Salty intermediate waters key for surface to deep heat transfer in the NAtlantic during the 2000s

Just a nice example of the subtle interplay between the ocean and the atmosphere. Source: Raquel Somavilla

Hace exactamente una semana en el magazine EOS Earth & Space Science News publicaron lo que se llama un Research Spotlight sobre mi último artículo titulado 'Mid-2000s North Atlantic shift: Heat budget and circulation changes' publicado en la revista Geophysical Research Letters. Hacer una traducción del artículo me lleva demasiado tiempo, pero un hacer una traducción del Research Spotlight junto con algún otro dato adicional es más rápido y creo que merece la pena. Aquí lo tenéis,. Seguid leyendo y cualquier duda o comentario ya sabéis, más abajo. No os cortéis.

Now exactly one week ago, the EOS Earth & Space Science news magazine published a Reserach Spotlight about my last paper published in the scientific journal Geophysical Research Letters and titled 'Mid-2000s North Atlantic shift: Heat budget and circulation changes'. Below you have a Spanish translation of the Research Spotlight, but those interested in the English version here again the link. Feel fee to ask below!

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

Back to Science: ‘Export of Algal Biomass from the Melting Arctic Sea Ice’.

Este verano participé en una campana oceanográfica de 10 semanas en el Ártico sobre la que os fui contando a lo largo de diferentes post (si queréis saber más podéis pinchar aquí, aquí, aquí, aquí o aquí :D). Fue fantástico poder participar en esa expedición no sólo por la experiencia como tal, sino porque, como creo que también os conté, el trabajo en equipo fue … fue … inspirador, estimulante, magnífico... No tengo el adjetivo adecuado. Entre los más de 50 científicos que participamos había expertos en oceanografía; procesos físicos en el hielo; producción primaria en el hielo; producción primaria en la columna de agua; exportación de carbono al océano profundo; zooplancton; biomarcadores; aerosoles; y organismos y procesos en el fondo del Ártico situado a más de 4000 metros de profundidad entre otros. Como veis, un poco de todo.

The last summer, I participated in an oceanographic cruise during 10 weeks in the Arctic Ocean. During that time, I told you what we were doing in our cruise along different posts (if you want to read more you can click here, here, here, here o here :D). It was fantastic to have the opportunity to participate in that expedition, not only because of the experience itself, but because the teamwork was… was… inspiring, stimulating, excellent. Among the 54 participating scientists, there were expertise in oceanography; sea-ice physics; sea-ice primary production; oceanic primary production; carbon export to the deep ocean; zooplankton; biomarkers; aerosols; and organisms and processes in the deep sea floor of the Arctic located at more than 4000 meters.

¿Por qué tanta gente trabajando en cosas distintas? Pues porque el objetivo de nuestra campaña ‘IceArc’ (Sea ice – ocean – sea floor interactions in the changing Arctic) era investigar las interacciones entre procesos físicos y biogeoquímicos que tienen lugar desde el hielo en la superficie hasta el fondo del Ártico, con especial atención en cómo estos procesos pueden estar viéndose afectados por los drásticos cambios en el Océano Ártico (principalmente aumento de temperatura y disminución de la cobertura de hielo durante el verano). Para ello, durante nuestra campana tomamos muestras para análisis en todas esas líneas de investigación que os he contado más arriba en la parte central del Océano Ártico, entre 82 y 89°N y 30 y 130°E entre Agosto y Octubre de 2012 (Fig. 1). Por desgracia, nuestra campana coincidió con un nuevo mínimo histórico en la cobertura de hielo al final del verano. 

Why were so many people working in quite different research topics? Because the aim of our cruise ‘IceArc’ (Sea ice – ocean – sea floor interactions in the changing Arctic) was to investigate the interactions between physical and biogeochemical processes that take place from the surface to the deep sea floor, with especial attention on how the severe changes in the Arctic Ocean (mainly temperature increase and decline of sea-ice extent) are affecting those processes. For that purpose, during the cruise we took samples for all the research areas that I have mentioned above in the ice-covered eastern-central basins between 82° to 89°N and 30° to 130°E in summer 2012. Unfortunately, during our cruise Arctic sea ice declined to a new record minimum.

Fig. 1. (a) Area cubierta por el hielo en el Artico a partir de observaciones (linea roja) y estimada a partir de modelos climáticos del IPCC (Intergovernmental Panel on Climate Change) (linea negra). (b) Nuestro recorido en la campana 'IceArc' durante el verano de 2012 (linea azul) mostrando los lugares donde realizamos estaciones en el hielo, la extensión de hielo en 2012 (area blanca) y el anterior mínimo historico de extensión de hielo registrado en 2007 (línea amarilla).
Fig. 1. (a) Observations of sea-ice extent in the Arctic (red line) and estimations obtained from IPCC (Intergovernmental Panel on Climate Change) climate models (black line). (b) Our path during the cruise 'IceArc' in summer 2012 (blue line) showing the 8 regions where we did ice-stations, the sea-ice extent in 2012 (white area) and the previous historical minimum registered in 2007 (yellow line).

High motivation (English version)

In Spanish here

 

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 (http://en.wikipedia.org/wiki/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).

Source: Tracking the Earth’s Energy. Trenberth, et al., Science (2010). 

High Motivation

Hace más de un mes, antes de mi largo ‘descanso’ del blog uno de vosotros me preguntó si sería posible tener acceso a mi contribución a la conferencia THOR y a otra previa ‘ICES/PICES Conference for Early Career Scientist. Oceans of Change’. He estado intentando ver la forma de subir dicha información al blog, y no es sencillo. Así que lo que hecho es crear una carpeta pública en dropbox donde dejaré colgado todo aquello que os pueda hacer público sin problema. Ahí tenéis ya ambas contribuciones. Si pincháis en los links no deberías tener problema pero si es así…comentario por favor! 

De la que estaba haciendo esto, estaba releyendo tanto los abstracts de esas conferencias como un link a una noticia en el periódico de Spiegel en Alemania, otros blogs, y algunos artículos publicados en los últimos meses y me he entusiasmado. Tanto, que además del abstract que había mandado para la EGU Viena para la sesión ‘Changes in Arctic and Antarctic sea ice and ocean: processes, observations, models and perspectives’ titulado ‘Increasing presence of Arctic Ocean Deep Waters in the Greenland Sea’, antes de ayer (a día de hoy debería decir hace una más de una semana) he enviado otro a la conferencia ‘IAPSO: North Atlantic and Climate Change’ titulado ‘A downwards heat and salt injection mechanism linking mid-latitudes and Polar Regions in the North Atlantic’. Espero poder presentarlos como presentación oral, pero esos tendrán que decidirlo otros y no yo. Tal como pueda los subiré a la carpeta.

Bueno, os cuento despacio el porqué de mi entusiasmo, que me acelero, y así no hay manera de explicarse. Y para esto nada mejor que daros enlace a un post que publique en Abril del año pasado ‘From the Surface for a Deeper Understanding’. Por si no queréis leerlo entero, resumiendo os contaba que el aumento de radiación (equivalente a decir calor para entendernos) medido en la atmósfera como consecuencia principalmente del aumento de la concentración de gases invernadero se esperaba que se viese reflejado en un calentamiento del océano, puesto que como sabéis la mayoría del calor en nuestro sistema climático (conjunto formado por la Atmósfera, Litosfera (http://es.wikipedia.org/wiki/Litosfera), Hidrosfera (océanos, ríos,  lagos, etc.), Criosfera (parte helada de la Tierra) y Biosfera) se almacena en el océano. Sin embargo, en la última década el calor almacenado en las capas superficiales del océano (primeros 700 m) ha aumentado a una velocidad mucho menor de la esperada (Fig. 1). Puesto que el resto del calor (el que se esperaba encontrar en las capas superficiales) no ha sido devuelto al espacio, lo más lógico es pensar que se encuentra en el océano profundo. Esto planteaba para mí dos cuestiones que relacionaban mi trabajo durando el doctorado estudiando la interacción atmósfera y variabilidad de la capa de mezcla y mi trabajo actualmente en el AWI estudiando los cambios en las aguas profundas del Ártico. La primera de estas preguntas era: ¿cuál es el mecanismo que ha permitido inyectar directamente el calor de la atmósfera al océano profundo tan eficazmente a diferencia de lo observado hasta hace una década? Hasta entonces se acumulaba en las capas superficiales. Y la segunda, ¿cuál es la contribución de las aguas profundas del Ártico a tal almacenamiento de calor puesto que sus cambios no han sido prácticamente estudiados?

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).

Source: Tracking the Earth’s Energy. Trenberth, et al., Science (2010).