Atlantic Explorer

Long-term observations over several decades are a powerful tool for investigating ocean physics, biology, and chemistry, and the response of the oceans to environmental change. The Bermuda Atlantic Time-Series Study, known as BATS, has been running continuously since 1988. The research goals of the BATS program are: (1) to improve our understanding of the time-varying components of the ocean carbon cycle and the cycles of related nutrient elements such as nitrogen, phosphorus, and silicon; and, (2) to identify the relevant physical, chemical and ecosystem properties responsible for this variability. In addition, the BATS program has strong and diverse broader impacts, contributing to the field of ocean sciences by providing high quality ocean observations and data for seagoing scientists and modelers, and a framework through which researchers can conceive and test hypotheses. This award will support operations of the BATS program for five more years. This research integrates ocean physics, chemistry and biology into a framework for understanding oceanic processes and ocean change in the North Atlantic subtropical gyre. The existing years of BATS data provide robust constraints on seasonal and interannual variability, the response of the Sargasso Sea ecosystem to natural climate variability, and signal detection of potential ocean changes.

Since 1978, the Oceanic Flux Program (OFP) has been continuously measuring particle fluxes in the deep Sargasso Sea, with a >90% temporal coverage of the 3200 m flux over its 45 years. The OFP is the longest-running time-series of its kind and has generated an exceptional record of temporal variability in the "biological pump", a term loosely applied here to material transfer from the surface to deep ocean resulting from upper ocean biological and physical processes. Two overarching goals drive core activities funded under the OFP grant. The first is to extend the time-series by collecting new samples of the highest quality, while ensuring they have a comprehensive oceanographic context. The second is to elucidate the processes that drive oceanic particle flux through comparative studies of flux magnitude and composition with concurrent observations of external forcing (e.g., synoptic scale meteorology, climate patterns), surface water physics and biology (e.g., mesoscale features, blooms), and interior processes (e.g., biological particle aggregation/disaggregation, elemental scavenging, authigenic mineralization).

Long-term observations over several decades are a powerful tool for investigating ocean physics, biology, and chemistry, and the response of the oceans to environmental change. The Bermuda Atlantic Time-Series Study, known as BATS, has been running continuously since 1988. The research goals of the BATS program are: (1) to improve our understanding of the time-varying components of the ocean carbon cycle and the cycles of related nutrient elements such as nitrogen, phosphorus, and silicon; and, (2) to identify the relevant physical, chemical and ecosystem properties responsible for this variability. In addition, the BATS program has strong and diverse broader impacts, contributing to the field of ocean sciences by providing high quality ocean observations and data for seagoing scientists and modelers, and a framework through which researchers can conceive and test hypotheses. This award will support operations of the BATS program for five more years. This research integrates ocean physics, chemistry and biology into a framework for understanding oceanic processes and ocean change in the North Atlantic subtropical gyre. The existing years of BATS data provide robust constraints on seasonal and interannual variability, the response of the Sargasso Sea ecosystem to natural climate variability, and signal detection of potential ocean changes.

One of the longest open-ocean hydrographic stations in the world is maintained at the Hydrostation S site (formerly known as the Panulirus site) located ~25 km southeast of Bermuda in the North Atlantic Ocean. This program of repeat biweekly hydrographic observations began in 1954 (by Hank Stommel) and now, in its seventh decade, has proved to be the catalyst for numerous studies of ocean physics, biological processes and biogeochemistry. Hydrostation S continues to be recognized as one of the most important sustained ocean time–series. The renewal of the Hydrostation S program is proposed herein, extending this invaluable time–series of ocean hydrography to almost 70 years. The upper ocean warming trend has strengthened (about +1.4° C since the 1970's; ~+0.8°C in last decade) with significant salinification (+0.16). Deeper waters such as the Labrador Sea Water has cooled by a few tenths of a degree and freshened with a marked decadal oscillation. The signature of deoxygenation has been observed at Hydrostation S in the upper ocean (about 4 µmoles kg -1 decade -1 decrease in dissolved oxygen) as well as the oxygen minimum zone (~2.5 µmoles kg -1 decade -1 ). Hydrostation S also supports the longest global ocean CO 2 and acidification time-series (from 1983 to present)

Coupled atmosphere-ocean general circulation models have long predicted that rising temperatures will result in enhanced stratification within the upper ocean, suppressing nutrient fluxes into the euphotic zone and negatively impacting primary and export production rates. However, fluxes of nutrients and carbon are controlled by complex linkages between physical mixing and biological processes. Our proposed study using Be-7 as a tracer of upper ocean mixing and transport processes in the Sargasso Sea will result in improved model parameterization of mixing and transport processes, and examine interdecadal variability of nutrient fluxes and oxygen utilization rates. To accomplish these goals, we will take part on eight cruises to the Bermuda Atlantic Times Series (BATS) site and other nearby locations during the period May 2026 to November 2027. Profiles from the upper water column will be obtained using in situ pumps that filter seawater through filters coated with iron hydroxide to absorb Be-7. Dissolved oxygen and nutrient concentrations, which are routinely collected by the times series personnel, will be modeled using diffusive mixing rates determined from Be-7 distributions, resulting in estimates of oxygen utilization and nutrient transport rates. Data collected in a similar study in 2007-08 will be provide for an interdecadal comparison.

Our joint NSF-NERC collaborative research project will integrate field observations from the Bermuda Atlantic Time-series Study (BATS) and Cape Verde Ocean Observatory (CVOO) study regions with targeted experimental studies and a state-of-the-art ocean biogeochemical model to constrain the processes that modulate interactions of iron with dissolved and particulate organic matter, and advance our ability to model the global iron cycle and the vertical export of iron and carbon in the upper ocean. We will collect seasonally resolved water column (upper 3,500 m) datasets from BATS during five cruises, shared with the monthly BATS program, spanning a full annual cycle. In late spring (cruise 3 of 5), we will augment the work at BATS with additional water column sampling along the way to, and at, the Cape Verde Ocean Observatory in the eastern North Atlantic, which provides a natural laboratory for contrasting iron speciation and subsurface oxygen conditions with the BATS region.

Long-term observations over several decades are a powerful tool for investigating ocean physics, biology, and chemistry, and the response of the oceans to environmental change. The Bermuda Atlantic Time-Series Study, known as BATS, has been running continuously since 1988. The research goals of the BATS program are: (1) to improve our understanding of the time-varying components of the ocean carbon cycle and the cycles of related nutrient elements such as nitrogen, phosphorus, and silicon; and, (2) to identify the relevant physical, chemical and ecosystem properties responsible for this variability. In addition, the BATS program has strong and diverse broader impacts, contributing to the field of ocean sciences by providing high quality ocean observations and data for seagoing scientists and modelers, and a framework through which researchers can conceive and test hypotheses. This award will support operations of the BATS program for five more years. This research integrates ocean physics, chemistry and biology into a framework for understanding oceanic processes and ocean change in the North Atlantic subtropical gyre. The existing years of BATS data provide robust constraints on seasonal and interannual variability, the response of the Sargasso Sea ecosystem to natural climate variability, and signal detection of potential ocean changes.

One of the longest open-ocean hydrographic stations in the world is maintained at the Hydrostation S site (formerly known as the Panulirus site) located ~25 km southeast of Bermuda in the North Atlantic Ocean. This program of repeat biweekly hydrographic observations began in 1954 (by Hank Stommel) and now, in its seventh decade, has proved to be the catalyst for numerous studies of ocean physics, biological processes and biogeochemistry. Hydrostation S continues to be recognized as one of the most important sustained ocean time–series. The renewal of the Hydrostation S program is proposed herein, extending this invaluable time–series of ocean hydrography to almost 70 years. The upper ocean warming trend has strengthened (about +1.4° C since the 1970's; ~+0.8°C in last decade) with significant salinification (+0.16). Deeper waters such as the Labrador Sea Water has cooled by a few tenths of a degree and freshened with a marked decadal oscillation. The signature of deoxygenation has been observed at Hydrostation S in the upper ocean (about 4 µmoles kg -1 decade -1 decrease in dissolved oxygen) as well as the oxygen minimum zone (~2.5 µmoles kg -1 decade -1 ). Hydrostation S also supports the longest global ocean CO 2 and acidification time-series (from 1983 to present)

Our joint NSF-NERC collaborative research project will integrate field observations from the Bermuda Atlantic Time-series Study (BATS) and Cape Verde Ocean Observatory (CVOO) study regions with targeted experimental studies and a state-of-the-art ocean biogeochemical model to constrain the processes that modulate interactions of iron with dissolved and particulate organic matter, and advance our ability to model the global iron cycle and the vertical export of iron and carbon in the upper ocean. We will collect seasonally resolved water column (upper 3,500 m) datasets from BATS during five cruises, shared with the monthly BATS program, spanning a full annual cycle. In late spring (cruise 3 of 5), we will augment the work at BATS with additional water column sampling along the way to, and at, the Cape Verde Ocean Observatory in the eastern North Atlantic, which provides a natural laboratory for contrasting iron speciation and subsurface oxygen conditions with the BATS region. Laboratory-based and shipboard incubation experiments will target the role that specific pools of organic ligands, dissolved organic carbon, and detrital particulate organic carbon play in water-column iron cycling. The resulting data, together with ancillary data provided by the BATS program, will be used to inform the biogeochemical model, thereby advancing our ability to model the global ocean cycling of iron and carbon, and better predict their sensitivity to environmental changes.

Long-term observations over several decades are a powerful tool for investigating ocean physics, biology, and chemistry, and the response of the oceans to environmental change. The Bermuda Atlantic Time-Series Study, known as BATS, has been running continuously since 1988. The research goals of the BATS program are: (1) to improve our understanding of the time-varying components of the ocean carbon cycle and the cycles of related nutrient elements such as nitrogen, phosphorus, and silicon; and, (2) to identify the relevant physical, chemical and ecosystem properties responsible for this variability. In addition, the BATS program has strong and diverse broader impacts, contributing to the field of ocean sciences by providing high quality ocean observations and data for seagoing scientists and modelers, and a framework through which researchers can conceive and test hypotheses. This award will support the operations of the BATS program for five more years.

One of the longest open-ocean hydrographic stations in the world is maintained at the Hydrostation S site (formerly known as the Panulirus site) located ~25 km southeast of Bermuda in the North Atlantic Ocean. This program of repeat biweekly hydrographic observations began in 1954 (by Hank Stommel) and now, in its seventh decade, has proved to be the catalyst for numerous studies of ocean physics, biological processes and biogeochemistry. Hydrostation S continues to be recognized as one of the most important sustained ocean time–series. The renewal of the Hydrostation S program is proposed herein, extending this invaluable time–series of ocean hydrography to almost 70 years. The upper ocean warming trend has strengthened (about +1.4° C since the 1970's; ~+0.8°C in last decade) with significant salinification (+0.16). Deeper waters such as the Labrador Sea Water has cooled by a few tenths of a degree and freshened with a marked decadal oscillation. The signature of deoxygenation has been observed at Hydrostation S in the upper ocean (about 4 µmoles kg -1 decade -1 decrease in dissolved oxygen) as well as the oxygen minimum zone (~2.5 µmoles kg -1 decade -1 ). Hydrostation S also supports the longest global ocean CO 2 and acidification time-series (from 1983 to present)

The biological carbon pump plays a crucial role in marine carbon sequestration, yet current estimates of carbon flux come with high uncertainties due to the heterogeneous nature of sinking particles. Our project addresses this challenge by linking large-scale ocean observations with experimental analyses on the microscopic scale and numerical modeling. Underwater particle images will be collected across a transect from Bermuda to the New England slope through an autonomous vehicle. Sampling efforts and sediment trap deployments on both ends of the transect will allow for detailed particle characterizations, including respiration rates, sinking velocities, carbon contents and genetic analyses. A numerical model will combine ocean current data with particle abundances and characteristics, aiming to improve mechanistic understanding and parametrization of the biological carbon pump. We request adding a day to a BATS cruise for collaborative sampling efforts on the Bermuda end.

Long-term observations over several decades are a powerful tool for investigating ocean physics, biology, and chemistry, and the response of the oceans to environmental change. The Bermuda Atlantic Time-Series Study, known as BATS, has been running continuously since 1988. The research goals of the BATS program are: (1) to improve our understanding of the time-varying components of the ocean carbon cycle and the cycles of related nutrient elements such as nitrogen, phosphorus, and silicon; and, (2) to identify the relevant physical, chemical and ecosystem properties responsible for this variability. In addition, the BATS program has strong and diverse broader impacts, contributing to the field of ocean sciences by providing high quality ocean observations and data for seagoing scientists and modelers, and a framework through which researchers can conceive and test hypotheses. This award will support operations of the BATS program for five more years. This research integrates ocean physics, chemistry and biology into a framework for understanding oceanic processes and ocean change in the North Atlantic subtropical gyre. The existing years of BATS data provide robust constraints on seasonal and interannual variability, the response of the Sargasso Sea ecosystem to natural climate variability, and signal detection of potential ocean changes.

One of the longest open-ocean hydrographic stations in the world is maintained at the Hydrostation S site (formerly known as the Panulirus site) located ~25 km southeast of Bermuda in the North Atlantic Ocean. This program of repeat biweekly hydrographic observations began in 1954 (by Hank Stommel) and now, in its seventh decade, has proved to be the catalyst for numerous studies of ocean physics, biological processes and biogeochemistry. Hydrostation S continues to be recognized as one of the most important sustained ocean time–series. The renewal of the Hydrostation S program is proposed herein, extending this invaluable time–series of ocean hydrography to almost 70 years. The upper ocean warming trend has strengthened (about +1.4° C since the 1970's; ~+0.8°C in last decade) with significant salinification (+0.16). Deeper waters such as the Labrador Sea Water has cooled by a few tenths of a degree and freshened with a marked decadal oscillation. The signature of deoxygenation has been observed at Hydrostation S in the upper ocean (about 4 µmoles kg -1 decade -1 decrease in dissolved oxygen) as well as the oxygen minimum zone (~2.5 µmoles kg -1 decade -1 ). Hydrostation S also supports the longest global ocean CO 2 and acidification time-series (from 1983 to present)

One of the longest open-ocean hydrographic stations in the world is maintained at the Hydrostation S site (formerly known as the Panulirus site) located ~25 km southeast of Bermuda in the North Atlantic Ocean. This program of repeat biweekly hydrographic observations began in 1954 (by Hank Stommel) and now, in its seventh decade, has proved to be the catalyst for numerous studies of ocean physics, biological processes and biogeochemistry. Hydrostation S continues to be recognized as one of the most important sustained ocean time–series. The renewal of the Hydrostation S program is proposed herein, extending this invaluable time–series of ocean hydrography to almost 70 years. The upper ocean warming trend has strengthened (about +1.4° C since the 1970's; ~+0.8°C in last decade) with significant salinification (+0.16). Deeper waters such as the Labrador Sea Water has cooled by a few tenths of a degree and freshened with a marked decadal oscillation. The signature of deoxygenation has been observed at Hydrostation S in the upper ocean (about 4 µmoles kg -1 decade -1 decrease in dissolved oxygen) as well as the oxygen minimum zone (~2.5 µmoles kg -1 decade -1 ). Hydrostation S also supports the longest global ocean CO 2 and acidification time-series (from 1983 to present)

Deployment (and eventual recovery) of multiple full-ocean depth moorings to study the nonlinear transfer of energy in the internal wave field from tidal frequencies and wavelengths to super-tidal frequencies and shorter wavelengths. The goal is to improve numerical forecast models that recently have been able to include ever more realistic internal waves.

One of the longest open-ocean hydrographic stations in the world is maintained at the Hydrostation S site (formerly known as the Panulirus site) located ~25 km southeast of Bermuda in the North Atlantic Ocean. This program of repeat biweekly hydrographic observations began in 1954 (by Hank Stommel) and now, in its seventh decade, has proved to be the catalyst for numerous studies of ocean physics, biological processes and biogeochemistry. Hydrostation S continues to be recognized as one of the most important sustained ocean time–series. The renewal of the Hydrostation S program is proposed herein, extending this invaluable time–series of ocean hydrography to almost 70 years. The upper ocean warming trend has strengthened (about +1.4° C since the 1970's; ~+0.8°C in last decade) with significant salinification (+0.16). Deeper waters such as the Labrador Sea Water has cooled by a few tenths of a degree and freshened with a marked decadal oscillation. The signature of deoxygenation has been observed at Hydrostation S in the upper ocean (about 4 µmoles kg -1 decade -1 decrease in dissolved oxygen) as well as the oxygen minimum zone (~2.5 µmoles kg -1 decade -1 ). Hydrostation S also supports the longest global ocean CO 2 and acidification time-series (from 1983 to present)

The BIOS-SCOPE team mission is to advance an understanding of ocean food web sources, sinks and transformations of dissolved and particulate organic matter in the context of defining characteristics of the seasonally oligotrophic Sargasso Sea. The location of the BIOS-SCOPE study, the Bermuda Atlantic Time-series Study (BATS) site, experiences vigorous physical mixing in winter / spring followed by quiescent and stratified periods in the summer / early fall that results in both spring phytoplankton blooms and extremely low-nutrient surface conditions in each annual cycle. The dramatic seasonality of BATS makes it an excellent site for exploring features of biogeochemistry related to ocean mixing and stratification, and for exploring the long-term consequences of ocean surface warming. This study site supports the longest running open ocean metagenomics time-series in oceanography northwestern Sargasso Sea. In its third phase the BIOS-SCOPE team is poised to integrate its range of skills to investigate specific mechanisms of organic matter production, oxidation and transformation in both DOM and POM. New metagenomic, transcriptomic and proteomic approaches will be used to further explore microbial ecology in this oligotrophic system and how it controls biogeochemical cycling.

Long-term observations over several decades are a powerful tool for investigating ocean physics, biology, and chemistry, and the response of the oceans to environmental change. The Bermuda Atlantic Time-Series Study, known as BATS, has been running continuously since 1988. The research goals of the BATS program are: (1) to improve our understanding of the time-varying components of the ocean carbon cycle and the cycles of related nutrient elements such as nitrogen, phosphorus, and silicon; and, (2) to identify the relevant physical, chemical and ecosystem properties responsible for this variability. In addition, the BATS program has strong and diverse broader impacts, contributing to the field of ocean sciences by providing high quality ocean observations and data for seagoing scientists and modelers, and a framework through which researchers can conceive and test hypotheses. This award will support operations of the BATS program for five more years. This research integrates ocean physics, chemistry and biology into a framework for understanding oceanic processes and ocean change in the North Atlantic subtropical gyre. The existing years of BATS data provide robust constraints on seasonal and interannual variability, the response of the Sargasso Sea ecosystem to natural climate variability, and signal detection of potential ocean changes.

One of the longest open-ocean hydrographic stations in the world is maintained at the Hydrostation S site (formerly known as the Panulirus site) located ~25 km southeast of Bermuda in the North Atlantic Ocean. This program of repeat biweekly hydrographic observations began in 1954 (by Hank Stommel) and now, in its seventh decade, has proved to be the catalyst for numerous studies of ocean physics, biological processes and biogeochemistry. Hydrostation S continues to be recognized as one of the most important sustained ocean time–series. The renewal of the Hydrostation S program is proposed herein, extending this invaluable time–series of ocean hydrography to almost 70 years. The upper ocean warming trend has strengthened (about +1.4° C since the 1970's; ~+0.8°C in last decade) with significant salinification (+0.16). Deeper waters such as the Labrador Sea Water has cooled by a few tenths of a degree and freshened with a marked decadal oscillation. The signature of deoxygenation has been observed at Hydrostation S in the upper ocean (about 4 µmoles kg -1 decade -1 decrease in dissolved oxygen) as well as the oxygen minimum zone (~2.5 µmoles kg -1 decade -1 ). Hydrostation S also supports the longest global ocean CO 2 and acidification time-series (from 1983 to present)

Since 1978, the Oceanic Flux Program (OFP) has been continuously measuring particle fluxes in the deep Sargasso Sea, with a >90% temporal coverage of the 3200 m flux over its 45 years. The OFP is the longest-running time-series of its kind and has generated an exceptional record of temporal variability in the "biological pump", a term loosely applied here to material transfer from the surface to deep ocean resulting from upper ocean biological and physical processes. Two overarching goals drive core activities funded under the OFP grant. The first is to extend the time-series by collecting new samples of the highest quality, while ensuring they have a comprehensive oceanographic context. The second is to elucidate the processes that drive oceanic particle flux through comparative studies of flux magnitude and composition with concurrent observations of external forcing (e.g., synoptic scale meteorology, climate patterns), surface water physics and biology (e.g., mesoscale features, blooms), and interior processes (e.g., biological particle aggregation/disaggregation, elemental scavenging, authigenic mineralization).

One of the longest open-ocean hydrographic stations in the world is maintained at the Hydrostation S site (formerly known as the Panulirus site) located ~25 km southeast of Bermuda in the North Atlantic Ocean. This program of repeat biweekly hydrographic observations began in 1954 (by Hank Stommel) and now, in its seventh decade, has proved to be the catalyst for numerous studies of ocean physics, biological processes and biogeochemistry. Hydrostation S continues to be recognized as one of the most important sustained ocean time–series. The renewal of the Hydrostation S program is proposed herein, extending this invaluable time–series of ocean hydrography to almost 70 years. The upper ocean warming trend has strengthened (about +1.4° C since the 1970's; ~+0.8°C in last decade) with significant salinification (+0.16). Deeper waters such as the Labrador Sea Water has cooled by a few tenths of a degree and freshened with a marked decadal oscillation. The signature of deoxygenation has been observed at Hydrostation S in the upper ocean (about 4 µmoles kg -1 decade -1 decrease in dissolved oxygen) as well as the oxygen minimum zone (~2.5 µmoles kg -1 decade -1 ). Hydrostation S also supports the longest global ocean CO 2 and acidification time-series (from 1983 to present)

Coupled atmosphere-ocean general circulation models have long predicted that rising temperatures will result in enhanced stratification within the upper ocean, suppressing nutrient fluxes into the euphotic zone and negatively impacting primary and export production rates. However, fluxes of nutrients and carbon are controlled by complex linkages between physical mixing and biological processes. Our proposed study using Be-7 as a tracer of upper ocean mixing and transport processes in the Sargasso Sea will result in improved model parameterization of mixing and transport processes, and examine interdecadal variability of nutrient fluxes and oxygen utilization rates. To accomplish these goals, we will take part on eight cruises to the Bermuda Atlantic Times Series (BATS) site and other nearby locations during the period May 2026 to November 2027. Profiles from the upper water column will be obtained using in situ pumps that filter seawater through filters coated with iron hydroxide to absorb Be-7. Dissolved oxygen and nutrient concentrations, which are routinely collected by the times series personnel, will be modeled using diffusive mixing rates determined from Be-7 distributions, resulting in estimates of oxygen utilization and nutrient transport rates. Data collected in a similar study in 2007-08 will be provide for an interdecadal comparison.

Our joint NSF-NERC collaborative research project will integrate field observations from the Bermuda Atlantic Time-series Study (BATS) and Cape Verde Ocean Observatory (CVOO) study regions with targeted experimental studies and a state-of-the-art ocean biogeochemical model to constrain the processes that modulate interactions of iron with dissolved and particulate organic matter, and advance our ability to model the global iron cycle and the vertical export of iron and carbon in the upper ocean. We will collect seasonally resolved water column (upper 3,500 m) datasets from BATS during five cruises, shared with the monthly BATS program, spanning a full annual cycle. In late spring (cruise 3 of 5), we will augment the work at BATS with additional water column sampling along the way to, and at, the Cape Verde Ocean Observatory in the eastern North Atlantic, which provides a natural laboratory for contrasting iron speciation and subsurface oxygen conditions with the BATS region. Laboratory-based and shipboard incubation experiments will target the role that specific pools of organic ligands, dissolved organic carbon, and detrital particulate organic carbon play in water-column iron cycling. The resulting data, together with ancillary data provided by the BATS program, will be used to inform the biogeochemical model, thereby advancing our ability to model the global ocean cycling of iron and carbon, and better predict their sensitivity to environmental changes.

Long-term observations over several decades are a powerful tool for investigating ocean physics, biology, and chemistry, and the response of the oceans to environmental change. The Bermuda Atlantic Time-Series Study, known as BATS, has been running continuously since 1988. The research goals of the BATS program are: (1) to improve our understanding of the time-varying components of the ocean carbon cycle and the cycles of related nutrient elements such as nitrogen, phosphorus, and silicon; and, (2) to identify the relevant physical, chemical and ecosystem properties responsible for this variability. In addition, the BATS program has strong and diverse broader impacts, contributing to the field of ocean sciences by providing high quality ocean observations and data for seagoing scientists and modelers, and a framework through which researchers can conceive and test hypotheses. This award will support operations of the BATS program for five more years. This research integrates ocean physics, chemistry and biology into a framework for understanding oceanic processes and ocean change in the North Atlantic subtropical gyre. The existing years of BATS data provide robust constraints on seasonal and interannual variability, the response of the Sargasso Sea ecosystem to natural climate variability, and signal detection of potential ocean changes.

One of the longest open-ocean hydrographic stations in the world is maintained at the Hydrostation S site (formerly known as the Panulirus site) located ~25 km southeast of Bermuda in the North Atlantic Ocean. This program of repeat biweekly hydrographic observations began in 1954 (by Hank Stommel) and now, in its seventh decade, has proved to be the catalyst for numerous studies of ocean physics, biological processes and biogeochemistry. Hydrostation S continues to be recognized as one of the most important sustained ocean time–series. The renewal of the Hydrostation S program is proposed herein, extending this invaluable time–series of ocean hydrography to almost 70 years. The upper ocean warming trend has strengthened (about +1.4° C since the 1970's; ~+0.8°C in last decade) with significant salinification (+0.16). Deeper waters such as the Labrador Sea Water has cooled by a few tenths of a degree and freshened with a marked decadal oscillation. The signature of deoxygenation has been observed at Hydrostation S in the upper ocean (about 4 µmoles kg -1 decade -1 decrease in dissolved oxygen) as well as the oxygen minimum zone (~2.5 µmoles kg -1 decade -1 ). Hydrostation S also supports the longest global ocean CO 2 and acidification time-series (from 1983 to present)

Long-term observations over several decades are a powerful tool for investigating ocean physics, biology, and chemistry, and the response of the oceans to environmental change. The Bermuda Atlantic Time-Series Study, known as BATS, has been running continuously since 1988. The research goals of the BATS program are: (1) to improve our understanding of the time-varying components of the ocean carbon cycle and the cycles of related nutrient elements such as nitrogen, phosphorus, and silicon; and, (2) to identify the relevant physical, chemical and ecosystem properties responsible for this variability. In addition, the BATS program has strong and diverse broader impacts, contributing to the field of ocean sciences by providing high quality ocean observations and data for seagoing scientists and modelers, and a framework through which researchers can conceive and test hypotheses. This award will support the operations of BATS program for five more years. This research integrates ocean physics, chemistry and biology into a framework for understanding oceanic processes and ocean change in the North Atlantic subtropical gyre. The existing years of BATS data provide robust constraints on seasonal and interannual variability, the response of the Sargasso Sea ecosystem to natural climate variability, and signal detection of potential ocean changes.

One of the longest open-ocean hydrographic stations in the world is maintained at the Hydrostation S site (formerly known as the Panulirus site) located ~25 km southeast of Bermuda in the North Atlantic Ocean. This program of repeat biweekly hydrographic observations began in 1954 (by Hank Stommel) and now, in its seventh decade, has proved to be the catalyst for numerous studies of ocean physics, biological processes and biogeochemistry. Hydrostation S continues to be recognized as one of the most important sustained ocean time–series. The renewal of the Hydrostation S program is proposed herein, extending this invaluable time–series of ocean hydrography to almost 70 years. The upper ocean warming trend has strengthened (about +1.4° C since the 1970's; ~+0.8°C in last decade) with significant salinification (+0.16). Deeper waters such as the Labrador Sea Water has cooled by a few tenths of a degree and freshened with a marked decadal oscillation. The signature of deoxygenation has been observed at Hydrostation S in the upper ocean (about 4 µmoles kg -1 decade -1 decrease in dissolved oxygen) as well as the oxygen minimum zone (~2.5 µmoles kg -1 decade -1 ). Hydrostation S also supports the longest global ocean CO 2 and acidification time-series (from 1983 to present).

One of the longest open-ocean hydrographic stations in the world is maintained at the Hydrostation S site (formerly known as the Panulirus site) located ~25 km southeast of Bermuda in the North Atlantic Ocean. This program of repeat biweekly hydrographic observations began in 1954 (by Hank Stommel) and now, in its seventh decade, has proved to be the catalyst for numerous studies of ocean physics, biological processes and biogeochemistry. Hydrostation S continues to be recognized as one of the most important sustained ocean time–series. The renewal of the Hydrostation S program is proposed herein, extending this invaluable time–series of ocean hydrography to almost 70 years. The upper ocean warming trend has strengthened (about +1.4° C since the 1970's; ~+0.8°C in last decade) with significant salinification (+0.16). Deeper waters such as the Labrador Sea Water has cooled by a few tenths of a degree and freshened with a marked decadal oscillation. The signature of deoxygenation has been observed at Hydrostation S in the upper ocean (about 4 µmoles kg -1 decade -1 decrease in dissolved oxygen) as well as the oxygen minimum zone (~2.5 µmoles kg -1 decade -1 ). Hydrostation S also supports the longest global ocean CO 2 and acidification time-series (from 1983 to present)

One of the longest open-ocean hydrographic stations in the world is maintained at the Hydrostation S site (formerly known as the Panulirus site) located ~25 km southeast of Bermuda in the North Atlantic Ocean. This program of repeat biweekly hydrographic observations began in 1954 (by Hank Stommel) and now, in its seventh decade, has proved to be the catalyst for numerous studies of ocean physics, biological processes and biogeochemistry. Hydrostation S continues to be recognized as one of the most important sustained ocean time–series. The renewal of the Hydrostation S program is proposed herein, extending this invaluable time–series of ocean hydrography to almost 70 years. The upper ocean warming trend has strengthened (about +1.4° C since the 1970's; ~+0.8°C in last decade) with significant salinification (+0.16). Deeper waters such as the Labrador Sea Water has cooled by a few tenths of a degree and freshened with a marked decadal oscillation. The signature of deoxygenation has been observed at Hydrostation S in the upper ocean (about 4 µmoles kg -1 decade -1 decrease in dissolved oxygen) as well as the oxygen minimum zone (~2.5 µmoles kg -1 decade -1 ). Hydrostation S also supports the longest global ocean CO 2 and acidification time-series (from 1983 to present)