martes, 11 de junio de 2013

About ‘NYT: Global Warming Taking a Break’

These are some brief comments to a post posting the New York Times article 'Global Warming Taking a Break'. Here, the link to Daily KOS where you can read the comments to this article. I would be happy to leave my comments directly there, but, to be honest, I have not been able to do so.
First, I agree completely with you, marsanges, that a very important paragraph of the article is ‘So the real question is where all that heat is going, if not to warm the surface. And a prime suspect is the deep ocean. Our measurements there are not good enough to confirm it absolutely, but a growing body of research suggests this may be an important part of the answer’.  By the way, marsanges, many thanks for leaving the link to my blog. I think you were especially thinking to leave the link to the post ‘High motivation’ where I wrote a pair of months ago about this topic.
Coming back to the NYT article, it is also important to note, as the article also points, that modeling work suggest that pauses in warming lasting a couple of decades should not surprise us. The work titled 'Model-based evidence of deep-ocean heat uptake during surface-temperature hiatus periods' by Meehl  et al (2011) and published in Nature Climate Change is a very good example.
I’m sorry MGross but I don’t agree with your comment ‘deep ocean temperatures have barely moved, and the data set isn't very good (due to the difficulty of collecting samples)’. There are plenty of recent works describing the rising temperatures of the deep ocean. About deep waters in the southern Ocean, I would recommend any of the papers published by Purkey and Johnson since 2010. I have a paper under review now in GRL on the same topic but for deep waters of the Arctic Mediterranean. I hope it will be accepted, and if it is the case it will be published with open access and I will be happy to leave you here the link.

It will be a pleasure if I can answer any question or comment that you can have both here or in the post previous High motivation.
Dedicated to marsanges: R.V. Polarstern in the last ice station close to the North Pole during the Arctic Cruise XXVII/3.  Source: Raquel Somavilla

4 comentarios:

  1. Hallo Mvr Somavilla

    I just made a comment out there, on that blog, which is the electronical equivalent of a bar, just mentioning your blog in passing cause thats a random place I read. I never thought you´d become aware of that! How did you? Did I unwittingly cause a ton of visitors to your place? Excuses! I dont want to influence this place in any way, you should be doing your science and whatever else you may want, it´s your blog. I´ll just be pleased to read anything you write here whenever you do. Just two things

    1) I hope you dont spend your time on arguing with climate science deniers. Thats generally useless; they are not people who want to learn - they are rather keeping you from doing what you should do, science. Dont let them.

    2) Ah no -- I hope you return to the science posts; that is the most interesting of all things. Just how can you find out whether or not something as remote as the deep greenland sea takes up heat? And if it is doing so by fractions of a degree, then can that not go on for a long while before it changes flow patterns? Just how long?

    and as fotoes go, what captured me into reading this blog was the foto of Polarstern in the ice with a teddy bear and a toy explorer. Hah. Groeten to you! Don´t let yourself be distracted!


    1. Hi,

      Don't worry. First, it's not bad at all that the blog receive more visits because of your comments in other blogs, webs ... As I said in the post: Thanks! And, second, I don't let them to distract me from my science. In general, I don't enter in this kind of discussions. Only scientific discussions interest me ;-). However, sometimes I read some comments or blogs that offend the intelligence, and I can't avoid to answer in some way.

      Schönes Wochenende,


  2. Hi again,

    This was the post that has stuck most to my mind:
    " Thousands of Meters Below The Ice." from last year.

    Therein you explained how the convection in the Greenland Sea occurs.
    "It is the result of a process known as open ocean convection which is a very effective mechanism of mixing due to the strong cooling during the winter months."
    In your recent abstract EGU2013-10905 I saw you writing:
    "However, during the last three decades, deep convection has come to a halt in the Greenland Sea."

    that is what I struggle to understand. Why was that happening? If convection used to be going on and homogenized this large water column then is it not now doing so anymore? Then how does it look now?
    I mean, convection doesnt just stop because it wants to. Excuse if I say it in this personalised fashion. But could you explain this?

    Thanks for your patience :)

  3. Hi again,

    As you say, deep convection doesn't stop because it wants to, and, of course, the halt of deep convection has consequences. The first is the change in the properties (temperature and salinity) of the Greenland Sea deep waters. How? Well, the values of temperature and salinity of the deep waters in the Greenland Sea are the result from the balance between deep convection providing fresh and cold waters and the advection of deep Arctic Ocean waters that are warmer and saltier than those observed in the Greenland Sea (In the first figure of the post 'Thousands of meters below the ice' you can see how the temperature and salinity of deep waters in the Greenland Sea is lower than that of the Arctic Ocean deep waters Thus, now that we don't have deep convection, the deep waters in the Greenland Sea are only replenish by the advection of Arctic Ocean deep waters. Because these waters are warmer and saltier than the Greenland Sea Deep Water, the deep waters in the Greenland Sea are getting warmer and saltier. From that, there are other derived consequences that I described in the paper submitted to GRL. As soon as I can make the information there public, I will.

    About the causes, it is one of things in which I'm working now, and it seems that there isn't one only cause. It seems that it was the sum of different changes, both in the atmosphere (winds and net heat gain/losses between the ocean and the atmopshere) and in the ocean (properties of the waters coming from southern latitudes (Atlantic Water) and from the Arctic Ocean (Polar Surface Water)).

    I hope I resolved some of your questions and many thanks for all of them.



Muchas gracias por tu comentario.
Many thanks for your comment.