Several extreme drought events occurred in 2015 around the globe. At CESBIO, combining hydrological modelling and remotely sensed surface soil moisture from SMOS, we monitored a number of them. We used CATDS (Centre Aval de Traitement des données SMOS) products.
The aproach was to use our root zone soil moisture information derived from SMOS to infer a water scarcity index. Water scarcity in the root zone (0-1.5m) is actually an efficient early warning system for agricultural droughts.
The figure above shows 5 of the major droughts which occurred in 2015. The small focus maps show the drought index during the drought events in each of the regions of interest. The losses caused by these droughts amount to billions.
So the next question is: are we facing long drought events that can impact food security at global scale?
In 2016 we may see even worse conditions. Our drought index seem to provide an alarming forecast. This was showcased by ESA during the Living Planet Symposium LPS2016 with this post using our latest root zone soil moisture map (see Water for crops – the SMOS root zone soil moisture).
We also produced the drought index map over North America for 2016 and it seems that after the Alberta fires and last year drought in the West coast of the US, the Eastern coast is now at risk. This forecast may change but it is clear that extremes conditions are breaking very old records, beyond the contribution of the El-Nino effect.
It was noticed by several users that our new RFI filter was overdoing things a bit (actually one of the flags was wrong) leading to a very reduced amount of available brightness temperatures.
We are working on this issue and already François and Stéphane have patched the bug and tests were carried out at CESBIO before implementation which is underway at CATDS.
The new products will have version number 310
Very soon the operational algorithm will release -less abusely filtered - L3TB data (with more measurements thus) and we will also reprocess the whole data set (both L3TB and RFI).
SMOS Monitors a gigantic early melt in Greenland in quasi real time
As reported here (credit Ruth Mottram, DMI) and here, just a few days ago on April 11 and 12 more than 10% of Greenland surface melted. This is very significant at this time of year (see cutting below from here).
From the late seventies with SMMR, passive microwave sensors have already shown their ability to monitor ice caps.
SMOS, thanks to its L-band capacity is sensitive to layering in the snow/ice pack but liquid water on the surface will also change drastically brightness temperatures and this is exactly what happened.
SMOS sees thus the brightness temperatures over Western Greenland decrease due to heavy surface melting.
The videos below show an animation of SMOS measurements over Greenland.
The the South Eastern part of Greenland, along the coast line, the brightness temperatures suddenly drop from relatively high values (> 240 K. orange colour) to values lower than 220 K. (light blue, green yellow).
Figure : Animation showing SMOS brightness temperatures (L3 TB from CATDS) in H polarization, for an incidence angles ranging between 40 to 45°.
By Arnaud Mialon
We would like to inform you that we have now released the SMOS soil moisture product available in near-real time (NRT) based on a neural network approach.
The netcdf product is disseminated within four hours from sensing. For the moment it is available from ESA’s SMOS data portal (https://smos-ds-02.eo.esa.int/oads/access/). From mid-April this product will also be available through EUMETCAST and GTS.
For further information on the product and access to data please see https://earth.esa.int/web/guest/missions/esa-operational-eo-missions/smos/news/-/article/smos-soil-moisture-product-in-nrt-based-on-neural-network-is-now-available