This dataset contains monthly-averaged surface fields of temperature, salinity, total alkalinity (TA), and dissolved inorganic carbon (DIC) derived from the GoMBio model for 1981-2014. GoMBio is a ROMS-based 8-km resolution ocean-biogeochemical model encompassing the entire Gulf of Mexico. Model details can be found in Gomez et al. (2018; https://doi.org/10.5194/bg-15-3561-2018) and Gomez et al. (2020; https://doi.org/10.5194/bg-17-1685-2020). We include the results of four model experiments: (1) model hindcast, (2) climatological Mississippi-Atchafalaya chemistry experiment (CLM_MC), (3) climatological river experiment (CLM_RIV), and (4) climatological forcing experiment (CLM_FORC). The model hindcast experiment was forced with surface fluxes of momentum, heat, and freshwater from the European Center for Medium Range Weather Forecast reanalysis product (ERA-Interim). We prescribed a time-evolving monthly series of freshwater discharge for 28 river sources in the U.S., and a climatological discharge for 10 rivers in the U.S. and 11 rivers in Mexico. We also prescribed time evolving concentration of nutrients, TA, and DIC for the Mississippi and Atchafalaya River System (MARS), and long-term climatological values for the other river sources. The CLM_MC and CLM_RIV experiments are like the model hindcast, but the river inputs were modified to evaluate the model sensitivity to changes in river runoff. In the CLM_MC experiment we used a monthly climatology for the MARS. In the CLM_RIV experiment we used climatological river discharge values for all rivers, as well as the climatological chemistry for the MARS. Finally, in the CLM_FORC experiment, we prescribed climatological patterns for rivers, surface fluxes and the open boundary conditions. The only exceptions were the atmospheric CO2 and the open boundary conditions for DIC, which varied as in the model hindcast. This last experiment was conducted to examine the influence of climate variability in ocean acidification patterns.

This dataset consists of dissolved inorganic carbon, total alkalinity, water temperature and salinity from laboratory analyzed discrete water samples taken at the Central Gulf of Mexico Ocean Observing System buoy moored at 28.9N, 90.5W off Coastal Louisiana from 2017-07-14 to 2022-02-20. These are validation samples for the NOAA Pacific Marine Environmental Laboratory (PMEL) Moored Autonomous pCO2 (MAPCO2®) system buoy CoastalLA_91W_30N, that includes SeaBird CTD and SAMI pH instruments.

GOMECC Gulf of Mexico and East Coast Carbon Cruise (RB 07-05). North American Carbon Program (NACP) Gulf of Mexico and East Coast Carbon (GOMECC) Cruise on board NOAA Ship Ronald H. Brown from Galveston in the northern Gulf of Mexico to Boston on the East coast. The cruise was designed to obtain a snapshot of concentrations and fluxes of key carbon, physical, and biogeochemical parameters in the coastal realm. The program is in support of the North American Carbon Program (NACP) that has as overriding goal to constrain fluxes of carbon over North America and adjacent seas. This project is in support of the North American Carbon Program (NACP) and represents a collaboration between the National Oceanic and Atmospheric Administration, the Earth System Research Laboratory, the University of Miami Rosenstiel School of Marine and Atmospheric Science, the University of South Florida, the University of Georgia, the University of New Hampshire, Texas AM University, the University of Colorado, the University of Southern Mississippi, Loyola College of Maryland, and Lamont Doherty Earth Observatory. The cruise departed Galveston, Texas on July 10, 2007 and arrived in Boston, Massachusetts on August 4, 2007.

This dataset contains discrete measured and calculated surface seawater properties from samples taken on the first week of every month over the course of one or two days between 11/2021 and 07/2022 (9 months) at the Equatorial Pacific region off the coast of Colombia, around Gorgona Island National Natural Park. The dataset contains also measured monthly sea-surface temperature (SST), sea-surface salinity (SSS), pH in total scale (derived directly from in situ pH measurements) with depth of 1.8 metres along 7 sampling sites in a coast-ocean gradient (1 to 7) with the following geographical coverage: 1. Lat. -78.201138 Lon. 3.0163611; 2. Lat. -78.221416 Lon. 2.9705833; 3. Lat. -78.163861 Lon. 2.9960278; 4. Lat. -78.101555 Lon. 2.9473889; 5. Lat. -78.101555 Lon. 2.9322222; 6. Lat. -78.122865 Lon. 2.8756667; 7. Lat. -77.979865 Lon. 2.7204915. The measurements were taken with two CTD divers (SonTek CastAway-CTD and Eijkelkamp CTD-Diver 11.11.60) and one Niskin bottle (5L). The water samples where taken to a oceanography lab in the Pontifical Xavierian University to be tested for total alkalinity (TA), and to the Autonomous University of Baja California for Dissolved Inorganic Carbon (DIC) measurements. This was done in order to calculate the carbon fluxes on a monthly scale throughout nine months during the 2021-2022 La Niña year for the whole study site, allowing for observations in the spatiotemporal flux behavior variability (shown in dataset as fco2_measured).

This data package contains Underway total alkalinity, water temperature, salinity and other variables collected from surface seawater during the NOAA Ship Ronald H. Brown GOMECC2021 cruise RB2103 (EXPOCODE 33RO20210913) in the Gulf of Mexico, North Atlantic Ocean from 2021-09-13 to 2021-10-21. Data were collected from the ship's underway seawater supply during the GOMECC-4 cruise. This effort was part of the NOAA Ocean Acidification Program (OAP) grant entitled "Expanding near-shore carbonate measurements along the East-coast and Gulf of Mexico through multiple collaborations". Along with total alkalinity, corresponding temperature and salinity measurements are included. Measurements of pCO2 taken on these cruises are available from NOAA's AOML.

This dataset contains seawater analyses conducted during the fourth Gulf of Mexico Ecosystems and Carbon Cycle (GOMECC-4) cruise on board the NOAA Ship Ronald H. Brown departing from Key West, FL into the Gulf of Mexico and then around the coastal waters of the Gulf of Mexico in a counter-clockwise direction. Samples were collected using a CTD-O2 rosette equipped with 24 niskin-style bottles. The cruise took place from September 13–October 21, 2021 and ended in St. Petersburg, FL. The effort was in support of the coastal monitoring and research objectives of NOAA’S Ocean Acidification Program. The expedition was designed to obtain a snapshot of key carbon, physical, and biogeochemical parameters as they relate to ocean acidification (OA) in the coastal realm. This was the fourth occupation of the Gulf of Mexico as part of the Ocean Acidification Program’s monitoring efforts, with the first three occurring in 2007, 2012 and 2017. The cruise included a series of 15 transects approximately orthogonal to the coast of the Gulf of Mexico and a 16th partial transect along the 27°N line between Florida and the Bahamas. On the transit between each of these transects, discrete samples were collected from the underway seawater line to obtain a comprehensive set of underway measurements.

This dataset contains discrete measurements of water temperature, salinity, total dissolved inorganic carbon (DIC), total titration alkalinity (TA), pH on total scale, and calcium concentration. These data were collected between April 2014 and April 2018 in Lavaca-Matagorda, Guadalupe-San Antonio, Nueces-Corpus Christi estuaries along the northwestern Gulf of Mexico.

The second Gulf of Mexico and East Coast Carbon (GOMECC-2) Cruise on board NOAA Ship Ronald H. Brown from Miami, took place in the Gulf of Mexico and then along the East US coast to Boston. The effort was in support of the coastal monitoring and research objectives of the NOAA Ocean Acidification Program (OAP). The cruise was designed to obtain a snapshot of key carbon, physical, and biogeochemical parameters as they relate to ocean acidification (OA) in the coastal realm. This was the second occupation, with the first occurring in 2007, and complemented mooring time series and other regional OA activities. The cruise included a series of 8 transects approximately orthogonal to the Gulf of Mexico and Atlantic coasts and a comprehensive set of underway measurements along the entire transect.

This dataset contains full-depth carbonate chemistry profile data at the seasonal frequency of ship-based hydrographic surveys for the Florida Straits at 27°N from 2002 to 2018. We firstly developed an algorithm to estimate subsurface (~50 m) dissolved inorganic carbon (DIC) using measured data from carbonate chemistry-focused research cruise surveys across the Florida Straits at 27°N. This algorithm was then applied to the long-term non-carbonate chemistry time-series dataset to generate a DIC record. Total alkalinity of the full water column was estimated from a linear relationship with salinity based on measured data from carbonate chemistry focused research cruise surveys across the Florida Straits at 27°N. Furthermore, subsurface pH and aragonite saturation state (Ωarag) were calculated from DIC and TA using CO2SYS (Van Heuven et al., 2009) with the first and second carbonic acid dissociation constants K1 and K2 from Lueker et al. (2000), the acidity constant of the ion HSO4- from Dickson (1990), and borate-to-salinity ratio from Lee et al. (2010). For surface mixed layer (<50 m), DIC, pH, and (Ωarag) were calculated from TA and fCO2, where the latter was calculated using algorithms provided by Wanninkhof et al. (2020) based on the observational data from the Atlantic Oceanographic and Meteorological Laboratory (AOML) Ship of Opportunity-CO2 (SOOP-CO2) program from Royal Caribbean international cruise ships.