On the structure and dynamics of Indian monsoon depressions

ERA-Interim reanalysis data from the past 35 years have been used with a newly-developed feature tracking algorithm to identify Indian monsoon depressions originating in or near the Bay of Bengal. These were then rotated, centralised and combined to give a fully three-dimensional 106-depression composite structure – a considerably larger sample than any previous detailed study on monsoon depressions and their structure. Many known features of depression structure are confirmed, particularly the existence of a maximum to the southwest of the centre in rainfall and other fields, and a westward axial tilt in others. Additionally, the depressions are found to have significant asymmetry due to the presence of the Himalayas; a bimodal mid-tropospheric potential vorticity core; a separation into thermally cold- (~–1.5K) and neutral- (~0K) cores near the surface with distinct properties; and that the centre has very large CAPE and very small CIN. Variability as a function of background state has also been explored, with land/coast/sea, diurnal, ENSO, active/break and Indian Ocean Dipole contrasts considered. Depressions are found to be markedly stronger during the active phase of the monsoon, as well as during La Niña. Depressions on land are shown to be more intense and more tightly constrained to the central axis. A detailed schematic diagram of a vertical cross-section through a composite depression is also presented, showing its inherent asymmetric structure.

All friends now? Critical conversations, West Indian literature and 'The Quarrel with History'

In this essay Alison Donnell returns to the material object of Edward Baugh's essay, published in the pages of the Trinidadian little magazine Tapia in 1977, in order to re-read the force of its arguments in the context of its own politicocultural history and to assess the significance of its publication venue. Donnell attends to Baugh's own standing in the highly charged field of Caribbean literary criticism as a critic of both Walcott and Naipaul, and acknowledges his creative contribution to this field as a poet. She also considers how, in the years between the original publication of Baugh's article and its republication, the questions of historical invisibility have entered newly disputed territories that demand attention to how gender, indigeneity, spirituality, and sexuality shape ideas of historical and literary legitimacy, in addition to those foundational questions around a politics of race and class.

The resolution sensitivity of the South Asian monsoon and Indo-Pacific in a global 0.35◦ AGCM

The South Asian monsoon is one of the most significant manifestations of the seasonal cycle. It directly impacts nearly one third of the world’s population and also has substantial global influence. Using 27-year integrations of a high-resolution atmospheric general circulation model (Met Office Unified Model), we study changes in South Asian monsoon precipitation and circulation when horizontal resolution is increased from approximately 200 to 40 km at the equator (N96 to N512, 1.9 to 0.35◦). The high resolution, integration length and ensemble size of the dataset make this the most extensive dataset used to evaluate the resolution sensitivity of the South Asian monsoon to date. We find a consistent pattern of JJAS precipitation and circulation changes as resolution increases, which include a slight increase in precipitation over peninsular India, changes in Indian and Indochinese orographic rain bands, increasing wind speeds in the Somali Jet, increasing precipitation over the Maritime Continent islands and decreasing precipitation over the northern Maritime Continent seas. To diagnose which resolution related processes cause these changes we compare them to published sensitivity experiments that change regional orography and coastlines. Our analysis indicates that improved resolution of the East African Highlands results in the improved representation of the Somali Jet and further suggests that improved resolution of orography over Indochina and the Maritime Continent results in more precipitation over the Maritime Continent islands at the expense of reduced precipitation further north. We also evaluate the resolution sensitivity of monsoon depressions and lows, which contribute more precipitation over northeast India at higher resolution. We conclude that while increasing resolution at these scales does not solve the many monsoon biases that exist in GCMs, it has a number of small, beneficial impacts.

Mid- to late Holocene Indian Ocean monsoon variability recorded in four speleothems from Socotra Island, Yemen

Four stalagmites covering the last 7.0 ka were sampled on Socotra, an island in the northern Indian Ocean to investigate the evolution of the northeast Indian Ocean Monsoon (IOM) since the mid Holocene. On Socotra, rain is delivered at the start of the southwest IOM in May–June and at the start of the northeast IOM from September to December. The Haggeher Mountains act as a barrier forcing precipitation brought by the northeast winds to fall preferentially on the eastern side of the island, where the studied caves are located. δ18O and δ13C and Mg/Ca and Sr/Ca signals in the stalagmites reflect precipitation amounts brought by the northeast winds. For stalagmite STM6, this amount effect is amplified by kinetic effects during calcite deposition. Combined interpretation of the stalagmites' signals suggest a weakening of the northeast precipitation between 6.0 and 3.8 ka. After 3.8 ka precipitation intensities remain constant with two superimposed drier periods, between 0 and 0.6 ka and from 2.2 to 3.8 ka. No link can be established with Greenland ice cores and with the summer IOM variability. In contrast to the stable northeast rainy season suggested by the records in this study, speleothem records from western Socotra indicate a wettening of the southwest rainy season on Socotra after 4.4 ka. The local wettening of western Socotra could relate to a more southerly path (more over the Indian Ocean) taken by the southwest winds. Stalagmite STM5, sampled at the fringe between both rain areas displays intermediate δ18O values. After 6.2 ka, similar precipitation changes are seen between eastern Socotra and northern Oman indicating that both regions are affected similarly by the monsoon. Different palaeoclimatologic records from the Arabian Peninsula currently located outside the ITCZ migration pathway display an abrupt drying around 6 ka due to their disconnection from the southwest rain influence. Records that are nowadays still receiving rain by the southwest winds, suggest a more gradual drying reflecting the weakening of the southwest monsoon.

Poetry, parables and codes: translating the letters of Indian soldiers

This chapter examines the role of translation in the work of the Indian Mail Censorship Department in France in the First World War, considering the position of the translator as an intermediary figure, and the implications for the military tasks of censorship and intelligence analysis of operating in this way from a foreign language.

An exploration of the role duality experienced by HR professionals as both implementers and recipients of HR practices: evidence from the Indian railways

This study provides an innovative perspective on empirically assessing HR by focusing on the duality of HR professionals’ experiences as both implementers and recipients or internal customers of HR practices given that they are also employees of the organization. We hypothesize that HR professionals experience HR practices more favorably from an implementer perspective as compared to an internal customer perspective. These differences in experiences are likely to be influenced by HR professionals’ hierarchical position in the HR department. Our analyses of 1,271 HR professionals employed by Indian Railways revealed a number of differences between the two types of experience. Some practices (recruitment and selection, training, and employee welfare) were viewed more negatively from the implementer perspective, whereas others (compensation, benefits, and employment relations) were rated more negatively from the internal customer perspective. Those holding more senior HR positions reported more positive experiences of training and employment relations from an internal customer perspective. Overall our contributions draw on the attribution theory and concepts of intraorganizational power and voice, and have implications concerning the effectiveness of HR practices. © 2015 Wiley Periodicals, Inc.

The interaction of moist convection and mid-level dry air in the advance of the onset of the Indian monsoon

The advance of the onset of the Indian monsoon is here explained in terms of a balance between the low-level monsoon flow and an over-running intrusion of mid-tropospheric dry air. The monsoon advances, over a period of about 6 weeks, from the south of the country to the northwest. Given that the low-level monsoon winds are westerly or southwesterly, and the midlevel winds northwesterly, the monsoon onset propagates upwind relative to midlevel flow, and perpendicular to the low-level flow, and is not directly caused by moisture flux toward the northwest. Lacking a conceptual model for the advance means that it has been hard to understand and correct known biases in weather and climate prediction models. The mid-level northwesterlies form a wedge of dry air that is deep in the far northwest of India and over-runs the monsoon flow. The dry layer is moistened from below by shallow cumulus and congestus clouds, so that the profile becomes much closer to moist adiabatic, and the dry layer is much shallower in the vertical, toward the southeast of India. The profiles associated with this dry air show how the most favourable environment for deep convection occurs in the south, and onset occurs here first. As the onset advances across India, the advection of moisture from the Arabian Sea becomes stronger, and the mid-level dry air is increasingly moistened from below. This increased moistening makes the wedge of dry air shallower throughout its horizontal extent, and forces the northern limit of moist convection to move toward the northwest. Wetting of the land surface by rainfall will further reinforce the north-westward progression, by sustaining the supply of boundary layer moisture and shallow cumulus. The local advance of the monsoon onset is coincident with weakening of the mid-level northwesterlies, and therefore weakened mid-level dry advection.

An unexpected legacy and its contribution to early Indian typography

Reprinted from Matrix 7 (Winter 1987) with revisions

An assessment of Indian monsoon seasonal forecasts and mechanisms underlying monsoon interannual variability in the Met Office GloSea5-GC2 system

We assess Indian summer monsoon seasonal forecasts in GloSea5-GC2, the Met Office fully coupled subseasonal to seasonal ensemble forecasting system. Using several metrics, GloSea5-GC2 shows similar skill to other state-of-the-art forecast systems. The prediction skill of the large-scale South Asian monsoon circulation is higher than that of Indian monsoon rainfall. Using multiple linear regression analysis we evaluate relationships between Indian monsoon rainfall and five possible drivers of monsoon interannual variability. Over the time period studied (1992-2011), the El Nino-Southern Oscillation (ENSO) and the Indian Ocean dipole (IOD) are the most important of these drivers in both observations and GloSea5-GC2. Our analysis indicates that ENSO and its teleconnection with the Indian rainfall are well represented in GloSea5-GC2. However, the relationship between the IOD and Indian rainfall anomalies is too weak in GloSea5-GC2, which may be limiting the prediction skill of the local monsoon circulation and Indian rainfall. We show that this weak relationship likely results from a coupled mean state bias that limits the impact of anomalous wind forcing on SST variability, resulting in erroneous IOD SST anomalies. Known difficulties in representing convective precipitation over India may also play a role. Since Indian rainfall responds weakly to the IOD, it responds more consistently to ENSO than in observations. Our assessment identifies specific coupled biases that are likely limiting GloSea5-GC2 prediction skill, providing targets for model improvement.

Participatory crop improvement: the challenges of and opportunities for institutionalisation in the Indian public research sector

This thesis considers Participatory Crop Improvement (PCI) methodologies and examines the reasons behind their continued contestation and limited mainstreaming in conventional modes of crop improvement research within National Agricultural Research Systems (NARS). In particular, it traces the experiences of a long-established research network with over 20 years of experience in developing and implementing PCI methods across South Asia, and specifically considers its engagement with the Indian NARS and associated state-level agricultural research systems. In order to address the issues surrounding PCI institutionalisation processes, a novel conceptual framework was derived from a synthesis of the literatures on Strategic Niche Management (SNM) and Learning-based Development Approaches (LBDA) to analyse the socio-technical processes and structures which constitute the PCI ‘niche’ and NARS ‘regime’. In examining the niche and regime according to their socio-technical characteristics, the framework provides explanatory power for understanding the nature of their interactions and the opportunities and barriers that exist with respect to the translation of lessons and ideas between niche and regime organisations. The research shows that in trying to institutionalise PCI methods and principles within NARS in the Indian context, PCI proponents have encountered a number of constraints related to the rigid and hierarchical structure of the regime organisations; the contractual mode of most conventional research, which inhibits collaboration with a wider group of stakeholders; and the time-limited nature of PCI projects themselves, which limits investment and hinders scaling up of the innovations. It also reveals that while the niche projects may be able to induce a ‘weak’ form of PCI institutionalisation within the Indian NARS by helping to alter their institutional culture to be more supportive of participatory plant breeding approaches and future collaboration with PCI researchers, a ‘strong’ form of PCI institutionalisation, in which NARS organisations adopt participatory methodologies to address all their crop improvement agenda, is likely to remain outside of the capacity of PCI development projects to deliver.