The Indian Institute of Geomagnetism is an autonomous research institution established by the Government of India's Department of Science and Technology. The facility is engaged in basic and applied research in geomagnetism, as well as allied areas of geophysics, atmospheric physics and space physics, as well as plasma physics. The Institute currently operates 12 magnetic observatories and actively participates in the Indian Antarctic Program.
This study investigates the interaction between Equatorial Plasma Bubbles (EPBs) and Medium Scale Traveling Ionospheric Disturbances (MSTIDs) observed on 31 January 2017 over low-latitude India using a multi-instrumental approach. OI Nightglow images from Panhala (16.48 degrees N, 74.6 degrees E, and 11.1 degrees N MLAT) and Gadanki (13.5 degrees N, 79.2 degrees E; similar to 6.6 degrees MLAT), ionosonde measurements from Tirunelveli, GPS TEC measurements from Hyderabad & Bangalore and geomagnetic data from India were analyzed to examine how MSTIDs influence EPB morphology, drift, and evolution. EPBs, typically drifting eastward after post-sunset pre-reversal enhancement of the zonal electric field via Rayleigh-Taylor instability, exhibited modulation by a south to north-westward propagating MSTID observed simultaneously at both ASI locations. This MSTIDs, induced elongation, intensification, and in some cases, dissipation of EPBs depending on their phase alignment. Keograms from both sites revealed consistent plasma perturbations, with Gadanki data confirming the presence and propagation of the same MSTID front, even near the magnetic equator. The h'F obtained from Canadian Advanced Digital Ionosonde observations from Tirunelveli (8.73 degrees N, 77.7 degrees E, and 1.6 degrees N MLAT) supported strong PRE-driven vertical uplift coinciding with EPB onset. Dual-frequency GPS-TEC analysis over Hyderabad (HYDE) and Bangalore (IISC) revealed quasi-periodic MSTIDs signatures with northwestward propagation indicating large-scale ionospheric disturbances likely driven by gravity waves. These results confirm MSTID-induced modulation of EPBs, validating gravity wave seeding as one of the key mechanism influencing equatorial ionospheric irregularities. The findings underscore the value of coordinated optical and radio measurements for understanding the horizontal and vertical coupling processes occurring at ionospheric altitudes.
Urbanisation and increasing vehicular emissions have led to a marked deterioration in air quality, particularly in rapidly developing Indian cities. This study evaluates the extent of anthropogenic pollution in the eastern region of Prayagraj, Uttar Pradesh, using a combined approach of magnetic susceptibility and Scanning Electron Microscope-Energy Dispersive X-ray Spectroscopy (SEM-EDS) analysis. A total of 111 samples, including road dust, topsoil, and tree leaf dust, were collected along five major traverses and analysed for low-frequency magnetic susceptibility (chi lf) and frequency-dependent susceptibility (chi fd%) to assess pollution load and magnetic grain characteristics. SEM-EDS imaging further confirmed the presence of angular to sub-rounded magnetic particles such as magnetite, hematite, ilmenite, pyrite, and trace heavy metals, including Pb, Ti, and Ce, associated with fossil fuel combustion and vehicular abrasion. Spatial variation in chi lf values enabled the classification of road sections into low, moderate, and high pollution zones, with northern and central parts of the city exhibiting significantly elevated magnetic signatures. The results underscore the effectiveness of magnetic susceptibility measurements and SEM imaging as rapid, non-destructive tools for urban pollution assessment. This integrated approach offers valuable insights for environmental monitoring, urban planning, and future pollution mitigation strategies in growing metropolitan areas.
Seismic activity can impact different layers of the Earth’s atmosphere; however, our understanding of lithosphere-atmosphere-ionosphere coupling mechanism still remains limited and is challenging. Previous studies predominantly feature seismo-ionospheric changes associated with large earthquakes/tsunamis. Seismic-induced changes in the Mesosphere-Lower Thermosphere (MLT) region have not been properly addressed and are limited to a few reports. We present, here, rare observations of anomalies in the temperature and airglow of the MLT region using Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on board Thermosphere Ionosphere Mesosphere Energetics Dynamics (TIMED) spacecraft measurements for 2025 Mw 8.8 Kamchatka Peninsula Earthquake. Beginning with the Mainshock at 23:24:52 UT on 29 July 2025, over a hundred aftershocks (with a majority exceeding intensity-scale of Mw 5.0) occurred near Petropavlovsk-Kamchatsky and Severo-Kuril’sk in Russia and activity continued beyond 31 July. We found an increase in temperature in the 73–83 km range on 30 July. However, the temperature decreased in the 87–97 km range on 30 and 31 July. Further, we noted a minor increase and distinct decrease in the volume emission rate of OH airglow on 30 July over the height range of 76–82 km and 83–90 km, respectively. Comparatively, significant decrease in OH airglow was seen on 31 July in the 81–96 km height range. Unusual gravity wave (GW) activity was, also, noted with predominant presence of waves with vertical wavelength of 18 km. Similar anomalous temperature enhancement and pronounced decrease in OH airglow was seen during the 2011 Mw 9.1 Tohoku-Oki earthquake as well.
The second Balloon Experiment on the Electrodynamics of Near Space (BEENS-2), launched from a tropical low-latitude site, utilized a novel, multi-material, lightweight payload designed for in situ measurements of stratospheric electric fields. Driven by a dual requirement for scientific precision and cost-effectiveness, the development of the payload necessitated overcoming complex engineering and manufacturing constraints. This article details the optimized structural design, the technical challenges encountered during the fabrication of critical components, and the innovative mechanical solutions implemented to ensure mission success. The structural integrity of the multi-material gondola is validated through Finite Element Analysis (FEA), which characterizes the displacement and stress distributions under simulated flight loads. Finally, the paper discusses the broader implications of these design strategies, offering a roadmap for implementing advanced manufacturing techniques and lightweight architectures in future high-altitude balloon and space-borne missions.
One of the most important criteria to distinguish wild grasses from those of cultivated ones lies in their pollen micro-morphological characteristics, which has proven to be an immensely useful tool in reconstruction of the past human influence and paleoecology. The investigation of 22 species of cereal and non-cereal pollen using Light Microscopy (LM), Confocal Laser Scanning Microscopy (CLSM), and Field Emission Electron Microscopy (FESEM) is a maiden attempt from India to develop a biometric threshold for distinguishing cereal and non-cereal pollen. When we realize pollen studies to solve the query related to anthropization or inception of agricultural activities, it is important to clearly distinguish pollen grains of wild from cultivated grasses from Central Ganga Plain, which is regarded as the food basket of the country. The 8 species of cereal and 14 species of non-cereal pollen possess significant differences in Grain Diameter (GD) and Annulus Diameter (AD). The paired threshold (46-9 mu m) appeared to be a discriminant pair, where cereal pollen bears the pollen grain and annulus diameter of above the threshold (>46, >9 mu m) and non-cereal possess less than (<46, <9 mu m). The pollen surface ornamentation of Poaceae pollen grains was also investigated extensively using FESEM for developing new tools to reconstruct past human habitation and climate. The various multivariate statistical analyses on the pollen micro-morphological characters, indicates the major clusters between the cereal and non-cereal pollen along with independent taxa, Zea mays. This extensive pollen morphological examination would provide a comprehensive dataset for the identification of fossil cereal and non-cereal pollen (upto the species level) in Ganga Plain and its comparison with other species growing around the country and neighboring regions.
