Articles | Volume 38, issue 3
https://doi.org/10.5194/angeo-38-725-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/angeo-38-725-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Comparison of quiet-time ionospheric total electron content from the IRI-2016 model and from gridded and station-level GPS observations
Gizaw Mengistu Tsidu
CORRESPONDING AUTHOR
Department of Earth and Environmental Sciences, Botswana International University of Science and Technology, Palapye, Botswana
Mulugeta Melaku Zegeye
Department of Physics, Addis Ababa University, Addis Ababa, Ethiopia
Related authors
Carlos Alberti, Frank Hase, Matthias Frey, Darko Dubravica, Thomas Blumenstock, Angelika Dehn, Paolo Castracane, Gregor Surawicz, Roland Harig, Bianca C. Baier, Caroline Bès, Jianrong Bi, Hartmut Boesch, André Butz, Zhaonan Cai, Jia Chen, Sean M. Crowell, Nicholas M. Deutscher, Dragos Ene, Jonathan E. Franklin, Omaira García, David Griffith, Bruno Grouiez, Michel Grutter, Abdelhamid Hamdouni, Sander Houweling, Neil Humpage, Nicole Jacobs, Sujong Jeong, Lilian Joly, Nicholas B. Jones, Denis Jouglet, Rigel Kivi, Ralph Kleinschek, Morgan Lopez, Diogo J. Medeiros, Isamu Morino, Nasrin Mostafavipak, Astrid Müller, Hirofumi Ohyama, Paul I. Palmer, Mahesh Pathakoti, David F. Pollard, Uwe Raffalski, Michel Ramonet, Robbie Ramsay, Mahesh Kumar Sha, Kei Shiomi, William Simpson, Wolfgang Stremme, Youwen Sun, Hiroshi Tanimoto, Yao Té, Gizaw Mengistu Tsidu, Voltaire A. Velazco, Felix Vogel, Masataka Watanabe, Chong Wei, Debra Wunch, Marcia Yamasoe, Lu Zhang, and Johannes Orphal
Atmos. Meas. Tech., 15, 2433–2463, https://doi.org/10.5194/amt-15-2433-2022, https://doi.org/10.5194/amt-15-2433-2022, 2022
Short summary
Short summary
Space-borne greenhouse gas missions require ground-based validation networks capable of providing fiducial reference measurements. Here, considerable refinements of the calibration procedures for the COllaborative Carbon Column Observing Network (COCCON) are presented. Laboratory and solar side-by-side procedures for the characterization of the spectrometers have been refined and extended. Revised calibration factors for XCO2, XCO and XCH4 are provided, incorporating 47 new spectrometers.
Anteneh Getachew Mengistu, Gizaw Mengistu Tsidu, Gerbrand Koren, Maurits L. Kooreman, K. Folkert Boersma, Torbern Tagesson, Jonas Ardö, Yann Nouvellon, and Wouter Peters
Biogeosciences, 18, 2843–2857, https://doi.org/10.5194/bg-18-2843-2021, https://doi.org/10.5194/bg-18-2843-2021, 2021
Short summary
Short summary
In this study, we assess the usefulness of Sun-Induced Fluorescence of Terrestrial Ecosystems Retrieval (SIFTER) data from the GOME-2A instrument and near-infrared reflectance of vegetation (NIRv) from MODIS to capture the seasonality and magnitudes of gross primary production (GPP) derived from six eddy-covariance flux towers in Africa in the overlap years between 2007–2014. We also test the robustness of sun-induced fluoresence and NIRv to compare the seasonality of GPP for the major biomes.
Temesgen Yirdaw Berhe, Gizaw Mengistu Tsidu, Thomas Blumenstock, Frank Hase, and Gabriele P. Stiller
Atmos. Meas. Tech., 13, 4079–4096, https://doi.org/10.5194/amt-13-4079-2020, https://doi.org/10.5194/amt-13-4079-2020, 2020
Short summary
Short summary
The retrieved CH4 and N2O VMR and column amounts from Addis Ababa, tropical site, are found to exhibit very good agreement with all coincident satellite observations (MIPAS, MLS, and AIRS). Furthermore, the bias obtained from the comparison is comparable to the precision of FTIR measurement, which allows the use of data in further scientific studies as it represents a unique environment of tropical Africa, a region poorly investigated in the past.
Anteneh Getachew Mengistu and Gizaw Mengistu Tsidu
Atmos. Meas. Tech., 13, 4009–4033, https://doi.org/10.5194/amt-13-4009-2020, https://doi.org/10.5194/amt-13-4009-2020, 2020
Short summary
Short summary
This paper assesses the performance of observed XCO2 from the GOSAT and OCO-2 satellites in capturing simulated XCO2 from the NOAA Carbon Tracker model over Africa. These satellite observations and Carbon Tracker mixing ratios near the surface are also compared to available in situ CO2 flask data from Assekrem, Algeria; Mt. Kenya; Gobabeb, Namibia; and Cape Town; as well as to data off the coast at Seychelles, Ascension Island, and at Izana, Tenerife.
Temesgen Yirdaw Berhe, Gizaw Mengistu Tsidu, Thomas Blumenstock, Frank Hase, Thomas von Clarmann, Justus Notholt, and Emmanuel Mahieu
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2019-209, https://doi.org/10.5194/amt-2019-209, 2019
Revised manuscript not accepted
Short summary
Short summary
This study aims to assess the latitudinal variation of MIPAS version
V5R_CH4_220 and V5R_CH4_224 uncertainty. Furthermore, we analyze the relationship between these uncertainties and the variability of water vapor. Mainly, the high uncertainty found in tropics for MIPAS CH4 220 is highly associated with variability of water vapour. However, this effect has been reduced in the new updated MIPAS CH4 224 datasets due to jointly fitted water profile with methane.
Matthias Frey, Mahesh K. Sha, Frank Hase, Matthäus Kiel, Thomas Blumenstock, Roland Harig, Gregor Surawicz, Nicholas M. Deutscher, Kei Shiomi, Jonathan E. Franklin, Hartmut Bösch, Jia Chen, Michel Grutter, Hirofumi Ohyama, Youwen Sun, André Butz, Gizaw Mengistu Tsidu, Dragos Ene, Debra Wunch, Zhensong Cao, Omaira Garcia, Michel Ramonet, Felix Vogel, and Johannes Orphal
Atmos. Meas. Tech., 12, 1513–1530, https://doi.org/10.5194/amt-12-1513-2019, https://doi.org/10.5194/amt-12-1513-2019, 2019
Short summary
Short summary
In a 3.5-year long study, the long-term performance of a mobile EM27/SUN spectrometer, used for greenhouse gas observations, is checked with respect to a co-located reference spectrometer. We find that the EM27/SUN is stable on timescales of several years, qualifying it for permanent carbon cycle studies.
The performance of an ensemble of 30 EM27/SUN spectrometers was also tested in the framework of the COllaborative Carbon Column Observing Network (COCCON) and found to be very uniform.
Anteneh Getachew Mengistu and Gizaw Mengistu Tsidu
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2018-84, https://doi.org/10.5194/amt-2018-84, 2018
Revised manuscript not accepted
Milkessa Gebeyehu Homa, Gizaw Mengistu Tsidu, and Derese Tekestebrihan Nega
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2017-133, https://doi.org/10.5194/acp-2017-133, 2017
Revised manuscript not accepted
Short summary
Short summary
This article provides aerosol climatology of Ethiopia for 21 years. The result showed that aerosol loading over the region is steadily increasing in different sizes. The dominant radius of the particulate matters are between 0.452–0.525 μm, & dominated by reflective type aerosol. This influence the solar radiation budget of the earth, which in turn influences the Earth's climate in different ways. Hence, it is the right time to give the right attention to air quality & climate change impacts.
Sabine Barthlott, Matthias Schneider, Frank Hase, Thomas Blumenstock, Matthäus Kiel, Darko Dubravica, Omaira E. García, Eliezer Sepúlveda, Gizaw Mengistu Tsidu, Samuel Takele Kenea, Michel Grutter, Eddy F. Plaza-Medina, Wolfgang Stremme, Kim Strong, Dan Weaver, Mathias Palm, Thorsten Warneke, Justus Notholt, Emmanuel Mahieu, Christian Servais, Nicholas Jones, David W. T. Griffith, Dan Smale, and John Robinson
Earth Syst. Sci. Data, 9, 15–29, https://doi.org/10.5194/essd-9-15-2017, https://doi.org/10.5194/essd-9-15-2017, 2017
Short summary
Short summary
Tropospheric water vapour isotopologue distributions have been consistently generated and quality-filtered for 12 globally distributed ground-based FTIR sites. The products are provided as two data types. The first type is best-suited for tropospheric water vapour distribution studies. The second type is needed for analysing moisture pathways by means of {H2O,δD}-pair distributions. This paper describes the data types and gives recommendations for their correct usage.
Matthias Schneider, Andreas Wiegele, Sabine Barthlott, Yenny González, Emanuel Christner, Christoph Dyroff, Omaira E. García, Frank Hase, Thomas Blumenstock, Eliezer Sepúlveda, Gizaw Mengistu Tsidu, Samuel Takele Kenea, Sergio Rodríguez, and Javier Andrey
Atmos. Meas. Tech., 9, 2845–2875, https://doi.org/10.5194/amt-9-2845-2016, https://doi.org/10.5194/amt-9-2845-2016, 2016
Short summary
Short summary
Tropospheric {H2O,δD} pairs can be observed by remote sensing techniques, but the data quality strongly depends on a comprehensive consideration of the complex nature and a careful calibration of the remote sensing data pairs. This paper reviews the quality assurance/documentation activities of the MUSICA project and demonstrates that MUSICA’s ground-based FTIR and space-based IASI {H2O,δD} pair products are accurate and can be generated at a global scale with high resolution and for long periods.
G. Mengistu Tsidu, T. Blumenstock, and F. Hase
Atmos. Meas. Tech., 8, 3277–3295, https://doi.org/10.5194/amt-8-3277-2015, https://doi.org/10.5194/amt-8-3277-2015, 2015
Short summary
Short summary
Intercomparison of precipitable water vapour from ERA-Interim, Fourier transform infrared spectrometer, GPS and radiosonde over complex topography of Ethiopia was made for the first time over a data-void region of eastern Africa. The study reveals weakness of ERA-Interim reanalysis in capturing diurnal and to some extent seasonal variabilities. The weakness can be improved through additional data assimilation, adaptation of convection and land surface modules to the reality in the region.
F. Hase, M. Frey, T. Blumenstock, J. Groß, M. Kiel, R. Kohlhepp, G. Mengistu Tsidu, K. Schäfer, M. K. Sha, and J. Orphal
Atmos. Meas. Tech., 8, 3059–3068, https://doi.org/10.5194/amt-8-3059-2015, https://doi.org/10.5194/amt-8-3059-2015, 2015
M. Frey, F. Hase, T. Blumenstock, J. Groß, M. Kiel, G. Mengistu Tsidu, K. Schäfer, M. K. Sha, and J. Orphal
Atmos. Meas. Tech., 8, 3047–3057, https://doi.org/10.5194/amt-8-3047-2015, https://doi.org/10.5194/amt-8-3047-2015, 2015
S. Takele Kenea, G. Mengistu Tsidu, T. Blumenstock, F. Hase, T. von Clarmann, and G. P. Stiller
Atmos. Meas. Tech., 6, 495–509, https://doi.org/10.5194/amt-6-495-2013, https://doi.org/10.5194/amt-6-495-2013, 2013
Carlos Alberti, Frank Hase, Matthias Frey, Darko Dubravica, Thomas Blumenstock, Angelika Dehn, Paolo Castracane, Gregor Surawicz, Roland Harig, Bianca C. Baier, Caroline Bès, Jianrong Bi, Hartmut Boesch, André Butz, Zhaonan Cai, Jia Chen, Sean M. Crowell, Nicholas M. Deutscher, Dragos Ene, Jonathan E. Franklin, Omaira García, David Griffith, Bruno Grouiez, Michel Grutter, Abdelhamid Hamdouni, Sander Houweling, Neil Humpage, Nicole Jacobs, Sujong Jeong, Lilian Joly, Nicholas B. Jones, Denis Jouglet, Rigel Kivi, Ralph Kleinschek, Morgan Lopez, Diogo J. Medeiros, Isamu Morino, Nasrin Mostafavipak, Astrid Müller, Hirofumi Ohyama, Paul I. Palmer, Mahesh Pathakoti, David F. Pollard, Uwe Raffalski, Michel Ramonet, Robbie Ramsay, Mahesh Kumar Sha, Kei Shiomi, William Simpson, Wolfgang Stremme, Youwen Sun, Hiroshi Tanimoto, Yao Té, Gizaw Mengistu Tsidu, Voltaire A. Velazco, Felix Vogel, Masataka Watanabe, Chong Wei, Debra Wunch, Marcia Yamasoe, Lu Zhang, and Johannes Orphal
Atmos. Meas. Tech., 15, 2433–2463, https://doi.org/10.5194/amt-15-2433-2022, https://doi.org/10.5194/amt-15-2433-2022, 2022
Short summary
Short summary
Space-borne greenhouse gas missions require ground-based validation networks capable of providing fiducial reference measurements. Here, considerable refinements of the calibration procedures for the COllaborative Carbon Column Observing Network (COCCON) are presented. Laboratory and solar side-by-side procedures for the characterization of the spectrometers have been refined and extended. Revised calibration factors for XCO2, XCO and XCH4 are provided, incorporating 47 new spectrometers.
Anteneh Getachew Mengistu, Gizaw Mengistu Tsidu, Gerbrand Koren, Maurits L. Kooreman, K. Folkert Boersma, Torbern Tagesson, Jonas Ardö, Yann Nouvellon, and Wouter Peters
Biogeosciences, 18, 2843–2857, https://doi.org/10.5194/bg-18-2843-2021, https://doi.org/10.5194/bg-18-2843-2021, 2021
Short summary
Short summary
In this study, we assess the usefulness of Sun-Induced Fluorescence of Terrestrial Ecosystems Retrieval (SIFTER) data from the GOME-2A instrument and near-infrared reflectance of vegetation (NIRv) from MODIS to capture the seasonality and magnitudes of gross primary production (GPP) derived from six eddy-covariance flux towers in Africa in the overlap years between 2007–2014. We also test the robustness of sun-induced fluoresence and NIRv to compare the seasonality of GPP for the major biomes.
Temesgen Yirdaw Berhe, Gizaw Mengistu Tsidu, Thomas Blumenstock, Frank Hase, and Gabriele P. Stiller
Atmos. Meas. Tech., 13, 4079–4096, https://doi.org/10.5194/amt-13-4079-2020, https://doi.org/10.5194/amt-13-4079-2020, 2020
Short summary
Short summary
The retrieved CH4 and N2O VMR and column amounts from Addis Ababa, tropical site, are found to exhibit very good agreement with all coincident satellite observations (MIPAS, MLS, and AIRS). Furthermore, the bias obtained from the comparison is comparable to the precision of FTIR measurement, which allows the use of data in further scientific studies as it represents a unique environment of tropical Africa, a region poorly investigated in the past.
Anteneh Getachew Mengistu and Gizaw Mengistu Tsidu
Atmos. Meas. Tech., 13, 4009–4033, https://doi.org/10.5194/amt-13-4009-2020, https://doi.org/10.5194/amt-13-4009-2020, 2020
Short summary
Short summary
This paper assesses the performance of observed XCO2 from the GOSAT and OCO-2 satellites in capturing simulated XCO2 from the NOAA Carbon Tracker model over Africa. These satellite observations and Carbon Tracker mixing ratios near the surface are also compared to available in situ CO2 flask data from Assekrem, Algeria; Mt. Kenya; Gobabeb, Namibia; and Cape Town; as well as to data off the coast at Seychelles, Ascension Island, and at Izana, Tenerife.
Temesgen Yirdaw Berhe, Gizaw Mengistu Tsidu, Thomas Blumenstock, Frank Hase, Thomas von Clarmann, Justus Notholt, and Emmanuel Mahieu
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2019-209, https://doi.org/10.5194/amt-2019-209, 2019
Revised manuscript not accepted
Short summary
Short summary
This study aims to assess the latitudinal variation of MIPAS version
V5R_CH4_220 and V5R_CH4_224 uncertainty. Furthermore, we analyze the relationship between these uncertainties and the variability of water vapor. Mainly, the high uncertainty found in tropics for MIPAS CH4 220 is highly associated with variability of water vapour. However, this effect has been reduced in the new updated MIPAS CH4 224 datasets due to jointly fitted water profile with methane.
Matthias Frey, Mahesh K. Sha, Frank Hase, Matthäus Kiel, Thomas Blumenstock, Roland Harig, Gregor Surawicz, Nicholas M. Deutscher, Kei Shiomi, Jonathan E. Franklin, Hartmut Bösch, Jia Chen, Michel Grutter, Hirofumi Ohyama, Youwen Sun, André Butz, Gizaw Mengistu Tsidu, Dragos Ene, Debra Wunch, Zhensong Cao, Omaira Garcia, Michel Ramonet, Felix Vogel, and Johannes Orphal
Atmos. Meas. Tech., 12, 1513–1530, https://doi.org/10.5194/amt-12-1513-2019, https://doi.org/10.5194/amt-12-1513-2019, 2019
Short summary
Short summary
In a 3.5-year long study, the long-term performance of a mobile EM27/SUN spectrometer, used for greenhouse gas observations, is checked with respect to a co-located reference spectrometer. We find that the EM27/SUN is stable on timescales of several years, qualifying it for permanent carbon cycle studies.
The performance of an ensemble of 30 EM27/SUN spectrometers was also tested in the framework of the COllaborative Carbon Column Observing Network (COCCON) and found to be very uniform.
Anteneh Getachew Mengistu and Gizaw Mengistu Tsidu
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2018-84, https://doi.org/10.5194/amt-2018-84, 2018
Revised manuscript not accepted
Milkessa Gebeyehu Homa, Gizaw Mengistu Tsidu, and Derese Tekestebrihan Nega
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2017-133, https://doi.org/10.5194/acp-2017-133, 2017
Revised manuscript not accepted
Short summary
Short summary
This article provides aerosol climatology of Ethiopia for 21 years. The result showed that aerosol loading over the region is steadily increasing in different sizes. The dominant radius of the particulate matters are between 0.452–0.525 μm, & dominated by reflective type aerosol. This influence the solar radiation budget of the earth, which in turn influences the Earth's climate in different ways. Hence, it is the right time to give the right attention to air quality & climate change impacts.
Sabine Barthlott, Matthias Schneider, Frank Hase, Thomas Blumenstock, Matthäus Kiel, Darko Dubravica, Omaira E. García, Eliezer Sepúlveda, Gizaw Mengistu Tsidu, Samuel Takele Kenea, Michel Grutter, Eddy F. Plaza-Medina, Wolfgang Stremme, Kim Strong, Dan Weaver, Mathias Palm, Thorsten Warneke, Justus Notholt, Emmanuel Mahieu, Christian Servais, Nicholas Jones, David W. T. Griffith, Dan Smale, and John Robinson
Earth Syst. Sci. Data, 9, 15–29, https://doi.org/10.5194/essd-9-15-2017, https://doi.org/10.5194/essd-9-15-2017, 2017
Short summary
Short summary
Tropospheric water vapour isotopologue distributions have been consistently generated and quality-filtered for 12 globally distributed ground-based FTIR sites. The products are provided as two data types. The first type is best-suited for tropospheric water vapour distribution studies. The second type is needed for analysing moisture pathways by means of {H2O,δD}-pair distributions. This paper describes the data types and gives recommendations for their correct usage.
Matthias Schneider, Andreas Wiegele, Sabine Barthlott, Yenny González, Emanuel Christner, Christoph Dyroff, Omaira E. García, Frank Hase, Thomas Blumenstock, Eliezer Sepúlveda, Gizaw Mengistu Tsidu, Samuel Takele Kenea, Sergio Rodríguez, and Javier Andrey
Atmos. Meas. Tech., 9, 2845–2875, https://doi.org/10.5194/amt-9-2845-2016, https://doi.org/10.5194/amt-9-2845-2016, 2016
Short summary
Short summary
Tropospheric {H2O,δD} pairs can be observed by remote sensing techniques, but the data quality strongly depends on a comprehensive consideration of the complex nature and a careful calibration of the remote sensing data pairs. This paper reviews the quality assurance/documentation activities of the MUSICA project and demonstrates that MUSICA’s ground-based FTIR and space-based IASI {H2O,δD} pair products are accurate and can be generated at a global scale with high resolution and for long periods.
G. Mengistu Tsidu, T. Blumenstock, and F. Hase
Atmos. Meas. Tech., 8, 3277–3295, https://doi.org/10.5194/amt-8-3277-2015, https://doi.org/10.5194/amt-8-3277-2015, 2015
Short summary
Short summary
Intercomparison of precipitable water vapour from ERA-Interim, Fourier transform infrared spectrometer, GPS and radiosonde over complex topography of Ethiopia was made for the first time over a data-void region of eastern Africa. The study reveals weakness of ERA-Interim reanalysis in capturing diurnal and to some extent seasonal variabilities. The weakness can be improved through additional data assimilation, adaptation of convection and land surface modules to the reality in the region.
F. Hase, M. Frey, T. Blumenstock, J. Groß, M. Kiel, R. Kohlhepp, G. Mengistu Tsidu, K. Schäfer, M. K. Sha, and J. Orphal
Atmos. Meas. Tech., 8, 3059–3068, https://doi.org/10.5194/amt-8-3059-2015, https://doi.org/10.5194/amt-8-3059-2015, 2015
M. Frey, F. Hase, T. Blumenstock, J. Groß, M. Kiel, G. Mengistu Tsidu, K. Schäfer, M. K. Sha, and J. Orphal
Atmos. Meas. Tech., 8, 3047–3057, https://doi.org/10.5194/amt-8-3047-2015, https://doi.org/10.5194/amt-8-3047-2015, 2015
S. Takele Kenea, G. Mengistu Tsidu, T. Blumenstock, F. Hase, T. von Clarmann, and G. P. Stiller
Atmos. Meas. Tech., 6, 495–509, https://doi.org/10.5194/amt-6-495-2013, https://doi.org/10.5194/amt-6-495-2013, 2013
Related subject area
Subject: Earth's ionosphere & aeronomy | Keywords: Modelling and forecasting
Modeling total electron content derived from radio occultation measurements by COSMIC satellites over the African region
Analysis of different propagation models for the estimation of the topside ionosphere and plasmasphere with an ensemble Kalman filter
The very low-frequency transmitter radio wave anomalies related to the 2010 Ms 7.1 Yushu earthquake observed by the DEMETER satellite and the possible mechanism
Performance of the IRI-2016 over Santa Maria, a Brazilian low-latitude station located in the central region of the South American Magnetic Anomaly (SAMA)
High-resolution vertical total electron content maps based on multi-scale B-spline representations
Validation and application of optimal ionospheric shell height model for single-site estimation of total electron content
Extending the coverage area of regional ionosphere maps using a support vector machine algorithm
Patrick Mungufeni, Sripathi Samireddipalle, Yenca Migoya-Orué, and Yong Ha Kim
Ann. Geophys., 38, 1203–1215, https://doi.org/10.5194/angeo-38-1203-2020, https://doi.org/10.5194/angeo-38-1203-2020, 2020
Short summary
Short summary
This study developed a model of total electron content (TEC) over the African region. The TEC data were derived from radio occultation measurements done by the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) satellites. Data during geomagnetically quiet time for the years 2008–2011 and 2013–2017 were binned according to local time, seasons, solar flux level, geographic longitude, and dip latitude. Cubic B splines were used to fit the data for the model.
Tatjana Gerzen, David Minkwitz, Michael Schmidt, and Eren Erdogan
Ann. Geophys., 38, 1171–1189, https://doi.org/10.5194/angeo-38-1171-2020, https://doi.org/10.5194/angeo-38-1171-2020, 2020
Short summary
Short summary
We focus on reconstructing the topside ionosphere and plasmasphere and assimilating the space-based Global Navigation Satellite System slant total electron content (STEC) measurements with an ensemble Kalman filter (EnKF). We present methods for realizing the propagation step without a physical model. We investigate the capability of our estimations to reconstruct independent STEC and electron density measurements. We compare the EnKF approach with SMART+ and the 3D ionosphere model NeQuick.
Shufan Zhao, XuHui Shen, Zeren Zhima, and Chen Zhou
Ann. Geophys., 38, 969–981, https://doi.org/10.5194/angeo-38-969-2020, https://doi.org/10.5194/angeo-38-969-2020, 2020
Short summary
Short summary
We use satellite data to analyze precursory anomalies of the western China Ms 7.1 Yushu earthquake by analyzing the signal-to-noise ratio (SNR) and using the full-wave model to illustrate a possible mechanism for how the anomalies occurred. The results show that very low-frequency (VLF) radio wave SNR in the ionosphere decreased before the Yushu earthquake. The full-wave simulation results confirm that electron density variation in the lower ionosphere will affect VLF radio signal SNR.
Juliano Moro, Jiyao Xu, Clezio Marcos Denardini, Laysa Cristina Araújo Resende, Régia Pereira Silva, Sony Su Chen, Giorgio Arlan da Silva Picanço, Liu Zhengkuan, Hui Li, Chunxiao Yan, Chi Wang, and Nelson Jorge Schuch
Ann. Geophys., 38, 457–466, https://doi.org/10.5194/angeo-38-457-2020, https://doi.org/10.5194/angeo-38-457-2020, 2020
Short summary
Short summary
The monthly averages of the F2 critical frequency (foF2), its peak height (hmF2), and the E-region critical frequency (foE) acquired by the DPS4-D installed in Santa Maria, Brazil, is compared to the International Reference Ionosphere (IRI-2016) model predictions. It is important to test the performance of the IRI over Santa Maria because it is located in the SAMA, which is a region particularly important for high-frequency (HF) ground-to-satellite navigation signals.
Andreas Goss, Michael Schmidt, Eren Erdogan, Barbara Görres, and Florian Seitz
Ann. Geophys., 37, 699–717, https://doi.org/10.5194/angeo-37-699-2019, https://doi.org/10.5194/angeo-37-699-2019, 2019
Short summary
Short summary
This paper describes an approach to model VTEC solely from NRT GNSS observations by generating a multi-scale representation (MSR) based on B-splines. The unknown model parameters are estimated by means of a Kalman filter. A number of products are created which differ both in their spectral and temporal resolution. The validation studies show that the product with the highest resolution, based on NRT input data, is of higher accuracy than others used within the selected investigation time span.
Jiaqi Zhao and Chen Zhou
Ann. Geophys., 37, 263–271, https://doi.org/10.5194/angeo-37-263-2019, https://doi.org/10.5194/angeo-37-263-2019, 2019
Mingyu Kim and Jeongrae Kim
Ann. Geophys., 37, 77–87, https://doi.org/10.5194/angeo-37-77-2019, https://doi.org/10.5194/angeo-37-77-2019, 2019
Short summary
Short summary
Spatial extrapolation of an ionosphere TEC map was carried out using a SVM learning algorithm. There has been much research on the temporal extrapolation or prediction of TEC time series, but the spatial extrapolation has rarely been attempted. Some researchers have performed simultaneous extrapolation both in time and in spatial domains, but this research covers the spatial extrapolation only by using an inner TEC map. This spatial TEC extrapolation can be useful for small countries.
Cited articles
Acharya, R. and Majumdar, S.: Comparison of observed ionospheric vertical TEC over the sea in Indian region with IRI-2016 model, Adv. Space Res., 63, 1892–1904, 2019. a
AghaKouchak, A. and Mehran, A.: Extended contingency table: Performance metrics for satellite observations and climate model simulations, Water Resour. Res., 49, 7144–7149, https://doi.org/10.1002/wrcr.20498, 2013. a, b
AghaKouchak, A., Habib, E., and Bárdossy, A.: Modeling radar rainfall estimation uncertainties: Random error model, J. Hydrol. Eng., 15, 265–274, 2009. a
AghaKouchak, A., Nasrollahi, N., Li, J., Imam, B., and Sorooshian, S.: Geometrical characterization of precipitation patterns, J. Hydrometeorol., 12, 274–285, 2011a. a
Axelrad, P., Comp, C. J., and Macdoran, P. F: SNR-based multipath error correction for GPS differential phase, IEEE T. Aero. Elec. Sys., 32, 650–660, 1996. a
Bardhan, A., Malini, A., Sharma, D. K., and Rai, J.: Equinoctial asymmetry in low latitude ionosphere as observed by SROSS-C2 satellite, J. Atmos. Sol.-Terr. Phy., 117, 101–109,
https://doi.org/10.1016/j.jastp.2014.06.003, 2014. a, b
Behrangi, A., Khakbaz, B., Jaw, T. C., AghaKouchak, A., Hsu, K., and Sorooshian, S.: Hydrologic evaluation of satellite precipitation products over a mid-size basin, J. Hydrol., 397, 225–237, 2011. a
Bilitza D.: International reference ionosphere: recent developments, Radio Sci., 21, 343–346, 2011. a
Bilitza, D.: International reference ionosphere 2000, Radio Sci., 36, 261–275, 2001. a
Bilitza, D., Rawer, K., Bossy, L., and Gulyaeva, T.: International reference ionosphere-past, present, and future: I. Electron density, Adv. Space Res., 13, 3–13, 1993a. a
Bilitza, D., Rawer, K., Bossy, L., and Gulyaeva, T.: International reference ionosphere-past, present, and future: II. plasma temperatures, ion composition and ion-drift, Adv. Space Res., 13, 15–23, 1993b. a
Bilitza, D., McKinnell, L. A., Reinisch, B., and Fuller-Rowell, T.: The international reference ionosphere today and in the future, J. Geod., 85, 909–920, https://doi.org/10.1007/s00190-010-0427-x, 2011. a
Bilitza, D., Altadill, D., Zhang, Y., Mertens, C., Truhlik, V., Richards, P., McKinnell, L.-A., and Reinisch, B.: The International Reference Ionosphere 2012 – a model of international collaboration, Journal of Space Weather Space Climate, 4, A07, https://doi.org/10.1051/swsc/2014004, 2014. a, b
Borghetti, A., Corsi, S., Nucci, C. A., Paolone, M., Peretto, L., and Tinarelli, R.: On the use of continuous-wavelet transform for fault location in distribution power systems, Int. J. Elec. Power, 28, 608–617, https://doi.org/10.1016/j.ijepes.2006.03.001, 2006. a
Bossler, J. D., Goad, C. C., and Bender, P. L.: Using the Global Positioning System (GPS) for geodetic positioning, B. Géod., 54, 553, https://doi.org/10.1007/BF02530713, 1980. a
Daniel, S. W.: Statistical Methods in the Atmospheric Sciences, 2nd Edn., International Geophysics Series, 91 pp., Elsevier, San Diego, USA, 2006. a
Davis, C. A., Brown, B. G., Bullock, R., and Halley-Gotway, J.: The method for object-based diagnostic evaluation (MODE) applied to numerical forecasts from the 2005 NSSL/SPC Spring Program, Weather Forecast., 24, 1252–1267, 2009. a
Dorigo, W. A., Scipal, K., Parinussa, R. M., Liu, Y. Y., Wagner, W., de Jeu, R. A. M., and Naeimi, V.: Error characterisation of global active and passive microwave soil moisture datasets, Hydrol. Earth Syst. Sci., 14, 2605–2616, https://doi.org/10.5194/hess-14-2605-2010, 2010. a
Entekhabi, D., Reichle, R. H., Koster, R. D., and Crow, W. T.: Performance metrics for soil moisture retrievals and application requirements, J. Hydrometeorol., 11, 832–840, 2010. a
Erdogan, E., Schmidt, M., Seitz, F., and Durmaz, M.: Near real-time estimation of ionosphere vertical total electron content from GNSS satellites using B-splines in a Kalman filter, Ann. Geophys., 35, 263–277, https://doi.org/10.5194/angeo-35-263-2017, 2017. a
Feleke, F. D., Mengistu Tsidu, G., and Abraha, G.: Climatology of quasi-two day oscillations from GPS-derived total electron content during 1999–2015, Ad. Space Res., 64, 1046–1064, https://doi.org/10.1016/j.asr.2019.05.048, 2019. a, b, c
Gebremichael, M.: Framework for satellite rainfall product evaluation, Geophysical Monograph Series, 265–275, https://doi.org/10.1029/2010GM000974, AGU-Wiley, Washington, D.C., 2010. a
Gilleland, E., Ahijevych, D., Brown, B. G., Casati, B., and Ebert, E. E.: Intercomparison of spatial forecast verification methods, J. Weather Forecast., 24, 1416–1430, 2009. a
Grynyshyna-Poliuga, O., Stanislawska, I., Pozoga, M., Tomasik, L., and Swiatek, A.: Comparison of TEC value from GNSS permanent station and IRI model, Adv. Space Res., 55, 1976–1980, https://doi.org/10.1016/j.asr.2014.11.029, 2015. a, b, c
Hajj, G. A., Kursinski, E. R., Romans, L. J., Bertiger, W. I., and Leroy, S. S.: A technical description of atmospheric sounding by GPS occulation, J. Atmos. Sol.-Terr. Phy., 64, 451–469, 2002. a
Hernández-Pajares, M., Juan, J. M., Sanz, J., Aragon-Angel, A., Gracia-Rigo, A., Salazer, D., and Escudero, M.: The ionosphere: effects, GPS modeling and the benefits for space geodetic techniques, J. Geod., 85, 887–907, https://doi.org/10.1007/s00190-011-0508-5, 2011. a
Hoffmann, P. and Jacobi, C.: Analysis of planetary waves seen in ionospheric total electron content (TEC) perturbations, Wiss. Mitteil. Inst. Meteorol. Univ. Leipzig, 37, 29–40, 2006. a
Komjathy, A.: Global ionospheric total electron content mapping using the Global Positioning System, University of New Brunswick Fredericton, New Brunswick, Canada, 1997. a
Kouris, S. S. and Fotiadis, D. N.: Ionospheric variability: a comparative statistical study, Adv. Space Res., 29, 977–985, 2002. a
Kouris, S. S., Xenos, T. D., Polimeris, K. V., and Stergiou, D.: TEC and foF2 variations: preliminary results, Ann. Geophys., 47, 1325-1332, https://doi.org/10.4401/ag-3346, 2004. a
Kumar, K. S., Kumar, C. V. A., George, B., Renuka, G., and Venugopal, C.: Analysis of the fluctuations of the total electron content (TEC) measured at Goose Bay using tools of nonlinear methods, J. Geophys. Res., 109, A02308, https://doi.org/10.1029/2002JA009768, 2004. a
Kumar, S.: Performance of IRI-2012 model during a deep solar minimum and a maximum year over global equatorial regions, J. Geophys. Res.-Space, 121, 5664–5674, https://doi.org/10.1002/2015JA022269, 2016. a
Kumar, S., Leong, E. T., Gulam, S. R., Samson, C. M. S., and Siingh, D.: Validation of the IRI-2012 model with GPS-based ground observation over a low-latitude Singapore station study, Earth Planets Space, 66, 1–17, 2014. a
Li, S., Li, L., and Peng, J.: Variability of ionospheric TEC and the performance of the IRI-2012 model at the BJFS station, China, Acta Geophys., 64, 1970–1987, https://doi.org/10.1515/acgeo-2016-0075, 2016. a
Liu, H., Wang, W., Richmond, A. D., and Roble, R. G.: Ionospheric variability due to planetary waves and tides for solar minimum conditions, J. Geophys. Res., 115, A00G01, https://doi.org/10.1029/2009JA015188, 2010. a
Liu, Z., Fang, H., Weng, L., Wang, S., Niu, J., and Meng, X.: A comparison of ionosonde measured foF2 and IRI-2016 predictions over China, Adv. Space Res., 63, 1926–1936, 2019. a
Lühr, H., Häusler, K., and Stolle, C.: Longitudinal variation of F region electron density and thermospheric zonal wind caused by atmospheric tides, Geophys. Res. Lett., 34, L16102, https://doi.org/10.1029/2007GL030639, 2007. a
Melbourne, W. G., Davis, E. S., Duncan, C. B., Hajj, G. A., Hardy, K. R., Kursinski, E. R., Meehan, T. K., Young, L. E., and Yunck, T. P.: The application of spaceborne GPS to atmospheric limb sounding and global change monitoring, National Aeronautics and Space Administration, Jet Propulsion Laboratory, California Institute of Technology National Technical Information Service, NASA, Pasadena, California, 1994. a
Mengistu, E., Damtie, B., Moldwin, M. B., and Nigussie, M.: Comparison of GPS-TEC measurements with NeQuick2 and IRI model predictions in the low latitude East African region during varying solar activity period (1998 and 2008–2015), Adv. Space Res., 61, 1456–1475, https://doi.org/10.1016/j.asr.2018.01.009, 2018. a, b
Mengistu Tsidu, G., Kidanu, G., and Abraha, G. F.: Tomographic Reconstruction of Ionospheric Electron Density Using Altitude-Dependent Regularization Strength over the Eastern Africa Longitude Sector, in: Ionospheric Space Weather, edited by: Fuller-Rowell, T., Yizengaw, E., Doherty, P. H., and Basu, S., https://doi.org/10.1002/9781118929216.ch11, AGU-Wiley, Washington, D.C., 2016. a
Morgan-Owen, G. J. and Johnston, G. T.: Differential GPS positioning, Electronics and Communication Engineering Journal (IET), 7, 11–21, 1995. a
Mosert, M., Gende, M., Brunini, C., Ezquer, R., and Altadill, D.: Comparisons of IRI TEC predictions with GPS and digisonde measurements at Ebro, Adv. Space Res., 39, 841–847, 2007. a
Mukherjee, S., Shivalika, S., Purohit, P. K., and Gwal, A. K.: Seasonal variation of total electron content at crest of equatorial anomaly station during low solar activity conditions, Adv. Space Res., 46, 291–295, https://doi.org/10.1016/j.asr.2010.03.024, 2010. a, b
Murphy, A. H.: Skill scores based on the mean square error and their relationships to the correlation coefficient, Mon. Weather Rev., 116, 2417–2424, 1998. a
Oberheide, J. and Gusev, O. A.: Observation of migrating and nonmigrating diurnal tides in the equatorial lower thermosphere, Geophys. Res. Lett., 29, 2167, https://doi.org/10.1029/2002GL016213, 2002. a
Ochoa, A., Pineda, L., Crespo, P., and Willems, P.: Evaluation of TRMM 3B42 precipitation estimates and WRF retrospective precipitation simulation over the Pacific–Andean region of Ecuador and Peru, Hydrol. Earth Syst. Sci., 18, 3179–3193, https://doi.org/10.5194/hess-18-3179-2014, 2014. a
Onohara, A. N., Batista, I. S., and Takahashi, H.: The ultra-fast Kelvin waves in the equatorial ionosphere: observations and modeling, Ann. Geophys., 31, 209–215, https://doi.org/10.5194/angeo-31-209-2013, 2013. a
Perna L., Pezzopane, M., Ezquer, R., Cabrera, M., and Baskaradas, J. A.: NmF2 trends at low and mid latitudes for the recent solar minima and comparison with IRI-2012 model, Adv. Space Res., 60, 363–374, https://doi.org/10.1016/j.asr.2016.09.025., 2017. a, b
Perna, L., Venkatesh, K., Pillat, V. G., Pezzopane, M., Fagundes, P. R., Ezquer, R. G., and Cabrera, M. A.: Bottom side profiles for two close stations at the southern crest of the EIA: Differences and comparison with IRI-2012 and NeQuick2 for low and high solar activity, Adv. Space Res., 61, 295–315, https://doi.org/10.1016/j.asr.2017.10.007, 2018. a, b
Praveen, G., Dashora, N., Sharma, S., and Pandey, R.: Characterization of low latitude GPS-TEC during very low solar activity phase, J. Atmos. Sol.-Terr. Phy., 72, 1309–1317, 2010. a
Rao, S. S., Monti, C., and Pandey, R.: Ionospheric variations over Chinese EIA region using foF2 and comparison with IRI-2016 model, Adv. Space Res., 62, 84–93, https://doi.org/10.1016/j.asr.2018.04.009, 2018. a, b, c
Rawer, K.: Synthesis of ionospheric electron density profiles with Epstein functions, Adv. Space Res., 8, 191–198, 1988. a
Rawer, K., Bilitza, D., and Ramakrishnan, S.: International reference ionosphere 78. Special Report, International Union of Radio Science (URSI), Brussels, Belgium, 1978. a
Saranya, P. L., Prasad, D. S. V. V. D., and Rama Rao, P. V. S.: Ionospheric vertical drifts over an Indian low latitude station and its comparison with IRI-2007 vertical drift model, Adv. Space Res., 54, 946–954, https://doi.org/10.1016/j.asr.2014.05.026, 2014. a, b
Scherliess, L., Thompson, D. C., and Schunk, R. W.: Longitudinal variability of low-latitude total electron content: Tidal influences, J. Geophys. Res., 113, A01311, https://doi.org/10.1029/2007JA012480, 2008. a, b, c, d
Schreiner, W. S., Sokolovskiy, S. V., Rocken, C., and Hunt, D. C.: Analysis and validation of GPS/MET radio occulation data in the ionosphere, Radio Sci., 34, 949–966, 1999. a
Sharma, D. K., Malini, A., and Ananna, B.: Variability of ionospheric parameters during solar minimum and maximum activity and assessment of IRI model, Adv. Space Res., 60, 435–443, https://doi.org/10.1016/j.asr.2016.11.027, 2017. a, b
Shubin, V. N.: Global median model of the F2-layer peak height based on ionospheric radio-occulation and ground-based Digisonde observations, Adv. Space Res., 56, 916–928, 2015. a
Shubin, V. N., Karpachev, A. T., and Tsybulya, K. G.: Global model of the F2 layer peak height for low solar activity based on GPS radio-occulation data, J. Atmos. Sol.-Terr. Phy., 104, 106–115, 2013. a
Takahashi, H., Lima, L. M., Wrasse, C. M., Abdu, M. A., Batista, I. S., Gobbi, D., Buriti, R. A., and Batista, P. P.: Evidence on 2–4 day oscillations of the equatorial ionosphere hF and mesospheric air glow emissions, Geophys. Res. Lett., 32, L12102, https://doi.org/10.1029/2004GL022318, 2005. a
Takahashi, H., Wrasse, C. M., Pancheva, D., Abdu, M. A., Batista, I. S., Lima, L. M., Batista, P. P., Clemesha, B. R., and Shiokawa, K.: Signatures of 3–6 day planetary waves in the equatorial mesosphere and ionosphere, Ann. Geophys., 24, 3343–3350, https://doi.org/10.5194/angeo-24-3343-2006, 2006. a
Takahashi, H., Wrasse, C. M., Fechine, J., Pancheva, D., Abdu, M. A., Batista, I. S., Lima, L. M., Batista, P. P., Clemesha, B. R., Schuch, N. J., Shiokawa, K., Gobbi, D., Mlynczak, M. G., and Russel, J. M.: Signatures of ultra-fast Kelvin waves in the equatorial middle atmosphere and ionosphere, Geophys. Res. Lett., 34, L11108, https://doi.org/10.1029/2007GL029612, 2007. a
Takahashi, H., Abdu, M. A., Wrasse, C. M., Fechine, J., Batista, I. S., Pancheva, D., Lima, L. M., Batista, P. P., Clemesha, B. R., Shiokawa, K., Gobbi, D., Mlynczak, M. G., and Russel, J. M.: Possible influence of ultra-fast Kelvin wave on the equatorial ionosphere evening uplifting, Earth Planets Space, 61, 455–462, 2009. a
Taylor, K. E.: Summarizing multiple aspects of model performance in a single diagram, J. Geophys. Res.-Atmos., 106, 7183–7192, 2001. a
Venkatesh, K., Fagundes, P. R., Seemala, G. K., de Jesus, R., de Abreu, A. J., and Pillat, V. G.: On the performance of the IRI-2012 and NeQuick2 models during the increasing phase of the unusual 24th solar cycle in the Brazilian equatorial and low-latitude sectors, J. Geophys. Res.-Space, 119, 5087–5105, https://doi.org/10.1002/2014JA019960, 2014. a
Wan, Q., Guanyi, M., Jinghua, L., Xiaolan, W., Jiangtao, F., Qi, L., and Weijun, L.: A comparison of GPS-TEC with IRI-TEC at low latitudes in China in 2006, Adv. Space Res., 60, 250–256, https://doi.org/10.1016/j.asr.2016.12.002, 2017. a
Wang, S., Huang, S., Fang, H., and Wang, Y.: Evaluation and correction of the IRI2016 topside ionospheric electron density model, Adv. Space Res., 58, 1229–1241, 2016. a
Wongcharoen, P., Kenpankho, P., Supnithi, P., Ishii, M., and Tsugawa, T.: Comparison of E layer critical frequency over the Thai station Chumphon with IRI, Adv. Space Res., 55, 2131–2138, 2015. a
Woo, K. T.: Optimum semicodeless carrier-phase tracking of L2, Navigation, 47, 82–99, https://doi.org/10.1002/j.2161-4296.2000.tb00204.x., 2000. a
Wu, Q., Solomon, S. C., Kuo, Y. H., Killeen, T. L., and Xu, J.: Spectral analysis of ionospheric electron density and mesospheric neutral wind diurnal nonmigrating tides observed by COSMIC and TIMED satellites, Geophys. Res. Lett., 36, L14102, https://doi.org/10.1029/2009GL038933, 2009. a
Yekoye, A., Kassa, T., and Nigussie, M.: Validation of IRI-2012 TEC model over Ethiopia during solar minimum (2009) and solar maximum (2013) phases, Adv. Space Res., 53, 1582–1594, https://doi.org/10.1016/j.asr.2014.02.017, 2014. a, b, c
Yu, S., Brian, E., Robin, D., Shao-Hang, C., and Stephen, E. S.: New unbiased symmetric metrics for evaluation of air quality models, Atmos. Sci. Lett., 7, 26–34, https://doi.org/10.1002/asl.125 2006. a
Zhang, H., Wang, J., Zhu, W.-Y., and Huang, C.: Gaussian random process and its application for detecting the ionospheric disturbances using GPS, Journal of Global Positioning Systems, 4, 76–81, 2005. a
Zhang, M.-L., Radicella, S. M., Shi, J.-K., Wang, X., and Wu, S.-Z.: Comparison among IRI, GPS-IGS and ionogram-derived total electron contents, Adv. Space Res., 37, 972–977, 2006. a
Short summary
The performance of the IRI-2016 model in simulating GPS-TEC is assessed based on various statistical tools during two distinct solar activity periods. In particular, the categorical metrics used in the study to assess the performance of the empirical and climatological IRI-2016 model at the margins of the TEC distribution reveal remarkable model skill in simulating the observed tails of the TEC distribution, which is much better than accurately simulating the observed climatology as designed.
The performance of the IRI-2016 model in simulating GPS-TEC is assessed based on various...