ESA’s Soil Moisture and Ocean Salinity Mission - An overview on the mission’s performance and scientific results

European Geosciences Union General Assembly 2014 (EGU2014), 27 april - 2 may 2014, Vienna, Austria.-- 1 pageThe Soil Moisture and Ocean Salinity (SMOS) mission, launched on 2 November 2009, is the European Space Agency’s (ESA) second Earth Explorer Opportunity mission. The scientific objectives of the SMOS mission directly respond to the need for global observations of soil moisture and ocean salinity, two key variables used in predictive hydrological, oceanographic and atmospheric models. SMOS observations also provide information on the characterisation of ice and snow covered surfaces and the sea ice effect on ocean-atmosphere heat fluxes and dynamics, which affects large-scale processes of the Earth’s climate system. This paper will provide an overview on the various aspects of the SMOS mission, such as 1. The performance of the mission after more than 5 years in orbit: The SMOS mission has been in routine operations since May 2010, following the successful completion of the 6-months commissioning phase. The paper will summarise the technical and scientific status of the mission, including the status of the RFI detection and mitigation and its effect on the data products. SMOS has so far provided very reliable instrument operations, data processing and dissemination to users. The paper will also provide an overview on the MIRAS instrument performance, including the instrument calibration and level 1 brightness temperature data processing. 2. An overview on the SMOS data products: SMOS provides continuously level 1 (brightness temperature) and level 2 (soil moisture and ocean salinity) to its scientific user community since summer 2010. SMOS also provides brightness temperature data (level 1 data) to ECMWF in near-real time (NRT), who assimilates the data into their forecasting system. New services have been established to deliver a tailored NRT data product via the WMO’s GTS and EUMETSAT’s EUMETCast data dissemination systems to other operational agencies. This will open up new operational applications for SMOS data. Other data products are under development, responding to the requirements of the science community in particular in the area of hydrology, climate, land use and ship routing, namely a frozen soil indicator, data products for freeze/thaw periods, sea ice thickness and vegetation water content. 3. Provide an update on the overall validation approach and recent activities: SMOS data products are continuously improved and approach the scientific mission objectives. Validation activities are essential to ensure high data quality. ESA in collaboration with national agencies and institutions maintains a frame for validation activities such as reference sites, ground based observations as well as campaigns. The paper will provide an update on recent activities, such as the activities at DOME-C. 4. Summarise the collaboration with other space-borne L-band sensors, such as NASA’s Aquarius and SMAP missionsPeer Reviewe

Nonradioactive heteroduplex tracking assay for the detection of minority-variant chloroquine-resistant Plasmodium falciparum in Madagascar

<p>Abstract</p> <p>Background</p> <p>Strains of <it>Plasmodium falciparum </it>genetically resistant to chloroquine (CQ) due to the presence of <it>pfcrt </it>76T appear to have been recently introduced to the island of Madagascar. The prevalence of such resistant genotypes is reported to be low (< 3%) when evaluated by conventional PCR. However, these methods are insensitive to low levels of mutant parasites present in patients with polyclonal infections. Thus, the current estimates may be an under representation of the prevalence of the CQ-resistant <it>P. falciparum </it>isolates on the island. Previously, minority variant chloroquine resistant parasites were described in Malawian patients using an isotopic heteroduplex tracking assay (HTA), which can detect <it>pfcrt </it>76T-bearing <it>P. falciparum </it>minority variants in individual patients that were undetectable by conventional PCR. However, as this assay required a radiolabeled probe, it could not be used in many resource-limited settings.</p> <p>Methods</p> <p>This study describes a digoxigenin (DIG)-labeled chemiluminescent heteroduplex tracking assay (DIG-HTA) to detect <it>pfcrt </it>76T-bearing minority variant <it>P. falciparum</it>. This assay was compared to restriction fragment length polymorphism (RFLP) analysis and to the isotopic HTA for detection of genetically CQ-resistant parasites in clinical samples.</p> <p>Results</p> <p>Thirty one clinical <it>P. falciparum </it>isolates (15 primary isolates and 16 recurrent isolates) from 17 Malagasy children treated with CQ for uncomplicated malaria were genotyped for the <it>pfcrt </it>K76T mutation. Two (11.7%) of 17 patients harboured genetically CQ-resistant <it>P. falciparum </it>strains after therapy as detected by HTA. RFLP analysis failed to detect any <it>pfcrt </it>K76T-bearing isolates.</p> <p>Conclusion</p> <p>These findings indicate that genetically CQ-resistant <it>P. falciparum </it>are more common than previously thought in Madagascar even though the fitness of the minority variant <it>pfcrt </it>76T parasites remains unclear. In addition, HTAs for malaria drug resistance alleles are promising tools for the surveillance of anti-malarial resistance. The use of a non-radioactive label allows for the use of HTAs in malaria endemic countries.</p

SMOS instrument performance and calibration after six years in orbit

ESA's Soil Moisture and Ocean Salinity (SMOS) mission, launched 2-Nov-2009, has been in orbit for over 6 years, and its Microwave Imaging Radiometer with Aperture Synthesis (MIRAS) in two dimensions keeps working well. The calibration strategy remains overall as established after the commissioning phase, with a few improvements. The data for this whole period has been reprocessed with a new fully polarimetric version of the Level-1 processor which includes a refined calibration schema for the antenna losses. This reprocessing has allowed the assessment of an improved performance benchmark. An overview of the results and the progress achieved in both calibration and image reconstruction is presented in this contribution.Peer ReviewedPostprint (author's final draft

The first reptilian circovirus identified infects gut and liver tissues of black-headed pythons

International audienceAbstractViral metagenomic analysis of the liver of a black headed python (Aspidites melanocephalus) euthanized for a proliferative spinal lesion of unknown etiology yielded the first characterized genome of a reptile-infecting circovirus (black-headed python circovirus or BhPyCV). BhPyCV-specific in situ hybridization (ISH) showed that viral nucleic acids were strongly expressed in the intestinal lining and mucosa and multifocally in the liver. To investigate the presence of this virus in other snakes and its possible pathogenicity, 17 snakes in the python family with spinal disease were screened with ISH yielding a second BhP positive in intestinal tissue, and a Boelen’s python (Morelia boeleni) positive in the liver. BhPyCV specific PCR was used to screen available frozen tissues from 13 of these pythons, four additional deceased pythons with and without spinal disease, and fecal samples from 37 live snakes of multiple species with unknown disease status. PCR detected multiple positive tissues in both of the ISH positive BhP and in the feces of another two live BhP and two live annulated tree boas (Corallus annulatus). Preliminary analysis indicates this circovirus can infect BhPs where it was found in 4/5 BhPs tested (2/2 with spinal disease, 2/3 live with unknown status), Boelen’s python (1/2 with spinal disease), and annulated tree boa (2/6 live with unknown status) but was not detected in other python species with the same spinal lesions. This circovirus’ causal or contributory role in spinal disease remains speculative and not well supported by these initial data

New total electron content retrieval improves SMOS sea surface salinity

International audienceThe European Space Agency (ESA)-led SMOS (Soil Moisture and Ocean Salinity) mission aims at monitoring both soil moisture (SM) and ocean surface salinity (OS) on a global scale. The SMOS instrument is a microwave interferometric radiometer which provides visibilities, from which brightness temperatures (TB) maps are reconstructed in the spacecraft' antenna reference frame. In this study, we investigate how to improve the retrieval of salinity thanks to a better knowledge of the ionospheric Total Electron Content (TEC). We show how both the SMOS bias correction (the so-called Ocean Target Transformation, OTT) and the half orbit TEC profile can be obtained from SMOS third Stokes parameter A3 using a location on the SMOS field of view (FOV) where the sensitivity of TB to TEC is highest. The resulting TEC global maps compare favorably with those built from the International Global navigation satellite system Service observations. TEC values obtained from A3 are next used to optimize the OTT estimation for every polarization, and proved to provide more stable values. Finally, improvements achieved in the salinity retrieved from SMOS data are reported

SMOS: an earth explorer mission to observe ocean salinity with a novel technology

SMOS (Soil Moisture and Ocean Salinity), launched on November 2, 2009, is the first satellite mission addressing sea surface salinity measurements from space. Its unique payload is MIRAS (Microwave Imaging Radiometer using Aperture Synthesis), a new two-dimensional interferometer designed by the European Space Agency (ESA) and operating at the microwave L-band. This paper presents the characteristics of the instrument, a summary of the sea surface salinity retrieval from SMOS observations and shows initial results obtained one year and a half after launch. The pioneer nature of this mission, both from the technological and data processing points of view, implies many challenges that require continuous improvements even the mission was declared operational in May 2010. At present there are still several issues being addressed by the SMOS team, mainly related to low level data processing but also to the retrieval of salinity from radiometric measurements, which prevent by now from reaching the mission objectives in terms of salinity accuracy. However, realistic salinity maps have been obtained and preliminary validation tests against in situ data indicate we are approaching our goals. SMOS will be a milestone in the route for incorporating salinity to operational remote sensingThe design, implementation and operation of SMOS has been possible thanks to the effort of many scientific, technological and industrial European teams for almost twenty years. The SMOS level 2 processor development was funded by ESA under different contracts. This work was also supported in part by the French Centre National d’Etudes Spatiales, and by the Spanish National R+D Plan for the SMOS Barcelona Expert Center on Radiometric Calibration and Ocean Salinity (http://www.smos-bec.icm.csic.es) activities, through project AYA2010-22062-C05 and previous grantsPeer Reviewe

Assessment of long-term vicarious calibration efforts of MERIS on land product quality

Since the launch of MERIS on ENVISAT long term activities using vicarious calibration approaches are set in place to monitor potential drifts in calibration in the radiance products of MERIS. We are using a stable, well monitored reference calibration site (Railroad Valley, Nevada, USA) to derive calibration uncertainties of MERIS over time. We are using interpolation of uncertainties to derive a second set of uncertainties for a national data validation in the Netherlands. A satellite image derived land use map of the Netherlands (LGN4) is used to determine the largest homogeneous land use classes using a standard purity index (SPI). Potential adjacency effects are minimized using moving window filters on the pixels of the aggregated map. Multiple error propagation is being used to assess the impact of calibration accuracy on land use classification. A classification in 9 land use classes is finally performed on MERIS FR images of the Netherlands using image based spectral unmixing and matched filtering with endmembers derived from the LGN. We conclude that the classification performance may significantly be increased, when taking into account long-term vicarious calibration results

Long-term MERIS land product accuracy assessment based on vicarious calibration and regional validation

Since the launch of MERIS on board of ENVISAT long term activities using vicarious calibration approaches have been set in place to monitor potential drifts in the calibration of the radiance products of MERIS. In this paper, a stable and well monitored reference calibration site named Railroad Valley Playa (Nevada, USA) is used to derive the calibration uncertainties of the MERIS FR TOA radiance over time. Subsequently, a linear interpolation of these uncertainties is performed for a set of images covering the whole of the Netherlands (which is used as a validation site). After this, the images over the Netherlands were corrected on the basis of the previously interpolated uncertainties and classified in 9 land use classes using linear spectral unmixing and matched filtering techniques. The classification endmembers were derived from an image-based land use map of the Netherlands (LGN4) after determining the most homogeneous areas for each land use type by means of a standard purity index and a moving window filter to minimize possible adjacency effects. Finally, the impact of the calibration accuracy over the land use classification is assessed by comparing classification results both for corrected and uncorrected images. We conclude that the classification performance may significantly be increased, when taking into account long-term vicarious calibration results

ESA’s Soil Moisture and Ocean Salinity Mission - Mission Status and Performance

SMOS+SOS Ocean Salinity Science and Salinity Remote Sensing Workshop, 26-28 november 2014, Exeter, United Kingdom.-- 2 pagesThe scientific objectives of the European Space Agency’s (ESA) Soil Moisture and Ocean Salinity (SMOS) mission directly respond to the need for global observations of soil moisture and ocean salinity, two key variables used in predictive hydrological, oceanographic and atmospheric models. SMOS observations also provide information on the characterisation of ice and snow covered surfaces and the sea ice effect on ocean-atmosphere heat fluxes and dynamics, which affects large-scale processes of the Earth’s climate system. This paper will 1. Provide an overview and update on theperformance of the mission after 5 years in orbit, summarising the technical and scientific status of the mission and the plan for mission extension. SMOS was the first satellite mission operating in the ITU resolution 750 (WRC-12) protected L-Band. Nevertheless strong interference sources have been detected worldwide. The paper will provide an update on the improvements made with regards to the RFI situation and its effect on the data. The paper will also provide an overview on the MIRAS instrument performance, including the instrument calibration and level 1 brightness temperature data processing. 2. Provide information on the recent evolution of the SMOS data products, in particular focussing on the recent improvements in the drifts and spatial biases in the level 1 brightness temperatures and its impact on the level 2 data products. Further to the already available level 1 near-real time (NRT) data products distributed by ESA, WMO’s GTS and EUMETSAT’s EUMETCast systems, new operational data products are under development, based on the requirements from the continuously growing user community. The paper will provide information about present and future dataproduct development, with a focus for applications over ocean. 3. Provide information on how to address the detailed recommendations that were made by ESA’s Earth Science Advisory Committee as part of the recent mid-term mission extension review, outlining the objectives for the extended mission operations. 4. Summarise the collaboration with other space-borne L-band sensors, such as NASA’s Aquarius and SMAP missionsPeer Reviewe