Journal of Climate Change - Volume 1, issue 1-2

Article Type: Editorial

Citation: Journal of Climate Change, vol. 1, no. 1-2, pp. i-i, 2015

Authors: Mohapatra, M. | Geetha, B. | Balachandran, S. | Rathore, L.S.

Article Type: Research Article

Abstract: Global warming and its impact on severe weather events have been one of the most popular topics of scientific interest during the recent decades. Several studies have examined impact of global warming over the frequency and intensity of tropical cyclones (TCs) forming over different oceanic basins. While some studies have reported a decrease in TC frequency and an increase in severe TC frequency during the recent years, some others are uncertain on whether changes in TC activity have exceeded the variability expected from natural causes. The present study analyses variability in TC activity over the North Indian Ocean (NIO) basin …[which comprises the Bay of Bengal (BOB) and the Arabian Sea (AS)] in the context of changing environmental conditions under global warming scenario based on data of 1951-2010. Significant trends in cyclonic disturbances (CD), TC and severe TC activity over NIO are noted and environmental features known to be associated with cyclonic activity, viz., sea surface temperature (SST), vertical wind shear (VWS), low level vorticity and mid-tropospheric humidity are examined in relation to the trends in the CD/TC/severe TC activity over the NIO. The trends are also analysed from the point of view of ENSO forcing. Significant decreasing trends are observed in CD frequency and their further intensification into severe TCs over BOB during the post-monsoon chief cyclone season and the monsoon season despite increasing SST. Concomitant with this decrease, there is a significant decreasing trend in mid-tropospheric humidity over BOB during both the seasons. Over the AS, no significant trends in frequency of CD, TC and severe TC are observed during the post-monsoon and monsoon seasons. However, probability of intensification into TCs and severe TCs over AS has increased in association with decrease in VWS over AS during the two seasons. There are no significant trends in the frequency of CDs, TCs and severe TCs over BOB and AS during the pre-monsoon season. However, frequency of CDs intensifying into TCs and TCs intensifying into severe TCs have increased significantly over AS and BOB respectively in association with decreased VWS over AS and increased low level cyclonic vorticity over BOB. Concomitant with the decreasing CD frequency, in general, a decrease in frequency of cyclogenesis over the southern parts of BOB leading to a northward shift of mean latitude of formation is also observed. Examination of role of ENSO on the CD, TC and severe TC trends indicates that the impact of ENSO has decreased in recent years. Show more

Keywords: Tropical cyclone, Trend, SST, Humidity, Vertical wind shear, Vorticity, ENSO

DOI: 10.3233/JCC-150001

Citation: Journal of Climate Change, vol. 1, no. 1-2, pp. 1-26, 2015

Authors: Soheb, Mohd | Ramanathan, AL. | Pandey, Pratima | Mandal, Arindan

Article Type: Research Article

Abstract: Glaciers are the most visible indicator of climatic change and are the store houses of fresh water as well as hydropower energy. The study of glaciers is important to understand climate change and the societal impacts of glacier response to climate change in terms of water resource management. Mass balance, length, area, equilibrium line altitude (ELA) and accumulation area ratio (AAR) are some of the parameters, which are directly or indirectly related to climatic conditions. This study attempts to infer the climatic conditions of Indian Himalaya (west to east) by analysing the glacier responses. Available mass balance, snout positions and …ELA/AAR of three glaciers viz. Chhota Shigri, Dokriani and Changme Khangpu glaciers have been considered as representatives of the three parts of Himalaya i.e. Western, Central and Eastern Himalaya respectively. Show more

Keywords: Climate change, Himalayan glaciers, Glacier mass balance, ELA, AAR

DOI: 10.3233/JCC-150002

Citation: Journal of Climate Change, vol. 1, no. 1-2, pp. 27-35, 2015

Authors: Didar-Ul Islam, S.M. | Bhuiyan, Mohammad A.H. | Ramanathan, AL.

Article Type: Research Article

Abstract: Coastal areas are more vulnerable to climate change and natural disasters. Due to increased weather extremes caused by climate change, the coastal communities fall at high risk of casualties and damages. According to DPSIR (Driver – Pressure – State – Impact –Response) framework, population, fisheries, aquaculture, agriculture and tourism are the main drivers of climate change at coastal Shyamnagar upazila which caused several social, financial, environmental and physical impacts. As most of the people are poor and living below the poverty line, the situation becomes worse during and after any climatic hazards. Natural capital, local economy, water and natural disaster …etc. are more vulnerable components at the study area in terms of Livelihood Vulnerability Index (LVI) as people are dependent on natural resources from Sundarban for livelihood. IPCC framework of LVI was also determined for this study. The order of LVI for studied unions are: Gabura (0.027)>Padma Pukur (0.0264)>Munshiganj, Kaikhali, Kashimari (0.0242)>Buri Goalini (0.020)>Atulia (0.0172)>Bhurulia (0.0108)>Ishwaripur (0.0105)>Ramjannagar (0.0102)>Nurnagar and Shyamnagar (0.003). According to the index values, the situation is worse at Gabura and Padma Pukur unions. However, most of the unions are highly vulnerable to climate change impacts in terms of exposure and sensitive components which have also exceeded the adaptive capacity. Show more

Keywords: Vulnerability index, DPSIR, Coastal region, Climate change, Bangladesh

DOI: 10.3233/JCC-150003

Citation: Journal of Climate Change, vol. 1, no. 1-2, pp. 37-45, 2015

Authors: Singh, Jitendra | Vittal, H. | Singh, Tarkeshwar | Karmakar, Subhankar | Ghosh, Subimal

Article Type: Research Article

Abstract: The Nonstationary analysis drew formidable attention to the flood frequency analysis (FFA) research community due to analytically perceivable impacts of climate change, urbanisation and concomitant land use pattern on the flood event series. Albeit, the inclusion of nonstationarity in FFA significantly enhanced the accurate estimation of the return period, however, its application is questionable when the flood variables (FV) are not having persisting significant nonstationarity. In such cases, the assumption of stationarity is still valid and will direct to accurate estimation of the flood quantiles. Hence, prior to conducting the comprehensive FFA, it is vital to inspect the existence of …stationarity/nonstationarity in the FV. This can be accomplished by a comprehensive trend analysis. The aim of present study is to emphasize the importance of a comprehensive trend analysis during FFA by proposing a framework to conduct the same. Further, the proposed framework has been demonstrated on unregulated daily streamflow series of two gauging stations, at the Kanawha Fall of Kanawha River, West Virginia, USA, and at the Baltara gauging station of Kosi River, Bihar, India. The results show that the annual maxima (AM) delineated flood peak series has a significant trend in both the gauging stations, providing sufficient evidence of nonstationarity, which is modelled by first- and second-order nonstationary analyses. A comparison between first-order and second-order nonstationarity analyses has also been performed, which suggests higher order nonstationary analysis might give more accurate information on the occurrence of flood extremes. Overall, our study highlights that the proposed framework is an important initial step before initiating FFA to avoid the ambiguity between the selection of stationary and nonstationary analysis. Show more

Keywords: Climatic variability, Frequency analysis, Nonstationary, Nonparametric, Return period, Trend analysis, Urbanisation

DOI: 10.3233/JCC-150004

Citation: Journal of Climate Change, vol. 1, no. 1-2, pp. 47-65, 2015

Authors: Singh, Gurmeet | Ganguly, Dipnarayan | Paneer Selvam, A. | Kakolee, Kakolee | Purvaja, R. | Ramesh, R.

Article Type: Research Article

Abstract: The significance of the seagrass ecosystem as global carbon sinks has been well studied worldwide; however, studies in India are sparse. Most research in India focuses on the distribution and ecology of seagrass and biogeochemistry has often been less studied. This paper describes the potential carbon sequestration, particularly carbon burial and uptake by seagrass ecosystems of India. The results reported the higher dissolved carbon uptake rates by seagrass ecosystem followed by high net ecosystem productivity. Below ground biomass dominated in the seagrass ecosystem which is a storehouse of buried carbon. High storage capacity of seagrass ecosystem is described through a …case study of Chilika lagoon where the carbon pool in the biomass and sediments were observed to range from 2.3 to 2.5 Gg C and 4.5 to 5.7 Gg C respectively. The study emphasized on the need of focused research, particularly, on the role of carbon in seagrass ecosystems in India. Show more

Keywords: Seagrass, C Sequestration, Blue carbon economy, Ecosystem service

DOI: 10.3233/JCC-150005

Citation: Journal of Climate Change, vol. 1, no. 1-2, pp. 67-74, 2015

Authors: Laskar, A.H. | Ramesh, R. | Burman, J. | Midhun, M. | Yadava, M.G. | Jani, R.A. | Gandhi, Naveen

Article Type: Research Article

Abstract: Stable oxygen and hydrogen isotopic compositions (δ18 O and δD) of rainwater collected between 2009 and 2011 CE from Hailakandi, southern Assam, north-eastern India have been measured to characterize the extreme rainfall phenomena, delineate moisture sources, determine amount effect and assess the prospect of local proxies for paleoclimate studies. The δ18 O values range from +0.7 to −13.8‰ while δD varies between +12 and −98‰. During the pre-monsoon months (March to May), heavy rains and thunderstorms, called nor’westers (Kal Baisakhi in local parlance), occur in some years giving rainfall as much as the monsoons. Strong evaporation and localised convection …due to elevated air and sea surface temperature in the region and over the adjacent Bay of Bengal seem to cause nor’wester activity. No amount effect is observed in rain. The d -excess values for nor’wester rains is very different from those of monsoon rain; very low d -excess values (up to −26‰) were observed in 2010 CE and attributed to vapour originated from re-evaporation of freshwater, contributed by the lowland water bodies and rivers. The meteoric water line for the nor’wester rains, unlike that for the monsoon season, is significantly different from the Global Meteoric Water Line (GMWL). During the monsoon, the rain becomes progressively more depleted in the heavier isotopes (D and 18 O), with the lowest δ values occurring in Sep-Oct. Oxygen isotope-based paleoclimatic study in this region appears to be confounded by a strong dependence of the rainwater isotopic composition on the source of moisture, uneven distribution of rains during the monsoon and the pre-monsoon seasons and the absence of amount effect. Show more

Keywords: Nor’westers, Monsoon, Stable isotopes, Meteoric water line, NE India

DOI: 10.3233/JCC-150006

Citation: Journal of Climate Change, vol. 1, no. 1-2, pp. 75-87, 2015

Authors: Kibria, Md. Golam | Saha, S.K. | Monsur, Md. Hussain | Rashid, Tohida | Rahman, Md. Zillur

Article Type: Research Article

Abstract: Sedimentological, palynological data indicate that mangrove community developed under transgressive condition in and around Maheskhali and Kutubdia Island areas during Mid Holocene time (7000 to 5500 years BP) leading to the locally wide spread deposition of organic-rich sediments. During Holocene time global rise and fall of eustatic sea level played an important role not only on the depositional environment but in creating a geomorphic feature on the island. Recurrent occurence of freshwater and mangrove pollen in Maheskhali and Kutubdia Island area indicate that these areas have undergone cyclic marine and non-marine influence. Since the Last Glacial Maximum (about 20,000 years …ago), sea level has risen by over 120 m at locations far from present and former ice sheets, as a result of loss of mass from these ice sheets. There was a rapid rise between 15,000 and 6,000 years ago at an average rate of 10 mm/yr. Based on geological data, global average sea level may have risen at an average rate of about 0.5 mm/yr over the last 6000 years and at an average rate of 0.1 to 0.2 mm/yr over the last 3000 years. Vertical land movements are still occurring today as a result of these large transfers of mass from the ice sheets to the ocean. During the last 6000 years, global average sea level variations on time-scales of a few hundred years and longer are likely to have been less than 0.3 to 0.5 m. First transgression was noticed around 6000-5500 cal BP and then a subsequent regression of the bay had been observed from around 5500 cal BP. This was again followed by another small scale transgression episode occurred around 2500—2000 cal BP. So the palynomorph assemblages from the Holocene sediment sample indicate that Maheskhali and Kutubdia Island and its surrounding area was an intertidal environment occupied by mangrove community. Show more

Keywords: Sea level, Vulnerability, Coastal community, Palynology, Transgression

DOI: 10.3233/JCC-150007

Citation: Journal of Climate Change, vol. 1, no. 1-2, pp. 89-97, 2015

Authors: Thapa, Amrit | Kayastha, Rijan Bhakta

Article Type: Research Article

Abstract: Climatic time series data are often nonlinear and non-stationary and hence the use of traditional techniques may not be suitable for their analysis. This research is focused on the monthly series of air temperature and precipitation data of 25 years from 1988 to 2012 at Langtang Meteorological Station (LMS), Kyangjing in Langtang River basin, Nepal to extract multi-scale cycles and trends. To address the non-linearity and non-stationary of these time series, we used Empirical Mode Decomposition (EMD) method. EMD decomposed LMS temperature and precipitation series into different oscillatory modes called Intrinsic Mode Functions (IMFs) and residue called trend. The extracted …IMFs are subjected to Fast Fourier Transform (FFT) to determine their average period along with their power density. There exist oscillations of 1 year, 3.13 years, 6.25 years, 8.33 years and 12.5 years in temperature data. Among these cycles, only 1 year cycle is distinguished from Gaussian white noise at 95% confidence level. The air temperature at LMS, Kyangjing reflects monotonic positive trend till 2006 but remains as nearly steady state around 3°C from the end of 2006. Similarly, the precipitation data is embedded with cycles of 6 months, 1 year, 2.08 years, 2.27 years and 8.33 years of which only the first three are statistically significant at 95% confidence level. The precipitation shows a mixed trend with decreasing pattern till mid 1990s, increasing pattern till mid 2000s and again decreasing pattern till 2012. One year cycle is dominant in both the time series data. The above results reflect that temperature and precipitation fluctuates on various time scales. The effect of the changes in temperature and precipitation has already been manifested in the form of melting glaciers in this region. The causes for these oscillations might be related to phenomenon like Quasi-biennial Oscillation (QBO), solar activity, El Nino, monsoon climate dynamics and other local characteristics of the basin. Show more

Keywords: Temperature, Empirical Mode Decomposition (EMD), Intrinsic Mode Function (IMF), Fast Fourier Transform (FFT), Periodicities, Trend

DOI: 10.3233/JCC-150008

Citation: Journal of Climate Change, vol. 1, no. 1-2, pp. 99-107, 2015

Authors: Ambalam, Kannan

Article Type: Research Article

Abstract: Traditionally, security is equated with national security, which has been seen as a matter of the military defense of states’ geographical borders and a process of ensuring unity and integrity of a country. Security is no longer narrowly defined as military security. In the era of globalization, the contemporary society is not confronted with a single tangible threat, but a variety of challenges, which are more intangible and complex. Environmental problems, particularly climate change emerged as an important source of non-military threat along with others. Among various regions, Africa is considered as the most vulnerable region in the world in …terms of climate change, because of its physical and socio-economic characteristics and its extreme climatic conditions. Though the climate change has various security implications, this paper analyzes few important aspects related to food security, desertification and migration and explains the link between the concept of security governance and the climate change in non-military perspective in African context. Show more

Keywords: Climate change, Desertification, Food security, Migration, Security governance

DOI: 10.3233/JCC-150009

Citation: Journal of Climate Change, vol. 1, no. 1-2, pp. 109-118, 2015