Featured Research

from universities, journals, and other organizations

Researchers Reveal Ocean Acidification At Station ALOHA In Hawaii

Date:
August 7, 2009
Source:
University of Hawaii at Manoa
Summary:
Despite the global environmental importance of ocean acidification, there are few studies of sufficient duration, accuracy and sampling intensity to document the rate of change of ocean pH and shed light on the factors controlling its variability. Researchers in Hawaii have recently addressed this issue.

This image shows the deployment of the spar buoy off the stern of the R/V Ka'Imikai-O-Kanaloa.
Credit: Image courtesy of University of Hawaii at Manoa HOT/SOEST

The burning of fossil fuels has released tremendous amounts of the greenhouse gas carbon dioxide (CO2) into the atmosphere, significantly impacting global climate. Were it not for the absorption of CO2 by the oceans, the alarming growth of atmospheric CO2 concentration would be substantially greater than it is.

Related Articles


However, this beneficial role of the oceans as a CO2 "scrubber" does not come without undesired consequences. When dissolved, CO2 acts as an acid, and lowers seawater pH. Since the beginning of the industrial age, CO2-driven acidification of the surface oceans has already caused a 0.1 unit lowering of pH, and models suggest that another 0.3 pH unit drop by the year 2050 is likely. Continued acidification of the sea may have a host of negative impacts on marine biota, and has the potential to alter the rates of ocean biogeochemical processes.

Despite the global environmental importance of ocean acidification, there are few studies of sufficient duration, accuracy and sampling intensity to document the rate of change of ocean pH and shed light on the factors controlling its variability.

In 1988, Dave Karl and Roger Lukas of the School of Ocean, Earth Science and Technology (SOEST) at the University of Hawai'i at Mānoa founded the Hawaii Ocean Time-series (HOT) program, in part to establish a long-term record of the oceanic response to rising atmospheric CO2. Monthly research cruises to Station ALOHA, north of Oahu, have yielded after 20 years the most detailed record to date on ocean acidification in the Pacific.

Reporting in this week's issue of Proceedings of the National Academy of Sciences, lead author and former SOEST researcher John Dore (now at Montana State University) presents an analysis of the changes of pH at Station ALOHA over time and depth. Dore, along with SOEST co-authors Karl, Lukas, Matt Church and Dan Sadler, found that over the two decades of observation, the surface ocean grew more acidic at exactly the rate expected from chemical equilibration with the atmosphere. However, that rate of change varied considerably on seasonal and inter-annual timescales, and even reversed for one period of nearly five years. The year-to-year changes appear to be driven by climate-induced changes in ocean mixing and attendant biological responses to mixing events.

The authors also found distinct layers at depth in which pH declines were actually faster than at the surface. Dore and colleagues attribute these strata of elevated acidification rates to increases in biological activity and to the intrusion at Station ALOHA of remotely formed water masses with different chemical histories.

About the Hawaii Ocean Time-series Program

Scientists working within the Hawaiian Ocean Time-series (HOT) project have been making repeated observations of the hydrography, chemistry and biology at a station north of Hawaii since October 1988. The objective of this research is to provide a comprehensive description of the ocean at a site representative of the central North Pacific Ocean. Cruises are made approximately once a month to Station ALOHA, the HOT deep-water station (22 45'N, 158W) located about 100 km north of Oahu, Hawaii. Measurements of the thermohaline structure, water column chemistry, currents, primary production and particle sedimentation rates are made over a 72-hour period on each cruise.

For more information about Hawaii Ocean Time-series Program please visit http://hahana.soest.hawaii.edu/hot/hot.html.


Story Source:

The above story is based on materials provided by University of Hawaii at Manoa. Note: Materials may be edited for content and length.


Journal Reference:

  1. John E. Dore, Roger Lukas, Daniel W. Sadler, Matthew J. Church and David M. Karl. Physical and biogeochemical modulation of ocean acidification in the central North Pacific. PNAS, 2009; 106 (30): 12235 DOI: 10.1073/pnas.0906044106

Cite This Page:

University of Hawaii at Manoa. "Researchers Reveal Ocean Acidification At Station ALOHA In Hawaii." ScienceDaily. ScienceDaily, 7 August 2009. <www.sciencedaily.com/releases/2009/08/090806112609.htm>.
University of Hawaii at Manoa. (2009, August 7). Researchers Reveal Ocean Acidification At Station ALOHA In Hawaii. ScienceDaily. Retrieved November 24, 2014 from www.sciencedaily.com/releases/2009/08/090806112609.htm
University of Hawaii at Manoa. "Researchers Reveal Ocean Acidification At Station ALOHA In Hawaii." ScienceDaily. www.sciencedaily.com/releases/2009/08/090806112609.htm (accessed November 24, 2014).

Share This


More From ScienceDaily



More Earth & Climate News

Monday, November 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

3D Map of Antarctic Sea Ice to Shed Light on Climate Change

3D Map of Antarctic Sea Ice to Shed Light on Climate Change

Reuters - Innovations Video Online (Nov. 24, 2014) A multinational group of scientists have released the first ever detailed, high-resolution 3-D maps of Antarctic sea ice. Using an underwater robot equipped with sonar, the researchers mapped the underside of a massive area of sea ice to gauge the impact of climate change. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Car Park Solution for Flexible Green Energy

Car Park Solution for Flexible Green Energy

Reuters - Innovations Video Online (Nov. 24, 2014) A British solar power start-up says that by covering millions of existing car park spaces around the UK with flexible solar panels, the country's power problems could be solved. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Ebola-Hit Sierra Leone's Late Cocoa Leaves Bitter Taste

Ebola-Hit Sierra Leone's Late Cocoa Leaves Bitter Taste

AFP (Nov. 23, 2014) The arable district of Kenema in Sierra Leone -- at the centre of the Ebola outbreak in May -- has been under quarantine for three months as the cocoa harvest comes in. Duration: 01:32 Video provided by AFP
Powered by NewsLook.com
NY Gov. on Flood Prep: 'prepared for the Worst'

NY Gov. on Flood Prep: 'prepared for the Worst'

AP (Nov. 23, 2014) First came the big storm. Now comes the big melt for residents of flood-prone areas around Buffalo. New York's governor says officials are preparing for the worst as the temperature is expected to rise and potentially melt several feet of snow. (Nov. 23) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins