Dora Pancheva

Prof. Dr. Dora Pancheva


Research Focus & Metrics

Academic Career Length

3Years (2024-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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30 October 2024 in Remote Sensing
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Journal Article
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RBRumiana Bojilova
Rumiana Bojilova
PMPlamen Mukhtarov
Plamen Mukhtarov
DPDora Pancheva
Dora Pancheva
The main idea of the present study is to investigate in detail the time evolution of the spatial inhomogeneities connected with the ionospheric response to the geomagnetic storm registered in the period of 10–11 May 2024. The obtained ionospheric anomalies represented by the relative deviations of the global Total Electron Content (TEC) data have been utilized in the analysis. The used global TEC data have been converted to a coordinate system with a modip latitude and geographical longitude. In addition to the maps illustrating the global spatial distribution of the geomagnetically forced ionospheric anomalies, a presentation of the observed longitudinal structures by sinusoidal approximation has also been used. The resulting positive and negative responses have been studied depending on the magnetic latitude, local times and the behavior of the geomagnetic activity parameters during the considered event. The interpretation takes into account the known mechanisms for the effect of the geomagnetic storm on the electron density. A special attention is focused on the differences in the two hemispheres at high and mid latitudes, where a simultaneous direct impact of the particle precipitation and the change in the temperature regime of the neutral atmosphere has been assumed. The low-latitude response as a result of the Equatorial Ionization Anomaly (EIA) associated with Disturbed Dynamo Electric Fields (DDEFs) and its relationship with local time has also been considered.

12 April 2024 in Atmosphere
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Journal Article
Open access
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DPDora Pancheva
Dora Pancheva
PMPlamen Mukhtarov
Plamen Mukhtarov
RBRumiana Bojilova
Rumiana Bojilova
This paper presents climatological features of the longitudinal structures WN4, WN3, and WN2 and their drivers observed in the lower thermospheric temperatures and in the ionospheric TEC. For this purpose, two long-term data sets are utilized: the satellite SABER/TIMED temperature measurements, and the global TEC maps generated with the NASA JPL for the interval of 2002–2022. As the main drivers of the longitudinal structures are mainly nonmigrating tides, this study first investigates the climatology of those nonmigrating tides, which are the main contributors of the considered longitudinal structures; these are nonmigrating diurnal DE3, DE2, and DW2, and semidiurnal SW4 and SE2 tides. The climatology of WN4, WN3, and WN2 structures in the lower thermosphere reveals that WN4 is the strongest one with a magnitude of ~20 K observed at 10° S in August, followed by WN2 with ~13.9 K at 10° S in February, and the weakest is WN3 with ~12.4 K observed over the equator in July. In the ionosphere, WN3 is the strongest structure with a magnitude of 5.9 TECU located at −30° modip latitude in October, followed by WN2 with 5.4 TECU at 30 modip in March, and the last is WN4 with 3.7 TECU at −30 modip in August. Both the climatology of the WSA and the features of its drivers are investigated as well.

6 March 2026 in Preprints.org
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Preprint
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DPDora Pancheva
Dora Pancheva
PMPlamen Mukhtarov
Plamen Mukhtarov
This paper investigates the seasonal and daily responses of the zonal‑mean O₃ mass‑mixing ratio to polar‑vortex disturbances during the boreal winter of 2023/2024, using MERRA‑2 data for the period 1 October 2023–30 April 2024. In addition to the expected latitudinal coupling during SSW events, the seasonal ozone field exhibited a pronounced zonally asymmetric distribution, referred to as the zonally asymmetric ozone oscillation (ZAOO), most evident in the lower stratosphere throughout the winter months. The seasonal behaviour of the ozone tendency was also investigated. To provide a plausible explanation for the observed features, a combination of the Quasi-biennial oscillation (QBO), dynamical transport, and photochemical processes was considered. For the first time, TEM diagnostics were applied to individual winter seasons and specific SSW events, enabling detailed examination of ozone‑tendency variability across latitude and altitude. The results provide clear quantification of the dynamical and net chemical contributions to both the seasonal (October–April) and specific SSW event ozone tendencies. These findings support systematic assessments of each intriguing winter and SSW event, offering new opportunities to identify links between SSW type and the dominant mechanisms shaping the ozone‑tendency response.