SMOS helps understanding the Gulf of Guinea cold tongue... Cold tongue and African Monsoon Provided by Christophe MAES Adding a pinch of salt or putting a little less cold water, the oceanic cooking recipe going on in the Gulf of Guinea may play a major role on the African monsoon rainfall patterns. In order to unravel the spicy recipe and shed some light on the processes driving the hydrological cycle - which is a key element...

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SMOS research products for the Cryosphere in Antarctica The aim of the CryoSMOS project, funded by the European Space Agency (ESA) and led by IFAC (Florence, Italy), is to evaluate the ability of SMOS observations to retrieve glaciological parameters or to monitor climatic processes in Antarctica. The study focused on some broad areas of the continent having specific physical characteristics: the Antarctic Plateau, the ice-shelves...

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SMOS helps discriminating water sources in cold seas Discriminating water sources from space in the Arctic Ocean: A case study for the southern Beaufort Sea using MODIS ocean color and SMOS salinity data A recent paper by Matsuoka et al. (2016), using SMOS ESA L2 SSS, found nice correlations between the interannual variability of SMOS SSS and ocean color CDOM (see fig 1 and 2 below) in the Mackenzie river mouth. Using this...

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Position opening at CESBIO Position opening at CESBIO In the framework of the SMOS (Soil Moisture and Ocean Salinity) follow on mission, the Centre d’Etudes Spatiales de la BIOsphère (CESBIO) is opening a position. The duration is 12 months with a possible extension. SMOS was launched in 2009 and has been running very smoothly ever since (see here or on this blog). SMOS relies on the use...

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Bye Piers! I discovered this morning that we have lost  Piers Sellers This is very sad news I have known him for many years while he was a scientist (SiB, Hapex, BOREAS etc...), then as an astronaut and finally as a NASA top level manager. He came to our 20th Birthday at CESBIO. He was a great friend, I enjoyed his friendliness and wit, not to mention his professional qualities....

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SMOS helps understanding the Gulf of Guinea cold tongue to eventually forecats rainfall amounts in Western Africa

Category : Non classé

Cold tongue and African Monsoon

Provided by Christophe MAES

Adding a pinch of salt or putting a little less cold water, the oceanic cooking recipe going on in the Gulf of Guinea may play a major role on the African monsoon rainfall patterns. In order to unravel the spicy recipe and shed some light on the processes driving the hydrological cycle – which is a key element for the West African societies, scientists endeavoured to understand the “Atlantic cold tongue process » [1]. « This equatorial zone of the ocean goes through, each year during the north hemisphere spring/summer period a double phenomenon which is closely related to the rainfall in western Africa as already known. Casimir Da-Allada, an oceanographer, explains that surface water cools down while its salinity increases to reach a maximum in June for salinity but only in July for the low temperatures.

bouee-pirata (c) IRD / B. Bourlès Bouée Pirata lors d’une campagne océanographique dans le golfe de Guinée

The challenge is to link these two parameters whose maxima are separated by a month. Eventually, researchers hope to anticipate the temperature from the salinity measurements obtained a month before to derive rainfall forecasts over West Africa. From such information, it would be possible to anticipate rainfall volume and decide as early as June, whether to sow high yield but water demanding seeds or, conversely, more rustic, lower yield, seeds able to survive droughts…

RZSM1(c) CESBIO A Albitar: Root zone soil moisture to estimate a drought index from SMOS

So as to study this possibility, scientists made use of the ESA led SMOS mission [2] as well as in situ PIRATA buoys measurements [3]. They have developed numerical simulation models and derived the salt budget of the cold tongue and identified the vertical transport processes in the water column. « According to our results, the salinity change occurring at the end of spring is linked to the seasonal equatorial sub current activity, which pushes upwards the deep water towards the surface” indicates the scientist. “Less subject to incoming fresh water (rainfall and river outflow), the sea water is saltier than surface water ». Ongoing studies evaluate the relevance of salinity as an indicator of intensity of the cool tongue seasonal onset. Once done, it will be necessary to confirm its ability to help better anticipate the African Monsoon.

[1] Da-Allada, C. Y., Jouanno, J., Gaillard, F., Kolodziejczyk, N., Maes, C., Reul, N. and Bourlès, B. (2017), Importance of the Equatorial Undercurrent on the Sea Surface Salinity in the Eastern Equatorial Atlantic in boreal spring. J. Geophys. Res. Oceans, 122

[2] Kerr, Y.H., Waldteufel, P., Wigneron, J.P., Delwart, S., Cabot, F., Boutin, J., Escorihuela, M.J., Font, J., Reul, N., Gruhier, C., Juglea, S.E., Drinkwater, M.R., Hahne, A., Martin-Neira, M., & Mecklenburg, S. (2010). The SMOS Mission: New Tool for Monitoring Key Elements of the Global Water Cycle. Proceedings of the Ieee, 98, 666-687

[3] Prediction and Research Moored Array in the Tropical Atlantic

SMOS research products for the Cryosphere in Antarctica

Category : L3, L4

The aim of the CryoSMOS project, funded by the European Space Agency (ESA) and led by IFAC (Florence, Italy), is to evaluate the ability of SMOS observations to retrieve glaciological parameters or to monitor climatic processes in Antarctica. The study focused on some broad areas of the continent having specific physical characteristics: the Antarctic Plateau, the ice-shelves and the coastal region. Four SMOS derived research products have been developed:

1) Estimation of the internal ice-sheet temperature

Contact : Giovanni Macelloni, g.macelloni@ifac.cnr.it – IFAC, Florence, Italy

2) Estimation of ice thickness

Contact : Niels Skou, ns@space.dtu.dk,DTU, ns@space.dtu.dk – Technical University of Denmark – Denmark

3) Indicator of the origin of ice-shelves variability;

Contact : Lars Kaleschke, lars.kaleschke@uni-hamburg.de, UHAM – University of Hamburg, Germany

4) Surface melting occurrence

Contact : Ghislain Picard, ghislain.picard@univ-grenoble-alpes.fr,IGE – Institut des Geosciences de l’Environnement – Grenoble, France

The data are available from the CATDS and can be found here (free)

Information regarding these products can be found here

More information is available there

Two examples are shown in the figures below. The top most represents the temperature of the ice packs at a depth of 500m. The lower one gives the number of days of melt in 2010/2011.

Tice@-500m in SM_TEST_MIR_ITUDP4_20100101T0000

fig_melt_nbdays_smos_2010-2011

SMOS helps discriminating water sources in cold seas

Category : L2, Ocean

Discriminating water sources from space in the Arctic Ocean: A case study for the southern Beaufort Sea using MODIS ocean color and SMOS salinity data

A recent paper by Matsuoka et al. (2016), using SMOS ESA L2 SSS, found nice correlations between the interannual variability of SMOS SSS and ocean color CDOM (see fig 1 and 2 below) in the Mackenzie river mouth. Using this region as a case study, they derive an algorithm using this two sets of data for getting reasonable fractions of river water. As stated by the authors ‘Application of this algorithm may lead to the discrimination of water sources in the surface layer of the Arctic Ocean in various environments where seawater, ice melt water, and river water are intermingled,which might be useful to improve our understanding of physical and biogeochemical processes related to each water source’.

babin-1

Fig.1 : Satellite images of CDOM absorption coefficient at 443 nm [aCDOM(443),m−1] using MODIS ocean color data in July to August 2010 to 2012 (from Matsuoka et al. (2016))

babin-2

Fig. 2 : Same as Fig. 1 for SMOS SSS (from Matsuoka et al. (2016)).

Atsushi Matsuoka, Marcel Babin, Emmanuel C. Devred, A new algorithm for discriminating water sources from space: A case study for the southern Beaufort Sea using MODIS ocean color and SMOS salinity data, Remote Sensing of Environment, Volume 184, October 2016, Pages 124-138, ISSN 0034-4257, http://dx.doi.org/10.1016/j.rse.2016.05.006. (//www.sciencedirect.com/science/article/pii/S0034425716301997)

Position opening at CESBIO

Category : Non classé, position opening

Position opening at CESBIO

In the framework of the SMOS (Soil Moisture and Ocean Salinity) follow on mission, the Centre d’Etudes Spatiales de la BIOsphère (CESBIO) is opening a position. The duration is 12 months with a possible extension.

SMOS was launched in 2009 and has been running very smoothly ever since (see here or on this blog). SMOS relies on the use of a new instrument: a 2 D interferometer to achieve both adequate spatial and temporal sampling and operates at L Band. It was followed by two other satellites SMAP and Aquarius with different observation modes but always operating at L band.

With these missions in flight, a wealth of science and applications has been derived ranging from hurricane or thin sea ice monitoring to drought or flood forecasting or climate monitoring.

It is however time to envision how to replace aging satellites and for this purpose the European Space Agency (ESA) initiated a study to define users’ requirements at low frequency passive microwaves.

The study was awarded to a European consortium led by CESBIO.  In this context CESBIO is opening a position to contribute to this project.

The role of the applicant is to basically participate within the consortium to the making of the project in the two main aspects:

Support management and coordination:

  • establish and operate web pages portal for both internal and external communication and management of the project activities
  • report and documentation
  • organise science meeting and write the related reports
  • liaise with ESA and the international members of the project

Support for technical studies depending on his skill:

  • contribute to establishing a list of the different products supported by L-Band measurements together with their accuracies and feasibility/ maturity from input of the community
  • Translate and trace requirements from science end users to requirements for geophysical parameters, and to passive L-Band products.
  • Contribute to a “cluster analysis” of products and applications according to their key requirements, like temporal and spatial resolution and radiometric accuracy
  • perform simulations to assess requirements when needed

Applicants should possibly hold a Ph.D. degree in remote sensing or should have equivalent experience in space research and in physics and geophysics. They should have good communication skills. The applicant should be fluent in English (written and spoken). A good practice is a plus. The applicant should have excellent  writing skills for reporting and documentation.

The work will take place within the SMOS team of CESBIO (Toulouse) and in collaboration with INRA (Bordeaux), several other teams in Italy, Spain, Switzerland, Finland, Portugal, as well ESA (Noordwijck NL) and CNES (Toulouse France).

Salary: Gross: about 2100 euros / month, depending on qualification and experience

Duration: 12 months minimum

Applications (application letter + CV+2 references) should be sent to Yann Kerr (Yann.kerr@cesbio.cnes.fr; phone: 05 61 55 85 22)

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