Evaluation of the Solar Quiet Reference Field (SQRF) Model for Space Weather Applications in the South America Magnetic Anomaly

Abstract In the present work, we evaluate the accuracy of the Solar Quiet Reference Field (SQRF) model for estimating and predicting the geomagnetic solar quiet (Sq) daily field variation in the South America Magnetic Anomaly (SAMA) region. This model is based on the data set of fluxgate magnetometers from 12 magnetic stations of the Embrace Magnetometer Network (Embrace MagNet) from 2010 to 2018. The model predicts the monthly average horizontal field of the geomagnetic quiet (Sq-H) daily variation solving a set of equations for the specified geographic coordinates in terms of the solar cycle activity, the day of the year, and the universal time. We carried out two comparisons between the prediction and observational data of the Sq-H field. The first part attempts to evaluate the accuracy for estimating the Sq-H field over Medianeira (MED, 25.30°S, 54.11°W, dip angle: -33.45°) by using linear interpolation on the SQRF coefficients and compared it with the data collected from April to December in 2018. It worth mentioning that none of the datasets collected at MED is part of the dataset used to build the SQRF model, hence the need to do interpolation. The second part of the analysis attempts to evaluate the accuracy for predicting the quiet daily field variation over Cachoeira Paulista (CXP, 22.70°S, 45.01°W, dip angle: -38.48°). The dataset collected at CXP prior to the period analyzed in the present work is part of the dataset used to build the SQRF model. Thus, the accuracy of the prediction is tested using magnetic data outside the time interval considered in the model. The results of the prediction for both locations show that the outputs from this empirical model present a good agreement with the Sq-H field obtained from the magnetic field data. The accuracy of the SQRF model (high correlation, r>0.9) provides a high potential for estimating and predicting geomagnetic quiet daily field variation for space weather applications, improving the scientific insight and capability of space weather prediction centers to predict the variability of the regular solar quiet field variation as reference conditions, which may include areas with no measurements.

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Evaluation of the Solar Quiet Reference Field (SQRF) model for space weather applications in the South America Magnetic Anomaly

Earth Planets and Space ◽

10.1186/s40623-021-01382-8 ◽

2021 ◽

Vol 73 (1) ◽

Author(s):

Sony Su Chen ◽

Clezio Marcos Denardini ◽

Láysa Cristina Araujo Resende ◽

Ronan Arraes Jardim Chagas ◽

Juliano Moro ◽

...

Keyword(s):

South America ◽

Magnetic Anomaly ◽

Space Weather ◽

Weather Prediction ◽

Magnetic Data ◽

Field Variation ◽

Reference Field ◽

The South ◽

Data Set ◽

Dip Angle

AbstractIn the present work, we evaluate the accuracy of the Solar Quiet Reference Field (SQRF) model for estimating and predicting the geomagnetic solar quiet (Sq) daily field variation in the South America Magnetic Anomaly (SAMA) region. This model is based on the data set of fluxgate magnetometers from 12 magnetic stations of the Embrace Magnetometer Network (Embrace MagNet) from 2010 to 2018. The model predicts the monthly average horizontal field of the geomagnetic quiet (Sq-H) daily variation solving a set of equations for the specified geographic coordinates in terms of the solar cycle activity, the day of the year, and the universal time. We carried out two comparisons between the prediction and observational data of the Sq-H field. The first part attempts to evaluate the accuracy for estimating the Sq-H field over Medianeira (MED, 25.30° S, 54.11° W, dip angle: − 33.45°) by using linear interpolation on the SQRF coefficients and comparing it with the data collected from April to December in 2018. None of the datasets collected at MED is part of the dataset used to build the SQRF model. The second part of the analysis attempts to evaluate the accuracy for predicting the quiet daily field variation over Cachoeira Paulista (CXP, 22.70° S, 45.01° W, dip angle: − 38.48°). The dataset collected at CXP before the period analyzed in the present work is part of the dataset used to build the SQRF model. Thus, the prediction accuracy is tested using magnetic data outside the time interval considered in the model. The prediction results for both locations show that this empirical model’s outputs present a good agreement with the Sq-H field obtained from the ground-based magnetometer measurements. The accuracy of the SQRF model (high correlation, r > 0.9) indicates a high potential for estimating and predicting geomagnetic quiet daily field variation. Concerning space weather applications, the model improves the scientific insight and capability of space weather prediction centers to predict the variability of the regular solar quiet field variation as reference conditions, which may include areas with no measurements.

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Evaluation of the Solar Quiet Reference Field (SQRF) Model for Space Weather Applications in the South America Magnetic Anomaly

10.21203/rs.3.rs-56044/v2 ◽

2020 ◽

Author(s):

Sony Su Chen ◽

Clezio Marcos Denardini ◽

Láysa C. A. Resende ◽

Ronan A. J. Chagas ◽

Juliano Moro ◽

...

Keyword(s):

South America ◽

Magnetic Anomaly ◽

Space Weather ◽

Linear Interpolation ◽

Field Variation ◽

Reference Field ◽

The South ◽

Data Set ◽

Magnetic Field Data ◽

Dip Angle

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Evaluation of the Solar Quiet Reference Field (SQRF) Model for Space Weather Applications in the South America Magnetic Anomaly

10.21203/rs.3.rs-56044/v1 ◽

2020 ◽

Author(s):

Sony Su Chen ◽

Clezio Marcos Denardini ◽

Láysa C. A. Resende ◽

Ronan A. J. Chagas ◽

Juliano Moro ◽

...

Keyword(s):

South America ◽

Magnetic Anomaly ◽

Space Weather ◽

Linear Interpolation ◽

Field Variation ◽

Reference Field ◽

The South ◽

Magnetic Field Data ◽

Functional Fitting ◽

Dip Angle

Abstract In the present work, we evaluate the accuracy of the Solar Quiet Reference Field (SQRF) model for forecasting and predicting the geomagnetic solar quiet (Sq) daily field variation in the South America Magnetic Anomaly (SAMA) region. The model simulates the monthly average horizontal field of the geomagnetic quiet (Sq-H) daily variation solving a set of functional fitting equations for the specified geographic coordinates. We carried out two comparisons between the simulated and observational data of the Sq-H field. The first part attempts to evaluate the accuracy for predicting the Sq-H field over Medianeira (25.30°S, 54.11°W, dip angle: -33.45°) by using linear interpolation on the SQRF coefficients. The second part of the analysis attempts to evaluate the accuracy for forecasting the quiet daily field variation over Cachoeira Paulista (22.70°S, 45.01°W, dip angle: -38.48°). The results of the simulation for both locations show that this empirical model presents a good agreement with the Sq-H field obtained from the magnetic field data. The accuracy of the SQRF model (high correlation, r>0.9) provides a high potential for estimating and forecasting geomagnetic quiet daily field variation for space weather applications. Therefore, this model could be useful in the Sq-H field regions near of SAMA.

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Performance of the IRI-2016 at the Brazilian low-latitude ionosphere over the South America Magnetic Anomaly during solar minimum

10.5194/angeo-2019-126 ◽

2019 ◽

Author(s):

Juliano Moro ◽

Jiyao Xu ◽

Clezio Marcos De Nardin ◽

Laysa Cristina Araújo Resende ◽

Régia Pereira Silva ◽

...

Keyword(s):

South America ◽

Magnetic Anomaly ◽

Critical Frequency ◽

Peak Height ◽

The South ◽

Iri Model ◽

Radio Science ◽

Critical Frequency Fof2 ◽

Dip Angle ◽

Navigation Signals

Abstract. In this work we analyse the ionograms obtained by the recent Digisonde installed in Santa Maria (29.7º S, 53.7º W, dip angle = − 37º), Brazil, to calculate the monthly averages of the F2 layer critical frequency (foF2), its peak height (hmF2), and the E-region critical frequency (foE) acquired during geomagnetically quiet days from September 2017 to August 2018. The monthly averages are compared to the 2016 version of the International Reference Ionosphere (IRI) model predictions in order to study its performance close to the center of the South America Magnetic Anomaly (SAMA), which is a region particularly important for High Frequency (HF) ground-to-satellite navigation signals. The foF2 estimated with the Consultative Committee International Radio (CCIR) and International Union of Radio Science (URSI) options predicts well throughout the year. Whereas, for hmF2, it is recommended to use the SHU-2015 option instead of the other available options (AMTB2013 and BSE-1979). The IRI-2016 model outputs for foE and the observations presented very good agreements.

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Multi-year GNSS monitoring of atmospheric IWV over Central and South America for climate studies

Annales Geophysicae ◽

10.5194/angeo-34-623-2016 ◽

2016 ◽

Vol 34 (7) ◽

pp. 623-639 ◽

Cited By ~ 13

Author(s):

Clara Eugenia Bianchi ◽

Luciano Pedro Oscar Mendoza ◽

Laura Isabel Fernández ◽

María Paula Natali ◽

Amalia Margarita Meza ◽

...

Keyword(s):

South America ◽

Water Vapour ◽

Weather Prediction ◽

High Rate ◽

Atmospheric Water ◽

Total Delay ◽

Data Set ◽

Atmospheric Water Vapour ◽

Climate Studies

Abstract. Atmospheric water vapour has been acknowledged as an essential climate variable. Weather prediction and hazard assessment systems benefit from real-time observations, whereas long-term records contribute to climate studies. Nowadays, ground-based global navigation satellite system (GNSS) products have become widely employed, complementing satellite observations over the oceans. Although the past decade has seen a significant development of the GNSS infrastructure in Central and South America, its potential for atmospheric water vapour monitoring has not been fully exploited. With this in mind, we have performed a regional, 7-year-long and homogeneous analysis, comprising 136 GNSS tracking stations, obtaining high-rate and continuous observations of column-integrated water vapour and troposphere zenith total delay. As a preliminary application for this data set, we have estimated local water vapour trends, their significance, and their relation with specific climate regimes. We have found evidence of drying at temperate regions in South America, at a rate of about 2 % per decade, while a slow moistening of the troposphere over tropical regions is also weakly suggested by our results. Furthermore, we have assessed the regional performance of the empirical model GPT2w to blindly estimate troposphere delays. The model reproduces the observed mean delays fairly well, including their annual and semi-annual variations. Nevertheless, a long-term evaluation has shown systematical biases, up to 20 mm, probably inherited from the underlying atmospheric reanalysis. Additionally, the complete data set has been made openly available as supplementary material.

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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)

Annales Geophysicae ◽

10.5194/angeo-38-457-2020 ◽

2020 ◽

Vol 38 (2) ◽

pp. 457-466

Author(s):

Juliano Moro ◽

Jiyao Xu ◽

Clezio Marcos Denardini ◽

Laysa Cristina Araújo Resende ◽

Régia Pereira Silva ◽

...

Keyword(s):

Magnetic Anomaly ◽

Critical Frequency ◽

Peak Height ◽

The South ◽

Iri Model ◽

Radio Science ◽

Critical Frequency Fof2 ◽

Dip Angle ◽

Navigation Signals ◽

Santa Maria

Abstract. In this work we analyze the ionograms obtained by the recent digisonde installed in Santa Maria (29.7∘ S, 53.7∘ W, dip angle = −37∘), Brazil, to calculate the monthly averages of the F2 layer critical frequency (foF2), its peak height (hmF2), and the E-region critical frequency (foE) acquired during geomagnetically quiet days from September 2017 to August 2018. The monthly averages are compared to the 2016 version of the International Reference Ionosphere (IRI) model predictions in order to study its performance close to the center of the South America Magnetic Anomaly (SAMA), which is a region particularly important for high-frequency (HF) ground-to-satellite navigation signals. The foF2 estimated with the Consultative Committee International Radio (CCIR) and International Union of Radio Science (URSI) options makes good predictions throughout the year, whereas, for hmF2, it is recommended to use the SHU-2015 option instead of the other available options (AMTB2013 and BSE-1979). The IRI-2016 model outputs for foE and the observations presented very good agreement.

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Occurrence and Modeling Examination of Sporadic‐ E Layers in the Region of the South America ( Atlantic ) Magnetic Anomaly

Journal of Geophysical Research Space Physics ◽

10.1029/2018ja026397 ◽

2019 ◽

Vol 124 (11) ◽

pp. 9676-9694 ◽

Cited By ~ 1

Author(s):

Fredson Conceição‐Santos ◽

Marcio T. A. H. Muella ◽

Laysa C. A. Resende ◽

Paulo R. Fagundes ◽

Vania F. Andrioli ◽

...

Keyword(s):

South America ◽

Magnetic Anomaly ◽

The South ◽

Sporadic E Layers ◽

Sporadic E

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The South America VLF Network (SAVNET): Providing new ground-based diagnostics of space weather conditions

2011 XXXth URSI General Assembly and Scientific Symposium ◽

10.1109/ursigass.2011.6050912 ◽

2011 ◽

Cited By ~ 1

Author(s):

Jean-Pierre Raulin

Keyword(s):

South America ◽

Space Weather ◽

Weather Conditions ◽

The South

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Comparison of long term series of total ozone and NO<sub>2</sub> column measurements in the southern tropics by SAOZ/NDACC UV-Vis spectrometers and satellites

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-6-4851-2013 ◽

2013 ◽

Vol 6 (3) ◽

pp. 4851-4893 ◽

Cited By ~ 1

Author(s):

M. Pastel ◽

J.-P. Pommereau ◽

F. Goutail ◽

A. Richter ◽

A. Pazmiño ◽

...

Keyword(s):

Indian Ocean ◽

South America ◽

Ozone Production ◽

South American ◽

American Continent ◽

The South ◽

Data Set ◽

Equatorial Latitude ◽

The Indian Ocean ◽

South American Continent

Abstract. Long series of ozone and NO2 total column measurements at the Southern tropics are available from two ground-based SAOZ (Système d'Analyse par Observation Zenithale) UV-visible spectrometers operated within the NDACC (Network for the Detection of Amtospheric Composition Change) deployed in Bauru in S-E Brazil and Reunion Island in the S-W Indian Ocean in 1995 and 1993 respectively. Although at the same latitude, the data show larger columns of both species above the South American continent than above the Indian Ocean. For verifying the reliability of these data before carrying out trend analysis, they have been compared to satellites observations available during the same period. However, since no single satellite was operating from 1995 until present, the comparison requires the building of a composite, called merged satellites series. As systematic differences exist between the individual data sets because of the many differences between instruments, spectral ranges, absorption cross-sections, and retrieval procedures used, the building of such a composite requires thorough evaluation and normalisation of each. From comparisons with SAOZ, the merged satellite data set build with EP-TOMS from 1995 to 2004 and OMI-TOMS from 2005 to 2012 are found best for ozone in the Southern tropics. After correction for biases with SAOZ, both are confirming the larger ozone columns reported by SAOZ above South America compared to the Indian Ocean shown to origin from ozone production by lightning NOx (LNOx) over the continent in the summer and the advection from Africa of ozone produced by biomass burning emissions in the winter. For NO2, best matching the SAOZ is a combination of GOME GDP4 1996–2003 and SCIAMACHY 2003–2012 products, after correction for the photochemical diurnal change of the concentration of the species between the SAOZ twilight observations and the time of satellites overpasses. The merged data series built from the data of these two satellites fully confirms the larger NO2 column reported by SAOZ above the South American continent as well as and its seasonality. The 35% larger column above Brazil in the summer is shown to be due to the NOx production in the upper troposphere by the frequent lightning during the thunderstorm season, whereas the winter maximum is shown to come from the larger exchange of NOx rich air with mid-latitudes in the lower stratosphere due to the more equatorial latitude of the subtropical jet above South America compared to the Indian Ocean.

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