About

Nicholas Bates is a professor in the School of Ocean Futures, a senior scientist, and the director of research at the Bermuda Institute of Ocean Sciences (BIOS). He has published more than 180 publications on ocean biogeochemistry, carbon cycling, and ocean acidification. Bates received his doctorate in oceanography in 1995 from the University of Southampton.

Research topics

• Environmental science
• Geology
• Ecology
• Oceanography
• Computer Science
• Geography
• Climatology
• Atmospheric sciences
• Biology
• Chemistry
• Environmental chemistry
• Paleontology
• Algorithm

Selected publications

• Decadal change in deep-ocean dissolved oxygen in the North Atlantic Ocean and North Pacific Ocean

  Deep Sea Research Part I Oceanographic Research Papers · 2025-06-16 · 1 citations

  articleOpen access

  Declining dissolved oxygen concentrations are documented at upper and mid ocean depths, but less is known about the deep ocean. Long time-series measurements of dissolved oxygen analyzed with Winkler titration over several decades reveal regional differences at six stations in the abyssal North Atlantic Ocean and North Pacific Ocean. A significant decline in dissolved oxygen was evident at two stations in the northeast Pacific Ocean at 4000 – 4200 m depth (Stations PAPA and M). A similar decreasing but insignificant trend was recorded in the Arctic region of the North Atlantic Ocean (HAUSGARTEN). However, there was no significant decrease in dissolved oxygen at two temperate stations in the North Atlantic Ocean (PAP, BATS) and at one tropical station in the central North Pacific Ocean (ALOHA) all at similar depths > 4000 m over similar time periods. Continued long time-series observations will be needed to monitor global deep ocean processes and the impact of changing climate. We compare these rare long-term observations with model estimations from historical (1850-2014) and projected (2015-2100) forcing under a continued high greenhouse gas emission scenario. • Here we examined deep-ocean time-series for long term changes in dissolved oxygen. • Long-term declines in dissolved oxygen were detected at two sites in the Pacific. • No change was found at others sites in the Pacific Ocean and Atlantic Ocean. Dissolved oxygen concentrations in the global ocean have been declining over the past several decades. This decline is most evident in the surface to mid-depths. At depths > 4000 m we report a significant decrease in dissolved oxygen over the past three decades at two long time-series stations in the northeast Pacific Ocean and a non-significant decline in the Arctic region of the North Atlantic Ocean. However, there was no significant decline in dissolved oxygen at three other long time-series stations, one in the central North Pacific Ocean and two in the temperate North Atlantic Ocean over the same period at similar depths. Long term monitoring at such stations is critical to interpreting biogeochemical changes in the deep ocean.

  PublisherDOI

• Global Carbon Budget 2024

  Earth system science data · 2025-03-14 · 478 citations

  articleOpen access

  Abstract. Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere in a changing climate is critical to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe and synthesize datasets and methodologies to quantify the five major components of the global carbon budget and their uncertainties. Fossil CO2 emissions (EFOS) are based on energy statistics and cement production data, while emissions from land-use change (ELUC) are based on land-use and land-use change data and bookkeeping models. Atmospheric CO2 concentration is measured directly, and its growth rate (GATM) is computed from the annual changes in concentration. The global net uptake of CO2 by the ocean (SOCEAN, called the ocean sink) is estimated with global ocean biogeochemistry models and observation-based fCO2 products (fCO2 is the fugacity of CO2). The global net uptake of CO2 by the land (SLAND, called the land sink) is estimated with dynamic global vegetation models. Additional lines of evidence on land and ocean sinks are provided by atmospheric inversions, atmospheric oxygen measurements, and Earth system models. The sum of all sources and sinks results in the carbon budget imbalance (BIM), a measure of imperfect data and incomplete understanding of the contemporary carbon cycle. All uncertainties are reported as ±1σ. For the year 2023, EFOS increased by 1.3 % relative to 2022, with fossil emissions at 10.1 ± 0.5 GtC yr−1 (10.3 ± 0.5 GtC yr−1 when the cement carbonation sink is not included), and ELUC was 1.0 ± 0.7 GtC yr−1, for a total anthropogenic CO2 emission (including the cement carbonation sink) of 11.1 ± 0.9 GtC yr−1 (40.6 ± 3.2 GtCO2 yr−1). Also, for 2023, GATM was 5.9 ± 0.2 GtC yr−1 (2.79 ± 0.1 ppm yr−1; ppm denotes parts per million), SOCEAN was 2.9 ± 0.4 GtC yr−1, and SLAND was 2.3 ± 1.0 GtC yr−1, with a near-zero BIM (−0.02 GtC yr−1). The global atmospheric CO2 concentration averaged over 2023 reached 419.31 ± 0.1 ppm. Preliminary data for 2024 suggest an increase in EFOS relative to 2023 of +0.8 % (−0.2 % to 1.7 %) globally and an atmospheric CO2 concentration increase by 2.87 ppm, reaching 422.45 ppm, 52 % above the pre-industrial level (around 278 ppm in 1750). Overall, the mean of and trend in the components of the global carbon budget are consistently estimated over the period 1959–2023, with a near-zero overall budget imbalance, although discrepancies of up to around 1 GtC yr−1 persist for the representation of annual to semi-decadal variability in CO2 fluxes. Comparison of estimates from multiple approaches and observations shows the following: (1) a persistent large uncertainty in the estimate of land-use change emissions, (2) low agreement between the different methods on the magnitude of the land CO2 flux in the northern extra-tropics, and (3) a discrepancy between the different methods on the mean ocean sink. This living-data update documents changes in methods and datasets applied to this most recent global carbon budget as well as evolving community understanding of the global carbon cycle. The data presented in this work are available at https://doi.org/10.18160/GCP-2024 (Friedlingstein et al., 2024).

  PublisherDOI

• Monitoring Impacts of the Gulf Stream and its Rings on the Physics, Chemistry, and Biology of the Middle Atlantic Bight Shelf and Slope from CMV Oleander

  Oceanography · 2025-01-01 · 2 citations

  articleOpen access

  Sustained observation is key to measuring physical and ecological variability in the Northwest Atlantic. Here we illustrate how a partnership with a merchant marine container vessel in service between New Jersey and Bermuda twice per week gives scientists a unique window into upper ocean currents, water properties, and marine ecology. Scientific observations collected from CMV Oleander, operated by Bermuda Container Line/Neptune Group, enable cross-disciplinary research, complement satellite measurements, and contribute to global observing programs—including the Global eXpendable BathyThermograph (XBT) Network, the Surface Ocean CO2 Atlas (SOCAT), and the Continuous Plankton Recorder (CPR) Survey. Recent co-located measurements along the Oleander Line document that fronts in temperature, salinity, and carbon dioxide concentrations align with the (sub)mesoscale circulation patterns. The sustained observations show warming and shrinking of the Slope Sea, a northward shift of the Gulf Stream, and warming of the “18°C water” (subtropical North Atlantic mode water) to 19°C.

  PublisherOA PDFDOI

• Impact of Eighteen Degree Water thickness variation on the thermal and biogeochemical structure in the euphotic layer

  Journal of Oceanography · 2025-03-08 · 4 citations

  articleOpen accessSenior author

  Abstract It has been recently found that North Pacific Subtropical Mode Water impacts the overlying thermal structure by uplifting the isotherms when it thickens. How the thickness variation of North Atlantic Subtropical Mode Water, also known as Eighteen Degree Water (EDW), affects the overlying thermal and biogeochemical structure through such uplifting effect has been investigated using Argo float data and shipboard observation data at Bermuda Atlantic Time-series Study site. When EDW was thicker, the overlying isotherms were uplifted, leading to a decrease in temperature centered at 50–100 dbar in the warm season; in addition, the oxycline existing around 100 dbar and the nitracline at 100–150 dbar also tended to be uplifted, leading to an increase of apparent oxygen utilization and nitrate concentrations in the lower euphotic layer; furthermore, there is a tendency that chlorophyll- a maximum around 100 dbar shallowed, and primary production integrated in the euphotic layer increased during the spring bloom season. Thus, although the core of thicker EDW tends to have less nitrate as shown by previous studies, thicker EDW tends to increase biological production in the euphotic layer through the enhanced uplifting effect.

  PublisherOA PDFDOI

• Biological, Biogeochemical, Bio‐Optical, and Physical Variability of the Southern Ocean Along 150°W and Its Relevance to the Great Calcite Belt

  Global Biogeochemical Cycles · 2025-08-01 · 3 citations

  articleOpen access

  Abstract We report hydrographic and biogeochemical measurements from a meridional transect performed along 150°W, 30°S to 60°S in the Southern Ocean, plus Polar waters to the east. Both of these areas are sites of annual high‐reflectance features in ocean color remote sensing, which were heretofore never confirmed with in situ measurements. This study aimed to document factors driving phytoplankton productivity and coccolithophore calcification within the circumpolar coccolithophore‐rich band known as the Great Calcite Belt (GCB). We measured concentrations of particulate inorganic carbon (PIC) and biogenic silica (BSi), two common biominerals, sources of ballast for organic matter, and contributors to optical reflectance. Results demonstrated that integrated euphotic standing stocks of PIC were highest in the GCB and at the Polar Front south of 54°S. BSi concentrations were highest south of 54°S. Integrated calcification rates were highest near the Polar and Subantarctic Fronts, whereas peak photosynthesis rates were observed in Subantarctic waters of the GCB, near the site of Subantarctic Mode Water formation. South of ∼54°S, optical particulate backscattering ( b bp ) of BSi dominated over PIC b bp by 10×, while in the GCB, PIC b bp dominated over BSi b bp by a similar magnitude. The slope of the particle size distribution function became less negative with depth, a trend that reflects larger particles becoming more abundant relative to smaller particles. Moreover, typical relationships between the particle size distribution slope and beam attenuation were only observed in the top 50 m depth, suggesting a fundamental difference in particle composition and size for deeper suspensions in this region.

  PublisherOA PDFDOI

• Two decibar averaged CTD profiles collected at the Bermuda Atlantic Time-series Study (BATS) site from October 1988 through June 2025

  2025-12-15

  datasetOpen access

  Data presented here are profiles of primary CTD parameters (pressure, depth, temperature, conductivity, and salinity) plus auxiliary measurements of dissolved oxygen, beam attenuation, relative fluorescence, and photosynthetic active radiation (PAR) at the BATS site 31° 40' N 64° 10'W for October 1988-June 2025. Profiles were collected using a standard Sea-Bird SBE-09 plus CTD during the monthly core BATS cruises and near biweekly BATS bloom cruises during the months of February through April depending on ship availability. Data are processed following the methods of Knap et al., 1997 with the final product being reported as two decibar averages and all profiles for each cruise are reported in a single cruise file. It should be noted that the two decibar profiles are reported for the downcast only and bottle marker data collected on the upcast are presented with the bottle data.

  PublisherDOI

• Global Carbon Budget 2025

  2025-11-13 · 18 citations

  articleOpen accessCorresponding

  Abstract. Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere in a changing climate is critical to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe and synthesise datasets and methodologies to quantify the five major components of the global carbon budget and their uncertainties. Fossil CO2 emissions (EFOS) are based on energy statistics and cement production data. Emissions from land-use change (ELUC) are estimated by bookkeeping models based on land-use and land-use change data. Atmospheric CO2 concentration is measured at surface stations, and the global atmospheric CO2 growth rate (GATM) is computed from the annual changes in concentration. The global net uptake of CO2 by the ocean (SOCEAN, called the ocean sink) is estimated with global ocean biogeochemistry models and observation-based fCO2-products. The global net uptake of CO2 by the land (SLAND, called the land sink) is estimated with dynamic global vegetation models. Additional lines of evidence on land and ocean sinks are provided by atmospheric inversions, atmospheric oxygen measurements, ocean interior observation-based estimates, and Earth System Models. The sum of all sources and sinks results in the carbon budget imbalance (BIM), a measure of imperfect data and incomplete understanding of the contemporary carbon cycle. All uncertainties are reported as ±1σ. For the year 2024, EFOS increased by 1.1 % relative to 2023, with fossil emissions at 10.3 ± 0.5 GtC yr−1 (including the cement carbonation sink, 0.2 GtC/yr), ELUC was 1.3 ± 0.7 GtC yr−1, for total anthropogenic CO2 emissions of 11.6 ± 0.9 GtC yr−1 (42.4 ± 3.2 GtCO2 yr−1). Also, for 2024, GATM was 7.9 ± 0.2 GtC yr−1 (3.73 ± 0.1 ppm yr−1), 2.2 GtC above the 2023 growth rate. SOCEAN was 3.4 ± 0.4 GtC yr−1 and SLAND was 1.9 ± 1.1 GtC yr−1, leaving a large negative BIM (−1.7 GtC yr−1), suggesting that the total sink or GATM is strongly overestimated in 2024. The global atmospheric CO2 concentration averaged over 2024 reached 422.8 ± 0.1 ppm. Preliminary data for 2025 suggest an increase in EFOS relative to 2024 of +1.1 % (0.2 % to 2.2 %) globally, and atmospheric CO2 concentration increasing by 2.3 ppm reaching 425.7 ppm, 52 % above the pre-industrial level (around 278 ppm in 1750). Overall, the mean and trend in the components of the global carbon budget are consistently estimated over the period 1959–2024, with a near-zero overall budget imbalance, although discrepancies of up to around 1 GtC yr−1 persist for the representation of annual to decadal variability in CO2 fluxes. Comparison of estimates from multiple approaches and observations shows: (1) a persistent large uncertainty in the estimate of land-use change emissions, (2) a low agreement between the different methods on the magnitude of the land CO2 flux in the northern extra-tropics, and (3) a discrepancy between the different methods on the mean ocean sink. This living data update documents changes in methods and datasets applied to this most-recent global carbon budget as well as evolving community understanding of the global carbon cycle. The data presented in this work are available at https://doi.org/10.18160/GCP-2025 (Friedlingstein et al., 2025c).

  PublisherOA PDFDOI

• Synthesis of data products for ocean carbonate chemistry

  2025-05-15

  preprintOpen access

  Abstract. As the largest active carbon reservoir on Earth, the ocean is a cornerstone of the global carbon cycle, playing a pivotal role in modulating ocean health and regulating climate. Understanding these crucial roles requires access to a broad array of data products documenting the changing chemistry of the global ocean as a vast and interconnected system. This review article provides a comprehensive overview of 60 existing ocean carbonate chemistry data products, encompassing compilations of cruise datasets, derived gap-filled data products, model simulations, and compilations thereof. It is intended to help researchers identify and access data products that best align with their research objectives, thereby advancing our understanding of the ocean's evolving carbonate chemistry.

  PublisherDOI

• Arctic Ocean inorganic carbon and acidification changes from 1994 to 2022 across the Chukchi Sea to the North Pole: A US contribution to the International Synoptic Arctic Survey Program

  2025-03-14

  preprintOpen accessSenior author

  The Arctic Ocean is undergoing rapid transformations due to the loss of sea ice, shifts in its heat budget and physical structure, and the “greening” of the polar surface ocean. These changes have profound implications for ocean biogeochemistry, the carbon cycle, and ocean acidification (OA). As part of the U.S. Synoptic Arctic Survey (SAS), we conducted a transect from the Chukchi Sea shelf to the North Pole during late summer 2022, enabling comprehensive sampling of the ocean carbon cycle in the seldom-sampled high Arctic. Discrete samples of Dissolved Inorganic Carbon (DIC) and Total Alkalinity (TA) were collected from CTD-hydrocasts spanning surface to deep waters, complemented by higher-frequency underway measurements of DIC, TA, and pH. These observations establish a critical baseline for tracking future changes in Arctic carbon dynamics, biogeochemistry, and acidification. Additionally, the 2022 US SAS dataset allows for comparison with earlier observations, including the 1994 Arctic Ocean Section (AOS), the 2005 Beringia expedition, and the 2015 GEOTRACES Arctic cruise. Our synthesis reveals significant and ongoing changes in the Arctic Ocean carbon cycle, including: (1) substantial uptake of anthropogenic CO₂; (2) alterations in the driving force for air-sea CO₂ exchange; (3) a decreasing capacity of the Arctic Ocean to absorb atmospheric CO₂; and (4) intensified impacts on surface pH and ocean acidification. These findings underscore the accelerating pace of carbon cycle changes in the high Arctic and highlight the importance of sustained monitoring.

  PublisherDOI

• Two decibar averaged CTD profiles collected during BATS Validation (BVAL) cruises from April 1991 through July 2025

  2025-12-15

  datasetOpen access

  Data presented here are 2 dbar CTD for BATS Validation (BVAL) cruises from April 1991 (BVAL cruise #50001) through July 2025 (BVAL cruise #50063). Profiles of primary CTD measurements (Pressure, Depth, Temperature, and Salinity) are reported along with auxiliary data for dissolved oxygen, beam attenuation coefficient, relative fluorescence, and photosynthetic Active Radiation (PAR). Profiles were collected using a standard Sea-Bird SBE-09 plus CTD. Data are processed following the methods of Knap et al., 1997 with the final product being reported as two decibar averages and all profiles. It should be noted that the two decibar profiles are reported for the downcast only and bottle marker data collected on the upcast are presented with the bottle data.

  PublisherDOI

Recent grants

• Collaborative Research: Transports and Transformations of Carbon and Nitrogen in the Western Arctic Ocean: A Contribution to the SBI Project

  NSF · $450k · 2002–2007

• Collaborative Research: The Great Southern Coccolithophore Belt

  NSF · $306k · 2010–2015

• The Bermuda Atlantic Time-series Study (BATS): Year 21-25

  NSF · $5.3M · 2008–2013

• Collaborative Research: The Bermuda Atlantic Time-series Study: Sustained Biogeochemical, Ecosystem and Ocean Change Observations and Linkages in the North Atlantic (Years 31-35)

  NSF · $7.1M · 2018–2024

• Collaborative Research Pacific-Arctic Carbon Synthesis - Transformations, Fluxes, and Budgets

  NSF · $120k · 2011–2016

Frequent coauthors

• Kim Currie

  National Institute of Water and Atmospheric Research

  93 shared

• Jón Ólafsson

  88 shared

• Pierre Friedlingstein

  Sorbonne Université

  87 shared

• Matthew J. Church

  University of Montana

  85 shared

• John E. Dore

  Montana State University

  84 shared

• Laura Lorenzoni

  83 shared

• Yrene Astor

  Universidad de Margarita

  81 shared

• Nathalie Lefèvre

  Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques

  80 shared

Education

• Ph.D.

  University of Southampton

  1995