The Indian Institute of Geomagnetism (IIG), Mumbai is a leading institute of the country, actively engaged in basic and applied research in Geomagnetism and allied areas of Geophysics, Atmospheric & Space Physics and Plasma Physics. Geomagnetism is an area of study that is truly multidisciplinary encompassing such disciplines like physics, mathematics, geology, geophysics, atmospheric physics, plasma physics, fluid dynamics, geochemistry and non-linear dynamics, to name a few. The study of Geomagnetism encompasses the entire Heliosphere starting from the centre of the Earth extending to all the planets and the Sun itself.
Since its inception in 1841, the Colaba-Alibag Observatory has been producing high quality geomagnetic records for more than 175 years. The Indian Institute of Geomagnetism (IIG) became autonomous in 1971 and is now under the Department of Science & Technology, Government of India. It currently operates 12 geomagnetic observatories and three regional centres at Tirunelveli, Prayagraj and Shillong. The Institute regularly participates in the Indian Expeditions to the Arctic and Antarctic.
The vision of IIG is to enable India become a global knowledge centre in Geomagnetism and allied fields. The Institute’s mandate is also to maintain and modernize the magnetic observatories under its magnetometer network, establish new observatories and publish high quality data as Indian Magnetic Data volumes. The magnetic records from these observatories serve as useful tools for the study of electrical current systems flowing in the near space environment, the understanding of which has a bearing on monitoring and assessing the health of satellite navigation systems. The World Data Center (WDC)-Geomagnetism, Mumbai, is now a member of the International Council for Science-World Data System. IIG is also involved in the calibration of magnetic compasses of Indian Navy, Indian Coast Guard, Naval Air Stations, and providing services to ISRO, DRDO, DoS, NHPC etc besides providing high resolution digital magnetic data to several research and other government organizations.
On the research front, IIG is engaged in understanding the processes occurring in the Earth’s interior on various time scales using a variety of geophysical tools. In the areas of space geomagnetism and plasma physics, radio and optical remote sensing along with geomagnetic field variations are employed as diagnostic tools to probe the Earth’s near space environment. Several theoretical studies are being carried out on charged particles, electric fields and currents in the space environment comprising the solar wind, magnetosphere and ionosphere.
Recently, three new interdisciplinary research programs viz., (a) Space Weather Prediction, (b) Climate Variability and Change and (c) Coupling & Dynamics of Lithosphere-Atmosphere-Magnetosphere (LAIM) have been initiated at IIG, which are likely to have immense societal value and relevance. A brief description of the activities pursued under each of these programs is provided below.
(a) Space Weather is generally referred to as disturbed weather in the Earth’s upper atmosphere and outer space due to energetic phenomena occurring on the Sun such as Coronal Mass Ejections (CME), Solar Flares, etc., which can have potential effects on satellite orbital position, payload electronics, radiation safety of astronauts, satellite communication/navigational systems, electrical power grids and long distance pipe-lines on Earth. It is therefore imperative to develop space weather forecasting models that can alert the users about the severity of space weather with a lead time of a few hours to a few days in order to mitigate the systems from related hazards.
(b) Identification and quantification of possible drivers of recent climate variability was addressed by IIG scientists adopting a novel information theory technique, namely, the Transfer Entropy. The global measurements of greenhouse gases, volcanic aerosols, solar activity, ENSO, Global Mean Temperature Anomaly (GMTA) made during 1984-2005 were utilized to estimate the information exchanged between GMTA and other variables. The analysis revealed that the greenhouse gases (mostly anthropogenic origin) together contribute to ~48% rise in global mean temperature. Natural events such as volcanic eruptions do make significant contribution (~23%) to the GMTA.
(c) IIG scientists have developed a theoretical tool that has the potential to capture the offshore ‘ahead of tsunami’ signatures in the ionosphere. This technique utilizes acoustic-gravity waves generated in tsunami waves to forecast the arrival of actual tsunami at the coastal locations. Identification of earthquake source characteristics using their ionospheric manifestations is another area of research pursued by IIG. A recent study of IIG examined the ionospheric response to the Gorkha Nepal earthquake from the viewpoints of source directivity, ruptures propagation and associated surface deformation over and near the fault plane.
As human kind faces the threat of global climate change, researchers at IIG are engaged in the multi-proxy reconstruction of past climate by analyzing several sediment cores from the Indian monsoon region. IIG is also engaged in identifying potential aquifer zones and in the assessment of groundwater quality in hard rock terrain of Maharashtra as their social responsibility. Studies using Synthetic Aperture Radar data from Sentinel-1 satellite and near-ﬁeld GPS data have helped in understanding the magnitude of slip / uplift / subsidence in the vicinity of the Main Himalayan Thrust.
An instrumentation group caters to the need of the scientists in the development and maintenance of the instruments used in the Institute’s observatories. This group developed in-house a low cost proton precession magnetometer with an accuracy of 0.1nT. It also developed a state-of-the-art windows-based data logging system for magnetic field data acquisition. A 256-core High Performance Computing system has been installed at IIG empowering the scientists to simulate the processes of Sun-Earth interactions.
The Institute has been constantly making endeavours to mobilize its resources by extending scientific and technical expertise as a part of Technology Development program, Consultancies and Services. Capacity building for scientific research is a major mission of the Institute. To attract, motivate and train young talent to undertake research in geomagnetism and allied areas, new initiatives have been taken by IIG, such as ‘Inspiring Minds of Post-graduates for Research in Earth and Space Sciences’ (IMPRESS) and Dr. Nanabhoy Moos Post-Doctoral Fellowship to research scientists.
Under the Science Outreach program, the Institute promotes several scientific exhibitions for students and its faculty and students participate in several state and national level scientific expositions every year. IIG got the distinction of organizing a special session on the Dynamic Earth and its Near and Far Environment: New Paradigms, at the 102nd Indian Science Congress at Mumbai during January 3-7, 2015. IIG jointly hosted the XVIth IAGA Workshop on ‘Geomagnetic Observatory Instruments, Data Acquisition and Processing’ with NGRI at Hyderabad during October 7-16, 2014. Several accolades were also bestowed on staff and students at numerous conferences.