Scientists Zero in On Global Ocean Temperatures During Last Interglaciation Period
However, those estimates of ocean temperatures show a high level of uncertainty, making it difficult to accurately project warming into the future and its impacts on sea level rise.
Now a team of scientists has assembled data from around the world in a comprehensive analysis of global ocean temperatures during the interglaciation period from 129,000 to 116,000 years ago. The team found that global average ocean temperatures were roughly half a degree (Celsius) warmer during that period than during pre-industrial times and nearly identical to the average temperature over the last 20 years.
Results of the study, which was supported by the National Science Foundation, appear this week in the journal Science.
“Half a degree may not sound like very much, but in terms of average global ocean temperature, it actually is quite substantial,” said lead author Jeremy Hoffman, who led the work as a doctoral student at Oregon State University, and is now a staff scientist with the Science Museum of Virginia. “The problem is that computer models have not been able to simulate this amount of warming for the last interglaciation. Because these are the same models used to project future temperatures, this suggests that they may be missing important processes that would result in even warmer temperatures than now considered.”
The last interglaciation period was one of the warmest periods on Earth in the last 800,000 years. A previous study by Oregon State researchers and published in Science documented the higher sea levels and scientists have hypothesized that warmer ocean temperatures may have been part of the process.
Peter Clark, an Oregon State climate scientist and co-author on the study, said one reason for warmer temperatures during the last interglaciation, and the decline of the Greenland ice sheet, was a shift in Earth’s orbit around the sun.
“Although carbon dioxide levels then were comparable to the pre-industrial era, solar insolation in the northern hemisphere during the summer was much higher,” said Clark, who has the title of distinguished professor in OSU’s College of Earth, Ocean, and Atmospheric Sciences. “This more intense solar insolation contributed to the warmer temperatures.”
The researchers believe the melting of the Greenland ice sheet weakened the Atlantic Meridional Overturning Circulation, or AMOC, a system of currents that usually brings warmer water from the tropics to the south. As it weakened, sea surface temperatures rose in the southern hemisphere, also contributing to warmer global temperatures.
“It was a double whammy,” Clark said. “Solar insolation warmed the northern hemisphere, a weakened AMOC warmed the south.”
Earth’s orbit around the sun is different today, resulting in less solar insolation. The planet has warmed by about one degree (Celsius) since 1750, however, because of human influence.
Other authors on the study included Andrew Parnell of University College Dublin in Ireland, and Feng He from the University of Wisconsin.
Source: http://www.ineffableisland.com/2017/01/scientists-zero-in-on-global-ocean.html
Anyone can join.
Anyone can contribute.
Anyone can become informed about their world.
"United We Stand" Click Here To Create Your Personal Citizen Journalist Account Today, Be Sure To Invite Your Friends.
Please Help Support BeforeitsNews by trying our Natural Health Products below!
Order by Phone at 888-809-8385 or online at https://mitocopper.com M - F 9am to 5pm EST
Order by Phone at 866-388-7003 or online at https://www.herbanomic.com M - F 9am to 5pm EST
Order by Phone at 866-388-7003 or online at https://www.herbanomics.com M - F 9am to 5pm EST
Humic & Fulvic Trace Minerals Complex - Nature's most important supplement! Vivid Dreams again!
HNEX HydroNano EXtracellular Water - Improve immune system health and reduce inflammation.
Ultimate Clinical Potency Curcumin - Natural pain relief, reduce inflammation and so much more.
MitoCopper - Bioavailable Copper destroys pathogens and gives you more energy. (See Blood Video)
Oxy Powder - Natural Colon Cleanser! Cleans out toxic buildup with oxygen!
Nascent Iodine - Promotes detoxification, mental focus and thyroid health.
Smart Meter Cover - Reduces Smart Meter radiation by 96%! (See Video).