Influence of Solar and Geomagnetic Activity on the Ionospheric Sporadic-E Layer Over Baghdad

Duraid A. Al-Shakarchi; Mohammed I. Abd-Almajied; Marwa M. Yaseen

doi:10.1088/1755-1315/1531/1/012002

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Publication Date

Fri Aug 01 2025

Journal Name

Iop Conference Series: Earth And Environmental Science

Volume

1531

DOI

10.1088/1755-1315/1531/1/012002

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Influence of Solar and Geomagnetic Activity on the Ionospheric Sporadic-E Layer Over Baghdad

Duraid A. Al-Shakarchi

Mohammed I. Abd-Almajied

Marwa M. Yaseen

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AbstractThis study examines the monthly mean diurnal variations of the ionospheric sporadic E (Es) layer’s critical frequency (<italic>foEs</italic>) and virtual height (<italic>h′Es</italic>) above Baghdad city (latitude 33.3˚N, longitude 44.4˚E) during Solar Cycle 22 (1988–1995). The analysis examines their correlation with solar activity, represented by sunspot numbers, and geomagnetic disturbances, particularly during the descending phase of the cycle. The findings revealed that <italic>foEs</italic> values were the highest during the solar maximum years (1989–1991), aligning with increased sunspot numbers and geomagnetic activity due to coronal mass ejections (CMEs). However, during the declining phase (1993–1994), <italic>foEs</italic> exhibited a stronger dependence on geomagnetic disturbances from the recurrent solar wind structure Stream Interaction Regions (SIRs), suggesting that transient interplanetary space phenomena play a significant role in Eslayer dynamics. Additionally, <italic>h′Es</italic> demonstrated a distinct two-peak diurnal pattern, with maxima occurring in the morning local time (0800–0900 LT) (UCT+3) and late afternoon (1600–1800 LT). Seasonal variations affected peak timing, with summer months experiencing a delayed second peak compared to winter and autumn. The highest <italic>h′Es</italic> values were observed in 1989 and 1994, reflecting the dual influence of solar maximum conditions and increased geomagnetic activity accompanied by minor and moderate disturbances during the descending phase of the cycle. These results highlighted the complex interplay between solar and geomagnetic influences on Es-layer variability.

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Publication Date

Thu Nov 19 2020

Journal Name

Indonesian Journal Of Chemistry

Determination of Eugenol in Personal-Care Products by Dispersive Liquid-Liquid Microextraction Followed by Spectrophotometry Using p-Amino-N,N-dimethylaniline as a Derivatizing Agent

dispersive liquid-liquid microextraction

derivatizing agent

eugenol

p-amino-N

N-dimethylaniline

Bahaa Malik

Omar

Sarmad Bahjat

Keith Edward

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Two simple methods for the determination of eugenol were developed. The first depends on the oxidative coupling of eugenol with p-amino-N,N-dimethylaniline (PADA) in the presence of K3[Fe(CN)6]. A linear regression calibration plot for eugenol was constructed at 600 nm, within a concentration range of 0.25-2.50 μg.mL–1 and a correlation coefficient (r) value of 0.9988. The limits of detection (LOD) and quantitation (LOQ) were 0.086 and 0.284 μg.mL–1, respectively. The second method is based on the dispersive liquid-liquid microextraction of the derivatized oxidative coupling product of eugenol with PADA. Under the optimized extraction procedure, the extracted colored product was determined spectrophotometrically at 618 nm. A l

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