Hawaii Ocean Time-series, School of Ocean and Earth Science and Technology, University of Hawai'i at Mānoa
Hawaii Ocean Time-series surface CO2 system data, Station ALOHA
Surface seawater carbonate chemistry at Station ALOHA, north of Oahu, Hawaii: one mean (0-30 dbar) per HOT cruise, roughly monthly from October 1988, of temperature, salinity, dissolved inorganic carbon, total alkalinity, measured and calculated pH (total scale, at 25 °C and in situ), CO2 partial pressure, aragonite and calcite saturation states and carbonate ion. Calculated pH (pHcalc_insitu) gives the longest continuous record; measured pH starts later. One open-ocean station, so it shows the trend at that site, not a global average. Cruises per year vary (5 in 2022). Some early carbon values were taken from Scripps' parallel ALOHA measurements, flagged in the notes column.
Numbers published from it
Licence and credit
- Licence
- No licence stated; free and open access with an NSF acknowledgement (HOT data policy)
- What the terms say
“The HOT project is committed to providing free and open access to its data set in a timely manner, and the use of these data is encouraged.”
From the producer's terms, checked 2026-10-04; re-checked automatically every week.
- Credit we give
- Hawaii Ocean Time-series (HOT) surface CO2 system data product, Station ALOHA (J. E. Dore, University of Hawai'i at Mānoa), last updated {version}; adapted from Dore et al. (2009), Proc Natl Acad Sci USA 106:12235-12240, doi:10.1073/pnas.0906044106.
- Notice
- This publication is based upon Hawaii Ocean Time-series observations supported by the U.S. National Science Foundation under Award #2241005.
- Copy of the raw file
- Allowed: we keep a public copy of every version we use.
- Cite as
- Dore, J.E., R. Lukas, D.W. Sadler, M.J. Church, and D.M. Karl. 2009. Physical and biogeochemical modulation of ocean acidification in the central North Pacific. Proc Natl Acad Sci USA 106:12235-12240.
Files
Tab-delimited text: 7 header lines (title, created and last-updated dates, citation, contact), a blank line, then 22 columns from cruise, days, date, temp, sal, ... pHcalc_insitu, pCO2calc_insitu, ... carbonate_insitu, notes. Missing = -999. The vintage is the "Last updated" date in the header.
https://hahana.soest.hawaii.edu/hot/hotco2/HOT_surface_CO2.txtThe product's readme: methods, column definitions (units, pH scale, CO2SYS constants) and the notes codes for non-standard sampling and filled values.
https://hahana.soest.hawaii.edu/hot/hotco2/HOT_surface_CO2_readme.pdf
Status
- Programme
- Product last updated 1 January 2026, covering cruises 1-355 (October 1988 to December 2024); 2025 cruises appear only as preliminary data on the HOT data system. Funded by the US National Science Foundation (award 2241005, to July 2028); the FY2027 US budget request (April 2026) proposes deep cuts to NSF.
- Updates
- About yearly (this edition 1 January 2026)
- Last check
- Unchanged since the last fetch (2026-10-05T11:03:20Z)