| EUMETSAT

Quality assessment and improvement of the EUMETSAT Meteosat Surface Albedo Climate Data Record

Author(s):

Lattanzio, A.; Fell, F.; Bennartz, R.; Trigo, I. F.; Schulz, J.

Publication title: Atmospheric Measurement Techniques

2015

| Volume: 8 | Issue: 10

2015

DOI: 10.5194/amt-8-4561-2015

Abstract:

Abstract. Surface albedo has been identified as an important parameter for understanding and quantifying the Earth's radiation budget. EUMETSAT genera… Abstract. Surface albedo has been identified as an important parameter for understanding and quantifying the Earth's radiation budget. EUMETSAT generated the Meteosat Surface Albedo (MSA) Climate Data Record (CDR) currently comprising up to 24 years (1982–2006) of continuous surface albedo coverage for large areas of the Earth. This CDR has been created within the Sustained, Coordinated Processing of Environmental Satellite Data for Climate Monitoring (SCOPE-CM) framework. The long-term consistency of the MSA CDR is high and meets the Global Climate Observing System (GCOS) stability requirements for desert reference sites. The limitation in quality due to non-removed clouds by the embedded cloud screening procedure is the most relevant weakness in the retrieval process. A twofold strategy is applied to efficiently improve the cloud detection and removal. The first step consists of the application of a robust and reliable cloud mask, taking advantage of the information contained in the measurements of the infrared and visible bands. Due to the limited information available from old radiometers, some clouds can still remain undetected. A second step relies on a post-processing analysis of the albedo seasonal variation together with the usage of a background albedo map in order to detect and screen out such outliers. The usage of a reliable cloud mask has a double effect. It enhances the number of high-quality retrievals for tropical forest areas sensed under low view angles and removes the most frequently unrealistic retrievals on similar surfaces sensed under high view angles. As expected, the usage of a cloud mask has a negligible impact on desert areas where clear conditions dominate. The exploitation of the albedo seasonal variation for cloud removal has good potentialities but it needs to be carefully addressed. Nevertheless it is shown that the inclusion of cloud masking and removal strategy is a key point for the generation of the next MSA CDR release. more

Radiance Simulations in Support of Climate Services

Author(s):

Poli, P.; Roebeling, R.; John, V.O.; Doutriaux-Boucher, M.; Schulz, J.; Lattanzio, A.; Petraityte, K.; Grant, M.; Hanschmann, T.; Onderwaater, J.; Sus, O.; Huckle, R.; Coppens, D.; Theodore, B.; August, T.; Simmons, A.J.; Bell, B.; Mittaz, J.; Hall, T.; Vidot, J.; Brunel, P.; Johnson, J.E.; Zamkoff, E.B.; Al-Jazrawi, A.F.; Esfandiari, A.E.; Gerasimov, I.V.; Kobayashi, S.

Publication title: Earth and Space Science

2023

| Volume: 10 | Issue: 10

2023

DOI: 10.1029/2023EA002868

Abstract:

Climate services are largely supported by climate reanalyses and by satellite Fundamental (Climate) Data Records (F(C)DRs). This paper demonstrates ho… Climate services are largely supported by climate reanalyses and by satellite Fundamental (Climate) Data Records (F(C)DRs). This paper demonstrates how the development and the uptake of F(C)DR benefit from radiance simulations, using reanalyses and radiative transfer models. We identify three classes of applications, with examples for each application class. The first application is to validate assumptions during F(C)DR development. Hereto we show the value of applying advanced quality controls to geostationary European (Meteosat) images. We also show the value of a cloud mask to study the spatio-temporal coherence of the impact of the Mount Pinatubo volcanic eruption between Advanced Very High Resolution Radiometer (AVHRR) and the High-resolution Infrared Radiation Sounder (HIRS) data. The second application is to assess the coherence between reanalyses and observations. Hereto we show the capability of reanalyses to reconstruct spectra observed by the Spektrometer Interferometer (SI-1) flown on a Soviet satellite in 1979. We also present a first attempt to estimate the random uncertainties from this instrument. Finally, we investigate how advanced bias correction can help to improve the coherence between reanalysis and Nimbus-3 Medium-Resolution Infrared Radiometer (MRIR) in 1969. The third application is to inform F(C)DR users about particular quality aspects. We show how simulations can help to make a better-informed use of the corresponding F(C)DR, taking as examples the Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR), the Meteosat Second Generation (MSG) imager, and the Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave Water Vapor Profiler (SSM/T-2). © 2023 The Authors. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA. more

Application Atmosphere CM-SAF Climate Data Records EUM-Secr NWP-SAF

Quality Assurance Framework Development Based on Six New ECV Data Products to Enhance User Confidence for Climate Applications

Author(s):

Nightingale, Joanne; Boersma, Klaas; Muller, Jan-Peter; Compernolle, Steven; Lambert, Jean-Christopher; Blessing, Simon; Giering, Ralf; Gobron, Nadine; De Smedt, Isabelle; Coheur, Pierre; George, Maya; Schulz, Jörg; Wood, Alexander

Publication title: Remote Sensing

2018

| Volume: 10 | Issue: 8

2018

DOI: 10.3390/rs10081254

Abstract:

Data from Earth observation (EO) satellites are increasingly used to monitor the environment, understand variability and change, inform evaluations of… Data from Earth observation (EO) satellites are increasingly used to monitor the environment, understand variability and change, inform evaluations of climate model forecasts, and manage natural resources. Policymakers are progressively relying on the information derived from these datasets to make decisions on mitigating and adapting to climate change. These decisions should be evidence based, which requires confidence in derived products, as well as the reference measurements used to calibrate, validate, or inform product development. In support of the European Union’s Earth Observation Programmes Copernicus Climate Change Service (C3S), the Quality Assurance for Essential Climate Variables (QA4ECV) project fulfilled a gap in the delivery of climate quality satellite-derived datasets, by prototyping a generic system for the implementation and evaluation of quality assurance (QA) measures for satellite-derived ECV climate data record products. The project demonstrated the QA system on six new long-term, climate quality ECV data records for surface albedo, leaf area index (LAI), fraction of absorbed photosynthetically active radiation (FAPAR), nitrogen dioxide (NO2), formaldehyde (HCHO), and carbon monoxide (CO). The provision of standardised QA information provides data users with evidence-based confidence in the products and enables judgement on the fitness-for-purpose of various ECV data products and their specific applications. more

AC-SAF Application Atmosphere EUM-Secr International cooperation Land Validation

Quantifying Daytime Heating Biases in Marine Air Temperature Observations from Ships

Author(s):

Cropper, TE; Berry, DI; Cornes, RC; Kent, EC

Publication title: JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY

2023

| Volume: 40 | Issue: 4

2023

DOI: 10.1175/JTECH-D-22-0080.1

Abstract:

Marine air temperatures recorded on ships during the daytime are known to be biased warm on average due to energy storage by the superstructure of the… Marine air temperatures recorded on ships during the daytime are known to be biased warm on average due to energy storage by the superstructure of the vessels. This makes unadjusted daytime observations unsuitable for many applications including for the monitoring of long-term temperature change over the oceans. In this paper a physics -based approach is used to estimate this heating bias in ship observations from ICOADS. Under this approach, empirically determined coefficients represent the energy transfer terms of a heat budget model that quantifies the heating bias and is applied as a function of cloud cover and the relative wind speed over individual ships. The coefficients for each ship are derived from the anomalous diurnal heating relative to nighttime air temperature. Model coefficients, cloud cover, and relative wind speed are then used to estimate the heating bias ship by ship and generate nighttime-equivalent time series. A variety of methodological approaches were tested. Application of this method enables the inclusion of some daytime observations in climate records based on marine air temperatures, allowing an earlier start date and giving an increase in spatial coverage compared to existing records that exclude daytime observations.SIGNIFICANCE STATEMENT: Currently, the longest available record of air temperature over the oceans starts in 1880. We present an approach that enables observations of air temperatures over the oceans to be used in the creation of long-term climate records that are presently excluded. We do this by estimating the biases inherent in daytime tem-perature reports from ships, and adjust for these biases by implementing a numerical heat-budget model. The adjust-ment can be applied to the variety of ship types present in observational archives. The resulting adjusted temperatures can be used to create a more spatially complete record over the oceans, that extends further back in time, potentially into the late eighteenth century. more

Application Atmosphere CM-SAF Climate Data Records

Quantifying the Impact of Aerosols on Geostationary Satellite Infrared Radiance Simulations: A Study with Himawari-8 AHI

Author(s):

Sun, H.; Wang, D.; Han, W.; Yang, Y.

Publication title: Remote Sensing

2024

| Volume: 16 | Issue: 12

2024

DOI: 10.3390/rs16122226

Abstract:

Aerosols exert a significant influence on the brightness temperature observed in the thermal infrared (IR) channels, yet the specific contributions of… Aerosols exert a significant influence on the brightness temperature observed in the thermal infrared (IR) channels, yet the specific contributions of various aerosol types remain underexplored. This study integrated the Copernicus Atmosphere Monitoring Service (CAMS) atmospheric composition reanalysis data into the Radiative Transfer for TOVS (RTTOV) model to quantify the aerosol effects on brightness temperature (BT) simulations for the Advanced Himawari Imager (AHI) aboard the Himawari-8 geostationary satellite. Two distinct experiments were conducted: the aerosol-aware experiment (AER), which accounted for aerosol radiative effects, and the control experiment (CTL), in which aerosol radiative effects were omitted. The CTL experiment results reveal uniform negative bias (observation minus background (O-B)) across all six IR channels of the AHI, with a maximum deviation of approximately −1 K. Conversely, the AER experiment showed a pronounced reduction in innovation, which was especially notable in the 10.4 μm channel, where the bias decreased by 0.7 K. The study evaluated the radiative effects of eleven aerosol species, all of which demonstrated cooling effects in the AHI’s six IR channels, with dust aerosols contributing the most significantly (approximately 86%). In scenarios dominated by dust, incorporating the radiative effect of dust aerosols could correct the brightness temperature bias by up to 2 K, underscoring the substantial enhancement in the BT simulation for the 10.4 μm channel during dust events. Jacobians were calculated to further examine the RTTOV simulations’ sensitivity to aerosol presence. A clear temporal and spatial correlation between the dust concentration and BT simulation bias corroborated the critical role of the infrared channel data assimilation on geostationary satellites in capturing small-scale, rapidly developing pollution processes. © 2024 by the authors. more

Atmosphere Method NWP-SAF Software for CDR development

Radiative Effect of Two Contrail Cirrus Outbreaks Over Western Europe Estimated Using Geostationary Satellite Observations and Radiative Transfer Calculations

Author(s):

Wang, X.; Wolf, K.; Boucher, O.; Bellouin, N.

Publication title: Geophysical Research Letters

2024

| Volume: 51 | Issue: 7

2024

DOI: 10.1029/2024GL108452

Abstract:

Estimation of the perturbation to the Earth's energy budget by contrail outbreaks is required for estimating the climate impact of aviation and verify… Estimation of the perturbation to the Earth's energy budget by contrail outbreaks is required for estimating the climate impact of aviation and verifying the climate benefits of proposed contrail avoidance strategies such as aircraft rerouting. Here we identified two successive large-scale contrail outbreaks developing in clear-sky conditions in geostationary and polar-orbiting satellite infrared images of Western Europe lasting from 22–23 June 2020. Their hourly cloud radiative effect, obtained using geostationary satellite cloud retrievals and radiative transfer calculations, is negative or weakly positive during daytime and positive during nighttime. The cumulative energy forcing of the two outbreaks is 7 PJ and −8.5 PJ, with uncertainties of 3 PJ, stemming each from approximately 15–20 flights over periods of 19 and 7 hr, respectively. This study suggests that an automated quantification of contrail outbreak radiative effect is possible, at least for contrails forming in clear sky conditions. © 2024. The Authors. more

Application Atmosphere Climate Data Records EUM-Secr

Radiometric Calibration of the Advanced Wind Scatterometer Radar ASCAT Carried Onboard the METOP-A Satellite

Author(s):

Wilson, J J W; Anderson, C; Baker, M A; Bonekamp, H; Saldaña, J Figa; Dyer, R G; Lerch, J A; Kayal, G; Gelsthorpe, R V; Brown, M A; Schied, E; Schutz-Munz, S; Rostan, F; Pritchard, E W; Wright, N G; King, D; Onel, Ü

Publication title: IEEE Transactions on Geoscience and Remote Sensing

2010

| Volume: 48 | Issue: 8

2010

DOI: 10.1109/TGRS.2010.2045763

Abstract:

The Advanced Wind Scatterometer (ASCAT) is a six-beam spaceborne radar instrument designed to measure wind fields over the oceans. An ASCAT instrument… The Advanced Wind Scatterometer (ASCAT) is a six-beam spaceborne radar instrument designed to measure wind fields over the oceans. An ASCAT instrument is carried by each of the three METOP satellites. The ASCAT calibration strategy is described and detailed results are presented concerning the radiometric calibration achieved. more

Climate Data Records EUM-Secr Validation

Random forest regression for improved mapping of solar irradiance at high latitudes

Author(s):

Babar, B.; Luppino, L.T.; Boström, T.; Anfinsen, S.N.

Publication title: Solar Energy

2020

| Volume: 198

2020

DOI: 10.1016/j.solener.2020.01.034

Abstract:

Datasets from meteorological reanalyses and retrievals from satellites are the available sources of large-scale information about solar radiation. How… Datasets from meteorological reanalyses and retrievals from satellites are the available sources of large-scale information about solar radiation. However, both the reanalyses and the satellite-based estimates can be severely biased, especially in high latitude regions. In this study, surface solar irradiance estimates from the ECMWF Reanalysis 5 (ERA5) and the Cloud, Albedo, Radiation dataset Edition 2 (CLARA-A2) were used as input to a random forest regression (RFR) model to construct a novel dataset with higher accuracy and precision than the input datasets. For daily averages of global horizontal irradiance (GHI) at Norwegian sites, CLARA-A2 and ERA5 respectively produced a root mean squared deviation (RMSD) of 17.9 Wm−2 and 27.1 Wm−2, a mean absolute deviation (MAD) of 11.9 Wm−2 and 17.5 Wm−2, and a bias of −1.5 Wm−2 and 4.3 Wm−2. In contrast, the proposed regression model provided an RMSD of 16.2 Wm−2, an MAD of 10.8 Wm−2, and a bias of 0.0 Wm−2. This shows that the RFR model is both accurate and precise, and significantly reduces both dispersion and bias in the new dataset with respect to the constituent sources. A sky-stratification analysis was performed and it was found that the proposed model provides better estimates under all sky conditions with particular improvements in intermediate-cloudy conditions. The proposed regression model was also tested on five Swedish locations and it was found to improve surface solar irradiance estimates to a similar degree as for the Norwegian locations, thus proving its consistency under similar climatic conditions. © 2020 International Solar Energy Society more

Application Atmosphere CM-SAF Climate Data Records

Rapid fCO2 rise in the northern Barents Sea and Nansen Basin

Author(s):

Ericson, Y.; Fransson, A.; Chierici, M.; Jones, E.M.; Skjelvan, I.; Omar, A.; Olsen, A.; Becker, M.

Publication title: Progress in Oceanography

2023

| Volume: 217

2023

DOI: 10.1016/j.pocean.2023.103079

Abstract:

Maps of surface water fugacity of CO2 (fCO2) over eastern Fram Strait, south-western Nansen Basin, and the north-western Barents Sea (73–84°N, 5–46°E)… Maps of surface water fugacity of CO2 (fCO2) over eastern Fram Strait, south-western Nansen Basin, and the north-western Barents Sea (73–84°N, 5–46°E) from September 1997 to December 2020 were made and used to investigate seasonal and temporal trends. The mapping utilized a neural network technique, the self-organizing map (SOM), that was trained with different combinations of satellite/observational/model data of sea surface temperature (SST), sea surface salinity (SSS), mixed layer depth (MLD), chlorophyll a (Chl a), sea ice concentration, and atmospheric mole fraction of CO2 (xCO2). The trained SOM was labelled with available surface ocean fCO2 data, and the labelled SOM was subsequently used to map the fCO2. The produced maps reveal that fCO2 in northern Barents Sea, at the border of the Nansen Basin, has increased significantly over the last decades by between 4.2 and 5.5 ± 0.6–1.1 µatm yr−1 over the winter to summer seasons. These rates are twice the rate of atmospheric CO2 increase, which was about 2 µatm yr−1. The spatial pattern coincides with the strongest decreases in sea ice concentration as well as with a salinification of the surface water. The former allows for a prolongation of the air-sea CO2 flux with resultant oceanic CO2 uptake in previously ice-covered waters, and the latter is caused by a shift from Arctic Water dominance to more saline waters containing more dissolved inorganic carbon, most likely of Atlantic Water origin although brine-release influenced deep water may also contribute. © 2023 The Authors more

Application Climate Data Records Cryosphere OSI-SAF Ocean

Recent Advances in Satellite Data Rescue

Author(s):

Poli, Paul; Dee, Dick P.; Saunders, Roger; John, Viju O.; Rayer, Peter; Schulz, Jörg; Holmlund, Kenneth; Coppens, Dorothee; Klaes, Dieter; Johnson, James E.; Esfandiari, Asghar E.; Gerasimov, Irina V.; Zamkoff, Emily B.; Al-Jazrawi, Atheer F.; Santek, David; Albani, Mirko; Brunel, Pascal; Fennig, Karsten; Schröder, Marc; Kobayashi, Shinya; Oertel, Dieter; Döhler, Wolfgang; Spänkuch, Dietrich; Bojinski, Stephan

Publication title: Bulletin of the American Meteorological Society

2017

| Volume: 98 | Issue: 7

2017

DOI: 10.1175/BAMS-D-15-00194.1

Abstract:

Abstract To better understand the impacts of climate change, environmental monitoring capabilities must be enhanced by deploying additional and more a… Abstract To better understand the impacts of climate change, environmental monitoring capabilities must be enhanced by deploying additional and more accurate satellite- and ground-based (including in situ) sensors. In addition, reanalysis of observations collected decades ago but long forgotten can unlock precious information about the recent past. Historical, in situ observations mainly cover densely inhabited areas and frequently traveled routes. In contrast, large selections of early meteorological satellite data, waiting to be exploited today, provide information about remote areas unavailable from any other source. When initially collected, these satellite data posed great challenges to transmission and archiving facilities. As a result, data access was limited to the main teams of scientific investigators associated with the instruments. As archive media have aged, so have the mission scientists and other pioneers of satellite meteorology, who sometimes retired in possession of unique and unpublished information. This paper presents examples of recently recovered satellite data records, including satellite imagery, early infrared hyperspectral soundings, and early microwave humidity soundings. Their value for climate applications today can be realized using methods and techniques that were not yet available when the data were first collected, including efficient and accurate observation simulators and data assimilation into reanalyses. Modern technical infrastructure allows serving entire mission datasets online, enabling easy access and exploration by a broad range of users, including new and old generations of climate scientists. more

EUM-Secr International cooperation Method

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