N. Clerbaux

N. Clerbaux
Royal Meteorological Institute of Belgium · Observations

About

90
Publications
16,158
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1,421
Citations
Citations since 2017
17 Research Items
646 Citations
2017201820192020202120222023020406080100120
2017201820192020202120222023020406080100120
2017201820192020202120222023020406080100120
2017201820192020202120222023020406080100120

Publications

Publications (90)
Article
Full-text available
The records of the Advanced Very High Resolution Radiometer (AVHRR) instrument observations can resolve the current lack of a long global climate data record of Reflected Solar Flux (RSF), by transforming these measurements into broadband flux at the top-of-atmosphere. This paper presents a methodology for obtaining daily mean RSF (Wm−2) from AVHRR...
Article
Full-text available
Geostationary observations offer the unique opportunity to resolve the diurnal cycle of the Earth's Radiation Budget at the top of the atmosphere (TOA), crucial for climate-change studies. However, a drawback of the continuous temporal coverage of the geostationary orbit is the fixed viewing geometry. As a consequence, imperfections in the angular...
Preprint
Full-text available
Geostationary observations offer the unique opportunity to resolve the diurnal cycle of the Earth's Radiation Budget at the top of the atmosphere (TOA), crucial for climate-change studies. However, a drawback of the continuous temporal coverage of the geostationary orbit is the fixed viewing geometry. As a consequence, imperfections in the angular...
Article
Full-text available
Clouds interact with atmospheric radiation and substantially modify the Earth's energy budget. Cloud formation processes occur over a vast range of spatial and temporal scales, which make their thorough numerical representation challenging. Therefore, the impact of parameter choices for simulations of cloud‐radiative effects is assessed in the curr...
Article
Full-text available
Data from the Advanced Very High Resolution Radiometer (AVHRR) have been used to create several long-duration data records of geophysical variables describing the atmosphere and land and water surfaces. In the Climate Monitoring Satellite Application Facility (CM SAF) project, AVHRR data are used to derive the Cloud, Albedo, and Radiation (CLARA) c...
Article
Full-text available
The current lack of a long, 30+ year, global climate data record of reflected shortwave top-of-atmosphere (TOA) radiation could be tackled by relying on existing narrowband records from the Advanced Very High Resolution Radiometer (AVHRR) instruments, and transform these measurements into broadband quantities like provided by the Clouds and the Ear...
Article
Full-text available
Decadal changes of the Reflected Solar Radiation (RSR) as measured by CERES from 2000 to 2018 are analysed. For both polar regions, changes of the clear-sky RSR correlate well with changes of the Sea Ice Extent. In the Arctic, sea ice is clearly melting, and as a result the earth is becoming darker under clear-sky conditions. However, the correlati...
Article
Full-text available
The Earth Radiation Budget (ERB) at the top of the atmosphere quantifies how the earth gains energy from the sun and loses energy to space. Its monitoring is of fundamental importance for understanding ongoing climate change. In this paper, decadal changes of the Outgoing Longwave Radiation (OLR) as measured by the Clouds and Earth’s Radiant Energy...
Article
Full-text available
Solar radiation is the main driver of the Earth's climate. Measuring solar radiation and analysing its interaction with clouds are essential for the understanding of the climate system. The EUMETSAT Satellite Application Facility on Climate Monitoring (CM SAF) generates satellite-based, high-quality climate data records, with a focus on the energy...
Conference Paper
Full-text available
The first Geostationary Earth Radiation Budget (GERB) instrument was launched during summer 2002 together with the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) on board the Meteosat-8 satellite. This broadband radiometer aims to deliver near real-time estimates of solar and thermal radiative fluxes at the top of the atmosphere (TOA) with...
Article
Full-text available
The Earth Radiation Budget at the top of the atmosphere quantifies how the Earth gains energy from the Sun and loses energy to space. It is of fundamental importance for climate and climate change. In this paper, the current state-of-the-art of the satellite measurements of the Earth Radiation Budget is reviewed. Combining all available measurement...
Article
Geostationary images have been used frequently in the past 50 years to derive geophysical information. As a complement to all-sky observations, clear-sky counterparts play an important role in the derivation of cloud properties. We investigated ways to improve estimates of top-of-atmosphere (TOA) visible clear-sky images, over the full spatial and...
Article
Full-text available
The CM SAF Top of Atmosphere (TOA) Radiation MVIRI/SEVIRI Data Record provides a homogenised satellite-based climatology of TOA Reflected Solar (TRS) and Emitted Thermal (TET) radiation in all-sky conditions over the Meteosat field of view. The continuous monitoring of these two components of the Earth Radiation Budget is of prime importance to stu...
Article
Full-text available
This study examines the evolution of the GERB-2 and GERB-1 Edition 1 shortwave radiance calibration between 2004–2007 and 2007–2012 respectively, through comparison with CERES instrument FM1 Edition 3A SSF instantaneous radiances. Two periods when simultaneous observations from both GERB-2 and GERB-1 were available, January 13th to February 11th 20...
Conference Paper
Full-text available
Within CM SAF, datasets of Top-Of-Atmosphere (TOA) radiation products from the Geostationary Earth Radiation Budget (GERB) instruments on the Meteosat Second Generation (MSG) satellites have been released in 2013. Since no GERB instrument was available on the Meteosat First Generation (MFG) satellites, only the period 2004-2011 is covered. As an al...
Conference Paper
Full-text available
Land surface heat and water vapour fluxes are key elements in our climate system: they materialize the feedback the land gives in return to atmosphere. In order to better apprehend the changes of this feedback over the years, a long record of data is necessary. The exploitation of the observations from EUMETSAT METEOSAT suite of satellites could be...
Article
Full-text available
The collective representation within global models of aerosol, cloud, precipitation, and their radiative properties remains unsatisfactory. They constitute the largest source of uncertainty in predictions of climatic change and hamper the ability of numerical weather prediction models to forecast high-impact weather events. The joint European Space...
Article
Full-text available
The Meteosat satellites have been operational since the early eighties, creating so far a continuous time period of observations of more than 30 years. In order to use this data for climate data records, a consistent calibration is necessary between the consecutive instruments. Studies have shown that the Meteosat First Generation (MFG) satellites...
Article
Since the early 1980s, the geostationary Meteosat instruments have been observing the earth at a high temporal and spatial resolution. The data record contains more than 30 years of observations and has become very useful for climate monitoring. With a compilation of 10 satellites, it is crucial to reach the highest possible consistency between the...
Article
Full-text available
This study reports on the exploitation of GNSS for weather forecasts, especially for nowcasting. We focus on GPS observations (post-processing with a time resolution of 15 min) and try to establish typical configurations of the humidity field which characterise convective systems and particularly which supply forerunners of their initiation associa...
Conference Paper
Since 2004, accurate top-of-the-atmosphere (TOA) broadband reflected solar and emitted thermal fluxes are available from the Geostationary Earth Radiation Budget (GERB) instruments on board the Meteosat Second Generation satellites. In the EUMETSAT Climate Monitoring SAF, those data are used to estimate monthly and daily mean TOA radiation products...
Conference Paper
Full-text available
The Earth Radiation Budget (ERB) and its geographical distribution is intimately linked with the earth’s climate and with the general circulation. We analyze 10 years of global Clouds and the Earth’s Radiant Energy System (CERES) measurements from 2000 to 2010 and 8 years of diurnally resolved Geostationary Earth Radiation Budget (GERB) from 2004 t...
Article
Full-text available
For more than 30 years, the Meteosat satellites have been in a geostationary orbit around the earth. Because of the high temporal frequency of the data and the long time period, this database is an excellent candidate for fundamental climate data records (FCDRs). One of the prerequisites to create FCDRs is an accurate and stable calibration over th...
Article
Full-text available
Precipitation is the main variable of the water cycle and a driving factor of the water resources availability. However, direct precipitation measurements are still too scarce to quantify the ongoing changes and to provide data for numerical models validation. Recently, Roebeling & Holleman (2009) have presented the Cloud Physical Properties (CPP)...
Article
Full-text available
This study reports on the exploitation of GNSS for weather forecasts, especially for nowcasting. We focus on GPS observations (post-processing with a time resolution of 15 min) and try to establish typical configurations of the humidity field which characterise convective systems and particularly which supply forerunners of their initiation associa...
Article
Full-text available
This study compared the Regional Atmospheric Climate Model version 2 (RACMO) with satellite data by simultaneously looking at cloud properties and top-of-atmosphere (TOA) fluxes. This study used cloud properties retrieved from Spinning Enhanced Visible and Infrared Imager (SEVIRI) data and TOA shortwave and longwave outgoing radiative fluxes measur...
Article
This paper describes the results obtained using Artificial Neural Networks (AAN) models to estimate the diurnal cycle of net radiation (Rn) at surface. The data used as input parameter in the AAN model were that measured by Geostationary Earth Radiation Budget (GERB-1) instrument, on board Meteosat 9 satellite. The data concerning Rn at the surface...
Article
Whenever possible, intercomparisons of Earth radiation budget data from different spaceborne instruments should be made as they are important steps in the overall validation process. Intercomparisons are also key elements to compile long-term climate datasets by merging data from several instruments. In this study the GERB Edition-1 and CERES Editi...
Article
The Geostationary Earth Radiation Budget (GERB) instrument is the first to measure the earth radiation budget from a geostationary orbit. This allows a full sampling of the diurnal cycle of radiation and clouds – which is important for climate studies, as well as detailed process studies, e.g. the lifecycle of clouds or particular aerosol events su...
Article
Because space-borne radiometers do not measure the Earth’s outgoing fluxes directly, angular distribution models (ADMs) are required to relate actual radiance measurement to flux at given solar angle, satellite-viewing geometries, surface, and atmospheric conditions. The conversion of one footprint broad-band radiance into the corresponding flux re...
Article
The method used to estimate the unfiltered longwave broadband radiance from the filtered radiances measured by the Geostationary Earth Radiation Budget (GERB) instrument is presented. This unfiltering method is used to generate the first released edition of the GERB-2 dataset. This method involves a set of regressions between the unfiltering factor...
Article
Comparisons between reflected shortwave (SW) fluxes at the top of atmosphere (TOA) from the Geostationary Earth Radiation Budget (GERB) and from the Clouds and the Earth's Radiant Energy System (CERES) broadband radiometers highlight systematic anomalies in the GERB SW flux over the Sahel region. Because radiometers do not measure the Earth's outgo...
Article
The aim of the Climate Monitoring SAF (CMSAF) is to provide the scientific community with a set of data derived from satellites to study and monitor the climate. Within the framework of the CMSAF, the Royal Meteorological Institue of Belgium (RMIB) is in charge of the development and the processing of the Top of the Atmosphere (TOA) products. These...
Article
The first Geostationary Earth Radiation Budget (GERB) instrument was launched during the summer 2002 together with the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) on board of the Meteosat-8 satellite. This broadband radiometer aims to deliver near real-time estimates of the top of the atmosphere (TOA) solar and thermal radiative fluxes a...
Article
The first Geostationary Earth Radiation Budget (GERB) instrument was launched during the 2002 summer together with the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) on board of the Meteosat-8 satellite. This broadband radiometer aims to deliver near real-time estimates of the top of the atmosphere solar and thermal radiative fluxes at high...
Article
The first Geostationary Earth Radiation Budget (GERB) instrument was launched during the 2002 summer together with the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) on board of the Meteosat-8 satellite. This broadband radiometer aims to deliver near real-time estimates of the top of the atmosphere solar and thermal radiative fluxes at high...
Article
The synergy between the Geostationary Earth Radiation Budget (GERB) broadband radiometer and the Spinning Enhanced Visible and Infra Red Imager (SEVIRI) on board the European meteorological satellite Meteosat-8 is exploited to estimate the diurnal variation of the direct short wave aerosols radiative forcing (DSWARF) from biomass burning over Afric...
Article
Full-text available
The launch of the Geostationary Earth Radiation Budget (GERB) instrument onboard the Meteostat 8 allows a diurnal sampling of the Earth's Radiation Budget for the first time, providing a unique and important addition to polar-orbiting measurements. However, preliminary data from the GERB instrument exhibit systematic asymmetry in the short-wave (SW...
Article
Full-text available
Because radiometers do not measure the Earth's outgoing fluxes directly, angular distribution models (ADMs) are used to invert measured radiances at the top of atmosphere (TOA) to fluxes. In this study, we have investigated if the use of the newly developed clear ocean Clouds and the Earth's Radiant Energy System (CERES) broadband short wave (SW) A...
Article
Full-text available
The paper presents the longwave radiance–to–flux conversion which has been developped, imple-mented and is currently applied to produce the GERB Edition-1 data. The method is based on regres-sions on the SEVIRI thermal channels. Some results of the validations of this part of the processing are presented which indicate an underestimation of the lim...
Article
Full-text available
The Geostationary Earth Radiation Budget (GERB) instrument on METEOSAT-8 is making the first measurements of the Earth's radiation budget from geostationary orbit. The first validated GERB Edition 1 products were released to the scientific community via the ggsps archive (http://ggsps.rl.ac.uk) earlier this year. This paper summaries the calibratio...
Article
Full-text available
This paper reports on a new satellite sensor, the Geostationary Earth Radiation Budget (GERB) experiment. GERB is designed to make the first measurements of the Earth's radiation budget from geostationary orbit. Measurements at high absolute accuracy of the reflected sunlight from the Earth, and the thermal radiation emitted by the Earth are made e...
Article
Full-text available
Measurements of the top‐of‐the‐atmosphere outgoing longwave radiation (OLR) for July 2003 from Meteosat‐7 are used to assess the performance of the numerical weather prediction version of the Met Office Unified Model. A significant difference is found over desert regions of northern Africa where the model emits too much OLR by up to 35 Wm−2 in the...
Article
Full-text available
Because radiometers do not measure the earth's outgoing flux directly, angular distribution models (ADMs) are used to invert measured radiances at the top of atmosphere (TOA) to flux. However, data used to build ADMs are generally not sorted for mixed scene types, and anisotropic correction factors for such scenes are not usually available. In the...
Article
Full-text available
The possibility to estimate the broadband shortwave and longwave radiances from the narrowband measurements of the SEVIRI instrument is investigated. For this, a data base of corresponding SEVIRI and CERES broadband observations has been collected. The data base is then used to derive the narrowband-to-broadband regressions as well as to validate t...
Article
Full-text available
We present the initial operation phase (IOP) of the CM-SAF Top Of the Atmosphere (TOA) flux products. Within the framework of the CM-SAF, the RMIB compute the Total Incoming Solar (TIS) fluxes, the Total Emitted Thermal (TET) fluxes and the Total Re- flected Solar (TRS) fluxes at the TOA. The products are delivered on a equal-area sinusoidal grid a...
Article
The Geostationary Earth Radiation Budget (GERB) instrument was launched during the 2002 summer together with the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) on board of the Meteosat Second Generation (MSG) satellite. This broadband radiometer will aim to deliver near real-time estimates of the top of the atmosphere (TOA) radiative fluxes...
Article
Full-text available
On 29th January 2004 the first Meteosat Second Generation satellite MSG-1, renamed to Meteosat-8 (MS-8), commenced routine operations. MS-8 carries the new Spinning Enhanced Visible and Infra Red Imager (SEVIRI) and a Geostationary Earth Radiation Budget (GERB) radiometer. GERB provides valuable short-and long wave broadband measurements of the Ear...
Article
Full-text available
An advanced operational algorithm has been developed for the routine calibration of the Meteosat radiometer solar channel. The calibration method relies on calculated radiances over bright desert sites whereas ocean targets are used for consistency checks. Calibration errors are estimated accounting for the uncertainties of both the sensor spectral...
Article
The Geostationary Earth Radiation Budget (GERB) instrument aboard the Meteosat Second Generation Satellite has 256 channels which measure total radiance and 256 channels which measure solar radiation reflected from the Earth. In order to validate the calibration of these channels, the Clouds and Earth Radiant Energy System (CERES) instrument aboard...
Article
This second part of the paper presents the first results obtained with actual SEVIRI data in the RMIB GERB Processing (RGP) system. At this time, the calibration of the SEVIRI instrument seems su#ciently accurate and the di#erent processings realized on this data seems to perform correctly.
Article
The first Meteosat Second Generation (MSG) satellite was launched in August 2002. This EUMETSAT satellite carries 2 new instruments on the geostationary orbit: the Spinning Enhanced Visible and InfraRed Imager, SEVIRI, and the Geostationary Earth Radiation Budget, GERB. The unique feature of GERB in comparison with previous measurement missions of...
Article
Full-text available
A new method to estimate composite top of the atmosphere (TOA) visible clear-sky reflectances for wide narrow band geostationary satellites such as the Meteosat constellation is presented. This method relies on some a priori knowledge of angular variations of TOA broadband reflectances associated with clear-sky conditions above mean surface types t...
Article
On 27th October 2002, after 15 months of small activity, the Mount Etna located on the island of Sicily, Italy (37.73°N, 15.00°E) erupted undergoing one of its most vigorous eruptions in years. During a few days, Europe's highest and most active volcano hurled lava and spewed significant amounts of ash and trace gases into the atmosphere. The smoke...
Article
The analysis of one year of Cloud and the Earth's Radiant Energy System (CERES) data from the Earth Observation System (EOS)-Terra satellite provides evidence that the longwave radiation escaping from the atmosphere exhibits significant variability according to the azimuthal angle of observation. A regional analysis of this variability shows that t...
Article
A radiance-to-flux conversion is needed to estimate radiative fluxes at the top of the atmosphere from directional measurements made by broadband (BB) radiometers on satellites. Such a conversion is known to be one of the major sources of error in the resulting instantaneous shortwave and longwave fluxes. This paper analyzes the possibility to impr...
Conference Paper
In this paper the system employed at the Royal Meteorological Institute of Belgium (RMIB) within the Climate Monitoring Satellite Application Facility (CM-SAF) for the production of Top Of the Atmosphere (TOA) radiation budget components is described. One of the goals of the CM-SAF is to provide consistent TOA and surface radiation budget component...
Article
The Geostationary Earth Radiation Budget (GERB) instrument has been launched this summer together with the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) on board of the Meteosat Second Generation (MSG) satellite. This broadband radiometer will aim to deliver near real–time estimates of the top of the atmosphere (TOA) radiative fluxes at th...
Article
Land surface albedo represents the proportion of the incoming radiative flux reflected by the surface. It is highly variable in space and time over terrestrial surfaces and plays a key role in surface-atmosphere interaction processes. In particular, it is used in numerical weather forecast and climate models to parametrize surface boundary radiativ...
Article
On 27th October 2002, after 15 months of small activity the Mount Etna located on the island of Sicily, Italy, (37o73^'N,15o00^'E) erupted undergoing one of its most vigorous eruptions in years. During few days running, the Europe's highest and most active volcano hurled lava and spewed significant amounts of ash and trace gases into the atmos...
Article
In this paper, we present a direct method, i.e. non-iterative, to retrieve cloud optical depth and cloud fraction on footprints made of several imager pixels. This method is based on an efficient parameterization of theoretical radiances computed by the SBDART radiative transfer code. We then compare the retrieval of both features on the same targe...
Article
Full-text available
MSG-1 (Meteosat Second Generation) satellite is planned to be launched in summer 2002. MSG will carry a new radiometer the Spinning Enhanced Visible and Infra Red Imager (SEVIRI) and a Geostationary Earth Radiation Budget (GERB) instrument. The GERB will provide accurate SW and LW spectral broadband measurements of the Earth in order to estimate th...
Article
The first Meteosat Second Generation (MSG) satellite is planned to be launched in summer 2002. This EUMETSAT's satellite will carry 2 new instruments on a geo- stationary orbit: the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) and the Geostationary Earth Radiation Budget (GERB). The unique feature of GERB in comparison with previous measu...