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Los filtros actuales son: Año inicio = 2021, Año final = 2026
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Cossu F., Trindade A., Portabella M., Verhoef A., Stoffelen A. (2025)
(BibTeX: cossu.etal.2025a)
Resumen: Ver
C-band scatterometers, such as ASCAT, measure ocean surface winds which
prove to very closely align with the local wind vector. Such scatterometers
are based on vertical (VV) polarization, whose modulation is well described
by the so-called Bragg scattering of e.m. waves. On the other hand, Ku-band
scatterometers, although less accurate, provide both vertical and horizontal
(HH) polarized measurements. The HH Normalized Radar Cross Section
(NRCS) is composed of a Bragg part which depends on the local wind and of
a non-Bragg part associated with breaking waves. The dual-polarized NRCS
of Ku-band scatterometers can therefore be exploited to detect wave breaking
events by analyzing the different HH and VV NRCS response to various sea
state and wind conditions.
In this study, we compare the normalized inversion residuals (MLENORM)
from the Haiyang-2C scatterometer (HSCAT-C) against several sea state
parameters and surface wind for three different sea state conditions. The
MLENORM is in fact a good noise estimator and it can be exploited to detect
a signal not modeled by the Geophysical Model Function (GMF), such as
the backscatter signal from breaking waves. The MLENORM is decomposed
into its HH and VV terms, using the measured and simulated NRCS, and the
ratio between the two terms is computed in order to highlight any possible
increase due to breaking waves.
In the surface wind plots, the MLENORM,HH/MLENORM,VV ratio (HH/VV
ratio) shows higher values for the growing sea condition, followed by the
fully developed sea and by the decaying sea, suggesting a more frequent
occurrence of breaking waves for wind-dominated conditions compared to
swell-dominated conditions. For all sea states, the maximum increase of the
HH/VV ratio is observed around 10 m/s.
For the sea state parameters related to wave height and wave period,
instead, the variation of the HH/VV ratios as a function of sea state is more
complex, perhaps due to the simultaneous combination of several parameters
(wind, wave height and wave period). Finally, the HH/VV ratio seems to be
rather insensitive to the directional characteristics of the wave spectrum and
to the angle between the wind and the waves.
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Cossu F., Makarova E., S. Rabaneda A., Portabella M., Tenerelli J., Reul N., Stoffelen A., Grieco G., Sapp J., Jelenak Z., Chang P., Lin W. (2024)
Proc. of the International Geoscience and Remote Sensing Symposium (IGARSS), Athens, Greece, 7-12 July, 2024. (BibTeX: cossu.etal.2024)
Resumen: Ver
In the framework of the MAXSS project, a multi-mission (MM) wind product under tropical cyclone conditions has been generated for the period 2010-2020, i.e., a synergistic product that combines the European Center for Medium- range Weather Forecast fifth reanalysis (ERA5) output with several scatterometer and radiometer wind data adjusted to the wind scale of hurricane hunter in situ observations. The errors of the satellite and MM wind products have been estimated with triple collocation analysis, while the different spatial representation of the datasets (i.e., representativeness error r2) is accounted for and computed through spatial variance analysis. The error analysis shows that C-band scatterometers have the lowest standard deviation errors (0.9 m/s) compared to those of the Ku-band scatterometers (1.4- 2.1 m/s), while radiometers have the largest errors (2.0-2.9 m/s). Finally, the analysis reveals that the MM wind product has a lower error (1.6 m/s) compared to ERA5 (2.6 m/s) under tropical cyclone conditions.
Palabras clave: error analysis, extreme winds, satellite, NWP, synergistic product
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Lin W., Grieco G., Portabella M. (2024)
Document prepared under ESA Contract Number: 4000137991/22/NL/IA. ol. D7, (BibTeX: lin.etal.2024)
Resumen: Ver
Within the SEASTARex project, the following tasks have been carried out by ICM:
To support MetaSensing for the planning of the airborne acquisitions over sea (flight
patterns and schedule) for the test flight in The Netherlands and for the open ocean
“wind” campaign south of Brittany.
To support MetaSensing in the development of the OSCAR L-1 processor, which should
contain all the required input parameters to the Numerical Weather Prediction
Satellite Application Facility (NWP SAF) Pencil-beam scatterometer Wind Processor
(PenWP), i.e., Normalized Radar Cross Section (NRCS), viewing geometry, Kp,
acquisition time/position, and flight parameters), as well as in the definition of the socalled wind vector cells (WVCs) and the NRCS integration/aggregation strategy.
To adapt the PenWP scatterometer processor to produce wind retrievals from the
OSCAR L-1 input.
To perform a preliminary ocean (target) calibration of the OSCAR NCRS data, using
collocated European Centre for Medium-range Weather Forecasts (ECMWF) wind
output and Advanced Scatterometer onboard Metop (ASCAT) wind data as calibration
reference.
To perform an analysis of the L2 ocean surface vector winds derived from NRCS-only
inversion for the OSCAR ocean flights.
This report summarizes the ICM R&D activities associated with the above tasks, with a
particular focus on measurement Kp characterization, NRCS ocean calibration and wind
retrievals based on the data acquired during the SEASTARex campaign near Brittany in May
2022. In particular, the analysis focuses on the May 22nd and 25th flights, for which the OSCAR
calibration over land and the instrument performance over ocean were reported to be
nominal [SEASTARex_DAR, 2023] [MS-SEASTARex ExtCal, 2023].
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de Macedo K.A.C., Barreto T., Placidi S., Meta A., McCann D., Gommenginger C., Martin A., Márquez Martinez J., Portabella M., Martin-Iglesias P., Casal T. (2024)
Proc. of the EUSAR 2024, Munich, Germany, 23-26 April, 2024. (BibTeX: demacedo.etal.2024)
Resumen: Ver
The OSCAR instrument is a gimbal-based multi-channel interferometric Ku-band SAR system recently developed and built within the framework of a European Space Agency funded project Ocean Surface Currents Airborne Radar demon- strator. The OSCAR system is tailored to the observations of the ocean surface motion and retrieval of wind. This paper presents the development background of the OSCAR instrument. It also presents the methodology and techniques used to process and calibrate the OSCAR data up to co-registered intra-channel phase interferometric complex SAR images. Calibration over land shows that velocity accuracy of 5cm/s is achieved. Results from the OSCAR functional campaing and from the first OSCAR operational campaign, the SeaSTARex, are presented.
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Makarova E., Portabella M., Stoffelen A. (2024)
Actas del XX Congreso de la Asociación Española de Teledetección. 753-756. ISBN. 978-84-9828-941-1. (BibTeX: makarova.etal.2024)
Resumen: Ver
The aim of this work is to correct the persistent local biases of numerical weather prediction (NWP) model ocean surface wind output. To model these biases several machine learning (ML) models and neural networks are being trained with the data derived from satellite scatterometer (radar) observations. To generate the predictions of the biases and apply the corrections to NWP output, the ML models are using several NWP and ocean model output parameters as input. This way the corrections of the NWP errors do not depend on the availability of the observational data and can be applied to both its operational use the development of long-term data series of valuable ocean forcing datasets. The results show that such models are able to substantially reduce NWP local biases and therefore its overall error variance.
Palabras clave: stress-equivalent winds, local biases, NWP models, scatterometer, machine learning, neural networks
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Makarova E., Portabella M., Stoffelen A., Li G., Lin W. (2024)
International Geoscience and Remote Sensing Symposium (IGARSS), Athens, Greece, 7-12 July, 2024. (P). (BibTeX: makarova.etal.2024a)
Resumen: Ver
This work addresses the need for modelling and correcting the persistent Numerical Weather Prediction (NWP) local biases of the ocean surface wind forecasts. For such purpose, several NWP and ocean model output parameters are used as inputs to the machine learning and neural network models tested here. The results show that such models are able to substantially reduce NWP local biases and therefore its overall error variance, opening the door for both its operational use as well the development of long-term data series of valuable ocean forcing datasets.
Palabras clave: stress-equivalent winds, NWP biases, scatterometer, machine learning, neural networks
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Makarova E., Portabella M., Stoffelen A. (2024)
Actas del XX Congreso de la Asociación Española de Teledetección. 753-756. ISBN. 978-84-9828-941-1. (BibTeX: makarova.etal.2024)
Resumen: Ver
The aim of this work is to correct the persistent local biases of numerical weather prediction (NWP) model ocean surface wind output. To model these biases several machine learning (ML) models and neural networks are being trained with the data derived from satellite scatterometer (radar) observations. To generate the predictions of the biases and apply the corrections to NWP output, the ML models are using several NWP and ocean model output parameters as input. This way the corrections of the NWP errors do not depend on the availability of the observational data and can be applied to both its operational use the development of long-term data series of valuable ocean forcing datasets. The results show that such models are able to substantially reduce NWP local biases and therefore its overall error variance.
Palabras clave: stress-equivalent winds, local biases, NWP models, scatterometer, machine learning, neural networks
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Pablos M., Turiel A., Camps A., Vall-Llossera M., Portabella M., González-Haro C., Olmedo E., López-Martínez C. (2024)
Proc. of the International Geoscience and Remote Sensing Symposium (IGARSS), Athens, Greece, 7-12 July, 2024. (P). (BibTeX: pablos.etal.2024)
Resumen: Ver
The spatial spectra of three Soil Moisture and Ocean Salinity (SMOS) soil moisture (SM) datasets, produced by the Barcelona Expert Center (BEC), were assessed in this study along zonal and meridional directions. The datasets are the Level 3 (L3) SM gridded at 25 km, the Level 4 (L4) SM at 1 km and an experimental L4 SM at ~300 m. Since the L4 products are obtained by a downscaling algorithm that uses Normalized Difference Vegetation Index (NDVI), NDVI data from MODIS (1 km) and Sentinel-3 (~300 m) were also analyzed.
Both L4 products provide useful spatial information of small-scale structures, with estimated effective spatial resolutions of ~5 km (for the L4 SM at 1 km) and ~1 km (for the L4 SM at ~300 m). Besides, they seem to describe large-scale structures (>50 km) better than the L3 SM at 25 km. The spatial patterns of the NDVI have an important impact on the spatial variability of the downscaled SM products.
Palabras clave: Soil moisture, power density spectrum, spatial resolution, SMOS, disaggregation.
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Wang S., Portabella M., Dong X., Lin W., Bao Q. (2024)
Proc. of the International Geoscience and Remote Sensing Symposium (IGARSS) Athens, Greece, 7-12 July, 2024. (BibTeX: wang.etal.2024)
Resumen: Ver
Satellite-derived, coincident ocean surface winds and
currents are of great importance to enhance our un-
derstanding of air-sea interactions. The data from a
flight campaign, carrying a Ka-band rotating pencil-
beam Doppler scatterometer (i.e., the so-called OSCOM
prototype), are exploited in this work. In particular,
data calibration and wind/current retrievals are per-
formed. The Normalized Radar Cross-Sections (NRCS,
σ0) or backscatter measurements are calibrated using
two different methods to account for the larger than
expected (by consolidated Geophysical Model Functions
or GMFs used in Ka-band scatterometry) azimuthal
modulation of the backscatter signal. Both methods
are based on the so-called target or numerical ocean
calibration (NOC). The first method consists of apply-
ing an azimuth-dependent calibration, while the second
is based on a modification of the GMF to match the
observed modulation after calibration. The retrieved
wind speeds range from 3 to 6 m/s, and the wind di-
rections are around 155 . The standard deviations for wind speed and direction against ECMWF winds are
lower than 0.9 m/s and 9 . The winds derived using azimuth-dependent calibration present lower wind speed bias and larger wind direction standard deviation with respect to the modified GMF calibration.
Palabras clave: Doppler scatterometer, calibration, ocean winds
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Grieco G., Stoffelen A., Verhoef A., Vogelzang J., Portabella M. (2023)
Proc. of the International workshop on metrology for the sea (Metrosea) Valetta, Malta, 4-6 October. (BibTeX: grieco.etal.2023)
Resumen: Ver
This paper presents a new methodology to improve
the sampling of coastal winds derived from the SeaWinds
scatterometer, which flew onboard the polar orbiting satellite
platform Quick Scatterometer (QuikSCAT) from 1999 until
2009. The coastal SeaWinds Normalized Radar Cross Sections
(σ0s) are corrected for land contamination using the so-called
“noise-regularization” procedure. The results show that this
methodology is effective in filling the typical coastal scatterometer
gap of ≈30 km. From a visual check on a coastal test area, the
distribution of the newly derived winds seems to be consistent
with that of the offshore winds. However, proper validation is
needed. This is left for the future.
Palabras clave: SeaWinds, ocean vector winds, coastal areas
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Llorach-Tó G., Martínez E., Del Río J., García-Ladona E. (2023)
In OCEANS 2023, June 2023, Limerick, Ireland. (BibTeX: llorach-to.etal.2023)
Resumen: Ver
Oceanographic data such as wave conditions
(height, period, direction), wind, and sea currents are often
difficult to interpret. What is the sea state given a certain wave
height, wave directional spreading, and wind speed (e.g., 2 m, 29º,
18 m/s)? An expert user might be able to imagine the sea
conditions with such information, but this will be almost
impossible for a non-expert user. The common approach for
visualizing oceanographic data and its variability is usually
through tables and 2D graphs, for example plots, bar diagrams,
and latitude-longitude maps. These visualizations are often limited
to displaying raw data values, which still require user
interpretation. With the purpose of providing a more intuitive
view of the marine environment and sea conditions to a
widespread audience, this work presents an experimental web
application. The open-source application represents in a realistic
and intuitive way the observations from a meteo-oceanographic
and seafloor observatory located in the Western Mediterranean;
the OBSEA observatory. The user can visualize the marine
observatory facilities within a 3D virtual environment that
changes and evolves according to the data acquired. This work
aims at a digital twin of the seafloor observatory using
near-real- time and historical data
Palabras clave: data visualization, 3D virtual environment, webGL, ocean simulation, digital twin
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Nunziata F., Migliaccio M., Buono A., Ferrentino E., Alparone M., Zecchetto S., Zanchetta A., Portabella M., Grieco G. (2023)
Proc. of the International Geoscience and Remote Sensing Symposium (IGARSS), Pasadena (CA), USA, 16-21 July, 2023. (BibTeX: nunziata.etal.2023)
Resumen: Ver
This study is to present the lesson learned during the activities related to the Italian Space Agency (ASI) funded APPLICAVEMARS project which aims at estimating sea surface
wind field from L-, C- and X-band Synthetic Aperture Radar
(SAR) imagery. The paper focuses on the X-band results and
it describes a new approach to estimate ancillary wind direction info from the SAR image itself using neural networks.
Palabras clave: Ocean, Wind field, SAR, NN
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Pablos M., Portal G., Camps A., Vall-llossera M., González-Haro C., Portabella M. (2023)
Proc. of the International Geoscience and Remote Sensing Symposium (IGARSS), Pasadena (CA), USA, 16-21 July, 2023. (BibTeX: pablos.etal.2023)
Resumen: Ver
A modification of the Barcelona Expert Center (BEC)
algorithm to downscale the Soil Moisture and Ocean Salinity
(SMOS) soil moisture (SM) to 300 m spatial resolution is
presented. It maintains the same functional relationship as the
currently implemented version but employs the following
inputs: SMOS brightness temperature (TB) and SM (25 km),
European Center for Medium Weather Forecast (ECMWF)
skin temperature (9 km), and Sentinel 3 Normalized
Difference Vegetation Index (NDVI, 300 m).
The performance of the downscaled SMOS SM at 300 m
is analyzed by means of a temporal validation with in-situ
observations from the Soil Moisture Measurements Stations
Network of the University of Salamanca (REMEDHUS) and
the Continuous Soil Moisture and Temperature Ground-
based Observation Network (RSMN) during the year 2021.
No significant differences in correlation, unbiased root mean
square difference (ubRMSD) and bias are obtained over both
networks compared to the 25 km and 1 km SM products,
suggesting the BEC downscaling algorithm could work at
hundreds of meters and result in a similar SM accuracy
Palabras clave: Soil moisture, disaggregation, downscaling, SMOS, Sentinel 3
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Portabella M., Cossu F., Makarova E., Rabaneda A.S. (2023)
Document prepared under ESA Contract Number: 4000132954/20/I-NB. (BibTeX: portabella.etal.2023)
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Xu X., Stoffelen A., Ni W., Portabella M., Rabaneda A.S. (2023)
Proc. of the International Geoscience and Remote Sensing Symposium (IGARSS), Pasadena (CA), USA, 16-21 July, 2023. (BibTeX: xu.etal.2023)
Resumen: Ver
C-band scatterometer winds have been adjusted for extreme
conditions and in this research extension to Ku-band
scatterometers is investigated. With rain rates from the
Global Precipitation Measurement mission collocated to the
Ku-band scatterometer observations to identify and exclude
rain contamination of winds, calibration of the Ku-band
observations can be done. Using high-wind cases extracted
from collocated C- and Ku-band observations, we develop a
calibration model and extend the Ku-band winds to 35 m/s.
Validation is obtained from the set not included in the model
derivation, indicating a speed error less than 10% for wind
speed larger than 30m/s. The modified speed is consistent
with the Step Frequency Microwave Radiometer
measurements, when collocated with another Ku-band
scatterometer. A comparison for the Tropical Cyclone Manyi in 2018 shows the adjustedd wind fits better with the besttrack information provided by the Chinese Meteorological
Administration, while more details are revealed. Results can
be improved after obtaining more collocations with the dualfrequency scatterometer “WindRad” onboard the FY-3E
satellite. A method for wind direction enhancement in
extreme conditions is also discussed.
Palabras clave: wind scatterometers, Ku-band and C-band collocations, extreme wind speed adjustment
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Cossu F., Portabella M., Lin W., Stoffelen A., Vogelzang J., Marseille G.J., de Haan S. (2022)
IEEE International Geoscience and Remote Sensing Symposium (IGARSS). 6494-6497. DOI: 10.1109/IGARSS46834.2022.9883249. (BibTeX: cossu.etal.2022)
Resumen: Ver
The resolution of regional numerical weather prediction
(NWP) models has continuously been increased over the
past decades, in part, thanks to the improved computational
capabilities. At such small scales, the fast weather evolution
is driven by wind rather than by temperature and pressure.
Over the ocean, where global NWP models are not able to
resolve wind scales below 150 km, regional models provide
wind dynamics and variance equivalent to 25 km or lower.
However, although this variance is realistic, it often results
in spurious circulation (e.g., moist convection systems), thus
misleading weather forecasts and interpretation. An accurate
and consistent initialization of the evolution of the 3-
dimensional (3-D) wind structure is therefore essential in
regional weather analysis. The research will focus on a
comprehensive characterization of the spatial scales and
measurement errors for the different operational space-borne
wind products currently used and/or planned to be used in
regional models. Regarding the characterization of the
spatial scales and measurement errors, the widely used triple
collocation analysis in scatterometry is further analyzed and
adapted for the purpose of this project. An algorithm for
collocating 4D wind observations from Aeolus, Mode-S
data, and ECMWF model output over a region of Western
Europe is will be presented, along with measurement errors
from triple collocation
Palabras clave: Aeolus, Mode-S, wind, triple collocation
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Grieco G., Stoffelen A., Vogelzang J., Verhoef A., Portabella M. (2022)
Proc. of the Oceans from Space 2022. Ed. Eds. V. Barale, J.F.R. Gower, L. Alberotanza, NSA Group, pp. 120-121. 120-121. (BibTeX: grieco.etal.2022d)
Resumen: Ver
This paper presents a new methodology to
correct the land-contaminated normalized radar crosssection (σ0)
measurements acquired by the scatterometer
SeaWinds, which flew aboard the QuikSCAT satellite
platform from 1999 to 2009, operated by the National
Aeronautics and Space Administration (NASA). This
method is based on the hypothesis that contaminated σ0s
are linearly dependent on the Land Contribution Ratio
(LCR) index, which is defined as the ratio of the footprint
area contaminated by the presence of land to the total
footprint area. Furthermore, the σ0 deviations from the
expected contaminated σ0 values are “regularized” by
homogenizing their distribution, making them
independent of land contamination. The preliminary
results show that this methodology is effective up to few
kilometers to the coast. In addition, it prevents the
presence of negative corrected
Palabras clave: Ocean vector wind, scatterometer, SeaWinds.
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Grieco G., Portabella M., Vogelzang J., Verhoef A., Stoffelen A. (2022)
(BibTeX: grieco.etal.2022c)
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Grieco G., Stoffelen A., Verhoef A., Vogelzang J., Portabella M. (2022)
IEEE International Workshop on Metrology for the Sea; Learning to Measure Sea Health Parameters (MetroSea). 383-387. DOI: 10.1109/MetroSea55331.2022.9950798. (BibTeX: grieco.etal.2022b)
Resumen: Ver
This paper presents a new methodology to cor-
rect the land-contaminated normalized radar cross-section (σ0)
measurements acquired by the SeaWinds scatterometer, which
flew onboard the QuikSCAT satellite platform from 1999 to
2009, operated by the National Aeronautics and Space Ad-
ministration (NASA). This method is based on the hypothesis
that contaminated σ0s are linearly dependent on the Land
Contribution Ratio (LCR) index, which is defined as the ratio
of the footprint area contaminated by the presence of land to
the total footprint area. Furthermore, the σ0 deviations from the
expected contaminated σ0 values are “regularized” by means of
an adimensional constant, which is defined as the ratio of the
noise level evaluated at the σ0 level of the sea to the noise level
of the expected contaminated σ0 level. The preliminary results
show that this methodology is effective up to few kilometers to the
coast. In addition, it prevents the excessive presence of negative
corrected
Palabras clave: Ocean vector wind, scatterometer, SeaWinds
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Grieco G., Portabella M., Stoffelen A., Vogeltang J., Verhoef A. (2022)
IEEE International Geoscience and Remote Sensing Symposium (IGARSS). 6919-6922. DOI: 10.1109/IGARSS46834.2022.9884598. (BibTeX: grieco.etal.2022a)
Resumen: Ver
This paper describes some preliminary steps to improve the
coastal winds retrieved from the Seawinds scatterometer onboard the QuikSCAT satellite platform. In particular, it describes a method for estimating the slice Normalized Radar
Cross Section (σ0) noise. Moreover, it shows a simple method
for selecting the best-suited σ0 domain for implementing a
Land Contribution Ratio (LCR) based σ0 correction scheme
aiming to reduce the land contamination from coastal measurements. The results are discussed with a particular focus on the differences between the noise characteristics of
the open ocean measurements compared to those acquired
on every type of surface, including land and ice, and their
consistency with the information reported in the QuikSCAT
files. In addition, the effects of the biases induced by the intra-footprint (egg) incidence angle variation on the noise estimation are shown. Finally, the differences between the σ0
dependency on LCR in the linear and logarithmic spaces are
analyzed. The preliminary results suggest that there are some
non-negligible differences between the open sea and the ”every kind of surface” noise characteristics, even if such differences are not reported in the QuikSCAT files. The intra-egg
σ0 biases may amount to approximately ±0.6 dB for H-Pol
acquisitions and half of that for V-Pol, but the impact on the
noise estimation amounts to less than 2%. Finally, the σ0
dependency on LCR is more pronounced in the linear space,
suggesting that this is the best-suited domain to implement the
LCR based σ0 correction scheme, which is now being tested
and developed
Palabras clave: Coastal winds, Normalized Radar Cross Section noise, QuikSCAT, Land Contribution Ratio
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Makarova E., Portabella M., Stoffelen A. (2022)
Associated Scientist report for the EUMETSAT OSI SAF, OSI_VSA22_01. (BibTeX: makarova.etal.2022)
Resumen: Ver
This work aims at creating a preliminary machine learning (ML) model for
correcting the European Centre for Medium-Range Weather Forecasts (ECMWF) ERA5
reanalysis stress-equivalent local wind biases, based on atmospheric and oceanic parameters.
Several errors in the ECMWF global output for near surface ocean winds have been reported
when validated against scatterometer observations. An existing approach for correcting these
biases (the so-called ERA* method) consists of scatterometer-based corrections accumulated over
a certain time window at each grid point, which allows to reduce local persistent biases. This
approach is sensitive to scatterometer sampling and, to collect a statistically significant number
of samples, assumes that such biases are static. This is not the case for errors due to moist
convection or the diurnal cycle. For operational purposes, the temporal window is lagged with
respect to the reanalysis forecast time and the time difference betweeen scatterometer-based
correction (SC) and sample data collections can be ten days.
We propose a preliminary ML setup that looks for the functional relationship between
several oceanic and atmospheric variables that describe the persistent NWP errors as observed
in the NWP-scatterometer differences. This would allow to predict the biases of the stress-
equivalent wind forecasts and using the bias corrections in coupled weather or seasonal forecasts,
or to account for these in climate runs. Such variables are first identified as ECMWF model
parameters, such as stress-equivalent winds, their derivatives (curl and divergence), atmospheric
stability related parameters, i.e., sea-surface temperature (SST), air temperature (Ta), relative
humidity (rh), surface pressure (sp), as well as SST gradients and ocean currents. This work
evaluates the feasibility of such approach and provides an overview of possible implementations
of this regression
Palabras clave: scatterometer-based corrections, ERA5 biases, Machine Learning, Ocean forcing
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Martin A., McCann D., Macedo K., Meta A., Gommenginger C., Portabella M., Marié L., Horstmann J., Filipot J.F., Marquez J., Martín-Iglesias P., Casal T. (2022)
Proc. of the Oceans from Space 2022. Ed. Eds. V. Barale, J.F.R. Gower, L. Alberotanza, NSA Group, pp. 128-129. 128-129. (BibTeX: martin.etal.2022)
Resumen: Ver
The ocean interacts with the atmosphere, land
and ice on multiple spatial scales including fine submesoscales that are often observed in high resolution optical images. Little is known about their dynamics
however. SeaSTAR is an innovative satellite mission
concept that proposes to address this gap by mapping
ocean current and wind vectors at 1 km resolution. In this
paper, we present the OSCAR instrument - an airborne
demonstrator of the SeaSTAR concept - and the first
results from a scientific campaign over the Iroise Sea in
May 2022. The capabilities of OSCAR are demonstrated
against ground truth data with very promising first
results. These results open the door to using OSCAR as a
scientific tool to provide unique 2D synoptic views of
ocean and atmosphere dynamics at km-scales.
Palabras clave: Doppler Oceanography, Total Surface Current, Wind
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Nunziata F., Migliaccio M., Buono A., Ferrentino E., Alparone M., Zecchetto S., Zanchetta A., Portabella M., Grieco G. (2022)
IEEE International Workshop on Metrology for the Sea (Metrosea), Milazzo, Italy, 3-5 October, 2022. (BibTeX: nunziata.etal.2022)
Resumen: Ver
In this study, wind speed is estimated from COSMO- SkyMed (CSK) Synthetic Aperture Radar (SAR) imagery using two approaches, which both exploit the X-band Geophysical Model Function (GMF) XMOD2 developed for the German TerraSAR-X SAR mission. The first approach uses external wind direction information provided by collocated ASCAT scat- terometer measurements; the second one incorporates wind direction derived from the SAR scene using the Continuous Wavelet Transform (CWT). Experimental results, obtained using a relatively small collocated CSK data set, show the robustness of the wind estimation from the CSK imagery that result in accurate enough estimates under a range of incidence angles that span between 30° and 50°. The CWT approach allows reliable wind estimates on a 1km spatial grid.
Palabras clave: Sea wind, SAR, GMF, CWT
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Nunziata F., Migliaccio M., Buono A., Ferrentino E., Alparone M., Zecchetto S., Zanchetta A., Portabella M., Grieco G. (2022)
IEEE International Geoscience and Remote Sensing Symposium (IGARSS). 5184-5187. (BibTeX: nunziata.etal.2022a)
Resumen: Ver
This abstract is to present preliminary results related to the
Italian Space Agency (ASI) funded APPLICAVEMARS
project which aims at estimating sea surface wind field from
L-, C- and X-band Synthetic Aperture Radar (SAR) imagery.
First experimental results related to C-band Sentinel-1 SAR
imagery are presented
Palabras clave: One, two, three, four, five
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Portabella M., Rabaneda A.S., Grieco G. (2022)
ESA report MAXSS-ATBD-satellite-wind-recalibration_v2 (Contract No. 4000132954/20/I-NB). (BibTeX: portabella.etal.2022a)
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Portabella M., Trindade A., Grieco G., Makarova and F. Cossu E. (2022)
IEEE International Geoscience and Remote Sensing Symposium (IGARSS). 6783-6786. DOI: 10.1109/IGARSS46834.2022.9883300. (BibTeX: portabella.etal.2022)
Resumen: Ver
The ERA* stress-equivalent wind (U10S) is a correction of
the ECMWF Fifth Reanalysis (ERA5) output by means of
geo-located scatterometer-ERA5 differences over a 3-day
temporal window, in which the combined sampling of the
Advanced Scatterometers on board the Metop satellite series
(ASCAT-A, -B, and -C) and the SCATSat-1 scatterometer
(OSCAT2) have been used, for the year 2019. ERA* can
correct for local, persistent NWP model output errors
associated with physical processes that are absent or
misrepresented by the model, e.g., strong current effects
(such as western boundary current systems, highly stationary),
wind effects associated with the ocean mesoscales (sea
surface temperature), coastal effects (land see breezes,
katabatic winds), Planetary Boundary Layer parameterization
errors, and large-scale circulation effects, e.g., at the inter-
tropical convergence zone
Palabras clave: ERA*, numerical weather prediction, ocean wind forcing, oceanic mesoscale, scatterometer wind
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Portabella M., Rabaneda A.S., Grieco G. (2022)
ESA report MAXSS-ATBD-satellite-wind-recalibration_v2 (Contract No. 4000132954/20/I-NB). (BibTeX: portabella.etal.2022a)
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Portabella M., Trindade A., Grieco G., Makarova E. (2022)
ESA report WOC-ESA-ODL-NR-009_T1_ERAstar_V2.0 (Contract No. 4000130730/20/I-NB). (BibTeX: portabella.etal.2022b)
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Portabella M., Trindade A., Grieco G., Makarova E. (2022)
ESA report WOC-ESA-ODL-NR-010_T1_ERAstar_V2.0 (Contract No. 4000130730/20/I-NB). (BibTeX: portabella.etal.2022c)
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Portabella M., Rabaneda A.S., Grieco G., Polverari F., Stoffelen A., Sapp J., Jelenak Z., Chang P., Cossu F. (2022)
Proc. of the Oceans from Space 2022. Ed. Eds. V. Barale, J.F.R. Gower, L. Alberotanza, NSA Group, pp. 122-123. 121-123. (BibTeX: portabella.etal.2022d)
Resumen: Ver
Accurate high and extreme sea surface wind
observations are essential for meteorological, ocean, and
climate applications. A method to inter-calibrate
spaceborne scatterometer and radiometer derived high
and extreme winds using NOAA hurricane “hunter” data
is presented. The proposed method is effective, providing
highly consistent satellite-derived extreme wind datasets
in the period 2009-2020. Further work is needed though
to consolidate an in-situ reference for extreme wind
calibration purposes.
Palabras clave: Ocean extreme winds, scatterometers, radiometers, inter-calibration.
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Alfredsson I., Anaya-Carlsson K., Barker M., Blanquer-Espert I., Carrillo R., Carrosán-Amilburu C., Cesevičiūtė I., Clare H., Diochnou V., Dobrucky M., Dumouchel S., Fazekas-Parragh J., Filiposka S., Fillery-Travis A., Flynn K., Gaillard V., Kalaitzi V., Konijn J., Kuchma I., La Rocca G., Lazzeri E., Legat D., Maarit-Sunikka A., Manola N., Matser V., Mayor L., Petra E., Petrillo C., Piera J., Portugal-Melo A., Proficz J., Psomopoulos F., T.D. Reimer R., Smith C., Stangeland E., Stoy L., Svendsen M., Toth-Czifra E. (2021)
Ed. Michelle Barker, Natalia Manola, Vinciane Gaillard, Iryna Kuchma, Emma Lazzeri and Lennart Stoy. The EOSC Executive Board. DOI: 10.2777/59065. ISBN. 978-92-76-28948-7. (BibTeX: alfredsson.etal.2021)
Resumen: Ver
Digital skills for FAIR1 and open science are a cornerstone of the European Open Science
Cloud (EOSC)’s operations and future. An EOSC network of skilled professionals is essential
to bring a culture change for sharing research outcomes, and to empower individuals and
institutions to develop and maintain EOSC competences, skills and capabilities.
The EOSC Skills and Training Working Group (WG) was formed in 2020 to identify a
framework for building competence and capabilities for EOSC.
Álvarez-Solas J., Blasco J., Gabarró C., Montoya M., Robinson A., Tabone I. (2021)
Criosfera: el hielo polar y su papel en el clima terrestre
Observando los polos. In: EAN 9788413522999 colección Divulgación. Ed. V. Balagué, M. Vila, C. Cardelús. CSIC y Catarata. ol. 34, Chap. 9. ISBN. 978-84-1352-299-9. (BibTeX: alvarezsolas.etal.2021)
Resumen: Ver
Las zonas polares, principales responsables del clima de nuestro planeta, están sufriendo cambios drásticos en su naturaleza debido a su alta sensibilidad al cambio global, que afectan directamente a la dinámica climática, oceanográfica y ambiental de latitudes extrapolares. El presente libro pretende dar una visión integral y multidisciplinar del estado del conocimiento de las zonas árticas y antárticas: su evolución geológica, los acuciantes problemas de contaminación de estos territorios, la caracterización de los diversos ecosistemas terrestres y marinos, así como la evolución pasada y futura del clima polar. El objetivo final es explicar, de forma clara y amena, las similitudes y diferencias entre ambos polos y concienciar sobre las alteraciones que están sufriendo debido al cambio global. Asimismo, se dan a conocer las investigaciones, de gran relevancia científica y social, realizadas por el personal científico y técnico del Consejo Superior de Investigaciones Científicas (CSIC), acercándonos a la historia y situación actual de la investigación polar en España
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Dong X., Chang P.S., Stoffellen A., Portabella M., Kuma R., Linow S., Zou J., Lin W., Xu X. (2021)
Proc. of the International Geoscience and Remote Sensing Symposium (IGARSS), Brussels, Belgium (online), 12-17 July, 2021. (BibTeX: dong.etal.2021)
Resumen: Ver
Decades of ocean surface vector wind (OSVW) data
acquired from space-based radar scatterometry have been
providing short and long-term researches and applications
information about ocean surfaces. The main objective of the
project, stands and metrics of ocean surface vector wind by
space-borne microwave remote sensing, of Working Group on
Calibration and Validation of the Committee on Earth
Observation Satellites (CEOS WGCV) , is to develop the
standard and guideline for the requirement, procedure,
processing and assessment for the spaceborne radar
scatterometer measurement calibration, wind retrieval
approaches, wind data validation and assessment for OSVW,
which will be used to assure the consistency of the data quality
of these satellites and instruments are the prerequisite for
related scientific researches and applications. This synthesizes
calibration, standardized practices of retrieval approaches for
ocean surface winds, development of guidelines/standards of
validation of ocean surface winds, and identifying and
organizing collocation related data. This presentation will
provide an overview of the project and the recent progresses
Palabras clave: Scatterometry, Calibration, Metrics, Data quality.
Escayo J., Fernández J., Gabarró C., Marsal S., Navarro G., Ugalde A. (2021)
Observaciones al límite. Instrumentación para la observación en zonas polares
Observando los polos. In: EAN 9788413522999 colección Divulgación. Ed. V. Balagué, M. Vila, C. Cardelús. CSIC y Catarata. ol. 34, Chap. 11. ISBN. 978-84-1352-299-9. (BibTeX: escayo.etal.2021)
Resumen: Ver
Las zonas polares, principales responsables del clima de nuestro planeta, están sufriendo cambios drásticos en su naturaleza debido a su alta sensibilidad al cambio global, que afectan directamente a la dinámica climática, oceanográfica y ambiental de latitudes extrapolares. El presente libro pretende dar una visión integral y multidisciplinar del estado del conocimiento de las zonas árticas y antárticas: su evolución geológica, los acuciantes problemas de contaminación de estos territorios, la caracterización de los diversos ecosistemas terrestres y marinos, así como la evolución pasada y futura del clima polar. El objetivo final es explicar, de forma clara y amena, las similitudes y diferencias entre ambos polos y concienciar sobre las alteraciones que están sufriendo debido al cambio global. Asimismo, se dan a conocer las investigaciones, de gran relevancia científica y social, realizadas por el personal científico y técnico del Consejo Superior de Investigaciones Científicas (CSIC), acercándonos a la historia y situación actual de la investigación polar en España.
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García-Ladona E., Allegue J.M., Ballabrera J., Pérez F. (2021)
DOI: 10.13140/RG.2.2.30493.23525. (BibTeX: garcialadona.etal.2021)
Resumen: Ver
Este documento recoge los aspectos técnicos relativos a los formatos y sistemas de intercambio de información entre las diferentes instituciones del proyecto Corrientes Oceánicas y Seguridad en el MedioMarinO(COSMO)
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Geyer A., Giralt S., Madurell T. (2021)
Madrid: Consejo Superior de Investigaciones Científicas. 83. ISBN. 978-84-00-10859-5. (BibTeX: geyer.etal.2021)
Resumen: Ver
Pocas áreas geográficas de nuestro planeta son tan fascinantes y, a su vez, tan desconocidas como las regiones polares. Su gran interés científico reside en el importante y decisivo papel que juegan en la dinámica y el futuro de nuestro planeta, especialmente en el actual contexto de cambio global, ya que las regiones polares son los grandes y principales motores reguladores del clima de la Tierra. Los drásticos cambios que están sufriendo en respuesta al aumento de temperatura, ocasionado por el incremento en la emisión de gases de efecto invernadero como consecuencia de las actividades humanas, están afectando directamente a la dinámica climática, oceanográfica y ambiental, tanto de los propios polos como de latitudes extrapolares. Este libro de fotografías persigue mostrar la belleza de estas regiones tan remotas a la par que proporcionar una visión integral y multidisciplinar del estado del conocimiento de las zonas polares, remarcando las semejanzas y diferencias entre el Ártico y la Antártida. Especialmente, busca concienciar a las nuevas generaciones sobre la importancia y vulnerabilidad de las regiones polares. Además, pretende resaltar la necesidad de una investigación enfocada a comprender y evaluar su papel en el futuro incierto de nuestro planeta en un contexto de transformación derivada del cambio global actual.
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Grieco G., Portabella M., Stoffelen A., Vogelzang J., Verhoef A. (2021)
Proc. of the International Geoscience and Remote Sensing Symposium (IGARSS), Brussels, Belgium (online), 12-17 July, 2021. (BibTeX: grieco.etal.2021)
Resumen: Ver
This paper presents the implementation of the Land Contri-
bution Ratio (LCR) methodology for the pencil-beam scat-
terometer QuikSCAT, with the aim of improving the coastal
sampling of the retrieved winds. This methodology is pre-
sented with two different models of the Spatial Response
Function (SRF): the analytical model and the parameterized
one, which is based on a pre-computed Look-up-Table (LUT)
of SRFs provided by the Brigham Young University (BYU).
Furthermore, a method to characterize the slice σ0 noise (Kp)
is presented and compared to the noise information provided
in the full resolution QuikSCAT files. The preliminary results
show that despite the overall consistency between the two
SRF models, their discrepancies may induce LCR differences
up to few percent. Furthermore, the Kp estimated by means
of the slice Normalized Radar Cross Section (σ0) is different
from the Kp provided in the files, while such differencies are
larger for certain slices and wind conditions. Such discrepan-
cies can impact the wind field retrievals and, as such, should
be further investigated.
Palabras clave: Coastal winds, pencil-beam scatterome- ters, QuikSCAT, Land Contribution Ratio
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Grieco G., Portabella M., Vogelzang J., Verhoef A., Stoffelen A. (2021)
Associated Scientist report for the EUMETSAT OSI SAF, OSI_VS20_03. (BibTeX: grieco.etal.2021a)
Resumen: Ver
An assessment of the noise affecting the QuikSCAT Normalized Radar Cross
Sections is carried out in this study. The estimation of Kp ( ^Kp) is
compared to the median of the Kp values ( ~Kp) provided in the Level 1B Full
Resolution (L1B) file with orbit number 40651, dated 10th of April 2007,
and the main differences are discussed. A sensitivity analysis aiming at
assessing the presence of any dependencies with respect to (w.r.t.) different
wind regimes, the kind of scattering surface, the scatterometer view and the
polarization of the signal is carried out. In addition, the presence of any
biases is assessed and discussed. Finally, a theoretical distribution model
is proposed and validated against the true measurements.
The main outcomes of this study demonstrate that H-Pol measurements are
noisier than those V-Pol and that the noise lowers with increasing levels, in line with the expectations. Furthermore, ^Kp may largely differ from ~Kp, especially for the peripheral slices w.r.t. to the footprint (egg) centroid. In particular, the Kp values provided for the slices with indices 0 and 1 seem to be overestimated, while the opposite happens for those with indices 6 and 7. In addition, the ^Kp values estimated over the sea surface are lower than those estimated without making any distinctions among the scattering
surfaces. This trend is not seen for ~Kp, for which the differences are almost absent. In addition, ^Kps relating to aft acquisitions do not differ from those relating to fore ones. Furthermore, some inter slice biases up to 0.8 dB are present for H-Pol acquisitions while they are up to 0.3 dB for V-Pol ones, in both cases increasing with the relative distance between the slices, in line with the general Geophysical Model Function (GMF) sensitivity as a function of incidence angle. These biases have a non at trend w.r.t. the acquisition azimuth angle for both polarizations. These small variations may be due to the changes in wind speed and direction sample for each bin. The theoretical model proves to be effective. It can be used both for simulation studies and for checking the accuracy of the noise.
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Grieco G., Portabella M., Stoffelen A., Vogelzang J., Verhoef A. (2021)
Proc. of the International Geoscience and Remote Sensing Symposium (IGARSS), Brussels, Belgium (online), 12-17 July, 2021. (BibTeX: grieco.etal.2021)
Resumen: Ver
This paper presents the implementation of the Land Contri-
bution Ratio (LCR) methodology for the pencil-beam scat-
terometer QuikSCAT, with the aim of improving the coastal
sampling of the retrieved winds. This methodology is pre-
sented with two different models of the Spatial Response
Function (SRF): the analytical model and the parameterized
one, which is based on a pre-computed Look-up-Table (LUT)
of SRFs provided by the Brigham Young University (BYU).
Furthermore, a method to characterize the slice σ0 noise (Kp)
is presented and compared to the noise information provided
in the full resolution QuikSCAT files. The preliminary results
show that despite the overall consistency between the two
SRF models, their discrepancies may induce LCR differences
up to few percent. Furthermore, the Kp estimated by means
of the slice Normalized Radar Cross Section (σ0) is different
from the Kp provided in the files, while such differencies are
larger for certain slices and wind conditions. Such discrepan-
cies can impact the wind field retrievals and, as such, should
be further investigated.
Palabras clave: Coastal winds, pencil-beam scatterome- ters, QuikSCAT, Land Contribution Ratio
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Lin W., Portabella M., Lv S., Stoffelen A., Wang Z. (2021)
Proc. of the International Geoscience and Remote Sensing Symposium (IGARSS), Brussels, Belgium (online), 12-17 July, 2021. (BibTeX: lin.etal.2021)
Resumen: Ver
In the context of the ocean surface vector wind virtual
constellation, the combined wind products from the ongoing
operational scatterometers will unprecedentedly increase the
spatial and temporal coverage of remote sensing winds, and
ease the development of gap-free sea surface wind data of
high quality and high spatial/temporal resolution for a
variety of applications, including a better marine forecasting
and monitoring. However, systematic differences do exist in
the wind products derived from different scatterometers,
which may result in detrimental impacts in these
applications. Therefore, the difference between the retrieved
winds from C- and Ku-band scatterometers is further
explored in this paper. In particular, sea surface temperature
(SST) effects, quality control and high wind sensitivity of
both C- and Ku-band scatterometers are analyzed, with the
objective to better understand the sources of the
inconsistencies, and to provide the wind users with support
and recommendations in terms of wind applications.
Palabras clave: Scatterometer, high wind, quality control, rain, wind variability.
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Logares R., Alós J., Catalán I., Crespo-Solana A., Del Campo J., Ercilla G., Fablet R., Fernández-Guerra A., Galí-Tapias M., Gasol J.M., González A.F., Hernández-García E., López C., Massana R., Montiel L., Palmer M., Pascual S., Pascual A., Pérez F., Portabella M., Ramasco J.J., Richter D., Sallarés V., Sánchez P., Sanllehi J., Turiel A., Villaseñor A. (2021)
White Paper 13: Ocean Science Challenges for 2030. Editorial CSIC. 163-179. ISBN. 978-84-00-10762-8. (BibTeX: logares.etal.2021)
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Pablos M., Turiel A., Vall-llossera M., Camps A., Portabella M. (2021)
Proc. of the International Geoscience and Remote Sensing Symposium (IGARSS), Brussels, Belgium (online), 12-17 July, 2021. (BibTeX: pablos.etal.2021a)
Resumen: Ver
The novel Correlated Triple Collocation (CTC) analysis
allows to assess three different data sources of similar spatial
resolutions, but with two of them being correlated. In
this study, the CTC was applied to estimate the unbiased
random errors of the global soil moisture (SM) data provided
by two L-band satellite missions —the Soil Moisture and
Ocean Salinity (SMOS) and the Soil Moisture Active Passive
(SMAP)— and one numerical model —the ERA5-Land. The
three existing SMOS SM products distributed by different
research institutions were also analyzed.
Preliminary results revealed that errors of SMOS and
SMAP SM are correlated, with correlations of ∼0.5–0.6.
Thus, only ERA5-Land can be considered as independent.
The lowest error was obtained for SMAP (0.025 m3m−3),
followed by ERA5-Land (0.036 m3m−3). Among the SMOS
SM, SMOS-IC had the lowest error (0.046 m3m−3), SMOS-
BEC showed an intermediate value (0.048 m3m−3), and
SMOS-CATDS had the highest error (0.055 m3m−3).
Palabras clave: Soil moisture, triple collocation, SMOS, SMAP, ERA5-Land
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Portabella M., Lin W., Stoffelen A., Xu X., Dong X. (2021)
Proc. of the International Geoscience and Remote Sensing Symposium (IGARSS), Brussels, Belgium (online), 12-17 July, 2021. (BibTeX: portabella.etal.2021b)
Resumen: Ver
With the advent of the golden era of scatterometry, with
seven scatterometers currently operating in orbit and a few
others to be launched in the near future, a wide variety of
scientific and operational applications will certainly benefit
from consolidated wind retrieval procedures. In particular,
an important component of the scatterometer wind
processing is the quality control (QC) procedure. Over the
last two decades, several QC indicators have been
developed for C-band and Ku-band scatterometers, and used
in the operational generation of sea surface wind products.
Such indicators mostly aim at identifying and filtering
retrieved wind quality degradation due to high wind
variability and/or rain contamination effects. As such, the
different QC indicators may be applied for different
oceanographic and meteorological applications. The
methods will be presented at the conference to motivate a
discussion on their application-dependent use and come up
with a consolidated view from the different user communities
Palabras clave: Scatterometer, wind, quality control, rain, wind variability.
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Portabella M., Trindade A., Grieco G., Makarova E. (2021)
ESA report WOC-ESA-ODL-NR-010_T1_ERAstar_V1.0 (Contract No. 4000130730/20/I-NB). (BibTeX: portabella.etal.2021a)
Resumen: Ver
The present document is the Product User Manual dedicated to the content and format
description of the ERA star stress-equivalent wind vector (U10S) and wind stress product.
This is the primary document that users should read before handling the product. It provides an overview of processing algorithm, technical product content and format and main validation results.
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Portabella M., Trindade A., Grieco G., Makarova E. (2021)
ESA report WOC-ESA-ODL-NR-009_T1_ERAstar_V1.0 (Contract No. 4000130730/20/I-NB). (BibTeX: portabella.etal.2021)
Resumen: Ver
The ERA* stress-equivalent wind (U10S) and stress vector product version 1.0 is a correction of the ECMWF Fifth Reanalysis (ERA5) output by means of geo-located scatterometer-ERA5 differences over a 3-day temporal window, in which the combined sampling of the Advanced Scatterometers on board the Metop satellite series (ASCAT-A, -B, and -C) and the SCATSat-1 scatterometer (OSCAT2) have been used, for the year 2019. ERA* can correct for local, persistent NWP model output errors associated with physical processes that are absent or misrepresented by the model, e.g., strong current effects (such as WBCS, highly stationary), wind effects associated with the ocean mesoscales (SST), coastal effects (land see breezes, katabatic winds), PBL parameterization errors, and large-scale circulation effects, e.g., at the ITCZ.
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Stoffelen A., Marseille G.J., Ni W., Mouche A., Polverari F., Portabella M., Lin W., Sapp J., Chang P., Zelenak J. (2021)
Proc. of the International Geoscience and Remote Sensing Symposium (IGARSS), Brussels, Belgium (online), 12-17 July, 2021. (BibTeX: stoffelen.etal.2021)
Resumen: Ver
How strong does the wind blow in a hurricane? This proves a question that is difficult to answer, but has farreaching consequences for satellite meteorology, weather forecasting and hurricane advisories. In the EUMETSAT CHEFS project, KNMI, ICM and IFREMER worked with international colleagues to address this question to prepare for the EPS-SG SCA scatterometer, which introduces C-band cross-polarization measurements to improve the detection of hurricane-force winds. To calibrate the diverse available satellite, airplane and model winds, in-situ wind speed references are needed. Unfortunately, these prove rather inconsistent in the wind speed range of 15 to 25 m/s, casting doubt on the higher winds too. Should we trust dropsondes at high and extreme winds or perhaps put more confidence in the moored buoy references? This dilemma will be presented to initiate a discussion with the international community gathered at IGARSS ‘21
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Tintoré J., Turiel A., Bartolomé R., Ballabrera J., Casas B., Dañobeitia J., Fernández F.F., García-Ladona E., Isern-Fontanet J., López C., Mourre B., Navarro G., Orfila A., Pascual A., Pelegrí J.L., Peters F., Piera J., Portabella M., Ruiz S., Simarro G., Sorribas J., Talone M. (2021)
White Paper 13: Ocean Science Challenges for 2030. Editorial CSIC. 17-32. ISBN. 978-84-00-10762-8. (BibTeX: tintore.etal.2021)
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Xu X., Stoffelen A., Portabella M., Lin W., Dong X. (2021)
Proc. of the International Geoscience and Remote Sensing Symposium (IGARSS), Brussels, Belgium (online), 12-17 July, 2021. (BibTeX: xu.etal.2021b)
Resumen: Ver
Uncertainties in wind inversion from scatterometer
observations are contributed by system and geophysical noise.
In practice, both can be quantified by the indicators applied in
the quality control (QC) procedures during wind processing.
In this research, the underlying principles of three reported
indicators, MLE, SE and Joss, are discussed for CSCAT. In the
observation scenes of this Ku-band scatterometer, one of the
major reasons for geophysical noise are rain clouds, which are
analyzed specifically with respect to those indicators. Finally,
examples for super typhoon Lekima, followed by Krosa in
2019, are discussed. We confirm that the MLE and Joss
indicators are relatively independent from each other, and
show different features in rain screening. The combined
application of them would result in a better result of rain
labelling. Another conclusion derived from this research is
that SE and Joss are similar indicators of spatial heterogeneity
in scatterometer wind fields, but that the wind speed
depression measured by Joss is a more unique indicator of rain
than SE. This research contributes to improving the quality of
wind retrieval from scatterometers.
Palabras clave: Uncertainties, Quality indicators, Rain clouds, MLE, SE, Joss, Ku-band Scatterometer, CSCAT.
