Do You Remember B15J? Well, was a good buoy, but wandered into the ocean away from home and … melted away!

Category : Cal/Val, L1, Non classé, Ocean

After the drifting iceberg (identified by SMOS blog followers as the B15J) was spotted on SMOS data, it has become attractive to follow the movement of this massive « natural buoy », serving as the oceans current indicator.

The iceberg trajectory has been determined from the SMOS browse data, and it is charted as a function of the first Stokes parameter (at the incidence angle 42.5).

traj

Animation based on consecutive single passes shows iceberg location during last three months.

Oct-Dec-singlepass-THUMBN

Note, that in the range between 114-140 K the color scale has been modified on purpose. This gives better ability to distinguish moving B15J from the surrounding open water, but also depicts regions characterized by the same brightness temperature range as the tracked iceberg.

When in the middle of October 2011 B15J started to move towards the equator, straying from Antarctica, its brightness temperature started to decrease steadily. The DGG pixels belonging to the iceberg area and having maximum intensity of the first Stokes parameter have been extracted to examine polarimetric characteristics of the tracked object. Sample of polarimetric characteristics, grouped into three months sets, confirms significant drop-off of the brightness temperature.

setblog

Unfortunately at the end of December 2011, the signature of B15J were barely apparent. The iceberg vanished in the Pacific Ocean, making further tracking not feasible.

NovDec-aver-week-THUMBN


Ewa Slominska

The answer…. to the quizz

Category : Data, Ocean

Yes, as most of you found out, it is an Iceberg (not that big wrt SMOS resolution, but large never the less)
Ewa Slominska gave me the following pictures with the blog post the other day…
The Area where the point was travelling looks like this at the time of SMOS over pass closest to the ENVISAT ASAR overpass.

iceberg-smos and if we super- impose SAR data we get…
iceberg Bingo! actually zooming a little more we see the iceberg
iceberg-zoom It is not that big!
More details on this link provided by Serge and Fernando at ESAC
http://www.natice.noaa.gov/pub/iceberg_images/jpeg/2011233_B15J.jpg

Artic summer and antarctic winter as seen by SMOS … and a quizz

Category : Data, L2, Ocean

This post was prepared by
Ewa Slominska
from
Space Research Center PAS
18 A, Bartycka
00-716 Warsaw, Poland

During their work with SMOS data, Ewa Slominska has produced the following animations of the temporal/seasonal changes in global distribution of Brightness Temperatures over the poles.

It was made using SMOS browse products (merging land and sea) interms of 1/2 Stokes 1 (i;.e, (TBh+TBV)/2) over 7 day periods.

Results obtained look very nice. On one hand we see expanding ice  around the Antarctica, and ice melting areas (like the Hudson Bay or the Buffin Bay) around The North Pole on the other hand all this during the May to August 2011 period. Only worry .. the RFI!

ascStokes1NorthMay-Aug_75

(Click on the picture to enlarge and to better visualise the animation)

Now the quizz… !
what could be the tiny light blue point, which floats at the longitudes
of the Ross Sea, towards the East, close to the ice-sea ridge?

ascStokes1SouthMay-Aug

Answer …..in a few days … Ewa has found the cause! what is your guess?

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