Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Data Files
• Related Publications
• Related Datasets
• Parameters
• Instruments
• Project Information
• Program Information
• Funding

Sample collection: Sea-surface water samples were collected in Niskin bottles during cruises in the Pacific Ocean, Atlantic Ocean, and the Gulf of Mexico. For a map of the sample, locations see Xue and Kieber 2021 (Figure S1). In the coral reef and Pacific Ocean samples offshore from the island of Mo’orea (French Polynesia), samples from the surface were hand-collected using a polypropylene bucket and then poured into an opaque polypropylene bottle. All water samples were gravity filtered through a 0.2 µm POLYCAP 75 AS Nylon filter into Qorpak glass bottles. Filtered samples were stored in dark at 4 degrees C until use, except for the Mo’orea samples which were used the same day in sunlight exposure experiments. The polypropylene bucket and bottles were rinsed several times using high-purity laboratory water (Milli-Q) and seawater prior to use. All glass bottles were rinsed using Milli-Q and baked at 550 degrees C for 6 hours.

Photochemical experiments: 0.2 µm-filtered samples were gently pulled into eight Teflon-sealed quartz tubes (Kieber et al. 1997) with no headspaces. Four quartz tubes wrapped with aluminum foil served as dark controls. The dark controls and four remaining quartz tubes were exposed to sunlight for 8 to 30 hours in a circulating water bath. At the end of an exposure experiment, a 15 milliliter (mL) aliquot of each sample was collected and stored frozen or at room temperature after acidification until the analysis for acrylate concentrations. Nitrate and nitrite actinometer solutions were irradiated along with the quartz tubes to determine photon exposure between 311 and 333 nm and between 330 and 380 nm, respectively (Jankowski et al. 1999; Kieber et al. 2007).

Acrylate quantification: A precolumn derivatization HPLC method was used to quantify acrylate (Tyssebotn et al. 2017; Xue and Kieber, 2021). Briefly, 300 µL of thiosalicylic acid reagent (20 mM) was added to a 3 mL seawater sample in a Qorpak borosilicate vial with the pH adjusted to 4.0. Samples were incubated in a 90 oC water bath for 6 hours. After the reacted sample was filtered through a 0.2 µm Nylon filter, 1 mL of the sample was injected into a Shimadzu reverse-phase HPLC with UV detection at 257 nm. The limit of detection for this method was 0.2 nM for an injection volume of 1 mL.

All samples were irradiated on the rooftop of the Jahn Laboratory in Syracuse, NY, except for the Pacific Ocean and Mo'orea coral reef samples (these two samples were irradiated in a water bath at the Gump Research Station). Seawater samples were filtered through a 0.2 m Nylon filter and stored in a pre-baked glass bottle with no headspace.  All samples were irradiated on the rooftop of the Jahn Laboratory in Syracuse, NY, except for the Pacific Ocean and Mo'orea coral reef samples (these two samples were irradiated in a water bath at the Gump Research Station. a330 is the absorption coefficient at 330 nm of each 0.2 µm-filtered seawater sample. Photon-based production rates were calculated by dividing the acrylate production by the photon exposure between 330 and 380 nm determined by nitrite actinometry. To determine the photochemical production of acrylate in seawater, four samples were exposed to sunlight for 8 - 30 hours; four samples were wrapped in aluminum foil to serve as dark controls. The sunlight photon exposures for each sunlight-exposure experiment between 311 and 333 nm and between 330 and 380 nm were determined using nitrate and nitrite actinometry. The concentration of acrylate produced in an experiment was calculated as the acrylate concentration in each light sample at the end of irradiation minus the average concentration in the dark controls. The hourly rate of acrylate production is determined by dividing the amount of acrylate produced by the time of sunlight exposure in sunlight exposure time in hours. The photon-based rate of acrylate production is equal to 1000 times the amount of acrylate produced divided by the nitrite photon exposure.  

BCO-DMO processing description:
- Converted dates to YYYY-MM-DD format
- Adjusted field/parameter names to comply with BCO-DMO naming conventions
- Converted longitude values to East to comply with BCO-DMO standards
- Added a conventional header with dataset name, PI names, version date
 

NSF Award Abstract:

This project would investigate the marine chemistry of the compound acrylate. Acrylate is a mostly overlooked by-product of a very well-studied process through which a compound known as DMSP (dimethylsulfoniopropionate), a compound produced by phytoplankton, is converted to the gas dimethylsulfide (known as DMS). This process is an important part of understanding the marine cycling of sulfur, and DMS plays a role in cloud formation and climate. Thus, these aspects of the conversion of DMSP to DMS have received considerable attention. On the other hand, very little is known about acrylate concentrations, fluxes, or impacts in the oceans, even though it is produced during the conversion of DMSP to DMS. Acrylate concentrations and fluxes should at times be substantial, especially in shallow-water coral reefs or during blooms of DMSP-rich phytoplankton that are common throughout the world's oceans and often harmful or toxic. It is likely that acrylate is a reactive form of marine organic matter that significantly impacts the carbon cycle and ecology of the upper ocean. This project will foster research and educational opportunities for undergraduates and one graduate student through several avenues including field work with international collaborators, attendance at national and local meetings, mentoring, preparing for and delivering college-level lectures, and presentations made to the general public at forums such as Syracuse's Milton J. Rubenstein Museum of Science. Results will be disseminated through peer-reviewed publications, media communications, web-based data bases, and presentations at scientific meetings, public forums and in the classroom.

A three-year project is proposed to study the effect of sunlight on the formation and loss of acrylate in seawater, to model these processes in the water column, and to determine if photoproduction and photolysis are important pathways in the marine acrylate cycle in a shallow-water coral reef. Four objectives are planned to carry out this research: (1) synthesize radiocarbon-labeled DMSP as a source of radiocarbon-labeled acrylate for photolysis and uptake studies; (2) conduct laboratory experiments using a solar simulator to study the photolysis and photoproduction of acrylate in water and seawater under varying conditions (e.g., pH, temperature, oxygen concentration); (3) determine temperature and wavelength-dependent quantum yields for acrylate photolysis and acrylate photoproduction in seawater using a monochromatic irradiation system; and (4) conduct a field study at the Richard Gump Research Station to determine rates of photolysis, photoproduction and microbial consumption of acrylate in a shallow-water coral reef.

The Surface Ocean Lower Atmosphere Study (SOLAS) program is designed to enable researchers from different disciplines to interact and investigate the multitude of processes and interactions between the coupled ocean and atmosphere.

Oceanographers and atmospheric scientists are working together to improve understanding of the fate, transport, and feedbacks of climate relevant compounds, and also weather and hazards that are affected by processes at the surface ocean.

Oceanographers and atmospheric scientists are working together to improve understanding of the fate, transport, and feedbacks of climate relevant compounds.

Physical, chemical, and biological research near the ocean-atmosphere interface must be performed in synergy to extend our current knowledge to adequately understand and forecast changes on short and long time frames and over local and global spatial scales.

The findings obtained from SOLAS are used to improve knowledge at process scale that will lead to better quantification of fluxes of climate relevant compounds such as CO2, sulfur and nitrogen compounds, hydrocarbons and halocarbons, as well as dust, energy and momentum. This activity facilitates a fundamental understanding to assist the societal needs for climate change, environmental health, weather prediction, and national security.

The US SOLAS program is a component of the International SOLAS program where collaborations are forged with investigators around the world to examine SOLAS issues ubiquitous to the world's oceans and atmosphere.

» International SOLAS Web site

Science Implementation Strategy Reports

US-SOLAS (4 MB PDF file)
Other SOLAS reports are available for download from the US SOLAS Web site