Panini’s Astadhyayi in the Eyes of Plant Invasion on Indian Subcontinent

Indigenous plantlore is a manifestation in a given community, based on adaptation and wisdom of local people and environment. It develops over times and continues so also. This treasure of traditional knowledge is used to sustain the community and its bioculture. In long past, people of great understanding, christalized their wisdom in some treatises such as the Panini’s Astadhyayi. This treatise is understood and well known for the genesis and development of Sanskrit knowledge. Ancient Sanskrit scripts usually contain information concerning culture and sustenance based on plant world. The present author analysed it in view of plant invasion on Indian landmass in Panini’s time. Total 45 exotic plant species belonging to 44 genera and 29 angiospermic families are divulged from it. These belong to nearly all corners of the Old and New Worlds. Majority of them (28 species) are cultigens and still continue even in modern period in India. Of course, rest of them are wild, naturalised and presently constitute integral part of Indian biodiversity. The importance of such ancient treatises is dilated in this communication.

Pali Tipitaka in The Perspective of Plant Invasion in India

This communication is an effort to decipher phytogeographic alterations particularly due to exotic plants associated with the teachings and disclosures of Lord Buddha. The various exotic taxa on Indian landmass in Lord Buddha’s time had an important role to play in human sustenance and civilization. The present author, therefore, analysed plant species as contained in ‘Pali Tipitaka’ in view of plant invasion in ancient period in Indian territory. It was possible to identify total 70 exotic plant species pertaining to 66 genera and 41 angiospermic families. Majority of them (47 species) are introduced for cultivation in India to sustain human life, while 19 species exhibit wildness and integral to Indian biodiversity in present time. Their native geographical regions are deciphered consulting relevant literature. They belong to both Old and New Worlds. Importance of ancient religious scriptures is brought under clearer focus from standpoint of phytogeography and plant invasion.

Assessment of Recent Changes in Dust over South Asia Using RegCM

Pre-monsoon dust aerosols over Indian regions are closely linked to the monsoon dynamics and Indian summer monsoon rainfall. Past observational studies have shown a decline in dust loading over the Indian landmass potentially caused by changing rainfall patterns over the desert regions. Such changes are expected to have far reaching impact on regional energy balance and monsoon rainfall. Using a regional climate-chemistry model, RegCM4.5 with an updated land module, we have simulated the long-term (2001-2015) changes in dust over the arid and semi-arid dust source regions of the North-Western part of the sub-continent. It is found that the area-averaged dust aerosol optical depth (AOD) over the arid and semi-arid desert regions has declined by 17% since the start of this millennium. The rainfall over these regions exhibits a positive trend of 0.1 mm day-1year-1 and a net increase of > 50%. The wet deposition is found to be dominant and ~5 fold larger in magnitude over dry deposition and exhibits total changes of ~ 79 % and 48% in the trends in atmospheric dust. As a response, significant change in the surface (11%), top of the atmosphere radiative forcing (7%), and widespread atmospheric cooling are observed in short wave domain of radiation spectrum, over the Northern part of the Indian landmass. Such quantification and long term change studies are necessary for understanding the regional climate change and the water cycle.

A Comparative Study on the Skill of CMIP6 Models to Preserve Daily Spatial Patterns of Monsoon Rainfall Over India

South Asian monsoon is a phenomena that plays out during June-September every year, due to the northward shift of the ITCZ which causes heavy rainfall over many countries of South Asia, including India. These rains are directly related to the lives and economic well-being of over a billion people. Indian monsoon is highly heterogeneous, due to the vast physiographic variations across the country. There is considerable interest among scientists and other stake-holders about possible future changes to Indian monsoon due to worldwide climate change. Simulations of future climate by global climate models under various scenarios can provide important clues for this. However, simulations of Indian monsoon in the historical period by global climate models under the CMIP5 family were found to be inaccurate in several aspects. Simulations by the new global climate models from the CMIP6 family are now available, and scientists are evaluating their ability to simulate Indian monsoon. In this work, we focus on one particular aspect of simulations by these models: the spatial distribution over daily rainfall over the Indian landmass during monsoon. We use a Machine Learning based probabilistic graphical model that can identify frequent spatial patterns of rainfall after creating a binary representation of rainfall. This model also helps us to identify spatial clusters, i.e., homogeneous regions within the Indian landmass with similar temporal characteristics of rainfall. We identify such frequent spatial patterns and spatial clusters from observed monsoon rainfall data, and also from simulations of monsoon rainfall by different CMIP6 models during the period 2000–2014. We evaluate the models by comparing the patterns and clusters identified from their simulations with those identified from observed data. We find that some of the CMIP6 models can simulate the spatial distribution of monsoon rainfall to a reasonable degree, but there are various limitations—most models underestimate extreme rainfall events and are unable to reproduce the regions of the landmass that are homogeneous with respect to rainfall.

DIVERSITY OF PTERIDOPHYTES IN WESTERN GHATS- A REVIEW

Pteridophytes are vascular cryptogams that dominated the earth 250 million years ago. Currently, there are 13,600 species of pteridophytes around the world, and is the second most dominant plant group. In India, there are 1200 pteridophyte species with 70 families and 192 genera. The pteridophyte hotspots in India are the Himalayas, Western Ghats, Eastern Ghats, Central India, and Andaman and the Nicobar Islands. The Western Ghats occupies only 6% of the Indian landmass and still holds a pteridophyte diversity of 383 species. Fern and fern allies are highly sensitive to changes in their natural habitat, thus habitat destruction, anthropogenic influences, climate change, etc., are causing a fast decline in their population. Epiphytic species are easily destroyed due to the felling of trees and because of this at present 41- 43% of epiphytic pteridophytes in India are reported to be threatened. It necessitates the frequent analysis of the pteridophyte flora of a region to ensure the existence of its species diversity. The potential of in-vitro and ex-situ conservation techniques can be explored for the conservation of threatened pteridophyte species

IRNSS/NavIC: Indigenous Indian Satellite Navigation Programme

India has a vibrant space programme, and over years has successfully operationalized communication and remote sensing satellites for the benefit of the country. In order to achieve self-reliance in satellite-based navigation service over Indian region, Indian Space Research Organization (ISRO) has initiated the NavIC (Navigation with Indian Constellation) Programme. NavIC is developed to give PNT (Position, Navigation and Time) services for users over Indian region and its neighbourhood with positional accuracy of 20 m and 10 Nano seconds time accuracy. It provides navigation services to Indian landmass and also it extends its service to 1500 km beyond the geopolitical boundary. This paper provides the overview about the IRNSS and its salient features.

A new approach for seasonal prediction using the coupled model CFSv2 with special emphasis onIndian Summer Monsoon Rainfall

<p>Predicting the Indian summer monsoon (ISM) is a challenging task due to the complexity of the climate system. Any improvement in the prediction skill of ISM in general circulation models would highly benefit the country as a whole due to its close linkage with the economy. In this study, we have adopted a new strategy to improve the ISM rainfall (ISMR) bias and prediction using the National Centers for Environmental Prediction-Climate Forecast System version 2 (NCEP-CFSv2). This model is currently used for the seasonal prediction in many countries including India but is known to have persistent dry bias over the Indian landmass. Three sets of hindcast experiments are carried out for 9 months each, for the period 2005-2019. The experiments differ from each other in the way they are initialized. Significant reduction in dry bias over the Indian landmass in the summer season with improved representation of tropical Indo Pacific sea surface temperature is reported from the new initialization  strategy. It is found that enhanced moisture transport to Indian landmass from the Arabian Sea,  improved representation of mean cyclonic circulation over north India, weak southeasterlies from Bay of Bengal and western Pacific together with enhanced Walker circulation contributed to the reduction  in dry bias over the Indian landmass. In addition to the above, the midlatitude circulation contribution by enhancing the strength of Subtropical High in the North Pacific resulted enhanced precipitation over the Indian landmass. The initialization strategy used here would be highly useful for improving the seasonal monsoon forecast.</p>