AuroraMag: Twin Explorer of Asymmetry in Aurora and Solar Wind-Magnetosphere Coupling See

In the present-day context, small satellites and their constellations consisting of varying sizes (nano, micro, pico satellites) are being favored for remote sensing and in situ probing of the heliosphere and terrestrial magnetosphere-ionosphere system. We introduce a mission concept aimed at concurrently observing Earth’s northern and southern auroral ovals while conducting in situ measurements of particles, fields, and electron temperature. The mission concept consists of two small satel...

Elevation dependency of precipitation and temperature over northeast India See

The study inspects the elevation dependency of temperature and precipitation across northeast India. Various gridded observations and outputs from high-resolution Regional Climate Models under the CORDEX-CORE framework have been employed. The better representation of the topography leads to higher orographic precipitation in the model environment. Positive vorticity led to strong convergence of the moisture-laden air resulting in high precipitation along the slopes of the mountains, w...

Neoarchean (ca. 2746–2501 Ma) magmatism: Evidence from east coast dykes of northeastern Southern Granulite Terrain, India See

We report new Sm–Nd whole rock-mineral isochron ages of 2514 ± 13 Ma (MSWD = 0.79) and 2651 ± 95 Ma (MSWD = 7.4) from two east coast dykes (ECD) of Southern Granulite Terrain (SGT), India. The ages from the representative maBc dyke samples correspond to the time of intrusion of ECD into the eastern part of SGT, indicating the presence of an older Archean crust in SGT near the Pondicherry coast. The Sm–Nd ages obtained from the present study, along with geochronological information from S...

Geodetic Evidence for Cascading Landslide Motion Triggered by Extreme Rain Events at Joshimath, NW Himalaya See

Slope instability due to tectonic, hydrological and anthropogenic activities cause severe landslides in Himalaya. Joshimath, a densely populated Himalayan town witnessed a catastrophic landslide event during December 2022 and January 2023 causing damages to ∼700 buildings. We use Interferometric synthetic aperture radar, Global Positioning System and rainfall measurements to probe the kinematics of the Joshimath landslide. We separate the seasonal and episodic deformation components using...

Differences in the characteristics and triggering mechanisms of two successive AL index onsets on 21st January 2005 See

Southward component of Interplanetary Magnetic Field (IMF) leads to the entry of energetic particles of solar origin into the magnetosphere. A part of this energy is subsequently released from the night-side as a geomagnetic substorm via the loading and unloading process in the magnetotail. However, other than this classical understanding of substorm, there exists an alternate particle entry mechanism, which mainly triggers weak to moderate substorms. So far, there is no clear understandi...

Effect of Background Wind and Dissipation Processes on the Semidiurnal Component of Atmospheric Solar Tides See

The equations governing the neutral wind velocities and temperature, which depict the oscillations of atmospheric tides, incorporate various elements of the atmosphere. These factors comprise background wind, temperature profiles, and the atmosphere's composition, including ozone, oxygen, carbon dioxide, water, etc. The current work describes the method of solution of the atmospheric tidal model and investigates the effects of background wind and dissipation processes on the migrati...

Special issue of SCOSTEP’s 15th Quadrennial Solar-Terrestrial Physics Symposium (STP-15)- Editorial See

The Scientific Committee on Solar-Terrestrial Physics (SCOSTEP, https://scostep.org/) runs the program of Predictability of the variable Solar-Terrestrial Coupling (PRESTO) in 2020–2024. The PRESTO program (https://scostep.org/presto/, Daglis et al., 2021) identifies predictability of the variable solar-terrestrial coupling performance metrics through modeling, measurements, and data analysis and to strengthen the communication between scientists and users. SCOSTEP's 15th Quadrennial Solar-Te...

Effect of the brightest gamma-ray burst (GRB 221009A) on low energy gamma-ray counts at sea level See

A gamma-ray burst, named GRB 221009A, occurred on 9 October 2022 and is the brightest ever observed GRB, whose frequency is now estimated as once in 10,000 years. This GRB was reported to be observed from many space missions, VLF receivers, and ground observations in optical and radio data. Additionally, a strikingly large number of very high energy (VHE) photons associated with this GRB were observed by the gamma-ray and cosmic ray observatory LHAASO. Though gamma-rays of cosmic origin ...

Simultaneous OI 630 nm imaging observations of thermospheric gravity waves and associated revival of fossil depletions around midnight near the equatorial ionization anomaly (EIA) crest See

We report F-region airglow imaging of fossil plasma depletions around midnight that revived afresh un der persisting thermospheric gravity wave (GW) activity. An all-sky imager recorded these events in OI 630 nm imag ing over Ranchi (23.3° N, 85.3° E; mlat. ∼ 19° N), India, on 16 April 2012. Northward-propagating and east–west aligned GWs (λ ∼ 210 km, v ∼ 64 m s−1 , and τ ∼ 0.91 h) were seen around midnight. Persisting for ∼ 2 h, this GW activity revived two co-existing and eastward-dri...

Impact of monsoon season rainfall spells on the ecosystem carbon exchanges of Himalayan Chir‑Pine and Banj‑Oak‑dominated forests: a comparative assessment See

The Chir-Pine (Pinus roxburghii) and Banj-Oak (Quercus leucotrichophora)-dominated ecosystems of central Himalaya provide significant green services. However, responses of these ecosystems, with respect to ecosystem carbon flux variability, to changing microclimate are not yet studied. Since quantification of ecosystem responses to fluctuation in the microclimate, particularly rainfall, is expected to be beneficial for management of these ecosystems, this study aims (i) to quantify a...

Climate change over Indonesia and its impact on nutmeg production: An analysis under high-resolution CORDEX-CORE regional simulation framework See

Nutmeg is an important spice and contributes significantly to the gross domestic product of Indonesia. The study examines the impact of climate change on Indonesia and the production of nutmeg over Banda Neira Island. For this, the outputs from high-resolution regional climate models under different representative concentration pathways (RCP2.6, RCP4.5 and RCP8.5), within the framework of Coupled Model Intercomparison Project 5/Coordinated Regional Climate Down-scaling Experiment-Coordi...

Impact of solar variability on Indian summer monsoon through large scale circulations See

Via large-scale circulations, the role of solar variability on the Indian summer monsoon is investigated. Standardized anomaly is used to identify years of solar maxima and minima. Statistical analysis such as moving mean, empirical mode decomposition, and wavelet analysis are used to determine the plausible relationship between solar variability, large scale circulations such as El- Ni˜ no 3.4 SST anomaly, Dipole Mode Index (DMI), and Atlantic Multidecadal Oscillation (AMO), and Indian summe...

‘Reach the Unreached’: a perspective for public outreach in Earth and space science See

Conducting public outreach activities for students and the general public has been an integral part of several research organizations. It is a way to communicate with common people to make them aware of the research work at any institution. However, the COVID-19 pandemic affected these activities. Even during the post-pandemic period, the response to public outreach programmes has been poor. To deal with this situation, an initiative called ‘Reach the Unreached’ has been implemented at the In...

Global Precipitation Experiment - A New World Climate Research Programme Lighthouse Activity See

The future state of the global water cycle and prediction of freshwater availability for humans around the world remain among the challenges of climate research and are relevant to several United Nations Sustainable Development Goals. The Global Precipitation EXperiment (GPEX) takes on the challenge of improving the prediction of precipitation quantity, phase, timing and intensity, characteristics that are products of a complex integrated system. It will achieve this by leveraging e...

Magnetotelluric evidence for the thermotectonic architecture of a Paleoproterozoic rift basin in southwestern India See

The Kaladgi basin is one of the major Paleoproterozoic rift basins in Peninsular India. Here we attempt to reconstruct the architecture of the basin and evaluate the deep tectonics using magnetotelluric evidence. We identify thermo-tectonic rejuvenations of the lithospheric structure, with the continental lithosphere showing tectonic channeling of the thermo-magmatic fluxes in lateral and vertical directions. Our magnetotelluric profile passes adjacent to the Ramdurg, Kaladgi and Bilg...

Effects of Solar Variability on Tropical Cyclone Activity See

The current study explores the relationship between solar variability and tropical cyclone (TC) activity using sunspot number (SSN) and TC best‐track data as respective proxies. We have considered six regions of the globe, for example, EP: Eastern Pacific, NA: North Atlantic, NI: North Indian, SI: South Indian, SP: South Pacific, and WP: Western Pacific. The results show strong anti‐correlation between yearly TC activity and yearly SSN while considering their 11‐year moving averages. This...

Imaging saline water ingress in coastal aquifers of Maharashtra using electrical resistivity technique constrained by geochemical data See

Due to rapid development in and around the coastal zones, there is a growing demand on the water resources. These regions are vulnerable to erosion, flooding due to river floods or tidal waves or rising sea level, saline water intrusion and contamination of the aquifers. The coastal zones are of attraction to tourists, besides activates like agriculture practices, aqua-culture, industries and effluents, which are having an immense bearing on environment apart from economic, social and cu...

Coupling of the solar driven prolonged and transient processes to the equatorial and low latitude ionosphere See

A brief summary of important and new findings is listed below: • Studied the local time response of the geomagnetic storms on the ESF irregularities over Indian region under geomagnetic storms based on Aarons criteria. The analysis of the results suggests that occurrence of ESF irregularities is always not followed the Aarons criteria. • The role of different seasons on the Aarons criteria also suggests that there is no consistent pattern emerged in the favor of Aarons criteria. The resul...

Statistical Scintillation Indices in Polar Ionospheric Climatology See

It has been established that polar cap patches are capable of triggering phase scintillation via various convective instabilities such as Gradient Drift, Gravitational Interchange, Current Convective, and Kelvin-Helmholtz Instabilities coupled with turbulent plasma processes in the cold and warm approximation. These multiple instabilities provide a qualitative density peaking mechanism which ultimately leads to the formation of highly dense and coherent nonlinear structures such as polar patc...