Research finds link between rainfall and ocean circulation in past and present

Posted: January 28, 2018 by oldbrew in climate, general circulation, Natural Variation, Ocean dynamics, research

The lead author found it ‘remarkable’ that ‘The results indicate that in present and past the Atlantic Ocean surface currents correlate with rainfall patterns in the Western Hemisphere.’
It turns out that ‘If we go back in increments of 30 [years], we’re well positioned to understand things on the order of centuries.’ Could we call it natural variation perhaps…?

Research conducted at The University of Texas at Austin has found that changes in ocean currents in the Atlantic Ocean influence rainfall in the Western Hemisphere, and that these two systems have been linked for thousands of years, reports

The findings, published on Jan. 26 in Nature Communications, are important because the detailed look into Earth’s past climate and the factors that influenced it could help scientists understand how these same factors may influence our climate today and in the future.

“The mechanisms that seem to be driving this correlation [in the past] are the same that are at play in modern data as well,” said lead author Kaustubh Thirumalai, postdoctoral researcher at Brown University who conducted the research while earning his Ph.D. at the UT Austin Jackson School of Geosciences. “The Atlantic Ocean surface circulation, and however that changes, has implications for how the rainfall changes on continents.”

Thirumalai conducted the work at The University of Texas Institute for Geophysics (UTIG), a research unit at the UT Jackson School of Geosciences. Co-authors include UTIG scientists, and researchers from the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center and the Massachusetts Institute of Technology.

The Atlantic Ocean surface circulation is an important part of the Earth’s global climate, moving warm water from the tropics towards the poles. The foundation of the research involved tracking the changes in ocean circulation in new detail by studying three sediment cores extracted from the seafloor of the Gulf of Mexico in 2010 during a scientific cruise. The samples give insight into factors that influenced the strength of the ocean current in about 30-year increments over the past 4,400 years.

“If we go back in increments of 30, we’re well positioned to understand things on the order of centuries,” Thirumalai said. “And the question we decided to ask was what can those reconstructions of temperature and salinity tell us about the greater Atlantic Ocean surface circulation.”

The small time increments scientists were able to capture in the cores are due to the large amounts of sediment that empty into the Gulf from rivers in Mexico and North America. The scientists extracted data about temperature and salinity data—factors that influence ocean current strength— from ocean-dwelling microorganisms called foraminifera preserved in the sediments.

The data showed that, in comparison to today, the Atlantic Ocean surface circulation was much weaker during the Little Ice Age, a cool period thought to be triggered by volcanic activity that lasted from 1450-1850. Since these set of ocean currents are known to influence global climate, the researchers were interested to see if it correlated with rainfall in the Western Hemisphere, and how such a correlation could change over time.

Continued here.

  1. stpaulchuck says:

    “Could we call it natural variation perhaps…?”

    WHOA there! I’m sorry sir, but the word ‘natural’ is forbidden in these discussions. You are hereby directed to replace all instances with ‘man-made’. – The Ministry Of Truth

    [reply] 😁

  2. Bitter@twisted says:

    Well smack me in the face with a wet fish……

  3. ren says:

    The solar shield now looks as it should during the minimum solar. Magnetic fields are already in the right place.

  4. Stephen Richards says:

    Is that really amazing. That sea temperature movements change rainfall patterns? Really? Are they really amazed? They should be dismissed if they are. Idiots

  5. oldbrew says:

    Quote: You need to have thirty years’ worth of data before you can “talk about climate” says Professor. [bold added]

    Remember that when alarmists moan about a heatwave or flood somewhere.
    – – –
    Using satellite data, a group of scientists has studied the development of temperature over the past 15 years in a large part of Greenland.

    More precisely, they looked at surface temperatures (the temperature close to the Earth’s surface) in a part of the country that is not covered by ice—around one fifth of the surface area of Greenland.

    Intuitively, you may think that temperature throughout all of Greenland has been increasing, but that is not the case. When you look at the yearly average, the ice-free parts of Greenland show a slight drop in temperature between 2001 and 2015. With swings in temperature from year to year.

    However, these results should not be interpreted as “proof” that the Earth is not warming, say the scientists behind the research, which is published in the journal Scientific Reports.

    This is weather, not climate
    You need to have thirty years’ worth of data before you can “talk about climate,” says Professor Bo Elberling, an environmental geochemist and senior scientist on the study.

    So we should be wary of discussing these results in the context of climate change, says Elberling, who is head of the Center for Permafrost (CENPERM) at the Department of Geosciences and Natural Resource Management at the University of Copenhagen, Denmark. [bold added]

  6. ren says:

    This is the forecast of a polar vortex pattern in the lower stratosphere on February 3.

  7. E.M.Smith says:

    Well it is encouraging that they are finding natural cycles and ocean driven changes of precipitation; however: Isn’t this all “old news”?

    I’ve written an article about changes of Gulf of Mexico circulation and cited a paper that stated lake sediments and pollen and more showed Florida warmed when Europe got cold due to the heat staying in the Gulf of Mexico as the Gulf Stream / Atlantic Drift slowed down. WITH changes of precipitation…

    So, OK, this guy extended it to Gulf forams… and maybe had a bit more direct precipitation focus.

    I guess the best thing is just that the work got published and doesn’t fawn over CO2.

    [reply] indeed

  8. E.M.Smith says:

    Another one from 2015 that “finds” changes of ocean currents change precipitation:

    Researchers at The University of Texas at Austin have found that a well-known period of abrupt climate change 12,000 years ago occurred rapidly in northern latitudes but much more gradually in equatorial regions, a discovery that could prove important for understanding and responding to future climate change.

    The research, published Sept. 2 in Nature Communications, focuses on the Younger Dryas, a cooling period that started when the North Atlantic Current, an ocean current, stopped circulating. The event caused Earth’s northern hemisphere to enter into a deep chill, with temperatures in Greenland dropping by approximately 18 degrees Fahrenheit in less than a decade.

    The event also caused rainfall to decrease in places as far away as the Philippines. However, whereas temperatures in Greenland responded quickly to the ocean current shutdown and subsequent reboot 1,000 years later, it took hundreds of years for rainfall in the Philippines to be affected and to recover.

    “We found that the temperature in Greenland is like a small ship that you can stop and turn quickly because of the influence of sea ice in the region, while rainfall in the tropics is like a big ship that takes a long time to course correct,” said Jud Partin, a research associate at the University of Texas Institute for Geophysics (UTIG) who led the study.

    This is in addition to the paper that found a connection between the Gulf Stream and Florida and in addition to a different one that found Texas rainfall cycled with a 1500 year beat as the oceans changed. Yet every time it is “new” and a surprise… Maybe only to the CO2 obsessed… but a decent literature search will find this is already understood… though it seems it is widely ignored.

  9. ren says:

    Surface temperature anomalies of the western Atlantic.

  10. ren says:

    Atlantic and Eastern Pacific – SST Color Loop

  11. Phoenix44 says:

    The Little Ice Age was “triggered by volcanic activity”? Whilst there are known volcanic eruptions during the period that led to very poor summers, there is no evidence that the LIA was “triggered” by volcanoes.

  12. oldbrew says:

    If the last maximum of oceanic tides did occur in 1433 (link below), that could have been the LIA trigger – or one of them – by stirring up cold water from the bottom of the oceans. My comment is here:

  13. ren says:

    La Nina does not give up.

    La Nina looks very good.

    The SOI index is also high.