Status of GFZ's GRACE/GRACE-FO RL06 Level-2 and Level-3 Data Products

2020 ◽  
Author(s):  
Christoph Dahle ◽  
Michael Murböck ◽  
Frank Flechtner ◽  
Rolf König ◽  
Henryk Dobslaw ◽  
...  
Keyword(s):  
Information Service ◽  
Gravity Potential ◽  
Research Centre ◽  
Science Data ◽  
Data Products ◽  
Terrestrial Water ◽  
Level 3 ◽  
User Friendly ◽  
Grace Mission ◽  
Level 2

<p>The GRACE Follow-On (GRACE-FO) mission was successfully launched on May 22<sup>nd</sup>, 2018 and continues the 15-year data record of monthly global mass changes from the GRACE mission (2002-2017). The German Research Centre for Geosciences (GFZ) as part of the GRACE/GRACE-FO Science Data System (SDS) has recently reprocessed the complete GRACE mission data (RL06 in the SDS nomenclature). These RL06 processing standards serve as common baseline for the continuation with GRACE-FO data.</p><p>This presentation provides an overview of the current processing status and the validation of the GFZ GRACE/GRACE-FO RL06 gravity field products. Besides its Level-2 products (monthly sets of spherical harmonic coefficients representing the Earth's gravity potential), GFZ additionally generates user-friendly Level-3 products in collaboration with the Alfred-Wegener-Institut (AWI) and TU Dresden. These Level-3 data products comprise dedicated mass anomaly products of terrestrial water storage over non-glaciated regions, bottom pressure variations in the oceans and ice mass changes in Antarctica and Greenland, available via GFZ's Gravity Information Service (GravIS) portal (http://gravis.gfz-potsdam.de/).</p>

The GravIS Portal: User-friendly Global Mass Variations from GRACE and GRACE-FO

2021 ◽  
Author(s):  
Christoph Dahle ◽  
Eva Boergens ◽  
Henryk Dobslaw ◽  
Andreas Groh ◽  
Ingo Sasgen ◽  
...  
Keyword(s):  
Time Series ◽  
Information Service ◽  
Research Centre ◽  
Data Sets ◽  
Ocean Bottom ◽  
Climatic Regions ◽  
Uncertainty Estimates ◽  
Terrestrial Water ◽  
User Friendly ◽  
Global Mean

<p>The German Research Centre for Geosciences (GFZ) maintains the “Gravity Information Service” (GravIS, gravis.gfz-potsdam.de) portal in collaboration with the Alfred-Wegener-Institute (AWI) and Technische Universität Dresden. Main objective of this portal is the dissemination of data describing mass variations in the Earth system based on observations of the satellite gravimetry missions GRACE and GRACE-FO.</p><p>The provided data sets encompass products of terrestrial water storage (TWS) variations over the continents, ocean bottom pressure (OBP) variations from which global mean barystatic sea-level rise can be estimated, and mass changes of the ice sheets in Greenland and Antarctica. All data sets are provided as time series of regular grids for each area, as well as in the form of regional basin averages. Regarding the latter, for the continental TWS data the user can choose between classical river basins and a novel segmentation based on climatic regions. For the oceans, the segmentation into different regions is derived similarly but based on modelled OBP data. All time series are accompanied by realistic uncertainty estimates.</p><p>All data sets can be interactively displayed at the portal and are freely available for download. This contribution aims to show the features and possibilities of the GravIS portal to researchers without a dedicated geodetic background, working in the fields of hydrology, oceanography, and cryosphere.</p>

SDS Level-2/-3 GFZ

2020 ◽  
Author(s):  
Christoph Dahle
Keyword(s):  
Data System ◽  
Current Status ◽  
Science Data ◽  
Level 3 ◽  
Level 2

<p>This presentation will give an overview of GFZ's activities within the GRACE-FO Science Data System (SDS) including the current status of Level-2 and Level-3 products.</p>

Study of the accuracy of monthly time-variable satellites gravity field estimates

2021 ◽  
Author(s):  
Hugo Lecomte ◽  
Severine Rosat ◽  
Mioara Mandea
Keyword(s):  
Gravity Field ◽  
Large Scale ◽  
Gravity Data ◽  
European Space Agency ◽  
Field Measurements ◽  
Time Variable ◽  
Research Centre ◽  
Data Products ◽  
Level 2

<p>The GRACE and GRACE Follow-On (GRACE-FO) missions have been providing monthly time-variable gravity field estimates since 2002 with a one-year gap between 2017 and 2018. The Level 2 data products are available through several processing centers with independent computation strategies. The Center of Space Research (CSR), the German Research Centre for Geosciences (GFZ) and the Jet Propulsion Laboratory (JPL) as part of the GRACE/GRACE-FO Science Data System (SDS) process gravity data with RL06 standards. The French National Centre for Space Studies (CNES) and the Graz University of Technology delivered GRACE gravity fields models respectively named <em>CNES/GRGS RL05</em> and <em>ITSG-GRACE2018</em>. Besides GRACE data, the European Space Agency (ESA) delivers Level 2 data products for the Swarm mission. Swarm data enables the evaluation of gap-filling methods between the GRACE and GRACE-FO missions. These datasets are very valuable inputs in studying the Earth's deep interior and could open new windows into the study of core-mantle boundary processes and core dynamics.</p><p> </p><p>Earth's core dynamical processes inferred from geomagnetic field measurements are characterized by large-scale patterns. Studying them via gravity field observations involves the use of spherical harmonic coefficients up to degree and order 10. Particular attention needs to be dedicated to Stokes coefficients that are affected by problematic reconstruction effects such as C<sub>2,0</sub> or C<sub>3,0</sub>. The comparison of time-series from various processing centers with Satellite-Laser Ranging (SLR) gravity products and hydrological loading models provides information on the consistency between different solutions and the accuracy of space gravity field measurements. The correction of hydrological and glacial isostatic adjustment (GIA) effects is an additional source of error in the determination of the gravity field. For example, the actual uncertainty of the GIA model over North America might lead to an error of 10% for some Stokes coefficients. Mismodelling in the seasonal loading could also affect the retrieved Stokes coefficients.</p><p> </p><p>This study firstly provides a comparison of existing gravity field solutions and their accuracy. Secondly, a detailed analysis of different error sources provides us with better estimates of the current limits in the determination of elusive signals coming from the deep Earth's interior. It also offers the possibility to better describe the external sources and then to minimize their contribution to the signal we are interested in.</p>

scholarly journals Ensemble-based satellite-derived carbon dioxide and methane column-averaged dry-air mole fraction data sets (2003–2018) for carbon and climate applications

2020 ◽  
Vol 13 (2) ◽  
pp. 789-819 ◽  
Author(s):  
Maximilian Reuter ◽  
Michael Buchwitz ◽  
Oliver Schneising ◽  
Stefan Noël ◽  
Heinrich Bovensmann ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Data Sets ◽  
Climate Data ◽  
Single Observation ◽  
Dry Air ◽  
Data Products ◽  
Level 3 ◽  
Global Bias ◽  
Level 2

Abstract. Satellite retrievals of column-averaged dry-air mole fractions of carbon dioxide (CO2) and methane (CH4), denoted XCO2 and XCH4, respectively, have been used in recent years to obtain information on natural and anthropogenic sources and sinks and for other applications such as comparisons with climate models. Here we present new data sets based on merging several individual satellite data products in order to generate consistent long-term climate data records (CDRs) of these two Essential Climate Variables (ECVs). These ECV CDRs, which cover the time period 2003–2018, have been generated using an ensemble of data products from the satellite sensors SCIAMACHY/ENVISAT and TANSO-FTS/GOSAT and (for XCO2) for the first time also including data from the Orbiting Carbon Observatory 2 (OCO-2) satellite. Two types of products have been generated: (i) Level 2 (L2) products generated with the latest version of the ensemble median algorithm (EMMA) and (ii) Level 3 (L3) products obtained by gridding the corresponding L2 EMMA products to obtain a monthly 5∘×5∘ data product in Obs4MIPs (Observations for Model Intercomparisons Project) format. The L2 products consist of daily NetCDF (Network Common Data Form) files, which contain in addition to the main parameters, i.e., XCO2 or XCH4, corresponding uncertainty estimates for random and potential systematic uncertainties and the averaging kernel for each single (quality-filtered) satellite observation. We describe the algorithms used to generate these data products and present quality assessment results based on comparisons with Total Carbon Column Observing Network (TCCON) ground-based retrievals. We found that the XCO2 Level 2 data set at the TCCON validation sites can be characterized by the following figures of merit (the corresponding values for the Level 3 product are listed in brackets) – single-observation random error (1σ): 1.29 ppm (monthly: 1.18 ppm); global bias: 0.20 ppm (0.18 ppm); and spatiotemporal bias or relative accuracy (1σ): 0.66 ppm (0.70 ppm). The corresponding values for the XCH4 products are single-observation random error (1σ): 17.4 ppb (monthly: 8.7 ppb); global bias: −2.0 ppb (−2.9 ppb); and spatiotemporal bias (1σ): 5.0 ppb (4.9 ppb). It has also been found that the data products exhibit very good long-term stability as no significant long-term bias trend has been identified. The new data sets have also been used to derive annual XCO2 and XCH4 growth rates, which are in reasonable to good agreement with growth rates from the National Oceanic and Atmospheric Administration (NOAA) based on marine surface observations. The presented ECV data sets are available (from early 2020 onwards) via the Climate Data Store (CDS, https://cds.climate.copernicus.eu/, last access: 10 January 2020) of the Copernicus Climate Change Service (C3S, https://climate.copernicus.eu/, last access: 10 January 2020).

scholarly journals Introducing the 4.4 km spatial resolution Multi-Angle Imaging SpectroRadiometer (MISR) aerosol product

2020 ◽  
Vol 13 (2) ◽  
pp. 593-628 ◽  
Author(s):  
Michael J. Garay ◽  
Marcin L. Witek ◽  
Ralph A. Kahn ◽  
Felix C. Seidel ◽  
James A. Limbacher ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Horizontal Resolution ◽  
Science Data ◽  
Data Set ◽  
Earth Observing System ◽  
Uncertainty Estimates ◽  
Level 3 ◽  
Land Surfaces ◽  
Langley Research Center ◽  
Level 2

Abstract. The Multi-angle Imaging SpectroRadiometer (MISR) instrument has been operational on the National Aeronautics and Space Administration (NASA) Earth Observing System (EOS) Terra satellite since early 2000, creating an extensive data set of global Earth observations. Here we introduce the latest version of the MISR aerosol products. The level 2 (swath) product, which is reported on a 4.4 km spatial grid, is designated as version 23 (V23) and contains retrieved aerosol optical depth (AOD) and aerosol particle property information derived from MISR's multi-angle observations over both land and water. The changes from the previous version of the algorithm (V22) have significant impacts on the data product and its interpretation. The V23 data set is created from two separate retrieval algorithms that are applied over dark water and land surfaces, respectively. Besides increasing the horizontal resolution to 4.4 km compared with the coarser 17.6 m resolution in V22 and streamlining the format and content, the V23 product has added geolocation information, pixel-level uncertainty estimates, and improved cloud screening. MISR data can be obtained from the NASA Langley Research Center Atmospheric Science Data Center at https://eosweb.larc.nasa.gov/project/misr/misr_table (last access: 11 October 2019). The version number for the V23 level 2 aerosol product is F13_0023. The level 3 (gridded) aerosol product is still reported at 0.5∘×0.5∘ spatial resolution with results aggregated from the higher-resolution level 2 data. The format and content at level 3 have also been updated to reflect the changes made at level 2. The level 3 product associated with the V23 level 2 product version is designated as F15_0032. Both the level 2 and level 3 products are now provided in NetCDF format.

scholarly journals Ensemble-based satellite-derived carbon dioxide and methane column-averaged dry-air mole fraction data sets (2003-2018) for carbon and climate applications

2019 ◽  
Author(s):  
Maximilian Reuter ◽  
Michael Buchwitz ◽  
Oliver Schneising ◽  
Stefan Noel ◽  
Heinrich Bovensmann ◽  
...  
Keyword(s):  
Data Sets ◽  
Climate Data ◽  
Single Observation ◽  
Dry Air ◽  
Data Products ◽  
Level 3 ◽  
Spatio Temporal ◽  
Global Bias ◽  
Level 2

Abstract. Satellite retrievals of column-averaged dry-air mole fractions of carbon dioxide (CO2) and methane (CH4), denoted XCO2 and XCH4, respectively, have been used in recent years to obtain information on natural and anthropogenic sources and sinks and for other applications such as comparisons with climate models. Here we present new data sets based on merging several individual satellite data products in order to generate consistent long-term Climate Data Records (CDRs) of these two Essential Climate Variables (ECVs). These ECV CDRs, which cover the time period 2003-2018, have been generated using an ensemble of data products from the satellite sensors SCIAMACHY/ENVISAT, TANSO-FTS/GOSAT and (for XCO2) for the first time also including data from the Orbiting Carbon Observatory-2 (OCO-2) satellite. Two types of products have been generated: (i) Level 2 (L2) products generated with the latest version of the “ensemble median algorithm” (EMMA) and (ii) Level 3 (L3) products obtained by gridding the corresponding L2 EMMA products to obtain a monthly 5ox5o data product in Obs4MIPs (Observations for Model Intercomparisons Project) format. The L2 products consists of daily NetCDF (Network Common Data Form) files, which contain in addition to the main parameters, i.e., XCO2 or XCH4, corresponding uncertainty estimates for random and potential systematic uncertainties and the averaging kernel for each single (quality-filtered) satellite observation. We describe the algorithms used to generate these data products and present quality assessment results based on comparisons with Total Carbon Column Observing Network (TCCON) ground-based retrievals. We found that the XCO2 Level 2 data set at the TCCON validation sites can be characterized by the following figures of merit (the corresponding values for the Level 3 product are listed in brackets): single observation random error (1-sigma): 1.29 ppm (monthly: 1.18 ppm); global bias: 0.20 ppm (0.18 ppm), spatio-temporal bias or “relative accuracy” (1-sigma): 0.66 ppm (0.70 ppm). The corresponding values for the XCH4 products are: single observation random error (1-sigma): 17.4 ppb (monthly: 8.7 ppb); global bias: −2.0 ppb (−2.9 ppb), spatio-temporal bias (1-sigma): 5.0 ppb (4.9 ppb). It has also been found that the data products exhibit very good long-term stability as no significant long-term bias trend has been identified. The new data sets have also been used to derive annual XCO2 and XCH4 growth rates, which are in reasonable to good agreement with growth rates from the National Oceanic and Atmospheric Administration (NOAA) based on marine surface observations. The presented ECV data sets are available (from December 2019 onwards) via the Climate Data Store (CDS, https://cds.climate.copernicus.eu/) of the Copernicus Climate Change Service (C3S, https://climate.copernicus.eu/).

scholarly journals The GFZ GRACE RL06 Monthly Gravity Field Time Series: Processing Details and Quality Assessment

2019 ◽  
Vol 11 (18) ◽  
pp. 2116 ◽  
Author(s):  
Christoph Dahle ◽  
Michael Murböck ◽  
Frank Flechtner ◽  
Henryk Dobslaw ◽  
Grzegorz Michalak ◽  
...  
Keyword(s):  
Time Series ◽  
Gravity Field ◽  
Transport Processes ◽  
Research Centre ◽  
Ocean Bottom ◽  
Science Data ◽  
Surface Mass ◽  
Surface Mass Transport ◽  
Grace Mission ◽  
Gravity Field Models

Time-variable gravity field models derived from observations of the Gravity Recovery and Climate Experiment (GRACE) mission, whose science operations phase ended in June 2017 after more than 15 years, enabled a multitude of studies of Earth’s surface mass transport processes and climate change. The German Research Centre for Geosciences (GFZ), routinely processing such monthly gravity fields as part of the GRACE Science Data System, has reprocessed the complete GRACE mission and released an improved GFZ GRACE RL06 monthly gravity field time series. This study provides an insight into the processing strategy of GFZ RL06 which has been considerably changed with respect to previous GFZ GRACE releases, and modifications relative to the precursor GFZ RL05a are described. The quality of the RL06 gravity field models is analyzed and discussed both in the spectral and spatial domain in comparison to the RL05a time series. All results indicate significant improvements of about 40% in terms of reduced noise. It is also shown that the GFZ RL06 time series is a step forward in terms of consistency, and that errors of the gravity field coefficients are more realistic. These findings are confirmed as well by independent validation of the monthly GRACE models, as done in this work by means of ocean bottom pressure in situ observations and orbit tests with the GOCE satellite. Thus, the GFZ GRACE RL06 time series allows for a better quantification of mass changes in the Earth system.

scholarly journals Introducing the 4.4 km Spatial Resolution MISR Aerosol Product

2019 ◽  
Author(s):  
Michael J. Garay ◽  
Marcin L. Witek ◽  
Ralph A. Kahn ◽  
Felix C. Seidel ◽  
James A. Limbacher ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Horizontal Resolution ◽  
Science Data ◽  
Data Set ◽  
Earth Observing System ◽  
Uncertainty Estimates ◽  
Level 3 ◽  
Land Surfaces ◽  
Langley Research Center ◽  
Level 2

Abstract. The Multi-angle Imaging SpectroRadiometer (MISR) instrument has been operational on the National Aeronautics and Space Administration (NASA) Earth Observing System (EOS) Terra satellite since early 2000, creating an extensive data set of global Earth observations. Here we introduce the latest version of the MISR aerosol products. The Level 2 (swath) product, which is reported on a 4.4 km spatial grid, is designated Version 23 (V23) and contains retrieved aerosol optical depth (AOD) and aerosol particle property information derived from MISR's multi-angle observations over both land and water. The changes from the previous version of the algorithm (V22) have significant impacts on the data product and its interpretation. The V23 data set is created from two separate retrieval algorithms that are applied over dark water and land surfaces, respectively. Besides increasing the horizontal resolution to 4.4 km compared with the coarser 17.6 m resolution in V22, and streamlining the format and content, the V23 product has added geolocation information, pixel-level uncertainty estimates, and improved cloud screening. MISR data can be obtained from the NASA Langley Research Center Atmospheric Science Data Center at https://eosweb.larc.nasa.gov/project/misr/misr_table. The version number for the V23 Level 2 aerosol product is F13_0023. The Level 3 (gridded) aerosol product is still reported at 0.5° x 0.5° spatial resolution with results aggregated from the higher-resolution Level 2 data. The format and content at Level 3 have also been updated to reflect the changes made at Level 2. The Level 3 product associated with the V23 Level 2 product version is designated F15_0032. Both the Level 2 and Level 3 products are now provided in NetCDF format.

Historical text archives and prosopography: the COEL database system

1998 ◽  
Vol 10 (1-3) ◽  
pp. 57-72 ◽  
Author(s):  
K. S. B. Keats-Rohan
Keyword(s):  
Research Tool ◽  
Direct Access ◽  
Specific Situation ◽  
Core Data ◽  
Secondary Sources ◽  
The Core ◽  
Level 3 ◽  
Full Discussion ◽  
Available Information ◽  
Level 2

The COEL database and database software, a combined reference and research tool created by historians for historians, is presented here through Screenshots illustrating the underlying theoretical model and the specific situation to which that has been applied. The key emphases are upon data integrity, and the historian's role in interpreting and manipulating what is often contentious data. From a corpus of sources (Level 1) certain core data are extracted for separate treatment at an interpretive level (Level 3), based upon a master list of the core data (Level 2). The core data are interdependent: each record in Level 2 is of interest in itself; and it either could or should be associated with an(other) record(s) as a specific entity. Sometimes the sources are ambiguous and the association is contentious, necessitating a probabilty-coding approach. The entities created by the association process can then be treated at a commentary level, introducing material external to the database, whether primary or secondary sources. A full discussion of the difficulties is provided within a synthesis of available information on the core data. Direct access to the source texts is only ever a mouse click away. Fully query able, COEL is formidable look-up and research tool for users of all levels, who remain free to exercise an alternative judgement on the associations of the core data. In principle, there is no limit on the type of text or core data that could be handled in such a system.

EVALUASI PELATIHAN DI PT. PUPUK KUJANG CIKAMPEK

2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Lania Muharsih ◽  
Ratih Saraswati
Keyword(s):  
Training Evaluation ◽  
Work Productivity ◽  
Learning Behavior ◽  
Level 3 ◽  
Level 1 ◽  
Four Levels ◽  
A Company ◽  
Level 2 ◽  
Evaluation Sheet ◽  
Assessment Factor

This study aims to determine the training evaluation at PT. Kujang Fertilizer. PT. Pupuk Kujang is a company engaged in the field of petrochemicals. Evaluation sheet of PT. Fertilizer Kujang is made based on Kirkpatrick's theory which consists of four levels of evaluation, namely reaction, learning, behavior, and results. At level 1, namely reaction, in the evaluation sheet is in accordance with the theory of Kirkpatrick, at level 2 that is learning should be held pretest and posttest but only made scale. At level 3, behavior, according to theory, but on assessment factor number 3, quantity and work productivity should not need to be included because they are included in level 4. At level 4, that is the result, here is still lacking to get a picture of the results of the training that has been carried out because only based on answers from superiors without evidence of any documents.   Keywords: Training Evaluation, Kirkpatrick Theory.    Penelitian ini bertujuan mengetahui evaluasi training di PT. Pupuk Kujang. PT. Pupuk Kujang merupakan perusahaan yang bergerak di bidang petrokimia. Lembar evaluasi PT. Pupuk Kujang dibuat berdasarkan teori Kirkpatrick yang terdiri dari empat level evaluasi, yaitu reaksi, learning, behavior, dan hasil. Pada level 1 yaitu reaksi, di lembar evaluasi tersebut sudah sesuai dengan teori dari Kirkpatrick, pada level 2 yaitu learning seharusnya diadakan pretest dan posttest namun hanya dibuatkan skala. Pada level 3 yaitu behavior, sudah sesuai teori namun pada faktor penilaian nomor 3 kuantitas dan produktivitas kerja semestinya tidak perlu dimasukkan karena sudah termasuk ke dalam level 4. Pada level 4 yaitu hasil, disini masih sangat kurang untuk mendapatkan gambaran hasil dari pelatihan yang sudah dilaksanakan karena hanya berdasarkan dari jawaban atasan tanpa bukti dokumen apapun.   Kata kunci: Evaluasi Pelatihan, Teori Kirkpatrick.

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