climate change :: Ocean Carbon & Biogeochemistry

Studying marine ecosystems and biogeochemical cycles in the face of environmental change

Archive for climate change

Where the primary production goes determines whether you catch tuna or cod

Posted by mmaheigan

· Friday, September 6th, 2019

Fishes are incredibly diverse, fill various roles in their ecosystems, and are an important resource—economically, socially, and nutritionally. The relationship between primary productivity and fish catches is not straightforward; fisheries oceanographers and managers have long struggled to predict abundances and fully understand the controls of cross-ecosystem differences in fish abundances and assemblages. A recent study in Progress in Oceanography modeled the relationships between fish abundances and assemblages and ecosystem factors such as physical properties and plankton productivity.

The mechanistic model simulated feeding, growth, reproduction, and mortality of small pelagic forage fish, large pelagic fish, and demersal (bottom-dwelling) fish in the global ocean using plankton food web estimates and ocean conditions from a high-resolution earth system model of the 1990s. Modeled fish assemblages were more related to the separation of secondary production into pelagic zooplankton or benthic fauna secondary production than to primary productivity. Specifically, the ratio of pelagic to benthic production drove spatial differences in dominance by large pelagic fish or by demersal fish. Similarly, demersal fish abundance was highly sensitive to the efficiency of energy transfer from exported surface production to benthic fauna.

The model results offer a systematic understanding of how marine fish communities are structured by spatially varying environmental conditions. With global climate change, the expected decrease in exported primary production would lead to fewer demersal fish around the world. This model provides a framework for testing the effect of changing conditions on fish communities at a global scale, which can also help inform managers of potential impacts on economic, social, and nutritional resources worldwide.

Figure 1: (A) Sample food web with three fish types, two habitats, two prey categories, and feeding interactions (arrows). Dashed arrow denotes feeding only occurs in shelf regions with depth <200 m. (B) Fraction of large pelagic vs. demersal fishes (LP/(LP+D)) as a function of the ratio of zooplankton production lost to higher predation (Zoop) to detritus flux to the seafloor (Bent) averaged over large marine ecosystems. Solid line: predicted linear model response, dashed lines: standard error. (Lower panels) Circles=mean biomasses (g m^-2) and lines=fluxes of biomass (g m^-2 d^-1) through the pelagic (top 100m) and benthic components of the food webs at two test locations, (C) Peruvian Upwelling (PUP) ecosystem and (D) Eastern Bering Sea (EBS) shelf ecosystem. Circles and lines scale with the modeled biomasses and fluxes. Circle color key: Gray=net primary productivity (NPP); yellow=medium and large zooplankton; red=forage fish; blue=large pelagic fish; brown=benthos; green=demersal fish.

Authors:
Colleen M. Petrik (Princeton University, Texas A&M University)
Charles A. Stock (NOAA Geophysical Fluid Dynamics Laboratory)
Ken H. Andersen (Technical University of Denmark)
P. Daniël van Denderen (Technical University of Denmark)
James R. Watson (Oregon State University)

Regional circulation changes and a growing atmospheric CO2 concentration drive accelerated anthropogenic carbon uptake in the South Pacific

Posted by mmaheigan

· Tuesday, August 6th, 2019

About one tenth of human CO₂ emissions are currently being taken up by the Pacific Ocean, which makes the seawater more corrosive to the calcium carbonate shells and skeletons of the plants and animals that live there. Now, thanks to hard work by international teams of scientists from the Global Ocean Ship-based Hydrographic Investigations Program (GO-SHIP), there are decades of data, enough to test how much this anthropogenic CO₂ accumulation varies throughout the Pacific Ocean and regionally on the timescales of decades.

Figure caption: Map of the concentration of human-emitted CO₂ along the sections where data were available from more than one decade, estimated for the year 2015.

Using a new take on an old technique, along with a wide variety of repeat biogeochemical measurements, a study in Biogeochemical Cycles revealed that Pacific anthropogenic CO₂ accumulation increased from the 1995-2005 decade to the 2005-2015 decade. While the magnitude of the decadal increase was consistent with increases in human CO₂ emissions over this period for most of the Pacific, the rate of change was greater than expected in the South Pacific subtropical gyre. The authors suggest that recent increases in circulation in the gyre region could have delivered an unexpectedly large amount of anthropogenic CO₂-laden seawater from the surface to the ocean interior. Programs like GO-SHIP will continue to be critical for tracking the fate of human CO₂emissions and associated feedbacks on climate and marine ecosystems.

Authors:
B. R. Carter (Univ. Washington and PMEL)
R. A. Feely, G. C. Johnson, J. L. Bullister (PMEL)
R. Wanninkhof (NOAA AOML)
S. Kouketsu, A. Murata (JAMSTEC
R. E. Sonnerup, S. Mecking (Univ. Washington)
P. C. Pardo (Univ. Tasmania)
C. L. Sabine (Univ. Hawai‘i, Mānoa)
B. M. Sloyan, B. Tilbrook (CSIRO, Australia)
K. Speer (Florida State University
L. D. Talley (Scripps Institution of Oceanography)
F. J. Millero (Univ. Miami)
S. E. Wijffels (CSIRO and WHOI)
A. M. Macdonald (WHOI)
N. Gruber (ETH Zurich)

A new era of observing the ocean carbonate system

Posted by mmaheigan

· Tuesday, August 6th, 2019

Amidst a backdrop of natural variability, the ocean carbonate system is undergoing a massive anthropogenic change. To capture this anthropogenic signal and differentiate it from natural variability, carbonate observations are needed across a range of spatial and temporal scales (Figure 1), many of which are not captured by traditional oceanographic platforms. A new review of autonomous carbonate observations published in Current Climate Change Reports highlights the development and deployment of pH sensors capable of in situ measurements on autonomous platforms, which represents a major step forward in observing the ocean carbonate system. These sensors have been rigorously field-tested via large-scale deployments on profiling floats in the Southern Ocean (Southern Ocean Carbon and Climate Observations and Modeling, SOCCOM), providing an unprecedented wealth of year-round data that have demonstrated the importance of wintertime outgassing of carbon dioxide in the Southern Ocean.

Figure 1: Observational capabilities and carbonate system processes as a function of time and space. Ocean processes that affect the carbonate system (solid color shapes—labeled in the legend) are depicted as a function of the temporal and spatial scales over which they must be observed to capture important variability and/or long-term change.

Most current autonomous platforms routinely measure only a single carbonate parameter, which then requires an algorithm to estimate a second parameter so that the rest of the carbonate system can be calculated. However, the ongoing development of sensors and systems to measure, rather than estimate, other carbonate parameters may greatly reduce uncertainty in constraining the full carbonate system. It is critical that the community continue to develop and adhere to best practices for calibration and data handling as existing sensors are deployed in increasing numbers and new sensors become available. Expanding autonomous carbonate measurements will increase our understanding of how anthropogenic change impacts natural variability and will provide a means to monitor carbon uptake by the ocean in real-time at high spatial and temporal resolution. This will not only help to understand the mechanisms driving changes in the ocean carbonate system, but will allow new insights in the role of mesoscale processes in regional and global biogeochemical cycles.

Authors:
Seth M. Bushinsky (Princeton University/University of Hawai’i Mānoa)
Yuichiro Takeshita (Monterey Bay Aquarium Research Institute)
Nancy L. Williams (Pacific Marine Environmental Laboratory – NOAA / University of South Florida)

Deep ocean carbon reconstruction helps decipher a million-year-old climate mystery

Posted by mmaheigan

· Tuesday, July 23rd, 2019

Approximately one million years ago, Earth’s periodic ice ages increased in strength and duration, shifting from a 41,000-year pacing to a 100,000-year pacing, both linked to Earth’s orbital variations. The causes of this climate shift known as the mid-Pleistocene transition (MPT) have been debated for decades.

A recent study in Nature Geoscience addresses how the ocean carbon cycle contributed to the MPT by quantifying the carbon inventory of the deep Atlantic Ocean during this time. Using trace element and isotope ratios of fossil marine foraminifera, the authors demonstrate that an abrupt weakening of deep ocean overturning circulation between 950,000 and 900,000 years ago occurred alongside a pronounced increase in carbon content of the deep Atlantic Ocean. This study revealed significantly higher carbon concentrations in the deep North and South Atlantic basins during the post-MPT 100,000-year ice ages relative to the 41,000-year ice ages prior to the MPT (Figure 1).

Figure 1 caption: The last two million years of glacial cycles, with present day on left and age increasing from left to right. Orange data are from 41,000-year ice ages; blue data are from,100,000-year ice ages. (A) Glacial-interglacial cycles demonstrated in benthic oxygen isotopes (green), with warmer interglacials up and peak ice ages downward. (B) Atmospheric CO₂ from ice core measurements (gray lines) and reconstructed from boron isotopes (circles) (C), Peak ice age neodymium isotope ratios indicating strength of density-driven deep ocean circulation (squares and triangles indicate two different sediment cores). (D) Peak ice age deep ocean carbon content (squares and diamonds indicate two independent reconstructions from the same South Atlantic sediment core).

These data indicate that since 950,000 years ago, the deep Atlantic Ocean has stored an extra 50 billion tons of carbon during peak ice ages. This study hypothesizes that this extra carbon was sequestered from the atmosphere via a feedback between Antarctic ice sheet extent and the efficiency of air-sea carbon exchange in the Southern Ocean. The authors propose that intensification of ice ages one million years ago was closely linked to enhanced ocean carbon storage and resultant lowering of atmospheric CO₂ levels.

While paleoclimatologists consider the MPT to be the most recent major climate transition, the magnitude of carbon perturbation at the MPT pales in comparison to today’s human emissions. Today, humans produce 50 billion tons of carbon in only five years. Studies of the carbon cycle across past climate transitions like the MPT provide key insights on how future climate may respond to today’s carbon cycle disruption.

Authors
Jesse Farmer (LDEO Columbia University; now at Princeton University and Max Planck Institute for Chemistry)
Bärbel Hönisch, Laura Haynes, Maureen Raymo, Steven Goldstein, Maayan Yehudai, Joohee Kim (LDEO Columbia University)
Heather Ford (Queen Mary University of London)
Dick Kroon, Simon Jung, Dave Bell (University of Edinburgh)
Maria Jaume-Seguí, Leopoldo Pena (University of Barcelona)

See this related popular article and video in the Washington Post.

The competing impacts of climate change and nutrient reductions on dissolved oxygen in Chesapeake Bay

Posted by mmaheigan

· Wednesday, June 12th, 2019

The Chesapeake Bay is a 200-mile-long estuary with both economic and ecological importance to the mid-Atlantic region. Runoff, pollution, and algae blooms resulting in hypoxia have been major issues over the past 50 years, and much work has been done to improve the water quality and health of the Bay. Dissolved oxygen concentrations will be altered in response to climate change, but whether this will counteract the benefits of reduced nutrient loading is an important scientific and management question. Specifically, what are the impacts of climate change on future Chesapeake Bay hypoxia and on progress towards meeting water quality standards associated with the Chesapeake Bay Total Maximum Daily Load (TMDL)?

(Left) Latitudinal along-bay dissolved oxygen (DO) transects for the Base scenario (Base+noCC) and TMDL scenario (TMDL+noCC) without climate change; transects for the absolute and percent changes in DO due to climate change (TMDL+CC). (Right) Cumulative hypoxic volume for six ranges of DO concentrations for each of the study years and each of the scenarios (colored circles).

A recent study in Biogeosciences quantified the competing impacts of climate change and nutrient reductions on Chesapeake Bay hypoxia. The authors used a 3-D modeling system along with projected mid-21st century changes in temperature, freshwater flow, and sea level, assuming fully achieved goals of TMDL nutrient reductions. Of these three climate change factors, increased temperature most strongly impacts future hypoxia, primarily due to decreased solubility year-round and increased respiration and remineralization in the spring. Sea level rise is expected to exhibit a small positive impact resulting from increased estuarine circulation and reduced residence time. Increased river flow is anticipated to exert a small negative impact due to increased nutrient loading.

These results demonstrate that climate change may limit the effectiveness of future management actions aimed at reducing nutrient inputs to the Chesapeake Bay. However, the positive impacts of mandated nutrient reductions still outweigh the negative impacts of climate change. Given that climate impacts are expected to intensify with time and large uncertainties remain among different climate projections, it is critical to continue examining how the Bay may evolve in the future by assessing the sensitivity of oxygen concentrations to different climate change scenarios.

Authors:
Isaac D. Irby (VIMS, William & Mary)
Marjorie A. M. Friedrichs (VIMS, William & Mary)
Fei Da (VIMS, William & Mary)
Kyle E. Hinson (VIMS, William & Mary)

Suddenly shallow: A new aragonite saturation horizon will soon emerge in the Southern Ocean

Posted by mmaheigan

· Monday, May 27th, 2019

Earth System Models (ESMs) project that by the end of this century, the aragonite saturation horizon (the boundary between shallower, saturated waters and deeper, undersaturated waters that are corrosive to aragonitic shells) will shoal all the way to the surface in the Southern Ocean, yet the temporal evolution of the horizon has not been studied in much detail. Rather than a gradual shoaling, a new shallow aragonite saturation horizon emerges suddenly across many locations in the Southern Ocean between now and the end of the century (Figure 1, left), as detailed in a new study published in Nature Climate Change.

Figure 1: Maximum step-change in the depth of the aragonite saturation horizon (left), timing of the step-change (center), and cause of the change (right). Xs on the time axis (center) indicate when the shallow horizon emerges in each ensemble member. (click image to enlarge)

The emergence of the shallow aragonite saturation horizon is apparent in each member of an ensemble of climate projections from an ESM, but the step change occurs during different years (Figure 1, center). The shoaling is driven by the gradual accumulation of anthropogenic CO₂ in the Southern Ocean thermocline, where the carbonate ion concentration exhibits a local minimum and approaches undersaturation (Figure 1, right).

The abrupt shoaling of the Southern Ocean aragonite saturation horizon occurs under both business-as-usual and emission-stabilizing scenarios, indicating an inevitable and sudden decrease in the volume of suitable habitat for aragonitic organisms such as shelled pteropods, foraminifers, cold-water corals, sea urchins, molluscs, and coralline algae. Widespread reductions in these habitats may have far-reaching consequences for fisheries, economies, and livelihoods.

Authors:
Gabriela Negrete-García (Scripps Institution of Oceanography)
Nicole Lovenduski (University of Colorado Boulder)

See also OCB2019 plenary session: Carbon cycle feedbacks from the seafloor (Wednesday, June 26, 2019)

South Pacific particulate organic carbon fate challenges Martin’s Law

Posted by mmaheigan

· Tuesday, May 14th, 2019

Joint science highlight with GEOTRACES

Carbon storage in the ocean is sensitive to the depths at which particulate organic carbon (POC) is respired back to CO₂ within the twilight zone (100-1000m). For decades, it has been an oceanographic priority to determine the depth scale of this regeneration process. To investigate this, GEOTRACES scientists are deploying new isotopic tools that provide a high-resolution snapshot of POC flux and regeneration across steep biogeochemical gradients in the South Pacific Ocean.

A recent paper in PNAS reported on particulate organic carbon (POC) fluxes throughout the water column (focusing on the upper 1000 m) along the GP16 GEOTRACES section between Peru and Tahiti (Figure 1A). POC fluxes (Figure 1B) were derived by normalizing concentrations of POC to ²³⁰Th following analysis of samples collected by in situ filtration. This work builds on a research theme initiated at the GEOTRACES-OCB synthesis workshop held at Lamont-Doherty Earth Observatory in 2016.

Figure caption: Site map and POC flux characteristics from GEOTRACES GP16 section. Plot A) shows the GP16 station locations as white circles, with nearby sediment trap deployments as black stars, with 2013 MODIS satellite-derived net primary productivity in the background. Plot B) shows POC fluxes from particulate 230Th-normalization from selected stations spanning the zonal extent of the GP16 section. Plot C) shows power law exponent b values for each GP16 station (blue), compared to estimates from bottom-moored sediment traps in the South Pacific (black and red dashed lines), a compilation of sediment traps in the North Pacific (green dashed line), and neutrally buoyant sediment traps in the subtropical North Pacific (yellow shaded band). GP16 regeneration length scales from 230Th-normalization agree most closely with the estimates from neutrally buoyant sediment traps.

The study results show that POC regeneration depth is shallower than anticipated, especially in warm stratified waters of the subtropical gyre. Regeneration depth—expressed in terms of the Martin-curve power-law exponent “b” (Figure 1C)—is shown to be greater than previous estimates (horizontal dashed lines), but similar to values obtained using neutrally buoyant sediment traps at the Hawaii Ocean Time-series Station Aloha. In contrast to the rapid regeneration of POC in warm stratified waters, POC regeneration within the ODZ is below our detection limits. Models have shown that shallower regeneration of POC leads to less efficient carbon storage in the ocean, making the authors speculate that global warming, yielding expanded and more stratified gyres, may induce a reduction of the ocean’s efficacy for carbon storage via the biological pump.

Authors:
Frank J. Pavia, Robert F. Anderson, Sebastian M. Vivancos, Martin Q. Fleisher (Columbia University)
Phoebe J. Lam (University of California Santa Cruz)
B.B. Cael (now at University of Hawai’i Manoa, formerly at MIT)
Yanbin Lu, Pu Zhang, R. Lawrence Edwards (University of Minnesota)
Hai Cheng (University of Minnesota and Xi’an Jiaotong University)

Antarctic Ocean CO2 helped end the ice age

Posted by mmaheigan

· Tuesday, April 2nd, 2019

Many scientists have long hypothesized that the ocean around Antarctica was responsible for changing CO₂ levels during ice ages, but lacked definitive evidence. A new study in Nature provides the most direct evidence of this process to date and provides crucial evidence of the mechanisms—including changing sea ice cover and bipolar seesaw (warming in the Southern Hemisphere during cooling in the Northern Hemisphere) events—that controlled CO₂ and climate during the ice ages.

Using samples of fossil deep-sea corals collected from 1000 m in the Drake Passage (Figure 1a), the authors were able to reconstruct the CO₂ content of the deep ocean. They found that the deep ocean CO₂ record was the “mirror image” of CO₂ in the atmosphere (Figure 1b), with the ocean storing CO₂ during an ice age and releasing it back to the atmosphere during deglaciation. CO₂ rise during the last ice age occurred in a series of steps and jumps associated with intervals of rapid climate change.

As well as helping scientists better understand the ice ages, the new findings also provide context to current CO₂ rise and climate change. Although the CO₂ rise that helped end the last ice age was dramatic in geological terms, CO₂ rise due to human activity over the last 100 years is even larger and about 100 times faster. CO₂ rise at the end of the ice age helped drive major melting of ice sheets resulting in sea level rise of >100 meters. These results bolster the idea that if we want to prevent dangerous levels of global warming and sea level rise in the future, we need to reduce CO₂ emissions as quickly as possible

Authors:
J. W. B. Rae (University of St Andrews, UK)
A. Burke (University of St Andrews, UK)
L. F. Robinson (University of Bristol, UK)
J. F. Adkins (California Institute of Technology)
T. Chen (University of Bristol, UK, Nanjing University, China)
C. Cole (University of St Andrews, UK)
R. Greenop (University of St Andrews, UK)
T. Li (University of Bristol, UK, Nanjing University, China)
E. F. M. Littley (University of St Andrews, UK)
D. C. Nita (University of St Andrews, UK, Babes-Bolyai University, Romania)
J. A. Stewart (University of St Andrews, UK, University of Bristol, UK)
B. J. Taylor (University of St Andrews, UK)

Rapid warming and salinity changes mask acidification in Gulf of Maine waters

Posted by mmaheigan

· Wednesday, February 20th, 2019

Why don’t we see ocean acidification in over a decade of high-frequency observations in the Gulf of Maine? The answer lies in a recent decade of changes that raised sea surface temperature and salinity, and in turn dampened the expected acidification signal and caused the saturation states of calcite minerals to increase. From 2004 to 2014, sea surface temperatures in the Gulf of Maine were higher than any observations recorded in the region over the past 150 years. This greatly impacted both CO₂ solubility and the sea surface carbonate system, as detailed in a recent paper in Biogeochemistry.

Over the 34 years of the time-series, the recent event is extreme, but interannual and decadal salinity and temperature variability also influenced carbonate system parameters, which makes it difficult to isolate and quantify an anthropogenic ocean acidification signal, especially if relying on shorter-term observations (Figure 1).

Figure 1: Modeled Ω_Aragonite (top panel) and pH (bottom panel) anomalies relative to monthly 2004 data. The red lines show trends prior to and after 2004, after which warming accelerated.

For those with a stake in profiting from or managing extractive resources that are susceptible to ocean acidification such as commercially important lobster and bivalves, understanding how ecosystems will be affected is critical. These analyses clearly demonstrate how physical processes can either accelerate or mitigate ocean carbonate system changes, thus confounding the detection of ocean acidification that is expected from increasing atmospheric carbon dioxide. To assess whether an ecosystem or species is at risk or aided by such processes, it is important to observe, understand, and be able to model all sources of carbonate system variability.

Authors:
Joe Salisbury and Bror Jönsson (Both at Ocean Processes Analysis Laboratory, University of New Hampshire)

The past, present, and future of artificial ocean iron fertilization experiments

Posted by mmaheigan

· Wednesday, January 23rd, 2019

Since the beginning of the industrial revolution, human activities have greatly increased atmospheric CO₂ concentrations, leading to global warming and indicating an urgent need to reduce global greenhouse gas emissions. The Martin (or iron) hypothesis suggests that ocean iron fertilization (OIF) could be a low-cost effective method for reducing atmospheric CO₂ levels by stimulating carbon sequestration via the biological pump in iron-limited, high-nutrient, low-chlorophyll (HNLC) ocean regions. Given increasing global political, social, and economic concerns associated with climate change, it is necessary to examine the validity and usefulness of artificial OIF (aOIF) experimentation as a geoengineering solution.

Figure 1. (a) Global annual distribution of surface chlorophyll concentrations (mg m^-3) with locations of 13 aOIF experiments. Maximum and initial values in (b) maximum quantum yield of photosynthesis (Fv/Fm ratios) and (c) chlorophyll-a concentrations (mg m^-3) during aOIF experiments. (d) Changes in primary productivity (ΔPP = [PP]_{post-fertilization (postf)} ‒ [PP]_{pre-fertilization (pref)}; mg C m^-2 d^-1). (e) Distributions of chlorophyll-a concentrations (mg m^-3) on day 24 after iron addition in the Southern Ocean iron experiment-north (SOFeX-N) from MODIS Terra Level-2 daily image and on day 20 in the SOFeX-south (SOFeX-S) from SeaWiFS Level-2 daily image (white dotted box indicates phytoplankton bloom during aOIF experiments). (f) Changes in nitrate concentrations (ΔNO₃^– = [NO₃^–]_postf ‒ [NO₃^–]_pref; μM). (g) Changes in partial pressure of CO₂ (ΔpCO₂ = [pCO₂]_postf ‒ [pCO₂]_pref; μatm). The color bar indicates changes in dissolved inorganic carbon (ΔDIC = [DIC]_postf ‒ [DIC]_pref; μM). The numbers on the X axis indicate the order of aOIF experiments as given in Figure 1a and are grouped according to ocean basins; Equatorial Pacific (EP) (yellow bar), Southern Ocean (SO) (blue bar), subarctic North Pacific (NP) (red bar), and subtropical North Atlantic (NA) (green bar).

A review paper published in Biogeosciences on aOIF experiments provides a thorough overview of 13 scientific artificial OIF experiments conducted in HNLC regions over the last 25 years. These aOIF experiments have demonstrated that iron addition stimulates substantial increases in phytoplankton biomass and primary production, resulting in drawdown of macro-nutrients and dissolved inorganic carbon (Figure 1). Many of the aOIF experiments have also precipitated community shifts from smaller (pico- and nano-) to larger (micro) phytoplankton. However, the impact on the net transfer of CO₂ from the atmosphere to below the winter mixed layer via the biological pump is not yet fully understood or quantified and appears to vary with environmental conditions, export flux measurement techniques, and other unknown factors. These results, including possible side effects, have been debated among those who support and oppose aOIF experimentation, and many questions remain about the effectiveness of scientific aOIF, possible side effects, and international aOIF law frameworks. Therefore, it is important to continue undertaking small-scale, scientifically controlled studies to better understand natural processes in the HNLC regions, assess the associated risks, and lay the groundwork for evaluating the potential effectiveness and impacts of large-scale aOIF as a geoengineering solution to anthropogenic climate change. Additionally, this paper suggests considerations for the design of future aOIF experiments to maximize the effectiveness of the technique and begin to answer open questions under international aOIF regulations.

Authors:
Joo-Eun Yoon (Incheon National University)
Il-Nam Kim (Incheon National University)
Alison M. Macdonald (Woods Hole Oceanographic Institution)

Funding for the Ocean Carbon & Biogeochemistry Project Office is provided by the National Science Foundation (NSF) and the National Aeronautics and Space Administration (NASA). The OCB Project Office is housed at the Woods Hole Oceanographic Institution.

Archive for climate change

Filter by Keyword