Description: Discrete water samples for determining CO concentrations were collected using a Niskin bottle at approximately 1 m water depth from a small boat at 14 stations in the western part of the Ria Formosa Lagoon. Samples were taken in the late afternoon (~17:00h local time) on 25 May 2021. The sampling was repeated at approximately the same time on 26 May 2021. Additionally, atmospheric samples for CO were collected at Stations 8, 9, 10, 11, 12, and 14 on 26 May 2021. Incubation experiment using waters from the effluent of the aquaculture facility Estação Piloto de Piscicultura em Olhão (EPPO) at the Instituto Português do Mar e da Atmosfera, I. P. (IPMA, I. P.) in Olhão. Seawater was collected in 3.5 L UV-transparent incubation bottles and were placed into 200 L incubation enclosures (incubators) at CCMAR of the University of Algarve in Faro. Bottles were incubated under light and dark conditions to investigate photochemical CO production. A total of 16 bottles (separated equally) were distributed between two incubators. One incubator was set to light conditions (Group A), and the other was set to dark conditions (Group B). The experiments were carried out for 48 h, with sampling from the incubation bottles conducted at time points 0, 24, and 48 h. At each time point (14:00 h local time), triplicate samples were collected to determine dissolved CO concentrations and CDOM absorbance. Chlorophyll a (Chl-a), fluorescent dissolved organic matter (FDOM), salinity, pH, and water temperature (T) were measured on board in 0.5 m water depth using a calibrated EXO2 multiparameter sonde (YSI Inc. Yellow Springs, Ohio, USA).

Description: Discrete water samples for determining CO concentrations were collected using a Niskin bottle at approximately 1 m water depth from a small boat at 14 stations in the western part of the Ria Formosa Lagoon. Samples were taken in the late afternoon (~17:00h local time) on 25 May 2021. The sampling was repeated at approximately the same time on 26 May 2021. Additionally, atmospheric samples for CO were collected at Stations 8, 9, 10, 11, 12, and 14 on 26 May 2021. Incubation experiment using waters from the effluent of the aquaculture facility Estação Piloto de Piscicultura em Olhão (EPPO) at the Instituto Português do Mar e da Atmosfera, I. P. (IPMA, I. P.) in Olhão. Seawater was collected in 3.5 L UV-transparent incubation bottles and were placed into 200 L incubation enclosures (incubators) at CCMAR of the University of Algarve in Faro. Bottles were incubated under light and dark conditions to investigate photochemical CO production. A total of 16 bottles (separated equally) were distributed between two incubators. One incubator was set to light conditions (Group A), and the other was set to dark conditions (Group B). The experiments were carried out for 48 h, with sampling from the incubation bottles conducted at time points 0, 24, and 48 h. At each time point (14:00 h local time), triplicate samples were collected to determine dissolved CO concentrations and CDOM absorbance. Chlorophyll a (Chl-a), fluorescent dissolved organic matter (FDOM), salinity, pH, and water temperature (T) were measured on board in 0.5 m water depth using a calibrated EXO2 multiparameter sonde (YSI Inc. Yellow Springs, Ohio, USA).

Description: Discrete water samples for determining CO concentrations were collected using a Niskin bottle at approximately 1 m water depth from a small boat at 14 stations in the western part of the Ria Formosa Lagoon. Samples were taken in the late afternoon (~17:00h local time) on 25 May 2021. The sampling was repeated at approximately the same time on 26 May 2021. Additionally, atmospheric samples for CO were collected at Stations 8, 9, 10, 11, 12, and 14 on 26 May 2021. Incubation experiment using waters from the effluent of the aquaculture facility Estação Piloto de Piscicultura em Olhão (EPPO) at the Instituto Português do Mar e da Atmosfera, I. P. (IPMA, I. P.) in Olhão. Seawater was collected in 3.5 L UV-transparent incubation bottles and were placed into 200 L incubation enclosures (incubators) at CCMAR of the University of Algarve in Faro. Bottles were incubated under light and dark conditions to investigate photochemical CO production. A total of 16 bottles (separated equally) were distributed between two incubators. One incubator was set to light conditions (Group A), and the other was set to dark conditions (Group B). The experiments were carried out for 48 h, with sampling from the incubation bottles conducted at time points 0, 24, and 48 h. At each time point (14:00 h local time), triplicate samples were collected to determine dissolved CO concentrations and CDOM absorbance. Chlorophyll a (Chl-a), fluorescent dissolved organic matter (FDOM), salinity, pH, and water temperature (T) were measured on board in 0.5 m water depth using a calibrated EXO2 multiparameter sonde (YSI Inc. Yellow Springs, Ohio, USA).

Description: Discrete water samples for determining CO concentrations were collected using a Niskin bottle at approximately 1 m water depth from a small boat at 14 stations in the western part of the Ria Formosa Lagoon. Samples were taken in the late afternoon (~17:00h local time) on 25 May 2021. The sampling was repeated at approximately the same time on 26 May 2021. Additionally, atmospheric samples for CO were collected at Stations 8, 9, 10, 11, 12, and 14 on 26 May 2021. Incubation experiment using waters from the effluent of the aquaculture facility Estação Piloto de Piscicultura em Olhão (EPPO) at the Instituto Português do Mar e da Atmosfera, I. P. (IPMA, I. P.) in Olhão. Seawater was collected in 3.5 L UV-transparent incubation bottles and were placed into 200 L incubation enclosures (incubators) at CCMAR of the University of Algarve in Faro. Bottles were incubated under light and dark conditions to investigate photochemical CO production. A total of 16 bottles (separated equally) were distributed between two incubators. One incubator was set to light conditions (Group A), and the other was set to dark conditions (Group B). The experiments were carried out for 48 h, with sampling from the incubation bottles conducted at time points 0, 24, and 48 h. At each time point (14:00 h local time), triplicate samples were collected to determine dissolved CO concentrations and CDOM absorbance. Chlorophyll a (Chl-a), fluorescent dissolved organic matter (FDOM), salinity, pH, and water temperature (T) were measured on board in 0.5 m water depth using a calibrated EXO2 multiparameter sonde (YSI Inc. Yellow Springs, Ohio, USA).

Description: Discrete water samples for determining CO concentrations were collected using a Niskin bottle at approximately 1 m water depth from a small boat at 14 stations in the western part of the Ria Formosa Lagoon. Samples were taken in the late afternoon (~17:00h local time) on 25 May 2021. The sampling was repeated at approximately the same time on 26 May 2021. Additionally, atmospheric samples for CO were collected at Stations 8, 9, 10, 11, 12, and 14 on 26 May 2021. Incubation experiment using waters from the effluent of the aquaculture facility Estação Piloto de Piscicultura em Olhão (EPPO) at the Instituto Português do Mar e da Atmosfera, I. P. (IPMA, I. P.) in Olhão. Seawater was collected in 3.5 L UV-transparent incubation bottles and were placed into 200 L incubation enclosures (incubators) at CCMAR of the University of Algarve in Faro. Bottles were incubated under light and dark conditions to investigate photochemical CO production. A total of 16 bottles (separated equally) were distributed between two incubators. One incubator was set to light conditions (Group A), and the other was set to dark conditions (Group B). The experiments were carried out for 48 h, with sampling from the incubation bottles conducted at time points 0, 24, and 48 h. At each time point (14:00 h local time), triplicate samples were collected to determine dissolved CO concentrations and CDOM absorbance. Chlorophyll a (Chl-a), fluorescent dissolved organic matter (FDOM), salinity, pH, and water temperature (T) were measured on board in 0.5 m water depth using a calibrated EXO2 multiparameter sonde (YSI Inc. Yellow Springs, Ohio, USA).

Description: Discrete water samples for determining CO concentrations were collected using a Niskin bottle at approximately 1 m water depth from a small boat at 14 stations in the western part of the Ria Formosa Lagoon. Samples were taken in the late afternoon (~17:00h local time) on 25 May 2021. The sampling was repeated at approximately the same time on 26 May 2021. Additionally, atmospheric samples for CO were collected at Stations 8, 9, 10, 11, 12, and 14 on 26 May 2021. Incubation experiment using waters from the effluent of the aquaculture facility Estação Piloto de Piscicultura em Olhão (EPPO) at the Instituto Português do Mar e da Atmosfera, I. P. (IPMA, I. P.) in Olhão. Seawater was collected in 3.5 L UV-transparent incubation bottles and were placed into 200 L incubation enclosures (incubators) at CCMAR of the University of Algarve in Faro. Bottles were incubated under light and dark conditions to investigate photochemical CO production. A total of 16 bottles (separated equally) were distributed between two incubators. One incubator was set to light conditions (Group A), and the other was set to dark conditions (Group B). The experiments were carried out for 48 h, with sampling from the incubation bottles conducted at time points 0, 24, and 48 h. At each time point (14:00 h local time), triplicate samples were collected to determine dissolved CO concentrations and CDOM absorbance. Chlorophyll a (Chl-a), fluorescent dissolved organic matter (FDOM), salinity, pH, and water temperature (T) were measured on board in 0.5 m water depth using a calibrated EXO2 multiparameter sonde (YSI Inc. Yellow Springs, Ohio, USA).

Description: The transit of RV SONNE from Las Palmas (departure: 11.12.2021) to Guayaquil, Ecuador (arrival: 11.01.2022) is directly related to the international collaborative project SO287-CONNECT of GEOMAR in cooperation with Hereon and the University of Bremen, supported by the German Federal Ministry of Education and Research (BMBF) between October 15 2021 and January 15 2024. The research expedition was conducted to decipher the coupling of biogeochemical and ecological processes and their influence on atmospheric chemistry along the transport pathway of water from the upwelling zones off Africa into the Sargasso Sea and further to the Caribbean and the equatorial Pacific. Nutrient-rich water rises from the deep and promotes the growth of plant and animal microorganisms, and fish at the ocean surface off West Africa. The North Equatorial Current water carries the water from the upwelling, which contains large amounts of organic material across the Atlantic to the Caribbean, supporting bacterial activity along the way. But how the nutritious remnants of algae and other substances are processed on their long journey, biochemically transformed, decomposed into nutrients and respired to carbon dioxide, has so far only been partially investigated. Air, seawater and particles were sampled in order to provide new details about the large cycles of carbon and nitrogen, but also of many other elements such as oxygen, iodine, bromine and sulfur. Inorganic and organic bromine and iodine compounds are generally emitted naturally from the ocean into the atmosphere, promote cloud formation and affect climate, and some even reach the stratosphere where they contribute to ozone depletion. We measured how much of these compounds are released from the ocean, and at what locations and how they are transformed in the ocean and in the atmosphere. Sargassum algae, which have become a nuisance on beaches in the western and eastern Atlantic, support life and contribute to carbon cycling in the middle of the Atlantic, the Sargasso Sea and in the Caribbean, while their contribution to halogen cycling and marine bromine and iodine emissions was previously unknown. We investigated the influence of various natural parameters such as temperature and solar radiation on the biogeochemical transformation processes in order to understand the influence of climate change on these processes in incubation experiments with seawater and algae. We investigated how anthropogenic signals such as shipping traffic influence the nitrogen and sulphur cycle in the ocean, as well as the impact of nitrogen oxides from ship exhaust and sulphurous, acidic and dirty water from purification systems on organisms and biochemical processes. Plastic debris was sampled from the surface waters to investigate its contribution to global biogeochemical transformation processes. The working hypotheses of the research program were:  Bioavailability of dissolved organic carbon in surface waters decreases along the productivity gradient and transport pathway from the Eastern to the Western Tropical North Atlantic.  Nutrient gradients from East to West constrain the microbial utilization of organic matter- contributing to an accumulation of C-rich organic matter due to a) limited mineralization and b) enhanced exudation- also leading to gel-like particles accumulation in the western tropical North Atlantic and Sargasso Sea.  Tropospheric and stratospheric ozone are strongly impacted by biogeochemical and ecological processes occurring around and in the NA gyre system related to marine iodine and bromine cycles.  The long-range transport of natural and anthropogenic organic matter in water and of gases and aerosols in the air impact carbon-export, biogeochemical cycles in the water column, and the release of gases and particles from the ocean significantly. 4 SONNE -Berichte, SO287, Las Palmas - Guayaquil, 11.12.2021 - 11.01.202 The data and samples obtained specifically target carbon, nutrient and halogen cycling, the composition of phytoplankton, bacteria, the transport and sequestration of macro algae and the air-sea exchange processes of climate relevant gases and aerosols. The influence of ecological and transport processes, as well as anthropogenic impacts on the North Atlantic gyre system, specifically in the Sargasso Sea and the influence of ship emissions throughout the Atlantic towards the west and into the Pacific will be investigated with the data.

Description: Carbon monoxide (CO) is an atmospheric trace gas that plays a crucial role in the oxidizing capacity of the Earth’s atmosphere. Moreover, it functions as an indirect greenhouse gas, influencing the lifetimes of potent greenhouse gases such as methane. Albeit being an overall source of atmospheric CO, the role of coastal regions in the marine cycling of CO and how its budget can be affected by anthropogenic activities, remain uncertain. Here, we present the first measurements of dissolved CO in the Ria Formosa Lagoon, an anthropogenically influenced system in southern Portugal. The dissolved CO concentrations in the surface layer ranged from 0.16 to 3.1 nmol L−1 with an average concentration of 0.75 ± 0.57 nmol L−1. The CO saturation ratio ranged from 1.7 to 32.2, indicating that the lagoon acted as a source of CO to the atmosphere in May 2021. The estimated average sea-to-air flux density was 1.53 μmol m−2 d−1, mainly fueled by CO photochemical production. Microbial consumption accounted for 83 % of the CO production, suggesting that the resulting CO emissions to the atmosphere were modulated by microbial consumption in the surface waters of the Ria Formosa Lagoon. The results from an irradiation experiment with aquaculture effluent water indicated that aquaculture facilities in the Ria Formosa Lagoon seem to be a negligible source of atmospheric CO.

Description: Nitric oxide (NO) is an atmospheric pollutant and climate forcer as well as a key intermediary in the marine nitrogen cycle, but the ocean’s NO contribution and production mechanisms remain unclear. Here, high-resolution NO observations were conducted simultaneously in the surface ocean and the lower atmosphere of the Yellow Sea and the East China Sea; moreover, NO production from photolysis and microbial processes was analyzed. The NO sea–air exchange showed uneven distributions (RSD = 349.1%) with an average flux of 5.3 ± 18.5 × 10–17 mol cm–2 s–1. In coastal waters where nitrite photolysis was the predominant source (89.0%), NO concentrations were remarkably higher (84.7%) than the overall average of the study area. The NO from archaeal nitrification accounted for 52.8% of all microbial production (11.0%). We also examined the relationship between gaseous NO and ozone which helped identify sources of atmospheric NO. The sea-to-air flux of NO in coastal waters was narrowed by contaminated air with elevated NO concentrations. These findings indicate that the emissions of NO from coastal waters, mainly controlled by reactive nitrogen inputs, will increase with the reduced terrestrial NO discharge.

Description: Nitric oxide (NO) is a short-lived intermediate of the oceanic nitrogen cycle, and it is produced by biological and photochemical processes in the ocean. Nitrogen dioxide (NO2) is a reactive atmospheric compound which has not been determined in the ocean so far. Here, we present the setup and validation of a novel continuous underway measurement system to measure dissolved NO and NO2 in the surface ocean. The system consists of a seawater/gas equilibration component coupled to a chemiluminescence detector. It was successfully deployed during a 12 day cruise to the East China Sea in May 2018. Dissolved NO and NO2 surface concentrations ranged from 〈limit of detection (LOD) to 98 × 10-12 mol L-1 and 〈LOD to 83 × 10-12 mol L-1, respectively. The ECS was supersaturated with NO but significantly undersaturated with NO2, indicating that the surface waters were a source for atmospheric NO but a sink for atmospheric NO2 at the time of our measurements.