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Ocean Temperatures Have Been Rising Since 19thC

October 12, 2018
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By Paul Homewood

 

h/t Dave

 

This paper published in 2012 has much relevance to m y post a couple of days ago about ocean temperatures:

 

 

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A new study contrasting ocean temperature readings of the 1870s with temperatures of the modern seas reveals an upward trend of global ocean warming spanning at least 100 years.

The research led by Scripps Institution of Oceanography at UC San Diego physical oceanographer Dean Roemmich shows a .33-degree Celsius (.59-degree Fahrenheit) average increase in the upper portions of the ocean to 700 meters (2,300 feet) depth. The increase was largest at the ocean surface, .59-degree Celsius (1.1-degree Fahrenheit), decreasing to .12-degree Celsius (.22-degree Fahrenheit) at 900 meters (2,950 feet) depth.

The report is the first global comparison of temperature between the historic voyage of HMS Challenger (1872-1876) and modern data obtained by ocean-probing robots now continuously reporting temperatures via the global Argo program. Scientists have previously determined that nearly 90 percent of the excess heat added to Earth’s climate system since the 1960s has been stored in the oceans. The new study, published in the April 1 advance online edition of Nature Climate Change and coauthored by John Gould of the United Kingdom-based National Oceanography Centre and John Gilson of Scripps Oceanography, pushes the ocean warming trend back much earlier.

"The significance of the study is not only that we see a temperature difference that indicates warming on a global scale, but that the magnitude of the temperature change since the 1870s is twice that observed over the past 50 years," said Roemmich, co-chairman of the International Argo Steering Team. "This implies that the time scale for the warming of the ocean is not just the last 50 years but at least the last 100 years."

Although the Challenger data set covers only some 300 temperature soundings (measurements from the sea surface down to the deep ocean) around the world, the information sets a baseline for temperature change in the world’s oceans, which are now sampled continuously through Argo’s unprecedented global coverage. Nearly 3,500 free-drifting profiling Argo floats each collect a temperature profile every 10 days.

Roemmich believes the new findings, a piece of a larger puzzle of understanding Earth’s climate, help scientists to understand the longer record of sea-level rise, because the expansion of seawater due to warming is a significant contributor to rising sea level. Moreover, the 100-year timescale of ocean warming implies that Earth’s climate system as a whole has been gaining heat for at least that long.

Launched in 2000, the Argo program collects more than 100,000 temperature-salinity profiles per year across the world’s oceans. To date, more than 1,000 research papers have been published using Argo’s data set.

https://www.sciencedaily.com/releases/2012/04/120401135345.htm

 

The significance of course is that the warming of the oceans began long before any impact from CO2 emissions.

HH Lamb has written extensively about how sea temperatures in the Atlantic fell radically during the LIA. Is the warming trend since then merely a return to earlier conditions?

10 Comments
  1. HotScot permalink
    October 12, 2018 12:11 pm

    My abiding contention is that historic land and sea temperatures are simply unfit for modern climate science.

    For a start , until possibly the 1940’s and WW2 weather forecasting was a regional service. There was no need for a global overview and readings were often taken by unqualified personnel.

    SST’s were largely measured by chucking a bucket on a rope overboard and you can bet your mortgage it was done by a deckhand or cabin boy with no scientific training whatsoever.

    SST’s were also taken along well plied trade routes, barely any measurements were taken from, for example, the southern ocean.

    Nor was there any control over how deep the bucket was sent and as only the top few centimetres of oceans are heated by the sun, the difference of a metre would have been considerable.

    I also learned from a contributor on WUWT that there was no recognised standards when engine room intakes were developed so the errors were roundly recognised as between +/-2C and +/- 4C, so potentially 8C of difference.

    Stevenson screens would almost certainly have been read by tea boys and janitors rather than expert’s. What self respecting scientist would trudge out in the rain, snow and wind to record a few measurements when the tea boy was going out for a ciggie anyway?

    And whilst satellites are getting better at recording measurements the early attempts were plagued with calibration, drift and component failure.

    Seriously, climate science needs to have a reality check on their data sources from the last 150 years and get real. No one in their right mind would rely on temperature measurements to within a tenth of a degree with all those variables.

    • Mike Jackson permalink
      October 12, 2018 12:54 pm

      Let us not forget (going off at a slight tangent) that anemometers, barometers, and thermometers became ubiquitous in the early 20th century at airfields because wind speed and direction, air pressure, and air temperature were very soon recognised as IMPORTANT for safe aviation.

      They tell us fractionally less than damn all about weather elsewhere or about “climate” anywhere and as air-fields have turned into air-ports their scientific usefulness is even less. Their value to eco-political-activists, on the other hand, has increased enormously!

      • October 12, 2018 1:55 pm

        And no airfields in the ocean anyway 🙂

    • mwhite permalink
      October 12, 2018 4:58 pm

      Two interesting presentations from Bob Tisdale

      and

      The second video is interesting if you want to know where some of the ocean temperatures came from.

  2. matelot 69 permalink
    October 12, 2018 1:50 pm

    I find it interesting that since anti-submarine warfare got into its stride during the cold war, ASW frigates all over the world have been measuring temperature “gradients” to great depths. Those damn russkies had a habit of finding a cold layer and hiding under it. All that data is being held somewhere. HM Hydrographic Office in the case of the UK I would suspect. This always told me that the Ocean temperature varies, not with depth, but with….ummmm….density and temperature! Who would have thought it?

  3. October 12, 2018 2:00 pm

    Reblogged this on Climate Collections.

  4. Gamecock permalink
    October 12, 2018 5:49 pm

    ‘Nearly 3,500 free-drifting profiling Argo floats each collect a temperature profile every 10 days.’

    Ocean surface: 140,000,000 square miles

    One Argo per 40,000 square miles of ocean. Measuring whatever random location currents have carried them to.

    ‘Dean Roemmich shows a .33-degree Celsius (.59-degree Fahrenheit) average increase in the upper portions of the ocean to 700 meters (2,300 feet) depth.’

    Increase from what? There was no Argo 100 years ago. He is comparing apples and tablespoons.

    ‘Launched in 2000, the Argo program’

    So we don’t even have data (sic) from 20 years ago to compare to.

    Data free science.

    Roemmich’s use of a decimal point shows he has a sense of humor.

    • Joe Public permalink
      October 12, 2018 7:59 pm

      “‘Nearly 3,500 free-drifting profiling Argo floats each collect a temperature profile every 10 days.’

      Ocean surface: 140,000,000 square miles”

      But that’s only the ‘surface’.

      When greenies whinge about ‘Ocean Temperatures’ rising, we also have to remind them that average ocean depth is about 3,688 metres, and its volume is about 1,338,000,000 cu km – all supposedly monitored by the 3,982 Argo floats which monitor only the top 2,000m

  5. Gamecock permalink
    October 13, 2018 12:13 am

    ‘Although the Challenger data set covers only some 300 temperature soundings (measurements from the sea surface down to the deep ocean) around the world, the information sets a baseline for temperature change in the world’s oceans’

    NO IT DOESN’T !!! It is the equivalent of NO DATA. 300 soundings in 140,000,000 square miles of ocean ?!?! This is stupid beyond belief!

    ‘which are now sampled continuously through Argo’s unprecedented global coverage. Nearly 3,500 free-drifting profiling Argo floats each collect a temperature profile every 10 days.’

    Being unprecedented must mean it’s really, really good.

    The Argo drifts with the current to a new location and gets new data there.

    See the problem? Think about it . . . .

    It drifts with the water. After 10 days, it’s in a new location, but IT’S THE SAME WATER. Effectively, Argo measures the same water every 10 days.

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