Current Science

R. P. Singh ¹

Affiliations
1 Indian Institute of Science Education and Research, Pune 411 008, IN

Abstract

No Abstract.

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R. P. Singh ¹, Somya S. Sarkar ¹, Manoj Kumar ¹, Anish Saxena ¹, U. S. H. Rao ¹, Arun Bhardwaj ¹, Jalshri Desai ¹, Jitendra Sharma ¹, Amul Patel ¹, Yogesh Shinde ¹, Hemant Arora ¹, A. R. Srinivas ¹, Jaya Rathi ¹, Hitesh Patel ¹, Meenakshi Sarkar ¹, Arpita Gajaria ¹, S. Manthira Moorthi ¹, Mehul R. Pandya ¹, Ashwin Gujrati ¹, Prakash Chauhan ¹, Kuriakose A. Saji ¹, D. R. M. Samudraiah ¹, A. S. Kiran Kumar ²

Affiliations
1 Space Applications Centre, Indian Space Research Organisation, Ahmedabad 380 058, IN
2 Indian Space Research Organisation, Bengaluru 560 231, IN

Abstract

Thermal Infrared Imaging Spectrometer (TIS), which operates in the infrared spectral region (7-13 μm), is one of the five instruments on-board the Mars Orbiting Mission (MOM). TIS was designed to detect emitted thermal infrared radiation from the Martian environment, which would enable the estimation of ground temperature of the surface of Mars and also map its surface composition. TIS instrument is a grating-based spectrometer which has spatial resolution of 258 m at periapsis (372 km). TIS hardware was realized with light-weight miniaturized components (total weight 3.2 kg) with power requirement of 6 W. Observations from TIS instrument were carried out during Earth-bound manoeuvres and cruise phase operations of MOM and the results were found to be in agreement with the laboratory measurements.

Keywords

Aerosol Optical Thickness, Mars Orbiter, Minerals Detection, Thermal Infrared Spectroscopy.

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R. K. Dwivedi ¹, R. P. Singh ¹, T. K. Bhattacharya ¹

Affiliations
1 Department of Farm Machinery and Power Engineering College of Technology, G.B. Pant University of Agriculture and Technology, Pantnagar 263 145, IN

Abstract

Deforestation, forest fire hazard and exploitation of forest have been warning threats to our environment and ecosystem globally. In the present study an attempt has been made to enhance the biodegradability and biomethanation potential of treated pine needles, the leaves of a coniferous tree (Pinus roxburghii) by using Trichoderma spp. and Pseudomonas spp. thereby, utilizing the pine needles for green energy. Studies were carried out in four litre capacity polymer reagent bottles as anaerobic bioreactor at mesophilic conditions (35 ± 1°C) for 80 days. The experiments were replicated thrice and the results compared with untreated ground pine needles substrate (control). The results showed a specific biomethane production of 0.269 l/g VS destroyed from bio-pretreated substrates whereas it was 0.133 l/g VS destroyed for untreated substrate with a biodegradability of 10.41% and 4.78% respectively. Results indicate that bio-pretreated substrate produced a cumulative biomethane yield of 21.3 l/kg pine needles which was 285% higher as compared to the untreated pine needles substrate (5.53 l/kg). The present study may promote utilization of forest litter as natural resource, thereby preventing the wild forest fires which destruct local ecology.

Keywords

Anaerobic Digestion, Biomethanation, Lignocellulose, Pine Needles, Renewable Energy.

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R. P. Singh ¹

Affiliations
1 Land Hydrology Division, Space Applications Centre, ISRO, Ahmedabad 380 015, IN

Abstract

The regional climate of planet Earth is controlled by the amount of energy received from the Sun and the way it is dispersed or redistributed. The Sun, like other stars, is a variable star emitting varying energy due to sunspot and magnetic activity cycles. The amount of solar energy incident at a location on Earth is constantly modulated on a variety of timescales ranging from millennia to seasons due to periodic changes in the Earth’s orbital precession, eccentricity, obliquity, etc., and the changing environmental conditions. The Earth receives maximum heat from the Sun over the tropics and distributes it polewards through atmospheric and oceanic circulations.The regional climate of planet Earth iscontrolled by the amount of energy receivedfrom the Sun and the way it isdispersed or redistributed. The Sun, likeother stars, is a variable star emittingvarying energy due to sunspot and magneticactivity cycles. The amount ofsolar energy incident at a location onEarth is constantly modulated on a varietyof timescales ranging from millenniato seasons due to periodic changes in theEarth’s orbital precession, eccentricity,obliquity, etc., and the changing environmentalconditions. The Earth receivesmaximum heat from the Sun over thetropics and distributes it polewardsthrough atmospheric and oceanic circulations.

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P. K. Gupta ¹, R. Pradhan ¹, R. P. Singh ¹, A. Misra ¹

Affiliations
1 Earth, Ocean, Atmosphere, Planetary Sciences and Applications Area (EPSA), Space Applications Centre, ISRO, Ahmedabad 380 015, IN

Abstract

This study reports the potential of SCATSAT-1 scatterometer data for catchment-scale hydrological applications related with river water level estimation and flood detection. New approaches have been developed for estimation of river water levels and detection of surface flooding using Oceansat-II scatterometer (OSCAT) and SCATSAT-1 scatterometer-based highresolution backscatter and brightness temperature (BT) datasets respectively. Ku-band sigma-0 and BT data, Shuttle Radar Topography Mission Digital Elevation Model and observed hydrometric data have been used in this study. Catchments of gauging sites and their influencing areas were delineated using the topography, wetness conditions and land-cover variations. OSCAT time series of scatterometer image reconstruction data were used to develop model function between basin water index and ground-observed river-stage datasets. Subsequently, inverting these functions on SCATSAT-1 observations, river water levels for 2017 were estimated at different gauging sites. A study on the magnitude of each flooding event in terms of intensity, duration and extent of area affected was also carried out using the scatterometerbased BT data analysis. The study demonstrated that high temporal resolution scatterometer data has the potential to fill the gap of coarser temporal resolution altimeters (10–35 days) for river heights and Synthetic Aperture Radar Data (7–25 days) for surface flooding with the advantage of capturing extreme events.

Keywords

Backscattering Coefficient, Brightness Temperature, River Water Level, Scatterometers, Soil Wetness.

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R. P. Singh ¹, Rohit Pradhan ¹

Affiliations
1 Land Hydrology Division (GHCAG/EPSA), Space Applications Centre, ISRO, Ahmedabad 380 015, IN

Abstract

Earth’s atmosphere comprises layers of gases and dust and plays a major role in sustaining life on the planet by creating adequate pressure allowing liquid water to exist, warming surface through greenhouse gases and balancing diurnal temperature extremes. Presence of clouds changes the radiation budget of Earth’s atmosphere. Observations from spacebased satellites play a key role in global monitoring of atmospheric phenomena such as cyclones, extreme rainfall events (EREs), concentration of greenhouse gases (GHGs) and other pollutants, etc. Recently, assimilation of satellite data in Numerical Weather Prediction (NWP) models has shown immense potential for improving forecasts.

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R. P. Singh ¹, Shard Chander ¹, Ratheesh Ramakrishnan ¹, Ashwin Gujrati ¹, Rohit Pradhan ¹, Chirag Wadhwa ¹, A. S. Rajawat ¹, Raj Kumar ¹

Affiliations
1 Space Applications Centre, Indian Space Research Organisation, Ahmedabad 380 015, IN

Abstract

In this study we identify a region of submarine groundwater discharge (SGD) near Okha coast, Gujarat, India using thermal infrared remote sensing technique. Observations of brightness temperature (BT) in the thermal infrared spectral region (10.6–11.19 μm) from Landsat-8 satellite in the coastal region showed unique localized cooling in the Arabian Sea during winter. We observed lowering of BT in the range 0.6°– 2.3°C in the coastal region associated with SGD in comparison to sea surface temperature of the ocean during low-tide conditions. Consistent geographical pattern of thermal contrast was observed near the same location (lat. 22°26′54.43″N, long. 69°00′41.67″E) when multi date (11 datasets) thermal data were analysed between 2015 and 2019 in winter. Generally, low-tide conditions show more cooling of ocean surface at the SGD site compared to high-tide conditions, which indicates the process of SGD. Satellite-based assessment was further validated using field- and ship-based measurements.

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