangor Phytoplankton Productivity estimates net production more (14C), a radioactive isotope of carbon Conference and book (PhytoplanktonPhytoplankton closely over 24 hours. Published used to measure rates of photosyn- Productivity: Carbon Assimilation in analyses based on the theory of thetic carbon assimilation in aquatic Marine and Freshwater Habitats, edited isotopic incorporation, however, systems. Dick and I had been using by Williams, David N. Thomas, and concluded that 14C should measure the 14C method on JGOFS cruises Colin S. Reynolds and published by gross production, not net. The to measure primary production. We Blackwells), I had reviewed the pub- resolution of this apparent paradox were in Bangor for the Phytoplank- lished productivity data from JGOFS, was to hypothesize that carbon

ton Productivity Conference at the including the data from oxygen-18 dioxide (CO2) originating from mi- 18 University College of North Wales, ( O) and (light-dark) oxygen (O2) tochondrial respiration was re-fi xed organized by Peter J. leB. Williams incubations. The 18O method should in photosynthesis before it could and his colleagues there. measure gross primary production, exit the cell. There was laboratory It had been 50 years since Einer where respiratory losses are not evidence to support this idea.

Steemann Nielsen of the University subtracted, while (light-dark) O2 If the above resolution is correct, of Copenhagen introduced then carbon uptake will 14 the C method to always be less than gross O2 biological oceanography, production because there is

the event that the Bangor a source of CO2 from within conference was organized the cells. In effect, photo- to celebrate. And here we synthesis is using more water were, still perplexed about molecules in photosynthesis

the data. Dick and I had (to produce O2) relative to done the standard incuba- carbon because there is an in- tions for 14C incorporation ternal source of carbon from devised by JGOFS, but mitochondrial respiration. with the added wrinkle Re-fi xation of carbon during of separate dawn-to-dusk photosynthesis satisfi es both and 24-hour incubations. the observational evidence We were therefore able to and the earlier conclusions measure the loss of the from isotopic theory. isotope overnight. Thus we had two issues Dick pointed out an occupying our minds that interesting feature of the spring and summer. First, it data; the overnight loss appeared that, after 12 hours, seemed not to depend on 14C behaves like 12C, a stable where the measurements isotope of carbon. It is not took place. Further, loss of preferentially retained in carbon overnight seemed the cells. The isotopes are at Figure 1: Components of respiration calculated from pro- to be a roughly constant metabolic equilibrium. ductivity data from the North Atlantic Bloom Experiment percentage of daytime (NABE) at 47°N/20°W, for the productivity measurements Second, the analysis of assimilation. If it was done on May 2, 1989. The fi lled circles are estimates of the JGOFS productivity data a respiratory loss, why phytoplankton respiration; the open circles are estimates wasn’t there a dependence of heterotrophic respiration (bacteria, protozoans and Continued on page 19 on temperature? We left microzooplankton).

6 U.S. JGOFS Newsletter – November 2004 The Microbial World At Macrobial Scales: Bacteria in JGOFS by Hugh W. Ducklow

procrastinated after the editor Shortly thereafter John Marra of Iasked me to write about “what Lamont-Doherty Earth Observatory, we learned in JGOFS” for this fi nal Sharon Smith, then of Brookhaven issue of U.S. JGOFS News, in part National Laboratory, and I joined the because it is pretty hard to address US JGOFS SSC, adding our perspec- such a question in a small space (but tive as biologists to the nascent see the article by Jorge Sarmiento, program. John Dunne and Robert Armstrong Around that time, I also began in this issue). So I decided to write working with Michael Fasham of about bacteria. They don’t take up Southampton Oceanography Centre much space, and they’re what I did on a model of ocean plankton in JGOFS. dynamics that incorporated a simple bacterial-DOM component. Hugh Ducklow The View Before JGOFS This model embodied the concept Heterotrophic bacteria in the there, where organic inputs are I sketched above and formed a ocean are less than 1 micron long lower, but where about 80% of strong rationale for including core and utilize dissolved organic matter the marine photosynthesis takes measurements of bacteria in JGOFS. (DOM) for energy and biomass. In place? JGOFS provided the means to And so began a long run of bacterial the early 1980’s when JGOFS was fi nd out. investigations in the JGOFS process conceived, ocean scientists were just studies and in both the Bermuda realizing the role and importance of The JGOFS Era Atlantic Time-series Study (BATS) bacterioplankton, following intro- In the summer of 1985 I was in- and the Hawaii Ocean Time-series duction of several new methods in volved in a post-fi eld study synthesis (HOT) Study. the previous 10 years, principally by of the Warm Core Rings project I was fortunate to have three great John Hobbie of the Marine Biological at Woods Hole Oceanographic graduate students during JGOFS. Laboratory and Jed Fuhrman, then Institution (WHOI) with James A hard-won BATS grant supported a student at Scripps Institution of McCarthy of Harvard University, Craig Carlson’s doctoral research. By Oceanography. Not surprisingly, David Nelson of Oregon State that time there was a lot of interest nearly all the observations were University and Terrence Joyce of in dissolved organic carbon (DOC), taking place near shore-based labora- WHOI. The initial Global Ocean Flux and Craig instituted core DOC mea- tories or on those few cruises where a Study (GOFS) workshop had taken surements in the BATS program. bacteriologist or two were allowed to place in Woods Hole the summer Craig’s work provided an early participate. before with no microbiologists realistic estimate of the effi ciency Bacteria are very numerous (mil- involved, although Bruce Frost of with which bacteria convert DOC lions per milliliter) in estuarine and the University of Washington had into biomass (less than 30%), and it coastal waters and very active. These illustrated the foodweb consequences demonstrated that export of DOC regions often receive high levels of of bacterial DOM usage in an elegant via vertical mixing is an important nutrient inputs from the land and talk at that meeting. part of the annual carbon budget in have high levels of photosynthesis, U.S. JGOFS was in the early stages the surface waters of the region. The the source of the DOM for the of development as a formal program annual export via mixing resets the bacteria. Early syntheses suggested under the leadership of Peter Brewer DOC inventory at the BATS study site that bacteria are highly effi cient, of WHOI, then chairman of the in the Sargasso Sea, keeping surface commandeering upwards of 50% new program’s scientifi c steering levels more or less stable in the long of all the organic matter produced committee (SSC). Jim took me over term. I consider this to be one of the by phytoplankton. But there had and introduced me to Peter, and I Top 10 JGOFS Discoveries and our been almost no observations in the rambled on about wanting to learn biggest contribution to the program. open sea. about the large-scale variations in Later, Matthew Church worked What are the bacteria doing out the ocean’s smallest inhabitants. in the HOT Program, co-advised

U.S. JGOFS Newsletter – November 2004 7 by David Karl of the University of gotrophic central Arabian Sea. I was studies, we have been synthesizing Hawaii and me. Matt showed that, ably assisted in the fi eld and labora- our observations and contributing in contrast to the situation at the tory in all these studies by Helen a unifi ed data set to the U.S. JGOFS BATS site, DOM is accumulating over Quinby, who has probably counted database. With Thomas Anderson of decadal time scales in the North more bacteria than any other single Southampton Oceanography Centre, Pacifi c gyre. human being. we have been working on models to Untangling the physical and We achieved a better understand- follow the fl ows of carbon through biological processes generating these ing of these patterns at a mechanistic bacterial consumers as part of the contrasting patterns is still helping level during the iron enrichment U.S. JGOFS Synthesis and Modeling us to understand the intricacies of studies. These large-scale manipula- Project (SMP). Tom’s models show carbon cycling in the open sea. tive experiments were not part that oceanic bacterial production Craig and Matt went on to stints of JGOFS per se, but they were has to be less than about 15% of directing the BATS and HOT observa- conceived by the late John Martin the simultaneous primary produc- tional programs, respectively, while he was active in U.S. JGOFS, tion unless subsidized by stored or illustrating the role of JGOFS in and they were strongly infl uenced imported DOC. training and employing new genera- by JGOFS. In a follow-on to our SMP work, we tions of oceanographers. My third JGOFS doctoral student are working with Dennis Hansell of Meanwhile, we went on to Jacques Oliver participated in the University of Miami to explain contribute bacterial abundance and the U.S. Southern Ocean Iron the variability of DOC concentra- productivity observations to the Experiment (SOFeX) in 2002 and tions and their role in supporting North Atlantic Bloom Experiment showed how bacteria responded to net heterotrophy in the open sea. (NABE), the Equatorial Pacifi c the increased DOC fl ux stimulated Dennis’s global-scale observations Process Study (EqPac), the Arabian by the iron additions suffi ciently to of DOC concentrations show how Sea Process Study and the Antarctic escape grazer control. Variations on basin-scale transports of DOC Environment and Southern these patterns were also observed constrain estimates of ocean metabo- Ocean Process Study (AESOPS), during two international iron lism. Thus at the end of JGOFS we collaborating along the way with experiments, the Southern Ocean have achieved a good mechanistic David Kirchman of the University Iron Release Experiment (SOIREE), picture of the regional- and global- of Delaware and Farooq Azam of conducted in antarctic waters scale regulation of bacteria and can Scripps Institution of Oceanography south of Australia in 1999, and the explain quantitatively their roles in and their students. Subarctic Ecosystem Response to the carbon cycle. In the North Atlantic and the Iron Enrichment Study (SERIES), Finally, I would like to acknowl- Ross Sea in the Antarctic, bacterial conducted in the northeast Pacifi c edge the central role JGOFS has dynamics are strongly infl uenced in 2002. Using genomic techniques, occupied in my career. I’m grateful by annual spring phytoplankton Jacques demonstrated that iron to the National Science Foundation’s blooms, breaking free from grazer enrichment not only affects bulk Chemical Oceanography and control, blooming themselves and bacterial properties but also leads to Biological Oceanography programs consuming semi-labile DOC. In changes in community composition and the Offi ce of Polar Programs for the equatorial Pacifi c, bacteria are at the species level. 20 years of generous support to do tightly controlled by the balance Genomic probes were just begin- this work. And I’ve been especially between DOC supply and removal ning to be used widely toward the fortunate to have wonderful students by protozoan grazers. Their numbers end of JGOFS. They represent the and colleagues. It goes without say- and production rates are remarkably next frontier in marine bacterial ing that this work would not have constant over time. ecology. The ability to follow species- been possible without them.❖ The Arabian Sea experiment level dynamics of oceanic bacteria (Editors’s note. Hugh Ducklow of the Vir- yielded a regional and seasonal view puts microbial ecology about where ginia Institute of Marine Sciences wrote to of bacterial variability. We saw both phytoplankton science was a cen- us from R/V Laurence M. Gould on his bloom-like patterns reminiscent of tury ago, when oceanographers in way home from Palmer Station in Antarc- the North Atlantic in the coastal up- Germany and the United Kingdom tica in mid November. Hugh served terms welling province and a low, uniform routinely discussed diatom and as a member and chairman on both the “background” state resembling that fl agellate blooms. U.S. JGOFS Scientifi c Steering Committee of the equatorial Pacifi c in the oli- Since the end of the process (SSC) and the JGOFS SSC.)

8 U.S. JGOFS Newsletter – November 2004 U.S. JGOFS Legacies: The Value Of Central Planning And Data Management by Ken O. Buesseler

am truly committee (SSC) to set program new model of how the ocean works. Ia “son priorities and data-quality standards. For those of us who grew up with of JGOFS,” They demanded the timely submittal the JGOFS open data system, it is having been of results and promoted the broad- hard to imagine going back to the fortunate est use of these data by the ocean days of individual data sets held by enough to sciences community. This may not each investigator, to be found only participate seem revolutionary in retrospect, but partially in a table or appendix to a in every U.S. these defi ning characteristics of U.S. paper or perhaps even deposited in JGOFS fi eld JGOFS, I would argue, have contrib- a data repository, but certainly not Ken Buesseler study from uted to the program’s many successes available online with supporting the 1989 North Atlantic Bloom and increased greatly the scientifi c documentation. Most often such Experiment on before becoming ex- impact of individual studies. data were only obtainable in useful ecutive scientist of the U.S. JGOFS Where does one see this impact? form by contacting each and every Planning and Data Management Of- Anyone who goes to a large investigator for his or her part of the fi ce (PDMO) at Woods Hole Oceano- national or international meeting larger scientifi c story one was trying graphic Isntitution (WHOI). From that includes ocean biogeochemistry to weave. both of these perspectives, I want to and/or carbon-cycle science will What is the price of this often refl ect on the value for a major ocean undoubtedly fi nd JGOFS data being underappreciated activity? program of centralized planning and presented in some talk or poster. At its busiest, the U.S. JGOFS data management. Why is this so common? PDMO was supported at a level From the inception of what The scientifi c community knows equivalent to 4% to 8% of total pro- was then the Global Ocean Flux the value of high-quality, well- gram costs. This included support Study (GOFS) in the mid 1980s, organized and readily available data. for more than 56 topical meetings Neil Andersen at the U.S. National These data are essential, as many of leading to 44 reports, publication Science Foundation and many other the cutting-edge questions in ocean of 48 issues of U.S. JGOFS News, program managers at the federal sciences today demand supporting initiation of a common web-based agencies worked with members of results to interpret the work of indi- system for sharing data and informa- the U.S. JGOFS scientifi c steering vidual investigators or to develop a tion, organization and sponsorship of 36 SSC meetings, two or three participants’ meetings after each pro- U.S. JGOFS Statistics cess study and annually during the • 272 principal investigators Synthesis and Modeling Project, and • Scientists at 75 institutions involved in U.S. JGOFS production of brochures and articles • 73 Scientists have served on the U.S. JGOFS Steering Committee for education and outreach. I’d argue • U.S. JGOFS grants to scientists in 26 states and the District of Columbia, this was money well spent. plus Bermuda, Canada, France, Germany and the United Kingdom We are at an important crossroads • Scientists from 22 countries collaborated on U.S. JGOFS projects in studies of the ocean carbon cycle. • More than 300 undergraduate and graduate students supported on U.S. Individual projects and small-scale JGOFS grants experiments are underway that are • 1,053 scientifi c publications to date designed to test important post- • 21 special issues of Deep-Sea Research II with 2 more underway JGOFS themes: the role of mesoscale • 343,000 nautical miles of ocean explored on research cruises (almost 16 eddies in the ocean cabon cycle, the times around the globe) effects of nitrogen and phosphorus • 3,040 days at sea (8+ years) conducting U.S. JGOFS fi eld studies cycling on phytoplankton growth, Data collected by the U.S. JGOFS Planning and Data Management the importance of iron and other Offi ce as of October 2004 Continued on page 16

U.S. JGOFS Newsletter – November 2004 9 U.S. JGOFS Data Management: Then And Now by Cynthia L. Chandler

ata management has been an The nature of the SMP results, Dintegral part of U.S. JGOFS since which included gridded output the program was launched. It is excit- from large-scale model simulations, ing to look back and see how far we required a new interface. Data man- have come in 15 years. agers and SMP coordinators started George Heimerdinger, then to look into interactive data access Northeast liaison offi cer for the systems, including the Distributed National Oceanographic Data Center, Ocean Data System (DODS) and the got the ball rolling in 1989 when Live Access Server (LAS). data gathered aboard R/V Atlantis In 2000, DMO staff members be- II duringduring tthehe NNorthorth AAtlantictlantic BBloomloom gan working with a team of software Experiment (NABE) began to arrive engineers at the National Oceanic at his offi ce at the Woods Hole and Atmospheric Administration’s Dave Gray Oceanographic Institution (WHOI). Cynthia Chandler Pacifi c Marine Environmental George received the data, typically in Laboratory and the Joint Institute the form of ASCII fi les on 5 1/4-inch By 1996, the Arabian Sea for the Study of the Atmosphere fl oppy disks, and worked diligently cruises had been completed, and the and Ocean at the University of with the contributors to collect Southern Ocean cruises had begun. Washington. The goal was to create metadata information and complete U.S. JGOFS was increasingly able to a customized LAS interface capable quality assurance testing. promote the exchange of data and of serving gridded data from SMP At the same time, Glenn Flierl information among investigators and projects as well as the merged data of the Massachusetts Institute of the sharing of the growing database products that DMO staff members Technology, James Bishop, then at with scientists worldwide who were were planning to put together from Lamont-Doherty Earth Observatory interested in cross-disciplinary selected process study data. (LDEO), David Glover of WHOI and biogeochemical research. By the end of 2000, nearly 80% of Satish Paranjpe of LDEO developed David Schneider joined the DMO the data from the four U.S. JGOFS a new object-oriented distributed in 1996 to work primarily on data process studies had been submitted, database system that provided access from the Arabian Sea and Southern and the DMO launched a synthesis to the growing collection of data. A Ocean fi eld studies. In 2000, Glover effort of its own. CTD and bottle series of workshops were organized to became director of the DMO, and profi le data from all cruises within a introduce scientists to the database Cynthia Chandler took over as data single process study were combined system and to provide training. manager when Hammond moved to in new data products organized By the end of 1992, the database another position at WHOI. by sampling device (CTD or bottle had grown to 16 megabytes and Synthesis and Modeling Project type). The most complex of these included observations from both (SMP) results started coming online products was the Southern Ocean NABE and the Equatorial Pacifi c in 1999, thanks to efforts by Joanie Niskin bottle data set, which came Process Study. Christine Hammond, Kleypas of the National Center for from 11 cruises and included 158 who joined the U.S. JGOFS Data Atmospheric Research. The data pol- different data variables in addition to Management Offi ce (DMO) at WHOI icy developed for the SMP, like the the metadata parameters. in 1994, took advantage of the one for the fi eld studies, emphasized By the end of 2002, the DMO was emerging Internet and developed a the need to provide investigators serving some 98% of the process World Wide Web browser interface with timely access to results as well study data, along with the growing for the U.S. JGOFS database. This ap- as tools to facilitate interdisciplin- collection of results generated by proach provided online, on-demand ary research and the successful SMP investigators, at http://usjgofs. access to the growing collection of interaction of fi eld researchers and whoi.edu/jg/dir/jgofs . The initial U.S. JGOFS data and metadata. modelers. volume of a fi nal data report was

10 U.S. JGOFS Newsletter – November 2004 published on CD-ROM and distrib- dictionary of core JGOFS parameters advances in technology that have uted fi rst to participants at the fi nal and several international data collec- occurred over the last decade and JGOFS Open Science Conference, tions on electronic media. a half, the basic principles for held in May 2003 in Washington, As U.S. JGOFS nears completion, managing data articulated by the D.C. the DMO is continuing to serve the JGOFS Working Group on Data So far, more than 800 copies of needs of the program. The DMO, Management in 1988 are still valid the fi rst volume of the U.S. JGOFS largely through the efforts of Jeff today. data report have been mailed to Dusenberry of WHOI, will continue They are: libraries, institutions and researchers to work with SMP investigators to • Scientists will generate data in a worldwide. Volume one includes all complete the online inventory of format useful for their needs. of the data acquired during the four data and results. The data server will • Oceanographic data sets are best U.S. JGOFS process studies between continue to provide access to the organized in terms of metadata. 1989 and 1998. A second volume, fi eld study data as well as SMP results • Data managers should avoid use also published on CD-ROM, includes as long as there is continued fund- of coded data values. a selection of SMP results. It was fi rst ing from the U.S. National Science • Users should be able to obtain distributed in July 2004 at the fi nal Foundation (NSF). all the data they require from one SMP investigators’ workshop. The The fi nal step toward preserving source and in a consistent format. DMO is preparing additional SMP the U.S. JGOFS data legacy will be to • Data interchange formats should results for a third volume, which will transfer information and materials be designed for the convenience of be published on DVD-ROM. from the planning offi ce and DMO scientifi c users. to the WHOI data library and ar- The working group also recognized International Collaboration chives. Data from the two U.S. JGOFS the special challenges presented U.S. JGOFS data managers time-series programs, the Hawaii by biological oceanographic data, benefi ted from participation in the Ocean Time-series (HOT) study and specifi cally the lack of universally JGOFS Data Management Task Team Bermuda Atlantic Time-series Study agreed-upon defi nitions for impor- (DMTT). Through collaboration with (BATS), will continue to be served tant terms such as “biomass” and data managers from seven other from the University of Hawaii and “production.” This is still true today. national JGOFS programs, DMO staff the Bermuda Biological Station for Finally, it has been enlightening members were able to facilitate the Research respectively. Data from the to search through the folders of contribution of U.S. JGOFS results U.S. JGOFS Global Survey of Carbon communications records going back to the international data collection Dioxide (CO2) in the Oceans is avail- to 1989 and NABE. One is reminded effort and to ensure data availability able online at the Carbon Dioxide how crucial it is to have dedicated and free and open communication Information and Analysis Center data personnel working with in- of results. The DMTT published (CDIAC). vestigators to gather complete and inventories of all JGOFS cruises, a In spite of the extraordinary accurate geographical, temporal and methodological metadata. This is an exciting time to be Internet addresses for U.S. JGOFS data and information working in the fi eld of ocean informatics. Data and information Home page http://usjgofs.whoi.edu management will continue to be Data server http://usjgofs.whoi.edu/jg/dir/jgofs recognized as essential components of any scientifi c endeavor. U.S. SMP home page http://usjgofs.whoi.edu/mzweb/syn-mod.htm JGOFS participants and other inter- SMP LAS http://usjgofs.whoi.edu/las ested scientists are most fortunate that the U.S. NSF recognized the HOT and BATS data http://usjgofs.whoi.edu/research/timeseries.html importance of data management

CO2 survey http://cdiac.esd.ornl.gov/ early on and supported it throughout the program. And we of the DMO JGOFS Open Science Conference http://usjgofs.whoi.edu/osc2003.html are most fortunate to work with such U.S. JGOFS fi nal data report http://usjgofs.whoi.edu/publications/ an extraordinary community of FinalDataRpt.html scientists and managers.❖

U.S. JGOFS Newsletter – November 2004 11 Final U.S. JGOFS SMP Workshop Marks End Of An Era by Scott C. Doney

n era came to an end last sum- approaches and thus the underlying deep sea to the thermocline. Irina Amer with the fi nal U.S. JGOFS assumptions about how ecosystems Marinov, also of Princeton, showed Synthesis and Modeling Project function can generate strikingly modeling results suggesting a decou- (SMP) science workshop, which took different behavior from the same pling of atmospheric carbon dioxide

place at Woods Hole Oceanographic observational data. Perhaps the best (CO2) and biological export because Institution (WHOI) in mid July. Be- quote of the meeting came from of the limited exchange between two ginning in 1996, the SMP has hosted Steele, who mused on how we can distinct circulation cells, mid-depth summer meetings each year to high- avoid generating “false models tested North Atlantic Deep Water fl ow and light research advances and outstand- by inadequate data.” deep Antarctic Bottom Water fl ow. ing science questions in marine bio- A second set of presentations While the main focus of the SMP geochemistry and modeling. While emphasized the role of ocean physics has been on the open ocean, as was the format and participants have in structuring marine biogeochem- true of the U.S. JGOFS fi eld pro- changed with time, the informal istry. William Jenkins of WHOI grams, there is growing evidence for atmosphere and stimulating discus- discussed the so-called “subtropical the global importance of continental sions have remained as hallmarks of nutrient spiral.” This new hypothesis shelf and margin systems. Three of these gatherings. proposes that vertical mixing in the plenary talks presented interest- The fi nal SMP workshop was western boundary currents such as ing new results from regional coastal smaller than most of its predecessors, the Gulf Stream provides a pathway carbon-cycle and ecosystem models. with only about 50 participants. for resupplying nutrients from the Katja Fennel of Rutgers University Events included a series of plenary mid and lower thermocline to the suggested that nitrogen losses from research presentations, posters from upper ocean to support biological sedimentary denitrifi cation on the individual SMP groups, open discus- productivity in the subtropical gyres. shelf and margin along the U.S. sions and the fi nal SMP clambake In a nicely complementary East Coast may exceed the regional and volleyball game. Many now- talk, Jorge Sarmiento of Princeton nitrogen input from rivers. Fei Chai familiar science themes were woven University highlighted the similar of the University of Maine and through the talks and posters pre- global-scale role of the Antarctic Nicolas Gruber of the University of sented at the workshop. Highlighted Circumpolar Current and California at Los Angeles presented topics included the effects of iron Subantarctic Mode Water formation fertilization on ocean biology and in transporting nutrients from the Continued on page 16 the marine carbon cycle, projected biogeochemical responses to future climate change, and the development and testing of more sophisticated marine ecosystem models. Validation of marine ecosystem models is diffi cult and often incom- plete because of the lack of informa- tion on key stocks and rates, even from the most data-rich fi eld sites. John Steele of WHOI and Edward Laws of the University of Hawaii presented plenary talks on two different approaches for optimizing model parameters against data, one with the objective of maximizing ecosystem resiliency and the other

with minimizing the aggregate fl ows Kleindinst Tom between model compartments. The Participants in the fi nal SMP workshop in July 2004.

12 U.S. JGOFS Newsletter – November 2004 The Future Of Ocean Biogeochemical Research by Scott C. Doney

lthough our basic understanding ning documents have explored Aof ocean biogeochemistry has these issues in detail. They include improved dramatically over the the “Ocean Carbon Transport, last decade and a half during the Exchanges and Transformations JGOFS era, many critical questions (OCTET)” report, produced in 2000 remain unresolved. Some of these by Cindy Lee and colleagues with questions would sound very familiar support from the National Science to the planners of the earliest Foundation (http://www.msrc. JGOFS projects. sunysb.edu/octet/); “A Large-Scale

For example, considerable CO2 Observing Plan: In Situ Oceans uncertainty still exists about the and Atmosphere (LSCOP),” produced seasonal-to-interannual variability by Michael Bender and colleagues in the air-sea fl ux of carbon dioxide in 2002 as a National Oceanic and

(CO2). Also, we do not yet know how Atmospheric Administration special the oceanic uptake of CO2 from the report; and the “United States Surface atmosphere is likely to evolve over Ocean - Lower Atmosphere Study

the next several centuries as ocean Kleindinst Tom (U.S. SOLAS) Workshop Report and circulation and ecological systems Scott Doney Recommendations” (http://www. change with greenhouse warming aoml.noaa.gov/ocd/solas), produced and other global environmental Addressing these questions by Rik Wanninkhof and colleagues perturbations. requires integrated research efforts in 2002. Other problems, not necessarily all on a variety of fronts, ranging from Recent advances in autonomous new, are currently receiving more at- monitoring the temporal evolution sensors and platforms, including tention. These include the ecological of the ocean inorganic carbon inven- fl oats, gliders, underwater vehicles responses to higher CO2 and lower tory to innovative process studies and cabled observatories, are likely pH in surface waters, biogeochemical of poorly understood biological and to alter the fi eld of ocean biogeo- transformations in the mesope- chemical dynamics. In a break with chemistry over the next decade in lagic ocean, coastal eutrophication, the past, the design of fi eld experi- fundamental ways, providing data interaction between open ocean ments should, from the start, build at much higher temporal and spatial systems and those of the continental on a backbone of long-term ocean densities than has been available margins, and the scientifi c underpin- observing system elements, satellite from ship-based studies. Similarly, nings for deliberate carbon mitiga- remote sensing, advanced numerical the application of new molecular and tion strategies such as CO2 injection models and data assimilation. genomic techniques to the ocean is and iron fertilization. Several recent scientifi c plan- driving a scientifi c revolution in ma- rine microbiology. Discoveries range Ongoing Ocean Carbon Observing Programs from previously unknown groups of organisms and novel metabolic path-

CLIVAR/CO2 Repeat Hydrography Program (http://ushydro.ucsd.edu/) ways to a deeper appreciation of the fundamental genetic and functional VOS Underway pCO2 Program (http://www.pmel.noaa.gov/co2/uwpco2/) diversity of oceanic microbes. Hawaii Ocean Time-series (HOT) study (http://hahana.soest.hawaii.edu/ Many of the needed research com- hot/hot_jgofs.html) ponents are already in place as part Bermuda Atlantic Time-series Study (BATS) (http://www.bbsr.edu/cintoo/ of ongoing ocean carbon observing bats/bats.html) programs (see accompanying box). Carbon Retention in a Colored Ocean (CARIACO) time-series study Following the dramatic success of (http://imars.usf.edu/cariaco/index.html) the satellite-mounted SeaWiFS ocean Monterey Bay time-series study (http://www.mbari.org/bog/Projects/ CentralCal/intro.htm) Continued on page 19

U.S. JGOFS Newsletter – November 2004 13 Open Questions After JGOFS: Winter Chlorophyll Levels In The Two Subpolar HNLC Regions by Karl Banse

ne question that persists after Second, during the solstices, and cell division rates? Conversely, OJGOFS is why offshore phyto- underwater irradiance and therefore since there seem to be enough small plankton chlorophyll is almost as phytoplankton cell division rate zooplankton around to suppress high in winter as it is in summer in appear to play almost no role, given the spring bloom and control the two subpolar regions, the subarctic that we see no relationship between phytoplankton concentration during Pacifi c and the subantarctic ring of pigment levels and mixed-layer the summer, why does wintertime water around Antarctica between the depths down to 250 meters, as I grazing not depress pigment levels Subtropical Convergence and the have shown in a 1996 article in to the low values seen in the North Polar Front. These regions are situat- Progress In Oceanography. Atlantic and the Antarctic proper? ed at low latitudes north and south Third, the strongly changing in- Finally, why does grazing keep (roughly between 45° and 60°). cident irradiance in the two HNLC phytoplankton concentrations at Both are high nutrient-low chloro- regions leads to markedly changing observed levels rather than reducing phyll (HNLC) regions, characterized integrated photosynthetic rates them to, say, a third of these levels by scarcity of iron and a general from one season to the next, yet the in the vast regions of the warm absence of spring phytoplankton chlorophyll changes little. We know open sea, which also exhibit little blooms. that lack of iron prevents blooms seasonal change of phytoplankton, Open-sea iron fertilization of the large phytoplankton species but because of scarcity of available experiments of the last decade in during spring and summer. But why nitrogen and phosphate? How does the HNLC regions have focused our do the small phytoplankton, which the oligotrophic ocean really work?❖ interest almost entirely on dramatic exhibit relatively high division (Editor’s note: Karl Banse is in the School phytoplankton blooms of large rates even under iron stress, not of Oceanography at the University of species inside the fertilized patches. accumulate more biomass during Washington.) The mechanisms underlying these the summer? blooms seem to be analogous to In an article in Biological those in the adjoining coastal Oceanography inin 11985,985, GG.T..T. EvansEvans regions or near the ice edge. In and J.S. Parslow presented a simple contrast, little attention has been analytical model on annual plank- paid to data from the control areas ton cycles. This model suggests outside the patches, beyond using that, if high food supply during the U.S. JGOFS News them for contrast. Such data could winter keeps enough zooplankton Published by the U.S. JGOFS answer the question: How do the around, the spring bloom will be Scientifi c Steering Committee subpolar HNLC regions, more than suppressed when Sverdrup’s critical Editor: Margaret C. Bowles one tenth of the entire ocean, work depth theorem would predict it. Designer: Jeannine M. Pires in their natural state? We now know that in HNLC U.S. JGOFS News reports on U.S. contribu- tions to the Joint Global Ocean Flux Study Several puzzles remain to be regions the very small phytoplank- (JGOFS) of the Scientifi c Committee on resolved. First, the chlorophyll in ton that can cope with low iron Oceanic Research (SCOR), a permanent the two regions is much higher levels are controlled by protozoans committee of the International Council of Scientifi c Unions (ICSU). JGOFS is a core in winter than it is in the North with about the same division project of the International Geosphere- Atlantic with its deep mixed layers rates as their prey. We also believe Biosphere Programme (IGBP). or in the Antarctic zone proper, that truly deep mixed layers in This is the fi nal U.S. JGOFS News. almost as high as summer levels. winter would negate phytoplankton For information, contact: Although the carbon-to-chlorophyll growth. But why do we fi nd in Mary Zawoysky ratio is probably higher in summer, the two subpolar HNLC regions U.S. JGOFS Planning Offi ce, MS #43 I doubt that the phytoplankton overall about as much chlorophyll Woods Hole Oceanographic Institution Woods Hole MA 02543-1047 U.S.A. carbon concentration in summer is in winter as in summer, in spite of (508) 289-2834 twice that of winter. the reduced underwater irradiance

14 U.S. JGOFS Newsletter – November 2004 New International Study To Focus On Trace Elements And Isotopes In The Ocean by Robert F. Anderson and Gideon M. Henderson

ince the late 1990s, marine geo- make signifi cant progress in trace studies. Sections and process studies Schemists have been working to element biogeochemistry. Advances will involve close cooperation among develop a comprehensive global in clean sampling protocols and fi eld and laboratory investigators and study of the ocean biogeochemical analytical techniques provide un- modelers. cycles of trace elements and their precedented capability for measure- The sections will cross regions that isotopes. These efforts have evolved ment of a wide range of elements. provide the most information about into an international program called New analytical methodologies that sources, sinks and internal cycling GEOTRACES. permit sampling at high density and of trace elements. Although no Creation of GEOTRACES was mo- new modeling strategies, applied commitments have yet been made tivated by the dual realization that successfully during the World Ocean to particular sections, priority will trace elements and their isotopes Circulation Experiment (WOCE) and be assigned to regions of prominent play critical roles in the ocean, but the Joint Global Ocean Flux Study sources or sinks, such as dust plumes, that our incomplete understanding (JGOFS), make this the right time to major rivers, hydrothermal plumes of their cycles limits our ability to mount a major international research and continental margins. Sections address problems in many areas of program to study the global marine will also sample principal water ocean science. For example, distribu- biogeochemical cycles of trace ele- masses as well as the major biogeo- tions, sources and sinks of trace ments and their isotopes. graphic provinces. elements serving as essential micro- GEOTRACES has two principal The resources needed for this nutrients are known so poorly that goals: to determine global oceanic global ocean survey will require their sensitivity to global change, as distributions of selected trace metals international cooperation. An well as their role in marine ecosys- and their isotopes, and to evaluate international program will also allow tems and the ocean carbon cycle, the sources, sinks and internal cy- intercalibration and standardization cannot be predicted or modeled in cling of these elements and thereby of methods used in the analytically- a meaningful way. The removal of characterize the physical, chemical challenging measurement of trace many dissolved trace elements from and biological processes regulating elements as well as their transfer the surface ocean via sinking par- their distributions. among national programs. ticles was discovered decades ago, yet Studies will be organized under Numerical models will offer we still lack quantitative rates and a two themes. Theme 1 will focus on opportunities to combine and evalu- mechanistic understanding of many modern cycling of trace elements ate physical and biogeochemical removal processes. and their isotopes by quantifying processes and allow us to infer fl uxes Paleoceanographic records demon- fl uxes at the principal ocean interfac- and source/sink rates from a com- strate striking correlations between es (the atmosphere, the continental parison of simulated trace element elemental and isotopic distributions margins and the mid-ocean ridges) fi elds with measured distributions. and independent indicators of and by determining rates of internal GEOTRACES will make use of a hier- climate variability. However, our cycling within the ocean through archy of models, including coupled ability to exploit these records to biological uptake, chemical scaveng- physical/biogeochemical general reconstruct processes and conditions ing and physical transport. Theme circulation models, box models, in the past is limited by incomplete 2 will focus on trace elements that chemical speciation models and characterization of their biogeo- serve as paleoceanographic proxies inverse models. chemistry in the modern ocean. in order to improve our understand- Recent advances in data assimila- Quantifi cation of past changes in ing of the factors controlling proxy tion and inverse modeling now allow ocean biogeochemistry provides vital distributions in the water column direct data utilization methods not constraints on ocean models and and in sediments. yet applied for determination of therefore on our ability to forecast GEOTRACES is intended to be trace element fl uxes. Inverse models future changes. global in scope, with ocean sections promise to be an important part Marine geochemists are poised to complemented by regional process of ongoing and future studies of

U.S. JGOFS Newsletter – November 2004 15 ocean circulation. Expanding these to provide oversight of the planning ment strategy, the development and approaches to assimilation of trace for GEOTRACES. The planning group distribution of standard reference element distributions offers a strat- organized under SCOR sponsorship materials, and the organization egy for quantifying fl uxes, including to prepare a science plan held its fi rst of intercalibration exercises. An the uptake and regeneration of trace meeting in June 2004 in Oxford, international planning offi ce will elements by sinking particles. United Kingdom. A draft of the be set up and managed under SCOR Formal planning of GEOTRACES science plan will be released for oversight. GEOTRACES will be con- began with an international public comment early in 2005, and ducted in close collaboration with workshop in Toulouse, France, in comments will be incorporated into a other international ocean research April 2003 that brought together revised document at the second plan- initiatives and modeling programs 85 scientists from 15 nations. The ning group meeting in May 2005. to ensure synergy between programs Toulouse meeting was followed by After the science plan has been com- and to avoid unnecessary duplication regional and national planning pleted, a scientifi c steering committee of effort.❖ workshops in Europe, North America (SSC) will be formed to oversee (Editor’s note: Robert Anderson, co-coordi- and Japan. Planning is underway for implementation of the program. nator of the U.S. JGOFS Antarctic Environ- similar workshops in Canada, China Early tasks for the GEOTRACES ment and Southern Ocean Process Study, and elsewhere. SSC, in preparation for the main fi eld is at Lamont-Doherty Earth Observatory. In 2003 the Scientifi c Committee program, include formulation of a Gideon Henderson is in the Department of on Oceanic Research (SCOR) agreed data submission policy and manage- Earth Sciences at Oxford University.)

Legacies–from page 9 and quality-controlled format and benefi t of the heroes who worked served up freely via a continually behind the scenes, not collecting micronutients, the transformations improving web-based system. new data or writing new research to sinking fl uxes in the mid water In the post-JGOFS era, self-selected papers but making it easier for the column, and the exchanges at the groups of investigators are moving rest of us to do so. It is to this group, ocean boundaries. On one hand, the ahead to tackle important questions the staff members who have worked JGOFS style of interdisciplinary fi eld related to the ocean carbon cycle. over the past 15 years in the PDMO and modeling work continues. But they have lost, hopefully only and the scientists who have served On the other, without centralized temporarily, the many benefi ts that on the SSC, that I want to offer planning, there are few organized were brought to us through central- my sincerest appreciation. Thanks workshops with project investigators, ized planning and data management to these individuals and to robust outside experts and modelers to in JGOFS. support for these activities from the evaluate and utilize data to their It is only appropriate that we federal agencies, JGOFS is more fullest. There is also no home for the acknowledge in this last issue of than the sum of its parts. I hope this “orphaned” data sets that are now U.S. JGOFS News our debt to these lesson is not lost as we move ahead accumulating on hard drives, rather underappreciated aspects of conduct- on the next generation of ocean than being organized into a common ing science. Scientists today reap the science studies.❖

SMP Workshop–from page 12 still underway. A third SMP special whoi.edu/mzweb/data.html), and volume of Deep-Sea Research II is in more are being posted regularly. simulation results for the eastern the works, with an expected publica- This resource will be maintained as boundary upwelling system along tion date of late 2005. The Regional long as possible online, and a subset the U.S. West Coast, where plankton Ecosystem Modeling Test-Bed will be preserved on discs (DVDs) by bloom dynamics are strongly Project, led by Marjorie Friedrichs of the U.S. JGOFS Data Management infl uenced by synoptic wind events, Old Dominion University, plans to Offi ce.❖ mesoscale eddies and topography. hold a workshop in early 2005. (Editor’s note: Scott Doney, Woods Hole The U.S. JGOFS Synthesis and Many of the synthetic data Oceanographic Institution, has served Modeling Project ends offi cially products and numerical simulations as co-chairman, with Jorge Sarmiento of in spring 2005. A variety of SMP produced by SMP investigators are Princeton University, of the U.S. JGOFS activities are continuing with about currently available online via the Synthesis and Modeling Project since a dozen funded research projects U.S. JGOFS web page (http://usjgofs. 1997.)

16 U.S. JGOFS Newsletter – November 2004 Publications Available From The U.S. JGOFS Planning Offi ce

U.S. JGOFS Reports U.S. GOFS Planning Report Number U.S. JGOFS Equatorial Pacifi c Process 10 (1989). Sediment Trap Technology Study Data and Science Workshop, Overview - Towards a Science Plan for and Sampling, Report of the U.S. GOFS No. 1 (1993). Proceedings Report, James GOFS: Program Elements, Priorities and Working Group on Sediment Trap Tech- Murray et al., 408 pp. Planning (1987). 19 pp. nology and Sampling, George Knauer and Vernon Asper co-chairmen, 94 pp. U.S. JGOFS Planning Report Number U.S. GOFS Report 2 (1986). Report of 18 (1993). Bio-optics in U.S. JGOFS, the U.S. GOFS Steering Committee on U.S. JGOFS Planning Report Number Tommy D. Dickey and David A. Siegel Plans for North Atlantic and Pacifi c Pi- 11 (1990). U.S. Joint Global Ocean Flux co-editors, 180 pp. lot Programs and Modeling, 55 pp. Study Long Range Plan, The Role of Ocean Biogeochemical Cycles in Climate U.S. JGOFS Planning Report Number U.S. GOFS Planning Report Number 4 Change, U.S. JGOFS Steering Committee, 19 (1995). BBOP Data Processing and (1987). Modeling in GOFS, Report of the 216 pp. Sampling Procedures, David A. Siegel et U.S. GOFS Working Group on Modeling al., 80 pp. in GOFS, Jorge Sarmiento, Bruce Frost U.S. JGOFS Planning Report Number and Joseph Wroblewski rapporteurs, 12 (1990). Isotopic Tracers, Report of a U.S. JGOFS Southern Ocean Process 142 pp. U.S. JGOFS Workshop on Radiochemis- Study Implementation Plan (1995). try, Michael P. Bacon chairman, Robert F. Robert F. Anderson and Walker O. Smith U.S. GOFS Planning Report Number Anderson rapporteur, 116 pp. Jr., 20 pp. 5 (1987). Benthic Studies in GOFS, Re- port of the U.S. GOFS Working Group U.S. JGOFS Planning Report Number U.S. JGOFS Synthesis and Modeling on Benthic Studies, Michael L. Bender 13 (1991). U.S. JGOFS: Arabian Sea Project Implementation Plan (1997). chairman, 149 pp. Process Study, Report of a National Jorge Sarmiento and Robert Armstrong, Planning Meeting, Sharon L. Smith et 73 pp. U.S. GOFS Planning Report Number 6 al., 168 pp. (1988). Ocean Margins in GOFS, Report U.S. JGOFS Planning Report Number of the U.S. GOFS Workshop on The Im- U.S. JGOFS Arabian Sea Process Study 20 (1997). North Atlantic Planning Re- pact of Ocean Boundaries on the Inte- Implementation Plan (1992). Sharon port, Hugh Ducklow et al., 92 pp. rior Ocean, George A. Knauer chairman, Smith, 26 pp. 245 pp. U.S. JGOFS Planning Report Number U.S. JGOFS Planning Report Number 21 (1998). Synthesis and Modeling Proj- U.S. GOFS Planning Report Number 7 14 (1992). Report of the U.S. JGOFS ect, Time-series Stations and Modeling (1988). Upper Ocean Processes, Report Workshop on Modeling and Data As- Planning Workshop Report, Scott C. of the U.S. GOFS Working Group on Up- similation, Mark R. Abbott chairman, Doney and Jorge L. Sarmiento, 97 pp. per Ocean Processes, Hugh W. Ducklow 28 pp. chairman, 88 pp. U.S. JGOFS Planning Report Number U.S. JGOFS Planning Report Number 22 (1999). Synthesis and Modeling U.S. GOFS Planning Report Number 8 15 (1992). Design for a Mesoscale Iron Project, Ocean Biogeochemical Response (1988). Data Management, Report of Enrichment Experiment, John Martin et to Climate Change Workshop Report, the U.S. GOFS Working Group on Data al., 26 pp. Scott C. Doney and Jorge L. Sarmiento, Management, Glenn R. Flierl chairman, 106 pp. 52 pp. U.S. JGOFS Planning Report Number 16 (1992). U.S. JGOFS Southern Ocean U.S. JGOFS Data Reports: HOT Ocean Color from Space (1989). U.S. Process Study Planning Workshop Re- GOFS Planning Offi ce. 18 pp. port, Robert F. Anderson chairman, U.S. JGOFS HOT Data Report H-1 114 pp. (1990). Hawaii Ocean Time-Series Data U.S. GOFS Planning Report Number 9 Report 1, HOT 1-12, Stephen Chiswell, (1989). Pacifi c Planning Report, Report U.S. JGOFS Planning Report Number Eric Firing et al., University of Hawaii, of the U.S. GOFS 3rd Pacifi c Planning 17 (1993). U.S. JGOFS Southern Ocean SOEST Technical Report #1, 269 pp. Meeting, Richard W. Eppley chairman, Process Study Science Plan, Robert F. 192 pp. Anderson, 67 pp.

U.S. JGOFS Newsletter – November 2004 17 Hawaii Ocean Time-Series Data Report U.S. JGOFS BATS Data Report B-3 JGOFS International Collection of 2, 1990 (1991). Christopher Winn, Ste- (1993). Bermuda Atlantic Time-Series CTD, XBT and SeaSoar Data, Arabian phen Chiswell et al., University of Ha- Study: Data Report for BATS 25-36, An- Sea Process Study (1990-1997) CD- waii, SOEST Technical Report 92-1, 175 thony H. Knap, Anthony F. Michaels et ROM. German JGOFS Data Management pp. and 5 1/4-inch diskette containing al., 339 pp. Offi ce, Kiel, Germany. data set. U.S. JGOFS BATS Data Report B-4 JGOFS International Collection DVD, Hawaii Ocean Time-Series Data Re- (1994). Bermuda Atlantic Time-Series Volume 1. Discrete Datasets (1989- port 3, 1991 (1993). Christopher Winn, Study: Data Report for BATS 37-48, An- 2000). Roger Lucas, David Karl and Eric Firing, thony H. Knap, Anthony F. Michaels et University of Hawaii, SOEST Technical al., 263 pp. Deep-Sea Research II Volumes Report 93-3, 228 pp. and 3 1/2-inch dis- kette containing data set. U.S. JGOFS BATS Data Report B-5 Copies of a number of special issues (1995). Bermuda Atlantic Time-Series of Deep-Sea Research, Part II on JGOFS Hawaii Ocean Time-Series Data Report Study: Data Report for BATS 49-60, An- programs are available from the U.S. 4, 1992 (1993). Luis Tupas, Fernando thony H. Knap, Anthony F. Michaels et JGOFS Planning Offi ce as well. All are Santiago-Mandujano et al., University of al., 240 pp. free unless otherwise noted: Hawaii, SOEST Technical Report 93-14, 248 pp. and 3 1/2-inch diskette contain- U.S. JGOFS BATS Data Report B-6 Murray, J.W., guest editor. A U.S. JGOFS ing data set. (1997). Bermuda Atlantic Time-Series Process Study in the Equatorial Pacifi c. Study: Data Report for BATS 61-72, An- Volume 42, nos. 2-3. 1995. Hawaii Ocean Time-Series Data Report thony H. Knap, Anthony F. Michaels et 5, 1993 (1994). Luis Tupas, Fernando al., 281 pp. Murray, J.W., guest editor. A U.S. JGOFS Santiago-Mandujano et al., University Process Study in the Equatorial Pacifi c, of Hawaii, SOEST Technical Report 94-5, Manuals on Protocols Part 2. Volume 43, nos. 4-6. 1996. 156 pp. and 3 1/2-inch diskette contain- ing data set. JGOFS Core Measurement Protocols. Murray, J.W., R. Le Borgne and Y. Dan- JGOFS Report No. 6 (1991). Scientifi c donneau, guest editors. A U.S. JGOFS Hawaii Ocean Time-Series Data Report Committee on Oceanic Research. 40 pp. Process Study in the Equatorial Pacifi c, 6, 1994 (1995). Luis Tupas, Fernando U.S. JGOFS BATS Method Manual Ver- Part 3. Volume 44, nos. 9-10. 1997. Santiago-Mandujano et al., University sion 4 (1997). Anthony H. Knap, An- of Hawaii, SOEST Technical Report 95-6, thony F. Michaels et al., 136 pp. Smith, Walker O. Jr. and Robert F. Ander- 199 pp. son, guest editors. U.S. Southern Ocean Other U.S. JGOFS publications JGOFS Program (AESOPS), Part II. Vol- Hawaii Ocean Time-Series Data Report ume 48, nos. 19-20. 2001. 7, 1995 (1996). David Karl, Luis Tupas et Bowles, Margaret C., editor. U.S. JGOFS al., University of Hawaii, SOEST Techni- News. Volumes 1 -12 (1989-2004). Doney, Scott C. and Joan A. Kleypas, cal Report 96-09, 228 pp. guest editors. The U.S. JGOFS Synthesis Buesseler, K.O., guest editor. Special Is- and Modeling Project: Phase II. Volume Hawaii Ocean Time-Series Data Report sue, JGOFS. Oceanography, vol. 14, no. 50, nos. 22-26. 2003. 8, 1996 (1997). Luis Tupas, Fernando 4. 2001. Santiago-Mandujano et al., University of Siegel, D.A., A.C. Thomas and J. Marra, Hawaii, 296 pp. A New Wave of Ocean Science. U.S. guest editors. Views of Ocean Processes JGOFS Planning and Data Management from the Sea-viewing Wide Field-of-view U.S. JGOFS Data Reports: BATS Offi ce. 2001. Sensor (Sea WiFS) Mission: Volume 1. Volume 51, nos. 1-3. 2004. $40 U.S. JGOFS BATS Data Report B-1A Publications on CD-ROM and DVD (1991). Bermuda Atlantic Time-Series Requests for publications should be Study: Data Report for BATS 1-12, An- U.S. JGOFS Final Data Report: Volume made to: thony H. Knap, Anthony F. Michaels et 1 (CD-ROM), Process Study Data (1989- Mary Zawoysky al., 268 pp. 1998); Volume 2 (CD-ROM), Synthesis U.S. JGOFS Planning Offi ce, MS #43 and Modeling Project, part 1; Volume Woods Hole Oceanographic Institution U.S. JGOFS BATS Data Report B-2 3 (DVD-ROM), Synthesis and Modeling Woods Hole, MA 02543-1047 USA (1992). Bermuda Atlantic Time-Series Project, part 2. email: [email protected] Study: Data Report for BATS 13-24, An- thony H. Knap, Anthony F. Michaels et al., 345 pp.

18 U.S. JGOFS Newsletter – November 2004 Future–from page 13 mooring systems. Science (http://www.carboncycle- Collectively, these efforts represent science.gov/occc-report.html). color sensor, data are now available a tremendous investment by the Related efforts are underway inter- from the MODIS instruments and U.S. government agencies and the nationally through SOLAS and the other sensors. In the future, ocean scientifi c community in studying the Integrated Marine Biogeochemistry color data will become an op- ocean carbon system. They form the and Ecosystem Research (IMBER) erational product from the NPOESS base for a much needed, coordinated study under the auspices of the satellite-mounted instruments. large-scale ocean biogeochemical International Geosphere-Biosphere A series of targeted, mid-sized program to follow on the successes Programme. ocean biogeochemical process of JGOFS. Oceanic responses to changing studies have been completed or are Building on the many previous climate conditions and the feedbacks underway, and plans are in place for community discussions, I recently between ocean and atmosphere are deploying an extensive new ocean led a working group of scientists in of more than academic interest. With observing infrastructure as part of developing just such a multi-agency OCCC, I hope that we have provided the NSF-sponsored Ocean Research implementation strategy for U.S. a blueprint for addressing pressing Interactive Observatory Networks ocean carbon research. Earlier this societal concerns and research ques- (ORION) (http://www.orionpro- year, we issued our report, titled tions for ocean biogeochemistry in gram.org/). ORION is likely to “Ocean Carbon and Climate Change the future.❖ include a regional cabled network, (OCCC): An Implementation coastal observatories and open-ocean Strategy for U.S. Ocean Carbon Cycle

(URI), and by Bender and Mary-Lynn Phytoplankton–from page 6 what we know, this makes sense. Dickson (also URI) for the Arabian Heterotrophic respiration is unlikely suggested that 14C uptake measures Sea cruises. to be directly dependent on solar ra- net production. A third ingredient For both data sets, twice the dark diation, but it is more closely related took more of a leap, and that was to loss of carbon overnight, when to the autotrophic biomass. The steep assume that phytoplankton respira- added to the daytime uptake, was decline of autotrophic respiration tion is the same during the day as equivalent to gross production (after is consistent with the idea that it at night. Thus, if there is metabolic applying the photosynthetic quo- is composed of respiratory energy equilibrium overnight, and if res- tient). This suggests that twice the used for growth combined with res- piration is equivalent both day and dark loss of carbon is a good estimate piration used for maintaining basal night, together with the observation of phytoplankton respiration. From cellular metabolism. that 14C estimates net or net primary there, the heterotrophic respiration, The analyses we have completed production during the day, then that is, from bacteria, protozoans and are only a beginning. There remain phytoplankton respiration can be microzooplankton can be calculated several issues to resolve for a more calculated to be twice the dark loss of from the difference between phyto- complete test of the hypothesis, such carbon overnight. plankton respiration and community as the effect of microzooplankton We tested this hypothesis using respiration. grazing on carbon assimilation, data from the JGOFS North Atlantic In the accompanying fi gure, I have other sources of respiration, the Bloom Experiment (NABE) and plotted the depth distribution of value of the photosynthetic quotient from two cruises during the U.S. phytoplankton and heterotrophic and the temperature dependence. JGOFS Arabian Sea expedition. It respiration for a station during Those interested in the topic can was only on two of these cruises NABE. This is the fi rst time that contact Barber or myself for reprints that both 12-hour and 24-hour 14C we can see the distribution of the of published work.❖ incubations and 18O gross produc- components of respiration in the (Editor’s note: John Marra, who is at tion measurements were done. The plankton. Lamont-Doherty Earth Observatory, served 18O incubations and analyses were While heterotrophic respiration as chief scientist on U.S. JGOFS cruises carried out during NABE by John is more or less constant with depth, in the North Atlantic, Arabian Sea and Kiddon and Michael Bender, then the autotrophic respiration of the Southern Ocean.) at the University of Rhode Island phytoplankton declines. From

U.S. JGOFS Newsletter – November 2004 19 Photo courtesy of Mary Zawoysky A fond farewell from the U.S. JGOFS team: Clockwise from left, Cyndy Chandler, Ken Buesseler, Mardi Bowles, Mary Zawoysky, and Dave Glover.

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