Data
Seawater carbon dioxide (pCO₂) at Station ALOHA, Hawaii, each cruise
Partial pressure of carbon dioxide in surface seawater at Station ALOHA, north of Oahu, for each Hawaii Ocean Time-series cruise since October 1988, in microatmospheres.
Latest value
389.9µatm
Station ALOHA, open North Pacific north of Oahu, Hawaii (22°45′N, 158°00′W); one station, 20 December 2024. Version 2026-01-01.
Seawater carbon dioxide (pCO₂) at Station ALOHA, Hawaii, each cruise (microatmospheres)
Seawater carbon dioxide (pCO₂) at Station ALOHA, Hawaii, each cruise (microatmospheres)
Show as a table
| Period | Value (µatm) | Status |
|---|---|---|
| 1988-10-31 | 330.9 | final |
| 1988-12-02 | 330.6 | final |
| 1989-01-08 | 324.3 | final |
| 1989-02-26 | 310.9 | final |
| 1989-03-27 | 317.7 | final |
| 1989-05-18 | 326.2 | final |
| 1989-06-24 | 334.3 | final |
| 1989-07-29 | 340.4 | final |
| 1989-08-24 | 343.8 | final |
| 1989-09-22 | 337.8 | final |
| 1989-10-18 | 350.5 | final |
| 1989-11-27 | 329.7 | final |
| 1990-01-05 | 310.8 | final |
| 1990-02-15 | 317.2 | final |
| 1990-03-19 | 310.1 | final |
| 1990-04-13 | 320.2 | final |
| 1990-05-09 | 324.3 | final |
| 1990-06-13 | 318.9 | final |
| 1990-07-25 | 329.7 | final |
| 1990-09-14 | 353.6 | final |
| 1990-11-19 | none (HOT's file has -999, its missing-value marker, for cruise 21.) | final |
| 1990-12-18 | 322.4 | final |
| 1991-02-03 | 317.4 | final |
| 1991-03-07 | 318.0 | final |
| 1991-04-10 | 319.2 | final |
| 1991-05-08 | 326.5 | final |
| 1991-06-05 | 327.3 | final |
| 1991-07-10 | 327.8 | final |
| 1991-08-10 | 339.7 | final |
| 1991-09-18 | 344.4 | final |
| 1991-10-21 | 338.6 | final |
| 1991-12-07 | 334.7 | final |
| 1992-01-05 | 324.1 | final |
| 1992-02-15 | 317.8 | final |
| 1992-03-06 | 321.9 | final |
| 1992-04-17 | 331.7 | final |
| 1992-06-09 | 325.5 | final |
| 1992-07-05 | 343.0 | final |
| 1992-08-05 | 342.4 | final |
| 1992-09-23 | 346.2 | final |
| 1992-10-20 | 351.6 | final |
| 1992-11-24 | 332.3 | final |
| 1992-12-16 | 324.0 | final |
| 1993-01-20 | 309.6 | final |
| 1993-02-17 | 310.8 | final |
| 1993-04-15 | 333.7 | final |
| 1993-05-21 | 331.0 | final |
| 1993-07-26 | none (HOT's file has -999, its missing-value marker, for cruise 48.) | final |
| 1993-09-15 | 360.2 | final |
| 1993-10-30 | 345.4 | final |
| 1994-01-20 | 298.3 | final |
| 1994-02-17 | 309.5 | final |
| 1994-03-09 | 323.4 | final |
| 1994-06-19 | 336.7 | final |
| 1994-07-25 | 351.4 | final |
| 1994-08-30 | 348.4 | final |
| 1994-09-23 | 349.2 | final |
| 1994-10-15 | 349.7 | final |
| 1994-11-19 | 335.1 | final |
| 1995-02-06 | 326.9 | final |
| 1995-03-04 | 323.6 | final |
| 1995-04-06 | 333.9 | final |
| 1995-05-07 | 325.1 | final |
| 1995-07-30 | 344.7 | final |
| 1995-08-29 | 345.1 | final |
| 1995-09-26 | 349.0 | final |
| 1995-10-27 | 339.5 | final |
| 1995-11-17 | 326.7 | final |
| 1996-01-17 | 331.8 | final |
| 1996-03-27 | 328.5 | final |
| 1996-04-24 | 332.8 | final |
| 1996-05-22 | 344.3 | final |
| 1996-06-26 | 344.8 | final |
| 1996-07-27 | 346.8 | final |
| 1996-08-21 | 352.7 | final |
| 1996-10-02 | 352.7 | final |
| 1996-10-30 | 345.8 | final |
| 1996-12-11 | 337.8 | final |
| 1997-01-08 | 330.4 | final |
| 1997-02-18 | 353.0 | final |
| 1997-03-12 | 328.0 | final |
| 1997-04-09 | 326.2 | final |
| 1997-05-07 | 338.2 | final |
| 1997-06-04 | 333.3 | final |
| 1997-07-09 | 350.0 | final |
| 1997-08-02 | 351.0 | final |
| 1997-09-25 | 359.2 | final |
| 1997-12-05 | 333.2 | final |
| 1998-01-11 | 332.5 | final |
| 1998-02-19 | 330.1 | final |
| 1998-03-18 | 337.2 | final |
| 1998-04-15 | 335.4 | final |
| 1998-05-13 | 338.1 | final |
| 1998-06-17 | 348.7 | final |
| 1998-07-15 | 361.6 | final |
| 1998-08-10 | 358.5 | final |
| 1998-09-28 | 365.5 | final |
| 1998-10-19 | 359.0 | final |
| 1998-11-11 | 359.6 | final |
| 1998-12-09 | 347.8 | final |
| 1999-01-13 | 352.7 | final |
| 1999-02-18 | 344.5 | final |
| 1999-03-17 | 311.8 | final |
| 1999-04-14 | 323.7 | final |
| 1999-05-10 | 345.0 | final |
| 1999-07-14 | 345.9 | final |
| 1999-08-13 | 365.4 | final |
| 1999-10-15 | 368.5 | final |
| 1999-11-09 | 359.7 | final |
| 1999-12-15 | 359.5 | final |
| 2000-02-03 | 346.3 | final |
| 2000-03-01 | 347.6 | final |
| 2000-03-29 | 348.6 | final |
| 2000-04-26 | 346.5 | final |
| 2000-05-25 | 371.1 | final |
| 2000-06-21 | 358.4 | final |
| 2000-07-26 | 354.3 | final |
| 2000-08-23 | 359.1 | final |
| 2000-10-18 | 373.2 | final |
| 2000-11-30 | 346.0 | final |
| 2000-12-20 | 347.5 | final |
| 2001-01-17 | 348.1 | final |
| 2001-02-14 | 353.9 | final |
| 2001-03-21 | 350.8 | final |
| 2001-04-18 | 347.7 | final |
| 2001-05-16 | 347.7 | final |
| 2001-06-14 | 344.1 | final |
| 2001-07-11 | 353.8 | final |
| 2001-08-08 | 364.7 | final |
| 2001-10-02 | 372.1 | final |
| 2001-10-23 | 353.9 | final |
| 2001-11-17 | 358.5 | final |
| 2001-12-14 | 349.4 | final |
| 2002-01-16 | 347.0 | final |
| 2002-02-21 | 335.9 | final |
| 2002-03-13 | 336.8 | final |
| 2002-05-21 | 358.4 | final |
| 2002-06-29 | 367.1 | final |
| 2002-08-28 | 367.5 | final |
| 2002-10-07 | 352.6 | final |
| 2002-11-04 | 351.9 | final |
| 2002-11-25 | 352.6 | final |
| 2002-12-19 | 347.4 | final |
| 2003-01-17 | 340.6 | final |
| 2003-02-26 | 339.5 | final |
| 2003-03-29 | 341.8 | final |
| 2003-04-24 | 343.6 | final |
| 2003-05-21 | 349.5 | final |
| 2003-06-20 | 357.3 | final |
| 2003-07-20 | 363.6 | final |
| 2003-08-21 | 355.7 | final |
| 2003-10-15 | 351.8 | final |
| 2003-11-10 | 351.3 | final |
| 2003-12-20 | 330.2 | final |
| 2004-01-22 | 344.7 | final |
| 2004-02-25 | 332.9 | final |
| 2004-03-20 | 321.3 | final |
| 2004-04-21 | 341.8 | final |
| 2004-05-19 | 349.4 | final |
| 2004-06-16 | 352.5 | final |
| 2004-07-13 | 365.6 | final |
| 2004-08-16 | 366.1 | final |
| 2004-09-29 | 366.0 | final |
| 2004-10-31 | 356.9 | final |
| 2004-11-28 | 347.6 | final |
| 2004-12-21 | 341.1 | final |
| 2005-02-02 | 343.5 | final |
| 2005-03-05 | 334.9 | final |
| 2005-05-18 | 350.2 | final |
| 2005-06-15 | 361.0 | final |
| 2005-07-17 | 373.7 | final |
| 2005-08-14 | 365.0 | final |
| 2005-09-10 | 380.0 | final |
| 2005-10-09 | 362.5 | final |
| 2005-11-12 | 356.3 | final |
| 2005-12-13 | 352.2 | final |
| 2006-01-25 | 330.3 | final |
| 2006-02-15 | 347.5 | final |
| 2006-03-10 | 335.4 | final |
| 2006-04-02 | 334.9 | final |
| 2006-05-27 | 352.4 | final |
| 2006-06-14 | 373.5 | final |
| 2006-07-13 | 359.2 | final |
| 2006-08-09 | 365.6 | final |
| 2006-09-16 | 363.3 | final |
| 2006-10-21 | 372.2 | final |
| 2006-11-09 | 362.6 | final |
| 2006-12-10 | 350.1 | final |
| 2007-02-07 | 338.0 | final |
| 2007-03-21 | 345.1 | final |
| 2007-05-05 | 358.9 | final |
| 2007-06-10 | none (HOT's file has -999, its missing-value marker, for cruise 192.) | final |
| 2007-07-08 | 377.1 | final |
| 2007-08-04 | 373.8 | final |
| 2007-09-03 | 378.6 | final |
| 2007-10-03 | 376.4 | final |
| 2007-12-02 | 372.1 | final |
| 2007-12-21 | 355.5 | final |
| 2008-01-30 | 347.4 | final |
| 2008-02-24 | 347.4 | final |
| 2008-05-28 | 371.1 | final |
| 2008-06-26 | 367.0 | final |
| 2008-07-27 | 376.9 | final |
| 2008-08-17 | 366.7 | final |
| 2008-10-11 | 361.0 | final |
| 2008-12-01 | 360.5 | final |
| 2008-12-15 | none (HOT's file has -999, its missing-value marker, for cruise 207.) | final |
| 2009-01-21 | 344.1 | final |
| 2009-02-18 | 337.0 | final |
| 2009-04-29 | 354.6 | final |
| 2009-05-28 | 374.7 | final |
| 2009-07-04 | 375.3 | final |
| 2009-07-25 | 384.4 | final |
| 2009-08-19 | 381.3 | final |
| 2009-09-25 | 390.8 | final |
| 2009-11-04 | 375.7 | final |
| 2009-12-10 | 363.7 | final |
| 2010-02-15 | none (HOT's file has -999, its missing-value marker, for cruise 218.) | final |
| 2010-03-10 | 347.4 | final |
| 2010-04-07 | 347.8 | final |
| 2010-05-19 | 359.9 | final |
| 2010-06-09 | 375.9 | final |
| 2010-07-09 | 373.1 | final |
| 2010-08-08 | 364.1 | final |
| 2010-09-04 | 373.2 | final |
| 2010-10-04 | 377.0 | final |
| 2010-11-21 | 370.4 | final |
| 2011-01-09 | none (HOT's file has -999, its missing-value marker, for cruise 228.) | final |
| 2011-01-29 | 355.4 | final |
| 2011-03-01 | 351.2 | final |
| 2011-04-12 | 353.3 | final |
| 2011-05-10 | 362.9 | final |
| 2011-07-20 | 370.5 | final |
| 2011-08-30 | 369.2 | final |
| 2011-09-27 | 377.0 | final |
| 2011-11-05 | 373.3 | final |
| 2011-11-29 | 361.6 | final |
| 2011-12-20 | 362.0 | final |
| 2012-01-19 | 356.3 | final |
| 2012-03-25 | 353.5 | final |
| 2012-05-02 | 364.5 | final |
| 2012-05-31 | 370.4 | final |
| 2012-06-27 | 377.6 | final |
| 2012-08-01 | 387.1 | final |
| 2012-08-18 | 392.1 | final |
| 2012-09-15 | 394.6 | final |
| 2012-10-08 | 384.1 | final |
| 2012-12-04 | 374.7 | final |
| 2013-02-13 | 362.7 | final |
| 2013-03-07 | 361.4 | final |
| 2013-04-06 | 363.7 | final |
| 2013-05-18 | 384.5 | final |
| 2013-06-26 | 385.5 | final |
| 2013-09-12 | 394.5 | final |
| 2013-10-02 | 379.5 | final |
| 2013-10-28 | 386.4 | final |
| 2013-11-27 | 370.8 | final |
| 2013-12-21 | 361.6 | final |
| 2014-01-16 | 363.4 | final |
| 2014-02-15 | 356.5 | final |
| 2014-03-06 | 362.8 | final |
| 2014-04-11 | 358.7 | final |
| 2014-06-01 | 368.2 | final |
| 2014-07-01 | 383.2 | final |
| 2014-09-15 | 398.7 | final |
| 2014-10-14 | 388.6 | final |
| 2014-11-22 | 371.2 | final |
| 2014-12-17 | 369.1 | final |
| 2015-02-25 | 365.4 | final |
| 2015-03-29 | 366.3 | final |
| 2015-04-22 | 360.3 | final |
| 2015-05-24 | 367.2 | final |
| 2015-06-20 | 383.5 | final |
| 2015-07-20 | 400.2 | final |
| 2015-08-13 | 389.9 | final |
| 2015-09-26 | none (HOT's file has -999, its missing-value marker, for cruise 276.) | final |
| 2015-10-14 | 378.4 | final |
| 2015-11-14 | 374.8 | final |
| 2015-12-09 | 369.0 | final |
| 2016-01-13 | 358.8 | final |
| 2016-02-10 | 360.0 | final |
| 2016-03-09 | 359.0 | final |
| 2016-04-15 | 362.7 | final |
| 2016-05-29 | 376.2 | final |
| 2016-07-12 | 382.3 | final |
| 2016-08-10 | 383.0 | final |
| 2016-10-16 | 385.8 | final |
| 2016-11-27 | 374.0 | final |
| 2017-01-24 | 371.8 | final |
| 2017-02-23 | 366.7 | final |
| 2017-03-29 | 363.5 | final |
| 2017-04-26 | 375.2 | final |
| 2017-05-24 | 376.9 | final |
| 2017-06-21 | 387.8 | final |
| 2017-08-09 | 390.4 | final |
| 2017-10-07 | 389.4 | final |
| 2017-11-09 | 378.6 | final |
| 2017-12-13 | 361.3 | final |
| 2018-01-18 | none (HOT's file has -999, its missing-value marker, for cruise 299.) | final |
| 2018-02-26 | 361.7 | final |
| 2018-04-18 | 361.9 | final |
| 2018-05-16 | 365.1 | final |
| 2018-06-27 | 385.4 | final |
| 2018-07-25 | 386.1 | final |
| 2018-09-11 | 397.3 | final |
| 2018-10-13 | 382.8 | final |
| 2018-11-17 | 381.6 | final |
| 2018-12-11 | none (HOT's file has -999, its missing-value marker, for cruise 308.) | final |
| 2019-01-16 | 369.8 | final |
| 2019-02-20 | 365.5 | final |
| 2019-05-03 | 381.3 | final |
| 2019-06-12 | 396.7 | final |
| 2019-07-02 | 395.0 | final |
| 2019-08-03 | 399.6 | final |
| 2019-09-05 | 412.1 | final |
| 2019-10-18 | 390.4 | final |
| 2019-12-19 | 381.0 | final |
| 2020-01-08 | 371.8 | final |
| 2020-01-31 | 378.5 | final |
| 2020-07-16 | 397.8 | final |
| 2020-08-08 | 396.5 | final |
| 2020-09-01 | 388.9 | final |
| 2020-09-27 | 395.7 | final |
| 2020-11-19 | 379.8 | final |
| 2020-12-19 | 378.0 | final |
| 2021-01-13 | 370.5 | final |
| 2021-02-17 | 377.5 | final |
| 2021-03-24 | 369.8 | final |
| 2021-04-14 | 368.0 | final |
| 2021-05-17 | 384.5 | final |
| 2021-06-23 | 398.2 | final |
| 2021-07-17 | 404.6 | final |
| 2021-10-29 | 396.0 | final |
| 2021-12-05 | 396.0 | final |
| 2022-03-28 | 390.5 | final |
| 2022-05-27 | 404.3 | final |
| 2022-07-10 | 396.2 | final |
| 2022-07-31 | 409.0 | final |
| 2022-09-01 | 408.8 | final |
| 2023-01-24 | 391.3 | final |
| 2023-03-29 | 397.3 | final |
| 2023-05-27 | 412.2 | final |
| 2023-08-11 | 419.0 | final |
| 2023-09-17 | 414.6 | final |
| 2023-10-09 | 405.0 | final |
| 2023-11-06 | 411.6 | final |
| 2023-11-29 | 405.9 | final |
| 2023-12-28 | 399.5 | final |
| 2024-04-03 | 384.9 | final |
| 2024-04-29 | 398.1 | final |
| 2024-07-18 | 413.2 | final |
| 2024-08-18 | 414.0 | final |
| 2024-09-08 | 409.9 | final |
| 2024-10-12 | 417.2 | final |
| 2024-12-20 | 389.9 | final |
Hawaii Ocean Time-series (HOT) surface CO2 system data product, Station ALOHA (J. E. Dore, University of Hawai'i at Mānoa), last updated 2026-01-01; adapted from Dore et al. (2009), Proc Natl Acad Sci USA 106:12235-12240, doi:10.1073/pnas.0906044106. No licence stated; free and open access with an NSF acknowledgement (HOT data policy).
Notes on individual values
- HOT notes for this cruise: No HOT DIC data; used Keeling DIC (code a). No HOT TA data; used Keeling TA (code b).
- HOT notes for this cruise: No HOT TA data; used Keeling TA (code b).
- HOT notes for this cruise: No TA data; assumed nTA of 2303.2 (code d).
- HOT notes for this cruise: No HOT DIC data; used Keeling DIC (code a).
- HOT notes for this cruise: No DIC data in upper 30 dbar; used value from 34.0 dbar (code e). No TA data in upper 30 dbar; used value from 51.3 dbar (code f).
- HOT notes for this cruise: No HOT DIC data; used Keeling DIC (code a). No HOT TA data; used Keeling TA (code b). Used temp and sal data from downcast before cable broke (code g). No phos data; assumed 0.07 (code h). No sil data; assumed 1.04 (code i). Rosette lost; samples collected with Go-flo bottle on Kevlar line (code j).
- HOT notes for this cruise: No sampling occurred (code k).
- HOT notes for this cruise: No rosette; samples collected with Niskin bottles on Kevlar line (code l).
- HOT notes for this cruise: No phos data; assumed 0.07 (code h).
- HOT notes for this cruise: No DIC or TA data in upper 30 dbar; used values from 34.9 dbar (code m).
- HOT notes for this cruise: No sil data; assumed 1.04 (code i).
- HOT notes for this cruise: No DIC or TA data in upper 30 dbar; used values from 44.9 dbar (code n).
- HOT notes for this cruise: No DIC, TA or pH sampling occurred in upper 200 dbar (code o).
- HOT notes for this cruise: No DIC, TA or pH sampling occurred (code p).
- HOT notes for this cruise: 10-30 dbar averages used due to transient influence of heavy rainfall on 5 dbar sample (code q).
Where it comes from
- Producer
- 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
- Version
- 2026-01-01
- Fetched
- 2026-10-05 (automatically), 46,975 bytes
- Fingerprint
- sha256 4356aa4650188b99f623ac2423e4d5a2af4b189077fd1efd1e2cfd8167161665ETag "b77f-647be0be1fe1b" · Last-Modified Tue, 06 Jan 2026 20:30:28 GMT
- Copies
- No Wayback copy recorded yet.Our copy of the exact file
- Cite the producer
- 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.
- Producer
- 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
- Version
- 2026-01-01
- Fetched
- 2026-10-05 (automatically), 573,080 bytes
- Fingerprint
- sha256 95ebe322ac08c965cc859679cad57bddbe596ebc138ec0381ed787ea9a03ba93ETag "8be98-647be0c50f0bc" · Last-Modified Tue, 06 Jan 2026 20:30:36 GMT
- Copies
- No Wayback copy recorded yet.Our copy of the exact file
- Cite the producer
- 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.
What was done to it
Read HOT_surface_CO2.txt, last updated 1 January 2026 (the vintage), and checked that its readme of the same date still defines the columns, the -999 missing marker and the notes codes as read here.
Code: pipeline/src/envdash/transforms/ocean/hot_aloha_co2.py · code sha256 c2648443192ff429… · inputs 4356aa465018… 95ebe322ac08…
Published the column pCO2calc_insitu (CO2 partial pressure in µatm calculated from DIC and alkalinity at in situ temperature) for each of the 355 cruises, 1988-10-31 to 2024-12-20, as printed, dated by the cruise's mid-day (1 October 1988 plus the days column). 9 cruises have -999 and are published as missing.
Code: pipeline/src/envdash/transforms/ocean/hot_aloha_co2.py · code sha256 c2648443192ff429… · inputs 4356aa465018… 95ebe322ac08…
Each cruise's notes codes are carried as a note in the readme's words, except c, r and s, which concern pH samples only. Nothing is averaged or filled.
Code: pipeline/src/envdash/transforms/ocean/hot_aloha_co2.py · code sha256 c2648443192ff429… · inputs 4356aa465018… 95ebe322ac08…
What it covers
- Geography
- Station ALOHA, open North Pacific north of Oahu, Hawaii (22°45′N, 158°00′W); one station
- Basis
- Mean of the cruise's 0–30 dbar samples; CO₂ partial pressure at in situ temperature, calculated by HOT with CO2SYS from measured dissolved inorganic carbon and total alkalinity (Mehrbach et al. constants as refit by Dickson and Millero; 10 dbar pressure assumed).
- Unit
- microatmospheres (µatm)