Roberto Sabia

Roberto Sabia
Telespazio-Vega for European Space Agency (ESA)

PhD

About

113
Publications
10,088
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998
Citations
Citations since 2017
32 Research Items
527 Citations
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2017201820192020202120222023020406080100120140
2017201820192020202120222023020406080100120140

Publications

Publications (113)
Article
Full-text available
This paper presents the first Soil Moisture and Ocean Salinity (SMOS) Sea Surface Salinity (SSS) dedicated products over the Baltic Sea. The SSS retrieval from L-band brightness temperature (TB) measurements over this basin is really challenging due to important technical issues, such as the land–sea and ice–sea contamination, the high contaminatio...
Article
Full-text available
Changes in the Earth’s water cycle can be estimated by analyzing sea surface salinity. This variable reflects the balance between precipitation and evaporation over the ocean, since the upper layers of the ocean are the most sensitive to atmosphere–ocean interactions. In situ measurements lack spatial and temporal synopticity and are typically acqu...
Preprint
Validation of satellite sea surface salinity (SSS) products is typically based on comparisons with in-situ measurements at a few meters depth, that are mostly done at a single location and time. The difference in term of spatio-temporal resolution between the in-situ near-surface salinity and the two-dimensional satellite SSS results in a sampling...
Preprint
Full-text available
Validation of satellite sea surface salinity (SSS) products is typically based on comparisons with in-15 situ measurements at a few meters depth, that are mostly done at a single location and time. The difference 16 in term of spatio-temporal resolution between the in-situ near-surface salinity and the two-dimensional 17 satellite SSS results in a...
Article
Full-text available
During submission of the paper http://dx.doi.org/10.5194/essd-14-307-2022 , an error was introduced in Fig. 6. The plots a and b were swapped.
Article
Full-text available
Measuring salinity from space is challenging since the sensitivity of the brightness temperature (T B) to sea surface salinity (SSS) is low (about 0.5 K/psu), while the SSS range in the open ocean is narrow (about 5 psu, if river discharge areas are not considered). This translates into a high accuracy requirement of the radiometer (about 2-3 K). M...
Preprint
Full-text available
This paper presents the first Soil Moisture and Ocean Salinity (SMOS) Sea Surface Salinity (SSS) dedicated products over the Baltic Sea. The SSS retrieval from L-band brightess temperature (TB) measurements over this basin is really challenging due to important technical issues, such as the land-sea and ice-sea contamination, the high contamination...
Conference Paper
The Soil Moisture and Ocean Salinity (SMOS) Earth Explorer Opportunity Mission of the European Space Agency (ESA) aims to provide a global and precise soil moisture estimation over land and salinity content over oceans. In this paper we focus on ocean application of the SMOS mission. The brightness temperature of the sea surface with small or moder...
Article
Full-text available
The Pilot-Mission Exploitation Platform (Pi-MEP) for salinity is an ESA initiative originally meant to support and widen the uptake of Soil Moisture and Ocean Salinity (SMOS) mission data over the ocean. Starting in 2017, the project aims at setting up a computational web-based platform focusing on satellite sea surface salinity data, supporting st...
Article
Full-text available
Sea Surface Salinity (SSS) is an increasingly used Essential Ocean and Climate Variable. The Soil Moisture and Ocean Salinity (SMOS), Aquarius, and Soil Moisture Active Passive (SMAP) satellite missions all provide SSS measurements, with very different instrumental features leading to specific measurement characteristics. The Climate Change Initiat...
Preprint
Full-text available
Measuring salinity from space is challenging since the sensitivity of the brightness temperature (TB) to sea surface salinity (SSS) is low (about 0.5 K / psu), while the SSS range in the open ocean is narrow (about 5 psu, if river discharge areas are not considered). This translates into a high accuracy requirement of the radiometer (about 2–3 K)....
Article
Full-text available
Operated since the end of 2009, the European Space Agency (ESA) Soil Moisture and Ocean Salinity (SMOS) satellite mission is the first orbiting radiometer that collects regular and global observations from space of two EssentialClimateVariablesoftheGlobalClimateObservingSystem:SeaSurfaceSalinity(SSS)andSoilMoisture. The National Aeronautics and Spac...
Article
Full-text available
The quality of the Soil Moisture and Ocean Salinity (SMOS) sea surface salinity (SSS) measurements has been noticeably improved in the past years. However, for some applications, there are still some limitations in the use of the Level-2 ocean salinity product. First, the SSS measurements are still affected by a latitudinal and seasonal bias. Secon...
Article
Full-text available
We derive water mass transformation and formation rates using satellite-derived datasets of salinity, temperature and fluxes of heat and freshwater over the North Atlantic, North Pacific and Southern Ocean. The formation rates are expressed in three coordinate systems: (1) density, (2) temperature-salinity and (3) latitude-longitude. In the North A...
Data
SPRINT presentation was a 4 minutes presentation previous to poster exhibition. IGARSS 2019
Poster
Full-text available
Despite representing only the 1% of the total ocean’s water, the discharge by Arctic rivers accounts for about the 11% of the freshwater flow into the ocean. This huge volume of low density freshwater restricts the mixing between surface and deep ocean layers, because of the induced strong stratification. The accumulation of low salinity water on t...
Article
Full-text available
Advances in L-band microwave satellite radiometry in the past decade, pioneered by ESA’s SMOS and NASA’s Aquarius and SMAP missions, have demonstrated an unprecedented capability to observe global sea surface salinity (SSS) from space. Measurements from these missions are the only means to probe the very-near surface salinity (top cm), providing a...
Article
After more than eight years of the European Space Agency (ESA) Soil Moisture and Ocean Salinity (SMOS) acquisitions, an exhaustive, empirical characterization of the biases and uncertainties affecting SMOS brightness temperatures over the ocean is possible. We show that both parameters strongly depend not only on the position in the field of view,...
Conference Paper
Through the separation of surface heat and freshwater fluxes into bins of Sea Surface Salinity (SSS) and Sea Surface Temperature (SST), we were able to use the increased spatial resolution offered by satellites to estimate Water-Mass (WM) Transformation and Formation rates both synoptically and systematically. We used data from the European Space A...
Article
The Soil Moisture and Ocean Salinity (SMOS) mission, launched in 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, oce...
Book
This book presents cutting-edge remote sensing research, outlining the advanced use of European Space Agency (ESA) satellite data in the context of climate change. The ESA, through its Support to Science Element (STSE) Programme, funds a network of young post-doc scientists pursuing 2-year cutting-edge research projects in the field of remote sensi...
Article
Full-text available
Approximately a quarter of the carbon dioxide (CO2) that we emit into the atmosphere is absorbed by the ocean. This oceanic uptake of CO2 leads to a change in marine carbonate chemistry resulting in a decrease of seawater pH and carbonate ion concentration, a process commonly called 'Ocean Acidification'. Salinity data are key for assessing the mar...
Article
An analysis is presented for the spatial and intensity distributions of North Atlantic extreme atmospheric events crossing the buoyant Amazon-Orinoco freshwater plume. The sea surface cooling amplitude in the wake of an ensemble of storm tracks travelling in that region is estimated from satellite products for the period 1998-2012. For the most int...
Article
A first estimation of satellite-based ocean surface T-S diagrams is performed by using SMOS Sea Surface Salinity (SSS) and OSTIA Sea Surface Temperature (SST) and comparing them with in-situ measurements interpolated fields obtained by the Argo-buoys for the North Atlantic and over the entire year 2011. The key objectives at the base of this study...
Article
Full-text available
The European Space Agency Soil Moisture and Ocean Salinity mission aims at estimating, over the oceans, sea surface salinity (SSS) with spatial and temporal coverage adequate for large-scale oceanography. Spatiotemporal averaging of the retrieved SSS [level-3 (L3) product] has to be properly performed in order to meet the challenging mission requir...
Article
Full-text available
After 2.5 years of the Soil Moisture and Ocean Salinity (SMOS) mission, the characterization of residual instrumental systematic errors in the measured brightness temperatures (TB) is still rather poor. This in turn negatively impacts the sea surface salinity retrievals and, as such, notably limits the mission’s success. The error mitigation method...
Conference Paper
Full-text available
A prospective sounding of the capabilities of a novel salinity retrieval by means of Support Vector Regression has been performed. Co-located SMOS measurements and additional auxiliary parameters have been considered, whilst salinity data collected by ARGO buoys represented the ground-truth to be matched by the algorithm. Salinity fields estimated...
Article
The European Space Agency, through its Support to Science Element (STSE) Programme, funds a network of young post-doc scientists undertaking cutting-edge research in the area of Remote Sensing. This so-called Changing Earth Science Network focuses on the exploitation of Earth Observation (EO) data to address major issues related to the broader cont...
Article
Full-text available
Capability for sea surface salinity observation was an important gap in ocean remote sensing in the last few decades of the 20th century. New technological developments during the 1990s at the European Space Agency led to the proposal of SMOS (Soil Moisture and Ocean Salinity), an Earth explorer opportunity mission based on the use of a microwave i...
Article
Full-text available
The Soil Moisture and Ocean Salinity (SMOS) mission was launched on November 2nd, 2009 aiming at providing sea surface salinity (SSS) estimates over the oceans with frequent temporal coverage. The detection and mitigation of residual instrumental systematic errors in the measured brightness temperatures are key steps prior to the SSS retrieval. For...
Conference Paper
A preliminary attempt of deriving a purely satellite-based Temperature-Salinity (T-S) diagram is presented, with the overall aim of assessing to what extent is possible, and in which geographical areas, to identify and trace water masses by satellite. This has been performed by using recent SMOS and Aquarius satellite SSS products in conjunction wi...
Article
Full-text available
This work summarizes the activities carried out by the SMOS (Soil Moisture and Ocean Salinity) Barcelona Expert Center (SMOS-BEC) team in conjunction with the CIALE/Universidad de Salamanca team, within the framework of the European Space Agency (ESA) CALIMAS project in preparation for the SMOS mission and during its first year of operation. Under...
Conference Paper
Full-text available
The Microwave Imaging Radiometer using Aperture Synthesis (MIRAS) instrument onboard the Soil Moisture and Ocean Salinity (SMOS) mission was launched on November 2nd, 2009 with the aim of providing, over the oceans, synoptic sea surface salinity (SSS) measurements with spatial and temporal coverage adequate for large-scale oceanographic studies. F...
Article
A study of the latitudinal trend of the retrieved salinity performances along a Southwards transect has been performed, analyzing the trade-off between geophysical effects in cold seawater and the concomitant temporal oversampling under various processing configurations. Quantitative sensitivity with respect to sea surface temperature gradient has...
Article
Full-text available
Soil Moisture and Ocean Salinity (SMOS), launched on 2 November 2009, is the first satellite mission addressing sea surface salinity (SSS) measurement from space. Its unique payload is the Microwave Imaging Radiometer using Aperture Synthesis (MIRAS), a new two-dimensional interferometer designed by the European Space Agency (ESA) and operating at...
Article
The interests of the scientific community working on the Soil Moisture and Ocean Salinity (SMOS) ocean salinity level 2 processor definition are currently focused on improving the performance of the retrieval algorithm, which is based on an iterative procedure where a cost function relating models, measurements, and auxiliary data is minimized. For...
Conference Paper
SMOS salinity inversion consists of minimizing the residual between measured and modeled brightness temperatures. The minimization procedure is a great challenge and crucial step, but its success depends on the quality of the forward model. Consequently, we present an empirical update of pre-launch L-band emissivity forward models, where the essent...
Technical Report
Full-text available
Release of SMOS level 2 Ocean Salinity (OS) products to general users. Abstract: This note was first issued in June 2010 as additional information to the release of salinity products to the SMOS Calibration/Validation teams, under request from the SMOS Mission Manager (S. Mecklenburg) to the SMOS Co-Lead Investigator for Ocean Salinity (J. Font). I...
Conference Paper
Preliminary results obtained during the commissioning phase of the Soil Moisture and Ocean Salinity (SMOS) mission are described, devoting special attention to the characterization of the systematic errors found in the measurements and the corresponding impact in the retrieved salinity product. The identified issues and objectives to consolidate an...
Article
The interest of the scientific community in global climate has been constantly increasing in the last years. Much effort has been devoted to better understand the water cycle and its role in global climate regulation. This is one of the objectives of the European Space Agency (ESA) Soil Moisture and Ocean Salinity (SMOS) mission, approved in May 19...
Conference Paper
Full-text available
SMOS (Soil Moisture and Ocean Salinity), launched in November 2, 2009 is the first satellite mission addressing the salinity measurement from space through the use of MIRAS (Microwave Imaging Radiometer with Aperture Synthesis), a new two-dimensional interferometer designed by the European Space Agency (ESA) and operating at L-band. This paper pres...
Conference Paper
Full-text available
Soil Moisture and Ocean Salinity (SMOS) mission is the second of European Space Agency's (ESA) Living Planet Programme Earth Explorer Opportunity Missions. SMOS's objective is to provide global and frequent Soil Moisture and Sea Surface Salinity maps. The single payload embarked on SMOS is the Microwave Imaging Radiometer by Aperture Synthesis (MIR...
Article
The Soil Moisture and Ocean Salinity mission will provide sea surface salinity maps over the oceans, beginning in late 2009. In this paper an ocean salinity error budget is described, an analysis needed to identify the magnitude of the error sources associated with the retrieval. Instrumental, external noise sources, and geophysical errors have bee...
Article
ESA's Soil Moisture and Ocean Salinity (SMOS) mission was launched on November, 2 2009, at 2.50 GMT from the Russian cosmodrome of Plesetsk. The SMOS single payload consists of a 2-D synthetic-aperture radiometer, the so-called Microwave Imaging Radiometer for Aperture Synthesis (MIRAS) which provides unprecedented global coverage L-band brightness...
Conference Paper
Full-text available
The Earth Explorer Soil Moisture and Ocean Salinity (SMOS) mission was successfully launched on November 2nd, 2009, in the framework of the European Space Agency Living Planet programme. It will provide long-awaited remotely-sensed Sea Surface Salinity (SSS) maps over the oceans with a 3-day revisiting time [1]. The SMOS Barcelona Expert Centre (SM...