viernes, 22 de febrero de 2013

High motivation (English version)

More than one month ago, before my long break from the blog, one of you asked me how would be possible to have access to my contributions to the THOR and ICES/PICES Conference for Early Career Scientist. Oceansof Change Conference contributions. I have been trying to find the way to show that information here, but it’s not an easy task. Thus, what I have done is to create a public folder in dropbox where I will share with you everything that I can make public without problems (it means no violating copyright and things like that). There, you already have both contributions. If you press in the links above, you shouldn’t have problems to get them, but in case you have…please leave a comment! 

While I was doing that, I re-read those abstract and additional informational in the Spiegel newspaper (in German, but google translator can help on that), other blogs, and some recent papers, and I got excited. So much so, besides the abstract that I submitted to the EGU Vienna for the session  Changes in Arctic and Antarctic sea ice and ocean: processes, observations, models and perspectives’ under the title ‘Increasing presence of Arctic Ocean Deep Waters in the Greenland Sea’, two days ago (nowadays I should say two weeks ago) I have submitted another one to the Conference ‘IAPSO: North Atlantic and Climate Change’ titled ‘A downwards heat and salt injection mechanism linking mid-latitudes and Polar Regions in the North Atlantic’. I hope to present both as oral presentation, but it doesn’t depend on me. As soon as I can upload them to our dropbox folder, I will do.

Now, let me tell you more slowly the reasons of my excitement because I try to say too many things at the same time, and in this way it’s impossible you can understand anything. And for that end, nothing better than to pass you the link to an old post published on April last year:From the Surface for a Deeper Understanding’. Just in case you are lazy to read it completely again, summarizing I told you there that due to the ocean is the main heat reservoir of the Earth’s climate system (which includes the Atmosphere, Lithosphere (, Hydrosphere (oceans, rivers, lakes, etc.), Cryosphere (part of the Earth frozen) and Biosphere), the increasing radiative forcing (here equivalent to say heat) in the atmosphere -mainly caused by the growing concentration of greenhouse gases- was expected to be reflected as a global ocean warming. However, in the last decade the upper ocean heat storage has decelerated, which has resulted in an active search for the missing heat in the deep ocean (Fig. 1). All of that brought up for me two questions relating my PhD work concerning the ocean-atmosphere interaction and mixed layer depth variability and my work nowadays at AWI studying the changes in the deep water masses of the Arctic. The first of these questions was: what is the mechanism able to transfer so efficiently the heat from the atmosphere to the deep ocean in contrast to past observations? Until the last decade, the heat was accumulated in the upper layers. And the second, which is the contribution of the deep Arctic Ocean waters to the World Ocean heat content since their changes have hardly studied yet?

Fig. 1. Where does the energy go? (A) Estimated rates of change of global energy. The curves are heavily smoothed  and somewhat simplified. From 1992 to 2003, the decadal ocean heat content changes (blue), along  with the contributions from melting glaciers, ice sheets, and sea ice and small contributions from land and  atmosphere warming, suggest a total warming (red) for the planet of 0.6 ± 0.2 W/m2 (95% error bars).  After 2000, observations from the top of the atmosphere (black, referenced to the 2000 values) increasingly diverge from the observed total warming (red).

In the abstract that I sent to the ‘ICES/PICES Conference for Early Career Scientist. Oceans of Change’ Conference, I told: 

 ‘The importance of the deep ocean in the Earth climate system has recently re-emerged, when atmospheric measurements indicate a net energy heat flux into the system while the increase of the upper ocean heat content seems to have decelerated. In this context, the deep water masses of the polar oceans take outstanding significance…’ 

And this is what other sources say now. In the Spiegel Newspaper:

They highlight the fact that the temperature hasn’t risen as expected according to the increase of radiative forcing in the atmosphere (Fig. 2). Among the different explanations, they stress the role of the deep ocean as a heat reservoir, as well as the necessity to augment the observations in the deep ocean. Although surprising, there are few measurements of the deep ocean that can help to find out whether that is the case (the heat is being stored in the deep ocean) or not.
Fig. 2. Global Temperature temporal evolution (black line). As observed, the temperature increase initiated at the beginning of the 70s stopped in the last decade. The eruption of the Pinatubo is indicated en the time axes because it released sulfur to the atmosphere, cooling the atmosphere during two years. Source : Met Office.

In el blog ‘My view of Climate Change’: 

They wonder how is possible that the transfer of heat that was predicted to be accumulating in the upper layers to the deep ocean hasn’t been observed? Is that a continuous process and that occurs allover the ocean? Or it’s on the contrary, an episodic phenomenon restricted to a few areas, as high latitudes where deep water formation takes place, and so areas where exists a direct connection between the atmosphere and the deep ocean?

And in the following papers: 

Warmand saline events embedded in the meridional circulation of the northern NorthAtlantic. Häkkinen et al., JGR (2011). 

Atlantic water in the Faroe area: sources andvariability. Larsen et al., ICES JMS (2012). 

Importance of density-compensated temperature change for deep North Atlantic Ocean heat uptake. Mauritzen et al., Nature Geoscience (2012)

Evidence Linking Arctic Amplification to Extreme Weather in Mid-Latitudes, Francis and Vavrus, GRL (2012)

Meteorology: Arctic warming favours extremes. Semenov, Nature (2012)  

They talked (the two first articles) about the transport of warm and salty waters from mid-latitudes in the North Atlantic (30-45°N) to the subpolar gyre (you have both areas in the map below) and farther North towards the Greenland and Norwegian seas or the Arctic Ocean, and how these anomalies can affect the deep water formation in the subpolar gyre and so the heat injection and storage injecting (third article). The last two talk about the relation between the sea-ice retreat in the Arctic Ocean and extreme atmospheric events as heat or cold waves, droughts, etc. at mid-latitudes in the North Atlantic through changes in the troposphere circulation.

Basins and currents in the North Atlantic. The subpolar and subtropical gyre are also shown by the black and white dash arrows, respectively. Source: Raquel Somavilla.
All of that has made me think that I was not crazy in April when I told you for first time about the possible relation between the ocean-atmosphere interaction at mid-latitudes and the deep waters at high latitudes in the North Atlantic. Besides the proofs that they provide, I have verified a pair of things more, and I have leapt to write the abstract about I told you at the beginning of the post ‘A downwards heat and salt injection mechanism linking mid-latitudes and Polar Regions in the North Atlantic’  for the Conference IAPSO: North Atlantic and Climate Change. Now, I still have a lot of work to do. That was just the beginning. Now, it’s turn to read a lot of bibliography and plot and analyze my data in different ways, until I will be ready (with all the necessary arguments and proofs) to write the paper where I will describe the complete history in the suitable scientific way. I will keep you informed :D

1 comentario:

  1. The abstract ‘A downwards heat and salt injection mechanism linking mid-latitudes and Polar Regions in the North Atlantic’ for the Conference ‘IAPSO: North Atlantic and Climate Change’ has been accepted for oral presentation. I hope to receive a lot of feedback from the presentation to complete and improve the work, but I will have to wait until July... too long?


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