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Patiāla, India

Nature of Precipitation - alkaline or acidic depends upon the concentration of major water soluble inorganic gaseous and soil derived particulates dissolved in it. If the concentration of cations is higher than that of anions the precipitations becomes alkaline and vice versa. pH is the main parameter indicating the nature of precipitation. If pH of rainwater <5.65 it is acidic and >5.65, it is alkaline,both in the pH scale ranging between 0 and 14. In this paper average ionic concentration (mg/lit) and their trends have been analyzed. Srinagar, Mohanbari, Jodhpur, Allahabad, Nagpur and Minicoy have been selected for the study of chemical precipitation during the period 1981-2001. Trends of different aerosols have been analyzed at the intervals 1981-87, 1988-94 and 1995-2001. It has been observed that percentage of anions has increased which results in the increase of acidic character of the precipitation. During the interval 1995-2001, Nagpur and Mohanbari had pH values 5.16 and 5.47 respectively which were in acidic range. Source

Shekhar M.S.,Research and Development Center | Pattanayak S.,Indian Institute of Technology Bhubaneswar | Mohanty U.C.,Indian Institute of Technology Bhubaneswar | Paul S.,Meteorological Office | Sravana Kumar M.,Research and Development Center
Journal of Earth System Science | Year: 2015

The heavy rainfall event during 14–17 June 2013 in Uttarakhand and more specifically, its occurrence around the Kedarnath region on 16 June 2013 with devastating floods and massive landslides ruined thousands of lives and properties. Increasing levels of water in two main rivers of the State, namely Alaknanda and Mandakini, resulted in the collapse of bridges, damaging and washing away of property worth many crores. In the present study, the advanced research version of the Weather Research and Forecasting (WRF) system (hereafter used as WRF model) is used to simulate this heavy rainfall event. The synoptic analysis at different locations such as Rudraprayag, Uttarkashi, Chamoli, Pauri, Tehri, Dehradun and adjoining districts suggested that the rainfall is about 200% more than normal. The rainfall associated with this event is well captured with the model simulation. The rainfall simulated by WRF model is in the range of 320–400 mm over Kedarnath during the actual occurrence of the event, which is in reasonably good agreement with the observed value of rainfall (325 mm) collected by Wadia Institute of Himalayan Geology. © Indian Academy of Sciences. Source

Persson A.,Meteorological Office
Meteorological Applications | Year: 2010

The problems of communicating essential processes in dynamic meteorology are discussed, with examples. It is argued that the difficulty in conveying the concepts is not a result of the non-linearity of atmospheric and ocean motions, but their counter-intuitive nature. Although this might motivate the highly mathematical way dynamic meteorology is communicated, issues arise when the mathematics is poorly or wrongly interpreted. It is suggested that communication would be improved by laboratory experiments and observational evidence, while an historical background could help explain why a particular phenomenon is important. © Crown Copyright 2010. Reproduced with the permission of the Controller of HMSO. © Crown Copyright 2010. Source

Simmonds P.G.,University of Bristol | Derwent R.G.,Rdscientific | Manning A.J.,Meteorological Office | O'Doherty S.,University of Bristol | Spain G.,National University of Ireland
Atmospheric Environment | Year: 2010

Simultaneous chloroform (CHCl 3) emission and ozone (O 3) deposition are regularly observed under nocturnal inversions during the summer months from and to the peat bogs in the vicinity of the Mace Head Atmospheric Research Station, Connemara, Co Galway, Ireland. Emissions were estimated using the nocturnal box model applied to routine atmospheric observations collected over a 14-year period from 1995 to 2008. Strict criteria were applied in the selection of events of low wind speed, under a stable night-time inversion layer in baseline air conditions, with no transport from Europe. The mean peatland CHCl 3 flux was 2.91 μg m -2 h -1 with highly variable fluxes ranging from 0.44 to 12.94 μg m -2 h -1. These fluxes are generally larger than those reported previously for similar biomes and if representative would make a significant contribution to the global estimated source of CHCl 3. Fluxes were not strongly correlated with either atmospheric temperature or the level of precipitation. Over the 14-year period there appears to have been a small increase in overall CHCl 3 emissions, although we stress that the nocturnal box model has a number of limitations and assumptions which should be taken into account. © 2009 Elsevier Ltd. Source

Mumby P.J.,University of Queensland | Mumby P.J.,University of Exeter | Wolff N.H.,University of Queensland | Bozec Y.-M.,University of Queensland | And 5 more authors.
Conservation Letters | Year: 2014

Ecosystem management frequently aims to manage resilience yet measuring resilience has proven difficult. Here, we quantify the ecological resilience of the largest reef in the Caribbean and map potential benefits of marine reserves under two scenarios of greenhouse gas emissions. Resilience is calculated using spatial ecological models and defined as the probability of a reef remaining in its coral-dominated basin of attraction such that it does not flip into an alternate, algal-dominated attractor. In practice, resilience is the probability that coral populations will maintain the ability to exhibit a recovery trend after acute disturbances such as hurricanes. The inputs required to estimate resilience are a reef's initial state, physical environment, and disturbance regime. One major driver of reef resilience is herbivory by parrotfish and recent action to protect parrotfish in Belize was found to have increased resilience 6-fold. However, the expected benefits of parrotfish protection to future coral cover were relatively modest with only a 2- to 2.6-fold improvement over a business-as-usual scenario, demonstrating how resilience and ecosystem states are decoupled. Global action to reduce greenhouse gas emissions had little impact on average coral state unless it was accompanied by local controls of fishing. However, combined global and local action reduced the rate of reef degradation threefold. Operationalizing resilience explicitly integrates available biophysical data and accommodates the complex interactions among ecological processes and multiple types of disturbance. © 2013 Wiley Periodicals, Inc. Source

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