{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,17]],"date-time":"2026-04-17T04:59:48Z","timestamp":1776401988310,"version":"3.51.2"},"reference-count":53,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2023,9,1]],"date-time":"2023-09-01T00:00:00Z","timestamp":1693526400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Italian PNRA","award":["PNRA18_002 89-A"],"award-info":[{"award-number":["PNRA18_002 89-A"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Among the effects of space weather, the degradation of air traffic communications and satellite-based navigation systems are the most notable. For this reason, it is of uttermost importance to understand the nature and origin of ionospheric irregularities that are at the base of the observed communication outages. Here we focus on polar cap patches (PCPs) that constitute a special class of ionospheric irregularities observed at very high latitudes in the F region. To this purpose we use the so-called PCP flag, a Swarm Level 2 product, that allows for identifying PCPs. We relate the presence of PCPs to the values of the first- and second-order scaling exponents and intermittency estimated from Swarm A electron density fluctuations and to the values of the Rate Of change of electron Density Index (RODI) for two different levels of geomagnetic activity, over a time span of approximately 3.5 years starting on 16 July 2014. Our findings show that values of RODI, first- and second-order scaling exponents and intermittency corresponding to measurements taken inside PCPs differ from those corresponding to measurements taken outside PCPs. Additionally, the values of the first- and second-order scaling exponents and of intermittency indicate that PCPs are in a turbulent state. Investigation of the coincidence of loss of lock (LoL) events with PCPs displayed that approximately 57.4% of LoLs in the Northern hemisphere and 45.7% in the Southern hemisphere occur in coincidence of PCPs when disturbed geomagnetic activity is considered. During quiet geomagnetic conditions these percentages decrease to 51.4% in the Northern hemisphere and to 20.1% in the Southern hemisphere.<\/jats:p>","DOI":"10.3390\/rs15174320","type":"journal-article","created":{"date-parts":[[2023,9,1]],"date-time":"2023-09-01T08:45:31Z","timestamp":1693557931000},"page":"4320","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Polar Cap Patches Scaling Properties: Insights from Swarm Data"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1836-4078","authenticated-orcid":false,"given":"Roberta","family":"Tozzi","sequence":"first","affiliation":[{"name":"Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, 00143 Rome, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2708-0739","authenticated-orcid":false,"given":"Paola","family":"De Michelis","sequence":"additional","affiliation":[{"name":"Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, 00143 Rome, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7395-4767","authenticated-orcid":false,"given":"Giulia","family":"Lovati","sequence":"additional","affiliation":[{"name":"Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, 00143 Rome, Italy"},{"name":"Dipartimento di Fisica, Universit\u00e0 di Roma Sapienza, 00185 Rome, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3403-647X","authenticated-orcid":false,"given":"Giuseppe","family":"Consolini","sequence":"additional","affiliation":[{"name":"INAF-Istituto di Astrofisica e Planetologia Spaziali, Via del Fosso del Cavaliere 100, 00133 Rome, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9459-4919","authenticated-orcid":false,"given":"Alessio","family":"Pignalberi","sequence":"additional","affiliation":[{"name":"Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, 00143 Rome, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5800-2322","authenticated-orcid":false,"given":"Michael","family":"Pezzopane","sequence":"additional","affiliation":[{"name":"Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, 00143 Rome, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4070-6828","authenticated-orcid":false,"given":"Igino","family":"Coco","sequence":"additional","affiliation":[{"name":"Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, 00143 Rome, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9691-8910","authenticated-orcid":false,"given":"Fabio","family":"Giannattasio","sequence":"additional","affiliation":[{"name":"Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, 00143 Rome, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5002-6060","authenticated-orcid":false,"given":"Maria Federica","family":"Marcucci","sequence":"additional","affiliation":[{"name":"INAF-Istituto di Astrofisica e Planetologia Spaziali, Via del Fosso del Cavaliere 100, 00133 Rome, Italy"}]}],"member":"1968","published-online":{"date-parts":[[2023,9,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"719","DOI":"10.1029\/RG026i004p00719","article-title":"High-latitude F region irregularities: A review and synthesis","volume":"26","author":"Tsunoda","year":"1988","journal-title":"Rev. Geophys."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"257","DOI":"10.26464\/epp2018025","article-title":"A brief review of equatorial ionization anomaly and ionospheric irregularities","volume":"2","author":"Balan","year":"2018","journal-title":"Earth Planet. Phys."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"e2020JA028103","DOI":"10.1029\/2020JA028103","article-title":"Ionospheric Plasma Irregularities Based on In Situ Measurements From the Swarm Satellites","volume":"125","author":"Jin","year":"2020","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Bhattacharyya, A. (2022). Equatorial Plasma Bubbles: A Review. Atmosphere, 13.","DOI":"10.3390\/atmos13101637"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1029\/2011RS004946","article-title":"Sharpening our thinking about polar cap ionospheric patch morphology, research, and mitigation techniques","volume":"47","author":"Carlson","year":"2012","journal-title":"Radio Sci."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"4452","DOI":"10.1002\/2015JA021188","article-title":"Electron density enhancements in the polar cap during periods of dayside reconnection","volume":"120","author":"Clausen","year":"2015","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1731","DOI":"10.1029\/92GL01993","article-title":"Production of polar cap electron density patches by transient magnetopause reconnection","volume":"19","author":"Lockwood","year":"1992","journal-title":"Geophys. Res. Lett."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1103\/PhysRevLett.6.47","article-title":"Interplanetary Magnetic Field and the Auroral Zones","volume":"6","author":"Dungey","year":"1961","journal-title":"Phys. Rev. Lett."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1262","DOI":"10.1029\/2018JA026063","article-title":"Ionospheric Plasma Irregularities Characterized by the Swarm Satellites: Statistics at High Latitudes","volume":"124","author":"Jin","year":"2019","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"195","DOI":"10.1029\/93RS01515","article-title":"Irregularity structures in the cusp\/cleft and polar cap regions","volume":"29","author":"Basu","year":"1994","journal-title":"Radio Sci."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"A12323","DOI":"10.1029\/2010JA015710","article-title":"In situ measurement of a newly created polar cap patch","volume":"115","author":"Lorentzen","year":"2010","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"L07104","DOI":"10.1029\/2012GL051407","article-title":"First in-situ measurements of HF radar echoing targets","volume":"39","author":"Moen","year":"2012","journal-title":"Geophys. Res. Lett."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"996","DOI":"10.1002\/2014GL062610","article-title":"Swarm in situ observations of F region polar cap patches created by cusp precipitation","volume":"42","author":"Goodwin","year":"2015","journal-title":"Geophys. Res. Lett."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"201","DOI":"10.1002\/2014GL062590","article-title":"Observation of polar cap patches and calculation of gradient drift instability growth times: A Swarm case study","volume":"42","author":"Spicher","year":"2015","journal-title":"Geophys. Res. Lett."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"289","DOI":"10.1002\/rds.20033","article-title":"Long-term analysis of ionospheric polar patches based on CHAMP TEC data","volume":"48","author":"Noja","year":"2013","journal-title":"Radio Sci."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"3439","DOI":"10.1002\/2015JA021895","article-title":"Polar cap plasma patch primary linear instability growth rates compared","volume":"121","author":"Burston","year":"2016","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"3837","DOI":"10.1002\/2016JA023750","article-title":"Interhemispheric study of polar cap patch occurrence based on Swarm in situ data","volume":"122","author":"Spicher","year":"2017","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"144","DOI":"10.1029\/JA087iA01p00144","article-title":"Non-linear evolution of plasma enhancements in the auroral ionosphere 1. Long wavelength irregularities","volume":"87","author":"Keskinen","year":"1982","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"De Michelis, P., Consolini, G., Tozzi, R., Pignalberi, A., Pezzopane, M., Coco, I., Giannattasio, F., and Marcucci, M.F. (2021). Ionospheric Turbulence and the Equatorial Plasma Density Irregularities: Scaling Features and RODI. Remote Sens., 13.","DOI":"10.3390\/rs13040759"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"6183","DOI":"10.1038\/s41598-021-84985-1","article-title":"Looking for a proxy of the ionospheric turbulence with Swarm data","volume":"11","author":"Consolini","year":"2021","journal-title":"Sci. Rep."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"e2022SW003129","DOI":"10.1029\/2022SW003129","article-title":"Ionospheric Turbulence: A Challenge for GPS Loss of Lock Understanding","volume":"20","author":"Consolini","year":"2022","journal-title":"Space Weather"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"351","DOI":"10.1186\/BF03351933","article-title":"Swarm: A constellation to study the Earth\u2019s magnetic field","volume":"58","author":"Hulot","year":"2006","journal-title":"Earth Planets Space"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"2655","DOI":"10.1002\/2016JA022571","article-title":"Thermal ion imagers and Langmuir probes in the Swarm electric field instruments","volume":"122","author":"Knudsen","year":"2017","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Pezzopane, M., Pignalberi, A., Coco, I., Consolini, G., De Michelis, P., Giannattasio, F., Marcucci, M.F., and Tozzi, R. (2021). Occurrence of GPS Loss of Lock Based on a Swarm Half-Solar Cycle Dataset and Its Relation to the Background Ionosphere. Remote Sens., 13.","DOI":"10.3390\/rs13112209"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1002\/2017RS006415","article-title":"Calibration and Validation of Swarm Plasma Densities and Electron Temperatures Using Ground-Based Radars and Satellite Radio Occultation Measurements","volume":"53","author":"Lomidze","year":"2018","journal-title":"Radio Sci."},{"key":"ref_26","unstructured":"(2023, August 31). Swarm L1b Product Definition. Available online: https:\/\/earth.esa.int\/documents\/10174\/1514862\/Swarm_L1b_Product_Definition."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"807","DOI":"10.1002\/2014JA020330","article-title":"Topside ionospheric irregularities as seen from multisatellite observations","volume":"120","author":"Zakharenkova","year":"2015","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"e2020JA027934","DOI":"10.1029\/2020JA027934","article-title":"On the 2015 St. Patrick\u2019s Storm Turbulent State of the Ionosphere: Hints From the Swarm Mission","volume":"125","author":"Pignalberi","year":"2020","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"703","DOI":"10.5194\/angeo-38-703-2020","article-title":"From the Sun to Earth: Effects of the 25 August 2018 geomagnetic storm","volume":"38","author":"Piersanti","year":"2020","journal-title":"Ann. Geophys."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"104675","DOI":"10.1016\/j.cageo.2020.104675","article-title":"TITIPy: A Python tool for the calculation and mapping of topside ionosphere turbulence indices","volume":"148","author":"Pignalberi","year":"2021","journal-title":"Comput. Geosci."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"e2021JA030183","DOI":"10.1029\/2021JA030183","article-title":"Ionospheric Plasma IRregularities-IPIR-Data product based on data from the Swarm satellites","volume":"127","author":"Jin","year":"2022","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_32","unstructured":"(2023, August 31). Swarm Product Specification for L2 Products and Auxiliary Products. Available online: https:\/\/earth.esa.int\/eogateway\/documents\/20142\/37627\/swarm-level-2-product-specification.pdf\/2979b351-b6a2-69b6-8539-9ed9f32984f0."},{"key":"ref_33","unstructured":"(2023, August 31). Swarm Handbook\u2014Level 2 Product Definitions Introduction. Available online: https:\/\/swarmhandbook.earth.esa.int\/article\/introduction#:~:text=Level%202%20products%20are%20typically,well%20as%20ground%2Dbased%20observations."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"23819","DOI":"10.1029\/95JA02700","article-title":"Adaptive identification and characterization of polar ionization patches","volume":"100","author":"Coley","year":"1995","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"2327","DOI":"10.1002\/2017JA024811","article-title":"Annual Occurrence Rates of Ionospheric Polar Cap Patches Observed Using Swarm","volume":"123","author":"Chartier","year":"2018","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"e2020JA028538","DOI":"10.1029\/2020JA028538","article-title":"Occurrence Distribution of Polar Cap Patches: Dependences on UT, Season and Hemisphere","volume":"126","author":"Kagawa","year":"2020","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"10726","DOI":"10.1029\/2019GL083952","article-title":"Hemispherical Shifted Symmetry in Polar Cap Patch Occurrence: A Survey of GPS TEC Maps From 2015\u20132018","volume":"46","author":"David","year":"2019","journal-title":"Geophys. Res. Lett."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"785","DOI":"10.1029\/JZ071i003p00785","article-title":"Auroral electrojet activity index AE and its universal time variations","volume":"71","author":"Davis","year":"1966","journal-title":"J. Geophys. Res."},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Frisch, U. (1995). Turbulence: The Legacy of A. N. Kolmogorov, Cambridge University Press.","DOI":"10.1017\/CBO9781139170666"},{"key":"ref_40","first-page":"476","article-title":"The Spectrum of Turbulence","volume":"164","author":"Taylor","year":"1938","journal-title":"Proc. R. Soc. Lond. Ser. A-Math. Phys. Sci."},{"key":"ref_41","first-page":"519","article-title":"Methods of using long-term storage in reservoirs","volume":"5","author":"Hurst","year":"1956","journal-title":"Proc. Inst. Civ. Eng."},{"key":"ref_42","unstructured":"Wiener, N. (1964). Time Series, M.I.T. Press."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"3100","DOI":"10.1002\/2015GL063603","article-title":"Magnetic field fluctuation features at Swarm\u2019s altitude: A fractal approach","volume":"42","author":"Consolini","year":"2015","journal-title":"Geophys. Res. Lett."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"105531","DOI":"10.1016\/j.jastp.2020.105531","article-title":"High-latitude polar pattern of ionospheric electron density: Scaling features and IMF dependence","volume":"217","author":"Consolini","year":"2021","journal-title":"J. Atmos. Sol.-Terr. Phys."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"2","DOI":"10.12942\/lrsp-2013-2","article-title":"The Solar Wind as a Turbulence Laboratory","volume":"10","author":"Bruno","year":"2013","journal-title":"Living Rev. Sol. Phys."},{"key":"ref_46","doi-asserted-by":"crossref","unstructured":"De Michelis, P., Consolini, G., Alberti, T., Tozzi, R., Giannattasio, F., Coco, I., Pezzopane, M., and Pignalberi, A. (2022). Magnetic Field and Electron Density Scaling Properties in the Equatorial Plasma Bubbles. Remote Sens., 14.","DOI":"10.3390\/rs14040918"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"91","DOI":"10.1007\/BF00241347","article-title":"The status of observations and theory of high latitude ionospheric and magnetospheric plasma turbulence","volume":"41","author":"Kintner","year":"1985","journal-title":"Space Sci. Rev."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"115","DOI":"10.1029\/JA093iA01p00115","article-title":"Simultaneous density and electric field fluctuation spectra associated with velocity shears in the auroral oval","volume":"93","author":"Basu","year":"1988","journal-title":"J. Geophys. Res."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"7799","DOI":"10.1029\/JA095iA06p07799","article-title":"Plasma structuring by the gradient drift instability at high latitudes and comparison with velocity shear driven processes","volume":"95","author":"Basu","year":"1990","journal-title":"J. Geophys. Res."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"1497","DOI":"10.1029\/JA079i010p01497","article-title":"In situ measurements of the spectral characteristics of F region ionospheric irregularities","volume":"79","author":"Dyson","year":"1974","journal-title":"J. Geophys. Res."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"755","DOI":"10.1029\/RS020i004p00755","article-title":"Unstable density gradients in the high-latitude ionosphere","volume":"20","author":"Cerisier","year":"1985","journal-title":"Radio Sci."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"609","DOI":"10.1002\/2016GL071168","article-title":"Localized polar cap precipitation in association with nonstorm time airglow patches","volume":"44","author":"Zou","year":"2017","journal-title":"Geophys. Res. Lett."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"10959","DOI":"10.1002\/2015JA021634","article-title":"Plasma turbulence and coherent structures in the polar cap observed by the ICI-2 sounding rocket","volume":"120","author":"Spicher","year":"2015","journal-title":"J. Geophys. Res. Space Phys."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/15\/17\/4320\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T20:45:05Z","timestamp":1760129105000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/15\/17\/4320"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,9,1]]},"references-count":53,"journal-issue":{"issue":"17","published-online":{"date-parts":[[2023,9]]}},"alternative-id":["rs15174320"],"URL":"https:\/\/doi.org\/10.3390\/rs15174320","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,9,1]]}}}