A critical note on the IAGA-endorsed Polar Cap (PC) indices: excessive excursions in the real-time index values

Abstract. The Polar Cap (PC) indices were approved by the International Association for Geomagnetism and Aeronomy (IAGA) in 2013 and made available at the web portal http://pcindex.org holding prompt (real-time) as well as archival index values. The present note provides the first reported examination of the validity of the IAGA-endorsed method to generate real-time PC index values. It is demonstrated that features of the derivation procedure defined by Janzhura and Troshichev (2011) may cause considerable excursions in the real-time PC index values compared to the final index values. In examples based on occasional downloads of index values, the differences between real-time and final values of PC indices were found to exceed 3 mV m−1, which is a magnitude level that may indicate (or hide) strong magnetic storm activity. Keywords. Magnetospheric physics (solar wind–magnetosphere interactions; polar cap phenomena) – ionosphere (modelling and forecasting)

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A critical note on the IAGA-endorsed Polar Cap index procedure: effects of solar wind sector structure and reverse polar convection

Annales Geophysicae ◽

10.5194/angeo-33-1443-2015 ◽

2015 ◽

Vol 33 (11) ◽

pp. 1443-1455 ◽

Cited By ~ 5

Author(s):

P. Stauning

Keyword(s):

Solar Wind ◽

International Association ◽

Sector Structure ◽

Polar Cap ◽

Azimuthal Component ◽

Index Procedure ◽

Polar Caps ◽

Critical Note ◽

Quiet Day ◽

Derivation Procedure

Abstract. The International Association of Geomagnetism and Aeronomy (IAGA) has recently endorsed a new Polar Cap (PC) index version to supersede the previous seven different versions of the PCN (North) index and the five different PCS (South) index versions. However, the new PC index has some adverse features which should be known and taken into account by users of the index. It uses in its derivation procedure an "effective" quiet day level (QDC) composed of a "basic" QDC and an added solar wind sector term related to the azimuthal component (By) of the interplanetary magnetic field (IMF). The added IMF By-related terms may introduce unjustified contributions to the PC index of more than 2 index units (mV m−1). Furthermore, cases of reverse convection during strong northward IMF Bz (NBZ) conditions included in the database for calculation of index coefficients can cause unjustified index enhancements of 0.5–1 mV m−1 during calm conditions, reduction of index values by more than 20 % during disturbed conditions, and inconsistencies between index coefficients and index values for the northern and southern polar caps. The aim here is to specify these adverse features and quantify their effects, and to suggest alternative steps for future modifications of the index procedure.

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Unreliable IAGA-endorsed Polar Cap (PC) index series and a different approach

10.5194/egusphere-egu2020-10195 ◽

2020 ◽

Author(s):

Peter Stauning

Keyword(s):

Solar Wind ◽

Real Time ◽

Space Weather ◽

Magnetic Data ◽

Reference Level ◽

Sector Structure ◽

Reference Levels ◽

Polar Cap ◽

The Real ◽

Critical Note

The Polar Cap (PC) indices are derived from the magnetic variations generated by the transpolar convection of magnetospheric plasma and embedded magnetic fields driven by the interaction with the solar wind. The PC indices are potentially very useful for Space Weather monitoring and forecasts and for related research. However, the PC index series in the near-real time and final versions endorsed by the International Association for Geomagnetism and Aeronomy (IAGA) have been proven unreliable (Stauning, 2013, 2015, 2018a,b,c, 2020). Both versions include solar wind sector (SWS) effects in the calculation of the reference levels from which magnetic disturbances are measured. The SWS effects are caused by current systems in the dayside Cusp region related to the Y-component, BY, of the Interplanetary Magnetic Field (IMF). However, the IAGA-endorsed handling of SWS effects may generate unfounded PC index changes of up to 3 mV/m at the nightside away from the Cusp. For the real-time PCN and PCS indices, their cubic spline-based reference level construction may cause additional unjustified index excursions of more than 3 mV/m with respect to the corresponding final index values. Noting that PC index values above 2 mV/m indicate geomagnetic storm conditions, such unjustified contributions are considered to invalidate the IAGA-endorsed PC index series. The presentation shall include a description of alternative derivation methods shown to provide more consistent index reference levels for both final and real-time PC indices, to reduce their unfounded excursions, and to significantly increase their reliability (Stauning, 2016, 2018b,c).References. Stauning, P. (2020): The Polar Cap (PC) index: invalid index series and a different approach. Space Weather, 2020SW002442 (submitted).Stauning, P. (2013). Comments on quiet daily variation derivation in &#8220;Identification of the IMF sector structure in near-real time by ground magnetic data&#8221; by Janzhura and Troshichev (2011). Annales Geophysicae, 31, 1221-1225. https://doi.org/10.5194/angeo-31-1221-2013 .Stauning, P. (2015). A critical note on the IAGA-endorsed Polar Cap index procedure: effects of solar wind sector structure and reverse polar convection. Annales Geophysicae, 33, 1443-1455. https://doi.org/10.5194/angeo-33-1443-2015 .Stauning, P. (2016). The Polar Cap (PC) Index.: Derivation Procedures and Quality Control. DMI Scientific Report SR-16-22. Available at: https://www.dmi.dk/fileadmin/user_upload/Rapporter/TR/2016/SR-16-22-PCindex.pdf .Stauning, P. (2018a). A critical note on the IAGA-endorsed Polar Cap (PC) indices: excessive excursions in the real-time index values. Annales Geophysicae, 36, 621&#8211;631. https://doi.org/10.5194/angeo-36-621-2018 .Stauning, P. (2018b): Multi-station basis for Polar Cap (PC) indices: ensuring credibility and operational reliability. Journal of Space Weather and Space Climate, 8, A07. https://doi.org/10.1051/swsc/2017036 .Stauning, P. (2018c). Reliable Polar Cap (PC) indices for space weather monitoring and forecast

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Reliable real-time Polar Cap (PC) indices for space weather monitoring and forecasts

Journal of Space Weather and Space Climate ◽

10.1051/swsc/2018031 ◽

2018 ◽

Vol 8 ◽

pp. A49 ◽

Cited By ~ 2

Author(s):

Peter Stauning

Keyword(s):

Real Time ◽

Space Weather ◽

International Association ◽

Magnetic Activity ◽

Magnetic Data ◽

Polar Cap ◽

International Scientific Community ◽

Order Of Magnitude ◽

General Basis ◽

Index Calculation

The Polar Cap (PC) indices were approved by the International Association for Geomagnetism and Aeromony (IAGA) by Resolution No. 3 (2013) noting that “IAGA … recommends use of the PC index by the international scientific community in its near-real time and definitive forms”. PC indices were made available in 2014 at the web portal http://pcindex.org holding near-real time as well as final index values. The near-real time PC index values are not permanently available. However, analyses of indices on basis of occasional downloads have detected differences between near-real time and final PC indices of up to 3.65 mV/m (Stauning, 2018b, Ann Geophys, 36, 621–631). At such differences, one or the other index may indicate (or hide) strong geomagnetic activity without justification in the actual conditions. The present work has disclosed the cause of observed large differences between real-time and final PC index values in the IAGA-endorsed versions. In addition, anticipated differences are derived on a general basis from the available basic magnetic data by using the index calculation procedures and calibration constants provided by the PC index suppliers. It is shown that corresponding or even larger anomalies are expected to be common during moderate to strong magnetic activity where the near-real time PC indices might otherwise prove very useful for space weather monitoring, e.g., for power grid protection. An alternative real-time PC index derivation scheme described here reduces the excessive differences between real-time and final PC index values by an order of magnitude.

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Comment on “Identification of the IMF sector structure in near-real time by ground magnetic data” by Janzhura and Troshichev (2011)

Annales Geophysicae ◽

10.5194/angeo-39-369-2021 ◽

2021 ◽

Vol 39 (2) ◽

pp. 369-377

Author(s):

Peter Stauning

Keyword(s):

Solar Wind ◽

Real Time ◽

International Association ◽

Magnetic Data ◽

Reference Level ◽

Sector Structure ◽

Polar Cap ◽

Ground Magnetic ◽

The Imf

Abstract. The only published description of the solar wind sector (SS) term used for the reference level in the post-event and real-time derivation of the Polar Cap (PC) indices, PCN (Polar Cap North) and PCS (Polar Cap South), in the version endorsed by the International Association for Geomagnetism and Aeronomy (IAGA) is found in the commented publication, Janzhura and Troshichev: Identification of the IMF sector structure in near-real time by ground magnetic data, Annales Geophysicae, 29, 1491–1500, 2011. Actually, the publication has served as a basis for the index endorsement by IAGA in 2013. However, neither the illustrations nor the results presented there have been derived by the specified near real-time method. Figures 1, 6, 7, and 8 display values derived by post-event calculations based on daily medians smoothed over 7 d centred on the day of interest. Figures 2, 3, and 4 display observed values smoothed over 7 d, while the remaining Fig. 5 displays averages over 4 months. In summary, there are strong disagreements between indications in the title, abstract, and statements in the text compared to the actual results and their illustrations.

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Comment on Identification of the IMF sector structure in near-real time by ground magnetic data by Janzhura and Troshichev (2011)

10.5194/angeo-2020-53 ◽

2020 ◽

Author(s):

Peter Stauning

Keyword(s):

Solar Wind ◽

Real Time ◽

International Association ◽

Magnetic Data ◽

Reference Level ◽

Sector Structure ◽

Polar Cap ◽

Ground Magnetic ◽

The Imf

Abstract. The only published description of the solar wind sector (SS) term used for the reference level in the post-event and real-time derivation of the Polar Cap (PC) indices, PCN (North) and PCS (South), in the version endorsed by the International Association for Geomagnetism and Aeronomy (IAGA) is found in the commented publication, Janzhura and Troshichev (2011): Identification of the IMF sector structure in near-real time by ground magnetic data, Annales Geophysicae, 29, 1491–1500. Actually, the publication has served as basis for the index endorsement by IAGA in 2013. However, neither the illustrations nor the results presented there have been derived by the specified near-real time method. Figs. 1, 6, 7, and 8 display values derived by post-event calculations based on daily medians smoothed over 7 days centred on the day of interest. Figs. 2, 3, and 4 display observed values smoothed over 7 days, while the remaining Fig. 5 displays averages over 4 months. In summary, there are strong disagreements between indications in the title, abstract, and statements in the text compared to the actual results and their illustrations.

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Syndrome and Outbreak Detection Using Chief-Complaint Data - Experience of the Real-Time Outbreak and Disease Surveillance Project

PsycEXTRA Dataset ◽

10.1037/e307182005-005 ◽

2004 ◽

Cited By ~ 3

Author(s):

Michael M. Wagner ◽

J. Espino ◽

F-C. Tsui ◽

P. Gesteland ◽

W. Chapman ◽

...

Keyword(s):

Real Time ◽

Disease Surveillance ◽

Chief Complaint ◽

Outbreak Detection ◽

The Real

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The Real-Time Neural Genesis of a Punchline

PsycEXTRA Dataset ◽

10.1037/e528942014-019 ◽

2014 ◽

Author(s):

Irving Biederman ◽

Ori Amir

Keyword(s):

Real Time ◽

The Real

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Real-Time System for Sending Data from Three Clients to One Server with MATLAB

ACMIT Proceedings ◽

10.33555/acmit.v2i1.7 ◽

2015 ◽

Vol 2 (1) ◽

pp. 35-41

Author(s):

Rivan Risdaryanto ◽

Houtman P. Siregar ◽

Dedy Loebis

Keyword(s):

Information System ◽

Real Time ◽

Time System ◽

Real Time System ◽

The Real ◽

Performance Time ◽

Data Process ◽

Effectiveness And Efficiency

The real-time system is now used on many fields, such as telecommunication, military, information system, evenmedical to get information quickly, on time and accurate. Needless to say, a real-time system will always considerthe performance time. In our application, we define the time target/deadline, so that the system should execute thewhole tasks under predefined deadline. However, if the system failed to finish the tasks, it will lead to fatal failure.In other words, if the system cannot be executed on time, it will affect the subsequent tasks. In this paper, wepropose a real-time system for sending data to find effectiveness and efficiency. Sending data process will beconstructed in MATLAB and sending data process has a time target as when data will send.

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