• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
  • Skip to footer

RealClimate

Climate science from climate scientists...

  • Start here
  • Model-Observation Comparisons
  • Miscellaneous Climate Graphics
  • Surface temperature graphics
You are here: Home / Archives for 2015

Archives for 2015

A new sea level curve

14 Jan 2015 by Stefan

The “zoo” of global sea level curves calculated from tide gauge data has grown – tomorrow a new reconstruction of our US colleagues around Carling Hay from Harvard University will appear in Nature (Hay et al. 2015). That is a good opportunity for an overview over the available data curves. The differences are really in the details, the “big picture” of sea-level rise does not change. In all curves, the current rates of rise are the highest since records began.

The following graph shows the new sea level curve as compared to six known ones.

haysl1

Fig 1 Sea level curves calculated by different research groups with various methods. The curves show the sea level relative to the satellite era (since 1992). Graph: Klaus Bittermann.

All curves show the well-known modern sea level rise, but the exact extent and time evolution of the rise differ somewhat. Up to about 1970, the new reconstruction of Hay et al. runs at the top of the existing uncertainty range. For the period from 1880 AD, however, it shows the same total increase as the current favorites by Church & White. Starting from 1900 AD it is about 25 mm less. This difference is at the margins of significance: the uncertainty ranges overlap. [Read more…] about A new sea level curve

References

  1. C.C. Hay, E. Morrow, R.E. Kopp, and J.X. Mitrovica, "Probabilistic reanalysis of twentieth-century sea-level rise", Nature, vol. 517, pp. 481-484, 2015. http://dx.doi.org/10.1038/nature14093

Filed Under: Climate Science, Instrumental Record, Oceans

Diagnosing Causes of Sea Level Rise

8 Jan 2015 by eric

Guest post by Sarah G. Purkey and Gregory C. Johnson,
University of Washington / NOAA

I solicited this post from colleagues at the University of Washington. I found their paper particularly interesting because it gets at the question of sea level rise from a combination of ocean altimetry and density (temperature + salinity) data. This kind of measurement and calculation has not really been possible — not at this level of detail — until quite recently. A key finding is that one can reconcile various different estimates of the contributions to observed sea level rise only if the significant warming of the deep ocean is accounted for. There was a good write-up in The Guardian back when the paper came out.– Eric Steig


Sea leave rise reveals a lot about our changing climate. A rise in the mean sea level can be caused by decreases in ocean density, mostly reflecting an increase in ocean temperature — this is steric sea level rise. It can also be caused by an increase in ocean mass, reflecting a gain of fresh water from land. A third, and smaller, contribution to mean sea level is from glacial isostatic adjustment. The contribution of glacial isostatic adjustment, while small, has a range of possible values and can be a significant source of uncertainty in sea level budgets. Over recent decades, very roughly half of the observed mean sea level rise is owing to changes in ocean density with the other half owing to the increased in ocean mass, mostly from melting glaciers and polar ice sheets. The exact proportion has been difficult to pin down with great certainty. [Read more…] about Diagnosing Causes of Sea Level Rise

References

  1. S.G. Purkey, G.C. Johnson, and D.P. Chambers, "Relative contributions of ocean mass and deep steric changes to sea level rise between 1993 and 2013", Journal of Geophysical Research: Oceans, vol. 119, pp. 7509-7522, 2014. http://dx.doi.org/10.1002/2014JC010180

Filed Under: Climate Science, Oceans

Unforced Variations: Jan 2015

7 Jan 2015 by group

This month’s open thread. Sorry for the slow start – you know what it’s like after the holidays…

Filed Under: Climate Science, Open thread

  • « Go to Previous Page
  • Page 1
  • Interim pages omitted …
  • Page 3
  • Page 4
  • Page 5

Primary Sidebar

Search

Search for:

Email Notification

get new posts sent to you automatically (free)
Loading

Recent Posts

  • Unforced variations: July 2025
  • Unforced variations: Jun 2025
  • Predicted Arctic sea ice trends over time
  • The most recent climate status
  • Unforced variations: May 2025
  • Unforced Variations: Apr 2025

Our Books

Book covers
This list of books since 2005 (in reverse chronological order) that we have been involved in, accompanied by the publisher’s official description, and some comments of independent reviewers of the work.
All Books >>

Recent Comments

  • Ron R. on Unforced variations: July 2025
  • CherylJosie on Unforced variations: July 2025
  • David on Unforced variations: July 2025
  • Richard on Predicted Arctic sea ice trends over time
  • Paul Pukite (@whut) on Unforced variations: July 2025
  • zebra on Predicted Arctic sea ice trends over time
  • Barton Paul Levenson on Unforced variations: July 2025
  • William on Unforced variations: July 2025
  • William on Unforced variations: July 2025
  • nigelj on Unforced variations: July 2025
  • The Prieto Principle on Predicted Arctic sea ice trends over time
  • The Prieto Principle on Predicted Arctic sea ice trends over time
  • The Prieto Principle on Unforced variations: July 2025
  • Ray Ladbury on Unforced variations: July 2025
  • nigelj on Unforced variations: July 2025
  • The Prieto Principle on Predicted Arctic sea ice trends over time
  • Piotr on Unforced variations: July 2025
  • The Prieto Principle on Unforced variations: July 2025
  • The Prieto Principle on Unforced variations: July 2025
  • The Prieto Principle on Unforced variations: July 2025

Footer

ABOUT

  • About
  • Translations
  • Privacy Policy
  • Contact Page
  • Login

DATA AND GRAPHICS

  • Data Sources
  • Model-Observation Comparisons
  • Surface temperature graphics
  • Miscellaneous Climate Graphics

INDEX

  • Acronym index
  • Index
  • Archives
  • Contributors

Realclimate Stats

1,368 posts

11 pages

244,269 comments

Copyright © 2025 · RealClimate is a commentary site on climate science by working climate scientists for the interested public and journalists.