Improved prediction of severe thunderstorms over the Indian Monsoon region using high-resolution soil moisture and temperature initialization

The hypothesis that realistic land conditions such as soil moisture/soil temperature (SM/ST) can significantly improve the modeling of mesoscale deep convection is tested over the Indian monsoon region (IMR). A high resolution (3 km foot print) SM/ST dataset prepared from a land data assimilation system, as part of a national monsoon mission project, showed close agreement with observations. Experiments are conducted with (LDAS) and without (CNTL) initialization of SM/ST dataset. Results highlight the significance of realistic land surface conditions on numerical prediction of initiation, movement and timing of severe thunderstorms as compared to that currently being initialized by climatological fields in CNTL run. Realistic land conditions improved mass flux, convective updrafts and diabatic heating in the boundary layer that contributed to low level positive potential vorticity. The LDAS run reproduced reflectivity echoes and associated rainfall bands more efficiently. Improper representation of surface conditions in CNTL run limit the evolution boundary layer processes and thereby failed to simulate convection at right time and place. These findings thus provide strong support to the role land conditions play in impacting the deep convection over the IMR. These findings also have direct implications for improving heavy rain forecasting over the IMR, by developing realistic land conditions

Progress in Tropical Cyclone Predictability and Present Status in the North Indian Ocean Region

Tropical cyclone (TC) is an important research area since it has a significant impact on human life, properties and environment. The researchers all over the world have been studying fundamental and advanced processes to better understand and thereby predict the genesis and evolution of TCs. This review chapter provides a brief overview on TC climatology, their basic characteristics, movement and intensification, research on structure analysis and prediction of these fascinating storms, with primary emphasis to North Indian Ocean (NIO). The role of ocean and atmosphere in determining the genesis and intensification of TCs is discussed. This chapter reviews the past and current research activities including inter-annual and intra-seasonal changes in TCs, current status of TC research using numerical weather prediction, gaps identified and relevant measures taken by the meteorological and government agencies in this direction, along with future directions in order to improve the understanding and predictability over the NIO region

Does changing contexts affect linkages throughout the mergers and acquisition process? A multiphasic investigation of motives, pre‐ and post‐acquisition and performance

Mergers and Acquisitions (M&A) is an important organizational change phenomena that has attracted significant research focus to many of its aspects but only recently has attention begun to investigate its complex multi-phasic nature and its embeddedness in multiple contexts. So far the influence of the macro context in M&A deals has been little studied and its interaction with M&A’s multiphasic nature has been ignored. This article aims to address this limitation by investigating whether different macro-economic wave and non-wave periods of M&A activity influence different phases of M&A in terms of motives, pre- and post-acquisition processes and acquisition performances. Drawing on a dataset of Greek M&As, an under researched M&A context, findings suggest that acquisitions in non-wave periods are driven by different motives from those in wave periods. Interestingly though, we found no statistically significant changes in pre- and post-acquisition processes and M&A performance between wave and non-wave periods. We suggest this organizational change finding maybe due to the early stage nature of Greek M&A and may also apply to other countries with similar levels of M&A experience. Further implications for theory and practice of these findings are discusse

Disenchanting secularism (or the cultivation of soul) as pedagogy in resistance to populist racism and colonial structures in the academy

This paper explores pedagogic strategies for resisting the racism of contemporary populism and age-old coloniality through challenging secularism in the academy, especially in social theory. Secularism sustains racism and imperialism in the contemporary academy and is inscribed, in part, through the norms of social theory. Post-secular social theory has been positioned by some as the decolonial answer, but often replicates the most problematic aspects of secularism. Whereas post-secularism affirms the previously denigrated side of the secular vs religious dualism, I am more interested in unworking those classificatory schemas, setting the critical thought of religious teachers in relation with ‘secular’ social and political theorists such that boundaries erode. The ambition in this is to resist the hierarchical orderings of knowledge that pit Islamic, indigenous, and feminised subjectivity as backwards, dangerous or intrinsically inferior to secular, Christian, rational knowledge. It is also to disenchant the secular Gods (progress, money, growth, health) and hold open space for critical play in relation to the transcendental - to create a permissive, legitimising, space for students’ spiritual dimension, conocimiento, or the cultivation of soul. The paper draws theoretical inspiration from Gloria Anzaldúa, Gayatri Chakravorty Spivak, and Sylvia Wynter. It also draws on a practical experiment in disenchanting secularism through teaching an undergraduate module in social theory called Capitalism and Religion

Voices of the Governed: towards a theory of the translocal

In this article I want to interrogate the political, economic, and social conditions that enable the extraction of natural and mineral resources from Indigenous and rural communities in Africa, the Americas, and the Asia-Pacific. The end of direct colonialism and the emergence of the development state did not necessarily translate into forms of local sovereignty for these communities who bore the brunt of development. I describe the emergence of resource wars in the postcolonial era and how organizational technologies of extraction, exclusion and expulsion lead to dispossession and death. I conclude by discussing possibilities of resistance and develop the notion of translocal resistance where local actors most affected by development are able to forge a series of temporary coalitions with international and national groups in an attempt to promote some form of participatory democracy. The article advance debates on postcolonialism by developing theoretical insights from translocal modes of resistance that open up new analytical spaces marked by particular configurations of market, state and civil society actors

Quantifying the impacts of defaunation on natural forest regeneration in a global meta-analysis

Intact forests provide diverse and irreplaceable ecosystem services that are critical to human well-being, such as carbon storage to mitigate climate change. However, the ecosystem functions that underpin these services are highly dependent on the woody vegetation-animal interactions occurring within forests. While vertebrate defaunation is of growing policy concern, the effects of vertebrate loss on natural forest regeneration have yet to be quantified globally. Here we conduct a meta-analysis to assess the direction and magnitude of defaunation impacts on forests. We demonstrate that real-world defaunation caused by hunting and habitat fragmentation leads to reduced forest regeneration, although manipulation experiments provide contrasting findings. The extirpation of primates and birds cause the greatest declines in forest regeneration, emphasising their key role in maintaining carbon stores, and the need for national and international climate change and conservation strategies to protect forests from defaunation fronts as well as deforestation fronts

Forest biodiversity, ecosystem functioning and the provision of ecosystem services

Forests are critical habitats for biodiversity and they are also essential for the provision of a wide range of ecosystem services that are important to human well-being. There is increasing evidence that biodiversity contributes to forest ecosystem functioning and the provision of ecosystem services. Here we provide a review of forest ecosystem services including biomass production, habitat provisioning services, pollination, seed dispersal, resistance to wind storms, fire regulation and mitigation, pest regulation of native and invading insects, carbon sequestration, and cultural ecosystem services, in relation to forest type, structure and diversity. We also consider relationships between forest biodiversity and multifunctionality, and trade-offs among ecosystem services. We compare the concepts of ecosystem processes, functions and services to clarify their definitions. Our review of published studies indicates a lack of empirical studies that establish quantitative and causal relationships between forest biodiversity and many important ecosystem services. The literature is highly skewed; studies on provisioning of nutrition and energy, and on cultural services, delivered by mixed-species forests are under-represented. Planted forests offer ample opportunity for optimising their composition and diversity because replanting after harvesting is a recurring process. Planting mixed-species forests should be given more consideration as they are likely to provide a wider range of ecosystem services within the forest and for adjacent land uses. This review also serves as the introduction to this special issue of Biodiversity and Conservation on various aspects of forest biodiversity and ecosystem services

Assessment of the Weather Research and Forecasting (WRF) model for simulation of extreme rainfall events in the upper Ganga Basin

Reliable estimates of extreme rainfall events are necessary for an accurate prediction of floods. Most of the global rainfall products are available at a coarse resolution, rendering them less desirable for extreme rainfall analysis. Therefore, regional mesoscale models such as the advanced research version of the Weather Research and Forecasting (WRF) model are often used to provide rainfall estimates at fine grid spacing. Modelling heavy rainfall events is an enduring challenge, as such events depend on multi-scale interactions, and the model configurations such as grid spacing, physical parameterization and initialization. With this background, the WRF model is implemented in this study to investigate the impact of different processes on extreme rainfall simulation, by considering a representative event that occurred during 15–18 June 2013 over the Ganga Basin in India, which is located at the foothills of the Himalayas. This event is simulated with ensembles involving four different microphysics (MP), two cumulus (CU) parameterizations, two planetary boundary layers (PBLs) and two land surface physics options, as well as different resolutions (grid spacing) within the WRF model. The simulated rainfall is evaluated against the observations from 18 rain gauges and the Tropical Rainfall Measuring Mission Multi-Satellite Precipitation Analysis (TMPA) 3B42RT version 7 data. From the analysis, it should be noted that the choice of MP scheme influences the spatial pattern of rainfall, while the choice of PBL and CU parameterizations influences the magnitude of rainfall in the model simulations. Further, the WRF run with Goddard MP, Mellor–Yamada–Janjic PBL and Betts–Miller–Janjic CU scheme is found to perform best in simulating this heavy rain event. The selected configuration is evaluated for several heavy to extremely heavy rainfall events that occurred across different months of the monsoon season in the region. The model performance improved through incorporation of detailed land surface processes involving prognostic soil moisture evolution in Noah scheme compared to the simple Slab model. To analyse the effect of model grid spacing, two sets of downscaling ratios – (i) 1 : 3, global to regional (G2R) scale and (ii) 1 : 9, global to convection-permitting scale (G2C) – are employed. Results indicate that a higher downscaling ratio (G2C) causes higher variability and consequently large errors in the simulations. Therefore, G2R is adopted as a suitable choice for simulating heavy rainfall event in the present case study. Further, the WRF-simulated rainfall is found to exhibit less bias when compared with the NCEP FiNaL (FNL) reanalysis data

An observational perspective on tropical cyclone activity over Indian seas in a warming environment

The genesis of tropical cyclones (TCs) over Indian seas comprising of Bay of Bengal (BoB) and Arabian Sea (AS) is highly seasonal with primary maximum in postmonsoon season (mid-September to December) and secondary maximum during premonsoon season (April and May). The present study is focused to demonstrate changes in genesis and intensity of TCs over Indian seas in warming environment. For this purpose, observational data of TCs, obtained from the India Meteorological Department (IMD), are analyzed. The sea surface temperature (SST), surface wind speed, and potential evaporation factor (PEF), obtained from the International Comprehensive Ocean Atmosphere Data Set (ICOADS), are also analyzed to examine the possible linkage with variations in TC activities over Indian seas. The study period has been divided into two epochs: past cooling period (PCP, period up to 1950) and current warming period (CWP, period after 1950) based on SST anomaly (became positive from 1950) over the BoB and AS. The study reveals that the number of severe cyclones (SCS) increases significantly (statistically significant at 99% confidence level) by about 41% during CWP though no such significant change is observed in cyclonic disturbances (CDs) and cyclones (CS) over Indian seas. It is also observed that the rate of dissipation of CS and SCS over Indian seas has been decreasing considerably by about 63 and 71%, respectively, during CWP. The analysis shows that the BoB contributes about 75% in each category of TCs and remaining 25% by the AS towards total of Indian seas. A detailed examination on genesis and intensity of TC over both the basins and the seasons illustrates that significant enhancement of SCS by about 65% during CWP is confined to the postmonsoon season of the BoB. Further, the BoB is sub-divided into northern, central, and southern sectors and the AS into western and eastern sectors based on genesis of TCs and SST gradient. Results show that in postmonsoon season during CWP, the number of SCS increases significantly by about 71% in southern BoB and 300% over western AS

Impact of Parameterization of Physical Processes on Simulation of Track and Intensity of Tropical Cyclone Nargis (2008) with WRF-NMM Model

The present study is carried out to investigate the performance of different cumulus convection, planetary boundary layer, land surface processes, and microphysics parameterization schemes in the simulation of a very severe cyclonic storm (VSCS) Nargis (2008), developed in the central Bay of Bengal on 27 April 2008. For this purpose, the nonhydrostatic mesoscale model (NMM) dynamic core of weather research and forecasting (WRF) system is used. Model-simulated track positions and intensity in terms of minimum central mean sea level pressure (MSLP), maximum surface wind (10 m), and precipitation are verified with observations as provided by the India Meteorological Department (IMD) and Tropical Rainfall Measurement Mission (TRMM). The estimated optimum combination is reinvestigated with six different initial conditions of the same case to have better conclusion on the performance of WRF-NMM. A few more diagnostic fields like vertical velocity, vorticity, and heat fluxes are also evaluated. The results indicate that cumulus convection play an important role in the movement of the cyclone, and PBL has a crucial role in the intensification of the storm. The combination of Simplified Arakawa Schubert (SAS) convection, Yonsei University (YSU) PBL, NMM land surface, and Ferrier microphysics parameterization schemes in WRF-NMM give better track and intensity forecast with minimum vector displacement error