The variation of ionosonde-derived hmF2 and its comparisons with International Reference Ionosphere (IRI) and Empirical Orthogonal Function (EOF) over Pakistan longitude sector during solar cycle 22

Fatima, Tooba; Ameen, Muhammad Ayyaz; Jabbar, Mehak Abdul; Baig, Mirza Jawwad

doi:10.1016/j.asr.2020.08.001

Cited by 9 publications

(4 citation statements)

References 36 publications

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“…It was established in the period of the Indus Valley Civilization, circa 5,000 BC. Latitude 30.18 N and longitude 71.48 E are the coordinates for Multan City (Fatima et al, 2021). Nonetheless, there has been no past research on the spatiotemporal changes in the urban green infrastructure, accept the authors own conference paper The inclusive governance of urban forest participants.…”

Section: Statement Of the Problem And Proposed Interventionmentioning

confidence: 98%

Urban forests and their contribution to sustainable urban development in a global context: a case study of Multan, Pakistan

Aleha,

Zahra,

Qureshi

et al. 2024

Front. Clim.

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Currently, cities and towns are home to over half of the global population, and this percentage will rise over the coming decades. Cities can be wonderful homes to live in if planned and maintained properly, but most urban developments have noticeably caused environmental destruction, which in turn results in issues like urban heat islands, flooding, and air pollution. Cities require forests as their breathing organs. The study refers to the case of Multan City, where the climate is deteriorating at an alarming rate due to rapid urbanization and the lack of vegetation. The study aims to provide an urban green infrastructure (UGI), which abides by the key proactive resilience principles of effectiveness, diversity, dependence, durability, versatility, autonomy, planning, and adaptability. A strategic literature review has been done to study the effects of urban forests, and various studies were reviewed as per the methodology adopted worldwide. The policy frameworks of the Sustainable Development Goals (SDGs) and the New Urban Agenda (NUA) were considered while selecting sites for implementing urban forests. A five-point Likert scale questionnaire was developed for the participation of the community nearby. Ten different sites were selected in the city based on ownership and feasibility, irrespective of SDG, NUA, and community opinions. The study concludes with the design suggestion of one site as a prototype in the given context.

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Section: Statement Of the Problem And Proposed Interventionmentioning

confidence: 98%

Urban forests and their contribution to sustainable urban development in a global context: a case study of Multan, Pakistan

Aleha,

Zahra,

Qureshi

et al. 2024

Front. Clim.

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“…It was first introduced by Dvinskikh (1988) and Dvinskikh and Naidenova (1991) into ionospheric studies. Since then, the EOF algorithm was widely used to build empirical models of the ionosphere (A et al, 2012;Fatima et al, 2021;Li et al, 2019Li et al, , 2021Zhang et al, 2021;Zhong et al, 2019, and references therein). In this study, the EOF algorithm was used to build the empirical model of effective scale heights based on the best-fit scale heights data set.…”

Section: Empirical Model Of Effective Scale Heightsmentioning

confidence: 99%

Section: Empirical Model Of Effective Scale Heightsmentioning

confidence: 99%

A Regional Model of Topside Ionospheric Effective Scale Heights Derived From Ionosonde and GNSS TEC

et al. 2023

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Ionospheric scale height is critical for the structure of electron density profile in the ionosphere. However, mostly, the effective scale heights (fitted with mathematical functions) instead of topside ionospheric scale heights were used to reconstruct the topside profile. In this study, a new method was proposed to estimate topside ionospheric effective scale heights from ionosonde and Global Navigation Satellite System (GNSS) vertical total electron content (TEC). First, the bottomside electron density profile can be estimated from ionograms. Then, combined the parameters of the F2 layer and effective scale heights, topside electron density profile can be estimated by Epstein Layer. Furthermore, ionosonde TEC can be compared with GNSS vertical TEC by adjusting effective scale heights to obtain best‐fit ionosonde TEC and effective scale heights. In this study, ionosonde and GNSS TEC data recorded at Zhangye station (39.40°N, 100.13°E) were used to test the performance. Results show that diurnal and seasonal characteristics of effective scale heights are consistent with previous studies. Furthermore, the Empirical Orthogonal Function technique was used to build a regional and empirical model of effective scale heights. Results show that the accuracy (between ±2.5 TECU) of ionosonde TEC are about 91.26% by comparing with GNSS TEC. Considered that the traditional methods mostly underestimated TEC, it indicates that the accuracy of ionosonde TEC can be improved significantly by the new model of effective scale heights. Furthermore, results show that the topside electron densities estimated by the proposed method are comparable with in situ observations measured by Swarm B.

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“…The height of the peak electron density in the ionospheric F2 layer (hmF2) is one of the critical parameters for predicting the HF communication link [10,11], which represents the distance from the point with the highest electron density in the ionosphere to the ground [12]. The prediction of hmF2 is helpful for the design [13,14] and operation of high-frequency propagation systems [15]. In addition, hmF2 is also helpful for calculating the drift velocity of vertical plasma, studying ionospheric electrodynamics, and enhancing the understanding of space weather environment [16].…”

Section: Introductionmentioning

confidence: 99%

A New Determining Method for Ionospheric F2-Region Peak Electron Density Height

Wang,

Yu,

Shi

et al. 2024

Remote Sensing

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The height of the F2 peak electron density (hmF2) is an essential parameter in studying ionospheric electrodynamics and high-frequency wireless communication. Based on ionosphere ray propagation theory, the physical relationship between M3000F2 and hmF2 is derived and visualized. Furthermore, based on the above physical theory and the machine learning method, this paper proposes a new model for determining hmF2 using propagation factor at a distance of 3000 km from the ionospheric F2 layer, time, and season. This proposed model is easy to understand and has the characteristics of clear principles, simple structure, and easy application. Furthermore, we used six stations in east Asia to verify this model and compare it with the other three models of the International Reference Ionosphere (IRI) model. The results show that the proposed model (PRO) has minor error and higher accuracy. Specifically the RMSE of the BSE, AMTB, SHU, and the PRO models were 20.35 km, 31.51 km, 13.59 km, and 5.68 km, respectively, and the RRMSE of the BSE, AMTB, SHU, and PRO models were 8.17%, 11.88%, 4.96%, and 2.12%, respectively. In addition, the experimental results show that the PRO model can better predict the trend of the hmF2 inflection point. This method can be further extended to add data sources and provide new ideas for studying the hmF2 over global regions.

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The variation of ionosonde-derived hmF2 and its comparisons with International Reference Ionosphere (IRI) and Empirical Orthogonal Function (EOF) over Pakistan longitude sector during solar cycle 22

Cited by 9 publications

References 36 publications

Urban forests and their contribution to sustainable urban development in a global context: a case study of Multan, Pakistan

Urban forests and their contribution to sustainable urban development in a global context: a case study of Multan, Pakistan

A Regional Model of Topside Ionospheric Effective Scale Heights Derived From Ionosonde and GNSS TEC

A New Determining Method for Ionospheric F2-Region Peak Electron Density Height

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