共查询到20条相似文献，搜索用时 31 毫秒
1.
《Geoforum》2014
This article contributes to the study of changing climate discourse and policy in emerging powers through a case study of climate discourse in India since 2007. Based on interviews with key actors in Indian climate politics and textual analysis, three general climate discourses – the Third World, Win–Win and Radical Green discourses – are identified. The discourses are characterised by different constructions of India’s identity, interests, climate change exposure and climate policy orientation. At the most general level, the article finds that there has been a general discursive shift from the Third World discourse to the Win–Win discourse, and that the latter discourse is in broad agreement with the dominant international climate change discourse of ecological modernisation and thus supports an alignment between Indian and international climate politics. We also find, however, that India’s domestic climate politics is marked by co-existence and tensions between the three climate discourses, producing a complex and at times contentious discursive politics over climate change, identity and development. The case study presented in this article moreover demonstrates how national interests are socially constructed and how changes in policy reflect changes in the dominant discourse. 相似文献
2.
《Geoforum》2017
Recent theories of temporary skilled international migration tend to be predicated on intra-company overseas transfers and secondments. In this paper we present original findings from a study of cricket migrants to highlight another important form of temporary international movements that enable upskilling from strategic, channelled placements into a foreign club, to propel the careers of young professionals on return migration to their respective home club. Drawing upon interviews with 35 early-career English cricketers, we reveal that moving to Australia for 3–6 months during the English domestic off-season is an increasingly common practice to extend the number of months playing the sport in both distinctive work and climatic conditions. Encountering different overseas sporting cultures and environments is becoming a normative part of formative training and development of young professional cricketers to make the ‘‘unfamiliar’ more ‘familiar’’ and enhance skills and competencies. We argue that these flows of international migrants have been facilitated by the post-2001 professionalization of cricket, and the institutionalisation of global networks between cricket organisations and key actors in the sport. We suggest that there are parallels between cricket placements and other sports and occupational sectors, such as temporary overseas moves linked to loans (e.g. football), visiting fellowships, internships and secondments, in ever-competitive global professional labour markets. 相似文献
3.
Various national and international communities have addressed women’s issues and taken various efforts to empower them so
as to enhance their social and health status and involve them in developmental activities. The Indian DHS survey (National
Family Health Survey, 1998–1999) provides an opportunity to study women’s empowerment in India. The survey collected information
on several dimensions of women’s empowerment from 90,303 ever-married women (ages 15–49), from all the states of India. Utilizing
these data sets, four indices – household autonomy index, mobility index, attitude towards gender index and attitude towards
domestic violence index – are constructed to measure the different dimensions of empowerment. Using these indices, the spatial
and socio-economic and cultural disparities that exist within India are analyzed. Finally, an attempt is made to identify
some important determinants for women’s empowerment using multiple logistic regression analysis. The results show that at
the national level, 43% of the women have high household autonomy; 23% of the women have high freedom to move outside their
home; 40% of the women have no gender preference attitude; and only 43% of the women defy domestic violence. But there are
significant divergences in these indices of women’s empowerment across the different states and socio-economic and cultural
settings within India. Women’s educational levels emerged as an important predictor for all the four dimensions of women’s
empowerment. Additionally, media exposure and age have emerged as the important predictors for some dimensions of woman’s
empowerment.
This paper was presented by Prof. Kamla Gupta at the International Geographical Union Conference (IGU), held in Canada, 2002. 相似文献
4.
Shangrila Joshi 《GeoJournal》2014,79(6):677-691
This paper examines India’s participation in ongoing climate politics with a lens of environmental justice (EJ). Using key-informant interviews conducted in Delhi and Copenhagen, I sought to understand how Indian officials conceptualized EJ in the context of climate change. I found my respondents to largely privilege ideas of historical responsibility and per capita equity in a North–South context. The North was seen to have an ecological debt towards the South and the South was seen to have a right to development and ecological space. I highlight two questions that inevitably arise from this framing of international environmental justice. What are the implications of this line of argument for the issue of domestic inequities within states? A related question is that if justice is seen as right to development, what exactly is meant by development? My findings indicate for the most part an uncritical acceptance of a neo-liberal vision of development based on an economic growth paradigm. Consequently, a direct link is observed between emissions and development, despite the impetus to delink them. There was also a marked reluctance among officials to discuss the topic of domestic inequities in India, and an inclination to dismiss them as a sovereignty issue. I suggest that an approach to EJ that combines the imperative of historical responsibility and ecological debt in an international context, with a ‘capabilities’ approach to EJ and development within the domestic context has potential to be more forceful and convincing than one that emphasizes the former but ignores the latter. 相似文献
5.
New geochemical data of the crater-facies Tokapal kimberlite system sandwiched between the lower and upper stratigraphic horizons of the Mesoproterozoic lndravati Basin a：：e presented. The kimberlite has been subjected to extensive and pervasive low-temperature alteration. Spinel is the only primary phase identifiable, while olivine macrocrysts and juvenile lapilli are largely pseudomorphed （talc-serpentine- carbonate alteration）. However, with the exception of the alkalies, major element oxides display systematic fractionation trends; likewise, HFSE patterns are well correlated and allow petrogenetic interpretation. Various crustal contamination indices such as （SiO2 ＋ AI：：O3 ~ Na20）]（MgO ~ K20） and Si] Mg are close to those of uncontaminated kimberlites. Similar La]Yb （＇79-109） of the Tokapal samples with those from the kimberlites of Wajrakarur （73-145） and Narayanpet （72-156）, Eastern Dharwar craton, southern India implies a similarity in their genesis. In the discriminant plots involving HFSE the Tokapal samples display strong affinities to Group 1I kimberlites from southern Africa and central India as well as to ＇transitional kimberlites＇ from the Eastern Dharwar craton, southern India, and those from the Prieska and Kuruman provinces of southern Africa. There is a striking ~;imilarity in the depleted-mantle （TOM） Nd model ages of the Tokapal kimberlite system, Bastar craton, th~ kimberlites from NKF and WKE Eastern Dharwar craton, and the Majhgawan diatreme, Bundelkhand craton, with the emplacement age of some of the lamproites from within and around the Palaeo~Mesoproterozoic Cuddapah basin, southern India. These similar ages imply a major tectonomagmatic event, possibly related to the break- up of the supercontinent of Columbia, at 1.3-1.5 Ga across the l：hree cratons. The ＇transitional＇ geochemical features displayed by many of the Mesoproterozoic po~：assic-ultrapotassic rocks, across these Indian cratons are inferred to be memories of the metasomatisi 相似文献
6.
Milan Bufon 《GeoJournal》2006,66(4):341-352
The European continent, the motherland of nationalism, and the part of the world where political borders and different territorial and cultural identities are mostly interrelated, is now facing new challenges regarding how best to represent its numerous interests within one system. With the increase of international integration European countries began to devote greater attention to the development problems of their border areas that had to be helped to undertake certain functions in the international integration process. The fostering of a more balanced regional development also resulted in a strengthening of regional characteristics, which the new model could no longer ignore. Regional characteristics in turn have always been preserved in Europe by persistent historical and cultural elements of ethnic and linguistic variety. Therefore, it is not surprising that the process of European integration based on the new regional development model was accompanied by a parallel process of ethnic or regional awakening of minorities and other local communities. The key question for contemporary European (though of course this is not limited to Europe) political geography is, then, how the process summarised under the twin labels of social convergence and deterritorialisation will effect the persistent maintenance of regional identities and the corresponding divergence of regional spaces. Or, in other words: is the ‘unity in diversity’ European programme ever practicable and exportable on a world-wide scale or are we to be absorbed by a new global ‘melting pot’? 相似文献
7.
《Geoforum》2017
The Self-Employed Women’s Association is almost universally praised for its work in organizing women in India’s informal sector but has never been examined from a critical perspective. In this study, we critically assess the SEWA movement both in terms of its big picture strategy and the grass roots of its movement. We find that the strategies and tactics employed by SEWA expose the Indian working class to significant imperialist intervention through donations by highly politicized groups, which have given these groups significant leverage over the organization. We will argue that SEWA as an organization is a product of hegemonic forms of imperialism, both in terms of the trade union and hegemonic imperialism. SEWA’s rise to significance can be seen in the spread of SEWA to various parts of India, but also importantly, to different countries in the global South and on the international stage in the UN apparatus and in the international trade union movement. The case of SEWA as a model of trade unionism is therefore an extremely important one to consider in terms of its impact in India but also on global labour politics. 相似文献
8.
The tectonic evolution of the Indian plate, which started in Late Jurassic about 167 million years ago (~ 167 Ma) with the breakup of Gondwana, presents an exceptional and intricate case history against which a variety of plate tectonic events such as: continental breakup, sea-floor spreading, birth of new oceans, flood basalt volcanism, hotspot tracks, transform faults, subduction, obduction, continental collision, accretion, and mountain building can be investigated. Plate tectonic maps are presented here illustrating the repeated rifting of the Indian plate from surrounding Gondwana continents, its northward migration, and its collision first with the Kohistan–Ladakh Arc at the Indus Suture Zone, and then with Tibet at the Shyok–Tsangpo Suture. The associations between flood basalts and the recurrent separation of the Indian plate from Gondwana are assessed. The breakup of India from Gondwana and the opening of the Indian Ocean is thought to have been caused by plate tectonic forces (i.e., slab pull emanating from the subduction of the Tethyan ocean floor beneath Eurasia) which were localized along zones of weakness caused by mantle plumes (Bouvet, Marion, Kerguelen, and Reunion plumes). The sequential spreading of the Southwest Indian Ridge/Davie Ridge, Southeast Indian Ridge, Central Indian Ridge, Palitana Ridge, and Carlsberg Ridge in the Indian Ocean were responsible for the fragmentation of the Indian plate during the Late Jurassic and Cretaceous times. The Réunion and the Kerguelen plumes left two spectacular hotspot tracks on either side of the Indian plate. With the breakup of Gondwana, India remained isolated as an island continent, but reestablished its biotic links with Africa during the Late Cretaceous during its collision with the Kohistan–Ladakh Arc (~ 85 Ma) along the Indus Suture. Soon after the Deccan eruption, India drifted northward as an island continent by rapid motion carrying Gondwana biota, about 20 cm/year, between 67 Ma to 50 Ma; it slowed down dramatically to 5 cm/year during its collision with Asia in Early Eocene (~ 50 Ma). A northern corridor was established between India and Asia soon after the collision allowing faunal interchange. This is reflected by mixed Gondwana and Eurasian elements in the fossil record preserved in several continental Eocene formations of India. A revised India–Asia collision model suggests that the Indus Suture represents the obduction zone between India and the Kohistan–Ladakh Arc, whereas the Shyok-Suture represents the collision between the Kohistan–Ladakh arc and Tibet. Eventually, the Indus–Tsangpo Zone became the locus of the final India–Asia collision, which probably began in Early Eocene (~ 50 Ma) with the closure of Neotethys Ocean. The post-collisional tectonics for the last 50 million years is best expressed in the evolution of the Himalaya–Tibetan orogen. The great thickness of crust beneath Tibet and Himalaya and a series of north vergent thrust zones in the Himalaya and the south-vergent subduction zones in Tibetan Plateau suggest the progressive convergence between India and Asia of about 2500 km since the time of collision. In the early Eohimalayan phase (~ 50 to 25 Ma) of Himalayan orogeny (Middle Eocene–Late Oligocene), thick sediments on the leading edge of the Indian plate were squeezed, folded, and faulted to form the Tethyan Himalaya. With continuing convergence of India, the architecture of the Himalayan–Tibetan orogen is dominated by deformational structures developed in the Neogene Period during the Neohimalayan phase (~ 21 Ma to present), creating a series of north-vergent thrust belt systems such as the Main Central Thrust, the Main Boundary Thrust, and the Main Frontal Thrust to accommodate crustal shortening. Neogene molassic sediment shed from the rise of the Himalaya was deposited in a nearly continuous foreland trough in the Siwalik Group containing rich vertebrate assemblages. Tomographic imaging of the India–Asia orogen reveals that Indian lithospheric slab has been subducted subhorizontally beneath the entire Tibetan Plateau that has played a key role in the uplift of the Tibetan Plateau. The low-viscosity channel flow in response to topographic loading of Tibet provides a mechanism to explain the Himalayan–Tibetan orogen. From the start of its voyage in Southern Hemisphere, to its final impact with the Asia, the Indian plate has experienced changes in climatic conditions both short-term and long-term. We present a series of paleoclimatic maps illustrating the temperature and precipitation conditions based on estimates of Fast Ocean Atmospheric Model (FOAM), a coupled global climate model. The uplift of the Himalaya–Tibetan Plateau above the snow line created two most important global climate phenomena—the birth of the Asian monsoon and the onset of Pleistocene glaciation. As the mountains rose, and the monsoon rains intensified, increasing erosional sediments from the Himalaya were carried down by the Ganga River in the east and the Indus River in the west, and were deposited in two great deep-sea fans, the Bengal and the Indus. Vertebrate fossils provide additional resolution for the timing of three crucial tectonic events: India–KL Arc collision during the Late Cretaceous, India–Asia collision during the Early Eocene, and the rise of the Himalaya during the Early Miocene. 相似文献
9.
《Geoforum》2016
This paper examines, first, the conditions under which irrigating farmers are being alienated from their water through a state-led process of dispossession, and then, second, details the dialectical process of farmers’ resistance to these efforts. The paper advances recent scholarship on water grabbing and ‘accumulation by dispossession’ by drawing on a case from northwestern India to explore the connections between non-agrarian economic growth, irrigated agriculture and farmer livelihoods. Specifically, it examines an urban water infrastructure development project that aims to provide water to Jaipur, the Indian state of Rajasthan’s capital city, through the appropriation of an existing rural dam/reservoir complex built for irrigation and redirecting it to domestic, commercial and industrial uses. Drawing on an examination of policy documents and interviews with farmers and state planners, this paper argues that these transfers must be understood as a supply-side solution to support economic growth, where the lack of stable water supplies is a barrier to capital accumulation. The paper contributes to critical scholarship by showing that the processes underpinning water’s reallocation are specific acts of ongoing ‘dispossession’ through extra-economic means under advanced neoliberal capitalism, which alienates water away from peasant producers towards new centers of capital accumulation, dialectically creating peasant resistance to these efforts. 相似文献
10.
A necessary condition for a migration to be considered as a “diaspora” is the upholding of contacts in the land of origin in various forms, real or imaginary, material or cultural. This paper examines whether this is so in the case of Indian South Africans, most of whose ancestors came to the country as indentured labourers between 1860 and 1911. A key contention was that there could be some cultural and emotional factors partly explaining the economic relations and the geography of flows between the South Africans of Indian origin and India. However, this eventually proved to be wrong. This is all the more paradoxical since the “Indian” identity is still very alive in Durban. However, it is highly fragmented, according to the generations, the religions and the socio-economic classes. India is still a key referent, but “transcendentally”: either as a country which has only an abstract existence, which is spoken of, even dreamt of, without ever being visited; or it is visited but considered only as a whole, since the region of one’s ancestors is almost never at the forefront. Furthermore, the vulnerable situation of “Indians” within South African society does not encourage stronger relationships with India. 相似文献
11.
Eddy covariance based methane flux in Sundarbans mangroves,India 总被引：1，自引：0，他引：1
Chandra Shekhar Jha Suraj Reddy Rodda Kiran Chand Thumaty A K Raha V K Dadhwal 《Journal of Earth System Science》2014,123(5):1089-1096
We report the initial results of the methane flux measured using eddy covariance method during summer months from the world’s largest mangrove ecosystem, Sundarbans of India. Mangrove ecosystems are known sources for methane (CH4) having very high global warming potential. In order to quantify the methane flux in mangroves, an eddy covariance flux tower was recently erected in the largest unpolluted and undisturbed mangrove ecosystem in Sundarbans (India). The tower is equipped with eddy covariance flux tower instruments to continuously measure methane fluxes besides the mass and energy fluxes. This paper presents the preliminary results of methane flux variations during summer months (i.e., April and May 2012) in Sundarbans mangrove ecosystem. The mean concentrations of CH4 emission over the study period was 1682 ± 956 ppb. The measured CH4 fluxes computed from eddy covariance technique showed that the study area acts as a net source for CH4 with daily mean flux of 150.22 ± 248.87 mg m?2 day?1. The methane emission as well as its flux showed very high variability diurnally. Though the environmental conditions controlling methane emission is not yet fully understood, an attempt has been made in the present study to analyse the relationships of methane efflux with tidal activity. This present study is part of Indian Space Research Organisation–Geosphere Biosphere Program (ISRO–GBP) initiative under ‘National Carbon Project’. 相似文献
12.
Soumyajit Mukherjee 《International Journal of Earth Sciences》2013,102(7):1851-1870
The Higher Himalayan Crystalline (HHC) in the Bhagirathi river section (India) on fieldwork reveals two extensional ductile top-to-N/NE shear sub-zones—the ‘South Tibetan Detachment System’ and the ‘Basal Detachment’—besides a preceding top-to-S/SW ductile shear. A top-to-N/NE brittle shear was identified as backthrusts from the HHC (except its northern portion) that occur repeatedly adjacent to numerous top-to-S/SW brittle shears as fore-thrusts. The northern portion of the HHC—the Gangotri Granite—exhibits infrequent total six extensional and compressional brittle shear senses. The backthrusts could be due to a low friction between the lower boundary of the HHC (i.e. the Main Central Thrust-Zone) and the partially molten hot rock materials of the HHC. Subduction of the Eurasian plate towards S/SW below the Indian plate more extensively in the Garhwal sector could be the second possible reason. Presence of two ductile extensional shear sub-zones may indicate channel flow (or several exhumation mechanisms) of the HHC in a shifting mode (similar to Mukherjee et al. in Int J Earth Sci 101:253–272, 2012). The top-to-S/SW extensional brittle shear exclusively within the upper (northern portion) of the HHC and a top-to-S/SW brittle shear within the remainder of it is a possible indicator of critical taper deformation mechanism. Thus, this work provides the field evidences of possibly both channel flow and critical taper conditions from a Higher Himalayan section, besides that by Larson et al. (Geol Soc Am Bull 122:1116–1134, 2010). 相似文献
13.
Tom Hargreaves 《Geoforum》2012,43(2):315-324
Drawing on Flyvbjerg’s (2001) call for the development of phronetic social science, this paper argues that much current research into pro-environmental behaviour (PEB) is misguided, and even potentially dangerous. After outlining Flyvbjerg’s argument, it reviews existing work on PEB and argues that, to date, it has predominantly sought after the Aristotelian intellectual virtues of either episteme or techne, and has neglected phronesis which Aristotle himself saw as most important. It then explores the ways in which aspects of a phronetic approach are being developed in cultural geography and environmental sociology, before offering a brief empirical case study of a PEB-change initiative to illustrate what a phronetic approach to research might look like. It concludes by calling for an improved and more reflexive dialogue between PEB researchers regarding the purpose and approach of their work, both in order to improve the relevance and impact of their research, and in order to help individuals and communities understand and confront the significant environmental challenges they currently face. 相似文献
14.
15.
Devajit Hazarika Dilip Kumar Yadav V. Sriram Abhishek Rai 《International Journal of Earth Sciences》2013,102(7):2061-2076
Teleseismic earthquake data recorded by 11 broadband digital seismic stations deployed in the India–Asia collision zone in the eastern extremity of the Himalayan orogen (Tidding Suture) are analyzed to investigate the seismic anisotropy in the upper mantle. Shear-wave splitting parameters (Φ and δt) derived from the analysis of core-refracted SKS phases provide first hand information about seismic anisotropy and deformation in the upper mantle beneath the region. The analysis shows considerable strength of anisotropy (delay time ~0.85–1.9 s) with average ENE–WSW-oriented fast polarization direction (FPD) at most of the stations. The FPD observed at stations close to the Tidding Suture aligns parallel to the strike of local geological faults and orthogonal to absolute plate motion direction of the Indian plate. The average trend of FPD at each station indicates that the anisotropy is primarily originated by lithospheric deformation due to India–Asia collision. The splitting data analyzed at closely spaced stations suggest a shallow source of anisotropy originated in the crust and upper mantle. The observed delay times indicate that the primary source of anisotropy is located in the upper mantle. The shear-wave splitting analysis in the Eastern Himalayan syntaxis (EHS) and surrounding regions suggests complex strain partitioning in the mantle which is accountable for evolution of the EHS and complicated syntaxial tectonics. 相似文献
16.
《Journal of Asian Earth Sciences》2007,29(2-3):205-214
The complex crustal structure of the Tien Shan has a strong impact on the distribution of strain induced by the India–Eurasia collision, with intracontinental deformation in Eurasia’s interior as a distant effect. The northward propagation of the India–Eurasia deformation front is suggested by the rejuvenation of mountain ranges and intermittent intramontane basins. The Tien Shan basement is formed by the rigid, heterogeneous Precambrian blocks (microcontinents) of Tarim, Issyk-Kul (or Central Tien Shan) and Aktyuz-Boordin, surrounded by a ‘soft’ matrix of Paleozoic accretion–collision belts. The Kyrgyz Tien Shan Mountains are situated between the active structures of the Tarim Plate and the Pamir indenter (south), and the stable Kazakhstan Shield (north). Underplating by the Tarim Plate and thrusting by the Pamirs are responsible for the building of the Cenozoic Tien Shan, the reactivation of its inherited structural fabric and the tectonic layering of the upper lithosphere underlying the area. Large earthquakes (M > 6) delineate the northern and southern margins of the Issyk-Kul microcontinent, indicating that crustal heterogeneity influenced the location of active structures in the northern Kyrgyz Tien Shan. 相似文献
17.
《Earth》2008,89(3-4):145-166
Using the most up-to-the-date information available, we present a considerably revised plate tectonic and paleogeographic model for the Indian Ocean bordering continents, from Gondwana's Middle Jurassic break-up through to India's collision with Asia in the middle Cenozoic. The landmass framework is then used to explore the sometimes complex and occasionally counter-intuitive patterns that have been observed in the fossil and extant biological records of India, Madagascar, Africa and eastern Eurasia, as well those of the more distal continents.Although the paleogeographic model confirms the traditional view that India became progressively more isolated from the major landmasses during the Cretaceous and Paleocene, it is likely that at various times minor physiographic features (principally ocean islands) provided causeways and/or stepping-stone trails along which land animals could have migrated to/from the sub-continent. Aside from a likely link (albeit broken by several marine gaps) to Africa for much of this time (it is notable, that the present-day/recent biota of Madagascar indicates that the ancestors of five land-mammal orders, plus bats, crossed the > 400-km-wide Mozambique Channel at different times in the Cenozoic), it is possible that the Kerguelen Plateau connected India and Australia–Antarctica in the mid-Cretaceous (approximately 115–90 Ma). Later, the Seychelles–Mascarene Plateau and nearby elevated sea-floor areas could have allowed faunas to pass between southern India and Madagascar in the Late Cretaceous, from around 85–65 Ma, with an early Cenozoic extension to this path forming as a result of the Reunion hot-spot trace islands growing on the ocean floor to the SSW of India. The modelling also suggests that India's northward passage towards Asia, with eventual collision at 35 Ma, involved the NE corner of the sub-continent making a glancing contact with Sumatra, followed by Burma from ~ 57 Ma (late Paleocene) onwards, a scenario which is compatible with the fossil record indicating that India–Asia faunal exchanges began occurring at about this time. Finally, we contend that a number of biologically-based direct terrestrial migration routes that have been proposed for last 15 m.y. of the Cretaceous (Asia to India; Antarctica to Madagascar and/or India) can probably be dismissed because the marine barriers, likely varying from > 1000 up to 2500 km, were simply too wide. 相似文献
18.
《Geoforum》2018
Academic research and media tend to emphasize the strong opposition to hydropower development in Sikkim, India, and position this as resistance to an environmentally-destructive, trans-local development, particularly by the culturally-rooted, ethnic minority Bhutia and Lepcha communities. There are several accounts of contestations of hydropower development projects in India’s Eastern Himalayan States – signifying robust and predictable indigenous people-place connections. Why then, was the implementation of the largest, Teesta Stage III Hydro Electric Project, located in Chungthang Gram Panchayat Unit in North Sikkim, in the heartland of the Bhutia-Lepcha region, not contested? In unraveling this anomaly, our focus is to understand how people-place connections are shaped and differentially experienced. Our findings are that hydropower development has elicited diverse responses locally, ranging from fierce contestation to indifference, to enthusiastic acceptance. The complexity and malleability of “place” and people’s “sense of place” provide evidence that indigeneity does not always indicate resistance to large-scale project interventions. In ethnically and socio-politically fractured communities like Chungthang, trans-local developments can reinforce ethno-social divides and disparities, and re-align traditional place-based ethno-centric solidarities along new politically-motivated lines. We argue that linear, one-dimensional views of local social coalescence around place belie more complex relations, which evolve dynamically in diverse socio-cultural and politico-economic contexts. 相似文献
19.
Suman Goyal M Mohapatra Ashish Kumar S K Dube Kushagra Rajendra P Goswami 《Journal of Earth System Science》2016,125(7):1353-1363
Indian region is severely affected by the tropical cyclones (TCs) due to the long coast line of about 7500 km. Hence, whenever any low level circulation (LLC) forms over the Indian Seas, the prediction of its intensification into a TC is very essential for the management of TC disaster. Satellite Application Centre (SAC) of Indian Space Research Organization (ISRO), Ahmedabad, has developed a technique to predict TCs based on scatterometer-derived winds from the polar orbiting satellite, QuikSCAT and Oceansat-II. The India Meteorological Department (IMD) has acquired the technique and verified it for the years 2010–2013 for operational use. The model is based on the concept of analogs of the sea surface wind distribution at the stage of LLC or vortex (T1.0) as per Dvorak’s classifications, which eventually leads to cyclogenesis (T2.5). The results indicate that the developed model could predict cyclogenesis with a probability of detection of 61% and critical success index of 0.29. However, it shows high over-prediction of the model is better over the Bay of Bengal than over Arabian Sea and during post-monsoon season (September–December) than in pre-monsoon season (March–June). 相似文献
20.
Ashish Sinha Lowell Stott Max Berkelhammer Hai Cheng R. Lawrence Edwards Brendan Buckley Mark Aldenderfer Manfred Mudelsee 《Quaternary Science Reviews》2011,30(1-2):47-62
Proxy reconstructions of precipitation from central India, north-central China, and southern Vietnam reveal a series of monsoon droughts during the mid 14th–15th centuries that each lasted for several years to decades. These monsoon megadroughts have no analog during the instrumental period. They occurred in the context of widespread thermal and hydrologic climate anomalies marking the onset of the Little Ice Age (LIA) and appear to have played a major role in shaping significant regional societal changes at that time. New tree ring-width based reconstructions of monsoon variability suggest episodic and widespread reoccurrences of monsoon megadroughts continued throughout the LIA. Although the El-Niño Southern Oscillation (ENSO) plays an important role in monsoon variability, there is no conclusive evidence to suggest that these megadroughts were associated with anomalous sea surface temperature anomalies that were solely the result of ENSO-like variability in the tropical Pacific. Instead, the causative mechanisms of these megadroughts may reside in protracted changes in the synoptic-scale monsoon climatology of the Indian Ocean. Today, the intra-seasonal monsoon variability is dominated by ‘active’ and the ‘break’ spells – two distinct oscillatory modes of monsoon that have radically different synoptic scale circulation and precipitation patterns. We suggest that protracted locking of the monsoon into the “break-dominated” mode – a mode that favors reduced precipitation over the Indian sub-continent and SE Asia and enhanced precipitation over the equatorial Indian Ocean, may have caused these exceptional droughts. Impetus for periodic locking of the monsoon into this mode may have been provided by cooler temperatures at the extratropical latitudes in the Northern Hemisphere which forced the mean position of the Inter-Tropical Convergence Zone (ITCZ) further southward in the Indian Ocean. 相似文献