West Monsoon Research Articles

Stream flow trends in up and midstream of Kirindi Oya river basin in Sri Lanka and its linkages to rainfall

Trend analysis of hydro-climatic variables provide useful information for effective planning, designing and management of water resources and agricultural production. Trends in observed stream flow at upstream and midstream gauging stations (GS), Wellawaya, Thanamalwila & rainfall and temperature in the Kirindi Oya river basin were assessed using the Mann-Kendall, Modified Mann-Kendall and Sen’s slope. Average rainfalls for the two catchments and for the entire basin were computed using ‘Thessen polygon’ method. The relationships between trends in stream flow and catchment rainfall were studied by Spearman’s Rho correlation coefficient . Five year Moving averaged Standardize Anomalies (FMSA) of both annual stream flow and rainfall at Wellawaya and Thanamalwila catchments were in a non-significant (p < 0.05) decreasing trend for 1994 to 2010.Though there was a positive correlation between annual catchment rainfall and stream flow of these two catchments, correlation was significant (p < 0.05) only at Thanamalwila (0.69) suggesting that the variation of annual stream flow at Thanamalwila GS was mainly attributed to the variation of catchment rainfall. However, variation of stream flow during North East Monsoon (NEM) season was mainly attributed to the variation of respective catchment rainfall of both the catchments as evident by significant higher ‘p’ at Wellawaya (0.61) and Thanamalwila (0.69). This study also found that trend of FMSA of South West Monsoon (SWM) rain was significantly (p < 0.05) decreasing for the entire basin, Thanamalwila and Wellawaya sub-catchments. Stream flow at Wellawaya GS during SWM was also found to be significantly decreasing while Thanamalwila stream flow was non-significantly decreasing. Both rainfall and stream flow during First Inter Monsoon (FIM) was in a significant increasing trend particularly in the month of April. These observed trends during SWM and FIM suggest an apparent early onset of SWM in the basin, or drastic deviation in receiving rain during SWM in the Kirindi Oya river basin.

Yield Gap Analysis and total Rainfall of Rice crop of Onset of Monsoon in Different Sectors of U.P

The onset date of south west monsoon in eastern U.P./central U.P. shifted to 19th/20th June from normal date 15th June. Total rainfall in relation to onset of monsoon decreased by 6% if monsoon reaches on 19th June in eastern U.P. as compare to rainfall of normal date (15th June) and 9.5%if monsoon reaches on 25th June. Consequent upon length of rainy season was also decreased from normal 108 days to 99 days in eastern U.P. whereas reduction in length of rainy season in other sectors of U.P. ranged between 12–13 days. Rainy day and rainfall intensity both reduced in all sectors of U.P. In eastern U.P. rainfall intensity reduced from 25 mm/day (1971–1990) to 17.2 mm/day (1992- 2011), i.e. 32% reduction hence crop planning may be made accordingly in respective sectors. Yield gap of crop has been calculated at particular amount of rainfall over the year of data with difference of maximum yield and minimum yield at same amount of rainfall. Variability of seasonal rainfall in different sectors of U.P. was also in same order and magnitude as that of total rainfall.

Assessment of wave and solar energy potential along Western coast of India

Renewable energy is the need of the day to address energy crisis in the world. Renewable energy share in India is nearly 14% of the total installed capacity. Ocean energy does not contribute to this share at all. With a long coast line ocean energy has enormous potential of electricity generation in India especially for remote coastal areas which are still deprived of electricity. Although India is blessed with large amount of solar power, but during south west monsoon months, western coast of India experiences rainy season for around three to four months i.e. from June to September. Wave energy potential increases during monsoon months, which is evident from considerable increase in significant wave height and mean wave period. A hybrid arrangement with wave energy and solar energy generation using stand alone micro-grids can solve the problem of energy deficit and can also supply households of remote coastal areas of India that have no electricity.

Identification of suitable housing system for dairy cattle in North East Zone of Tamil Nadu, India, with respect to microclimate.

Aim:To identify the suitable roofing pattern for dairy cattle in North East Zone of Tamil Nadu, India, based on micro climatic conditions.Materials and Methods:Initially, survey was conducted to identify and categorize the major housing patterns existing in the region for further detailed investigation. In total, 30 farmers/farms consisting of five housing types with six replicates were selected. Temperature and temperature humidity index (THI) were recorded using the maximum-minimum thermometer and digital thermo-hygrometers. The study was conducted for 1 year covering four seasons namely South West monsoon (June-August), North East monsoon (September-November), cold season (December-February), and summer season (April-May). The data were statistically analyzed using statistical package SPSS 17.Results:Animal shelters with cement sheets recorded the highest temperature (26.71±1.13°C) and THI (77.23±1.76) at 8.00 am, whereas the lowest temperature (24.83±1.17°C) and THI (74.54±1.72) were recorded in the thatched shed. There was significant difference (p<0.01) in temperature and THI at 8.00 am during South West monsoon and North East monsoon seasons between the housing types. During cold and summer seasons, there was no significant difference (p≥0.05) in the environmental variables among various shelter systems.Conclusion:Thatched housing is found to be the suitable one with respect to the climatic variables, followed by tile roof and metal roof. The cement sheet roofed housing is found to be the most unsuitable one in the region for dairy cattle.

Recent changes of rainfall Regime of Hakwatuna Oya watershed of Sri Lanka

This study was conducted to verify farmers' claim, which was also verified by a field survey, that the availability of water in the Hakwatuna Oya irrigation scheme in Sri Lanka has decreased due to variability of rainfall in the watershed area as a result of climate change. Daily rainfall data of 10 selected stations representing “Hakwatuna Oya” watershed over a 50 year period (1961-2010) were used in this study. The linear regression analysis was used to study the annual trend of rainfall during the study period from 1961-2010. The variability of rainfall during recent decades (1991-2000, 2001- 2010) and the most recent 20-year period (1991-2010) was compared with the base period of 1961-1990, recommended by the World Meteorological Organization (WMO) for climate studies, using Coefficient of Variation (CV %), student t- test and confidence interval at 95 percent. The results showed that there was no significant trend of annual rainfall over the last 50 years. In relation to the four rainfall seasons, there was no significant variability of rainfall during the last two decades compared to the base period, except for few stations. However, the rainfall variability of South West Monsoon (SWM), Yala and Maha seasons displayed significant differences in mean rainfall for Siyabalangamuwa rainfall station, which is the closest to the Hakwatuna Oya scheme in the Intermediate zone. The mean rainfall during post 1990 period was lower than the base period during SWM and Yala season whereas it has increased during Maha season.

Host range of Phytophthora sp. causing leaf fall disease of nutmeg(Myristica fragrans Houtt.)

Leaf fall disease caused by Phytophthora sp. has become a serious problem in major nutmeg growing areas of Kerala during South - West monsoon period. Host range study was carried out to find out the infectivity of Phytophthora isolates of nutmeg on other known hosts of Phytophthora spp. including arecanut, coconut, cocoa, rubber, black pepper, cardamom, camboge, vanilla, rose, coreopsis, eucalyptus, colocasia and citrus. Phytophthora isolates of nutmeg showed characteristic symptoms on rubber, vanilla, rose, coreopsis, eucalyptus and citrus, whereas, cocoa, black pepper and colocasia developed hypersensitive reaction and the pathogen failed to cause infection on arecanut, coconut, cardamom and camboge.

Monsoon-influenced variations in productivity and lithogenic flux along offshore Saurashtra, NE Arabian Sea during the Holocene and Younger Dryas: A multi-proxy approach

A sediment core from NE Arabian Sea was studied to reveal the variations in shelf environment of western continental margin of India. A multi-proxy analysis based on planktonic foraminifera abundance (PFA), benthic foraminifera abundance (BFA), planktonic-benthic foraminiferal ratio (P/B), CaCO3 percentage (wt%), Oxygen (δ18OG. ruber) and Carbon (δ18OG. ruber) isotopes of foraminifera as well as sediment X-ray studies were carried out on 3.4m long core SK-240/485 recovered from offshore Saurashtra, NE Arabian Sea. The study aims to understand the monsoon variability in the NE Arabian Sea offshore Saurashtra since the late Pleistocene-Holocene transition and how monsoon climate coupled with sea-level change influenced paleo-productivity pattern. Six AMS radiocarbon dates place the core in the time interval 12–1Ka. Our study reveals that there have been three periods of major changes in the monsoonal climate, productivity and sea level; viz. 12–8Ka (Younger Dryas and early Holocene); 8–4Ka (middle Holocene) and 4–1Ka (late Holocene). The studied time period was also marked by weakened south west monsoon (SWM) during the cold events such as Younger Dryas (YD), Abrupt Event (AE) centring around 9.8Ka as well as 8.2 and 4Ka cold events. The Younger Dryas and early Holocene shows the low sea level stand and less Indus river discharge. Thereafter during middle and late Holocene the monsoon strengthened which resulted in raised sea level and increased Indus river discharge. The proxy records broadly suggest relatively low foraminiferal productivity at the core location during the Younger Dryas and early Holocene. We record a moderate foraminiferal productivity during the middle Holocene between 8 and 4Ka, which suggest the mesotrophic condition. The foraminiferal productivity however was relatively high since 4Ka suggesting the eutrophic conditions at the core site.

Shift in Climate Class Over Tamil Nadu

Climate being a significant driver for best selection of crops in a region, allocation of similar climatic zones has always received plunge.Twenty per cent or more precipitation decrease is anticipated for many parts of the arid regions in the next century. Rainfall is a crucial agro-climatological factor in the seasonally arid parts of the world and its analysis is an essential prerequisite for agricultural planning in India. Ninety years (1911-2000) of both South West Monsoon (SWM) and North East Monsoon (NEM) rainfall data of Tamil Nadu (excluding urbanite Chennai)and potential evapotranspiration data were collected and analysed. The moisture index (Im) was computed based on Thornthwaite and Mather model. Based on the moisture index value of the SWM and NEM, the districts were classified under different climate groups.Over 90 years study, seven districts comes under arid (E), 17 under semi-arid(D), five under dry sub humid(C1) and one each in moist sub humid(C2) and per humid (A) class respectively(SWM period). During NEM no districts registered under (E) or (D) climate class. Further seven districts fell each in (C1) and (C2) class respectively and12 districts comes under Humid(B) and five districts under (A) climate class for Tamil Nadu.During SWM, both the data slice (30 years) and decadal (10 years) analysis explored Trichy district might experience severe moisture stress compared to the past. Madurai, Perambalur and Virudhunagar showed a change from (B1) to (C2) during NEM which showed there might be a change in reduction in soil moisture status among the data slice period. Remaining districts fell within the same climate group.

Pemetaan Potensi Energi Angin di Perairan Indonesia Berdasarkan Data Satelit QuikScat dan WindSat

There were two kinds of monsoon winds in Indonesia. They are the east and the west monsoon winds. Both of them blow alternately in a year through the Indonesian territory. The velocity and energy of monsoon winds in Indonesian territorial sea were mapped by using MatLab program. The velocity and energy data were obtained by using QuikSCAT satellite from January 1999 until December 2009, meanwhile WindSat from January 2004 until December 2014. The results show that high energy of monsoon winds start from Indian oceans until Nusa Tenggara sea, then from Arafuru sea to Banda sea, Java sea, Karimata strait and the southern region of south Sulawesi.

Numerical modelling approach for the management of seasonal influenced river channel entrance

The dynamic nature of a river channel entrance is commonly seasonal dependant. This is evidenced in the topography of river channel entrances in East Coast of Borneo which is influenced by both North East (NE) and South West (SW) monsoons on top of surrounding parameters such as waves and tides, sedimentation as well as climate change. Advanced numerical modelling technique is frequently used as a leading approach to investigate the complicated nature of river channel entrance to well represent actual conditions of a designated area. This paper presented a mesoscale numerical modelling method by integrating reductionist and reduced complexity model approach along with local seasonal conditions to well represent river channel entrance problem and propose management measures. The model was established with a set of numerical equilibrium equations and calibrated parameters to reflect the features of regional conditions with the combination of local validated modelling parameters. The model had accurately represented the effects of both NE and SW monsoons in terms of hydraulics and sediment dynamics at the Petagas river channel entrance, as verified by site data and satellite imagery. In addition, the accuracy of the model provides confidence in the implementation of improvement measures at the river channel entrance. The improvement scheme includes a training channel and a breakwater in improving flushing capacity, thus preventing sedimentation and upstream flooding, allowing proper navigation through the river. In conclusion, the accurate investigational result from this numerical model had successfully demonstrated its scientific role in solving dynamic river channel entrance, which can serve as a numerical modelling approach for solving similar river channel entrance problems especially in the East Coast of Borneo with predominant inter-annual seasonal variations.

Effects of eutrophication on the planktonic food web dynamics of marine coastal ecosystems: The case study of two tropical inlets

We studied the plankton dynamics of two semi-enclosed marine coastal inlets of the north of Jurong Island separated by a causeway (SW Singapore; May 2012–April 2013). The west side of the causeway (west station) has residence times of ca. one year and is markedly eutrophic. The east side (east station) has residence times of one month and presents lower nutrient concentrations throughout the year. The higher nutrient concentrations at the west station did not translate into significantly higher concentrations of chlorophyll a, with the exception of some peaks at the end of the South West Monsoon. Microzooplankton were more abundant at the west station. The west station exhibited more variable abundances of copepods during the year than did the east station, which showed a more stable pattern and higher diversity. Despite the higher nutrient concentrations at the west station (never limiting phytoplankton growth), the instantaneous phytoplankton growth rates there were generally lower than at the east station. The phytoplankton communities at the west station were top-down controlled, largely by microzooplankton grazing, whereas those of the east station alternated between top-down and bottom-up control, with mesozooplankton being the major grazers. Overall, the trophic transfer efficiency from nutrients to mesozooplankton in the eutrophic west station was less efficient than in the east station, but this was mostly because a poor use of inorganic nutrients by phytoplankton rather than an inefficient trophic transfer of carbon. Some hypotheses explaining this result are discussed.

Beban Pencemar Dan Kapasitas Asimilasi Amonium dan Nitrat Saat Pucak Musim Barat di Teluk Jakarta

Jakarta Bay is a bay that has an important role in Jakarta, but the activity in this area lead to the potential for pollution mainly ammonium and nitrate. Pollution peaks generally occur during the rainy season (west monsoon). Pollution that enters the bay can be neutralized naturally by water as long as the amount does not exceed the asimilation capacity. This study aims to calculate the total input (load), assimilation capacity, and residence time of ammonium and nitrate in Jakarta Bay in the rainy season. Data from this study is derived from secondary data. For the total input of pollutants are calculated from the input stream, the atmosphere and the boundary. From the research found that the Jakarta Bay had a total load of pollutants NH4 at 115.8 x 109 mmol N /month and NO3 46.5 x 109 mmol N/month. The biggest contributor to the pollution comes from the boundary NH4 is 56.9% and NO3 from the river 70.1%. Load from Citarum river for NH4 around 3.8 x 1010 mmol N/month and NO3 around 3.0 x 1010 mmol N/month higher than Marunda, Priok and Angke the rivers. Assimilation capacity of Jakarta bay for NH4 around 25.7 x 109 mmol N /month and NO3 of 24.1 x 109 mmol N /month. It shows the total load of pollutants entering the Jakarta Bay is greater than the assimilation capacity. The residence time of water in the Bay of Jakarta is 13.3 days longer than the residence time of NH4 and NO3 which were only 8.6 and 9.2 days.

Impact of GCM boundary forcing on regional climate modeling of West African summer monsoon precipitation and circulation features

In this study, the latest version of the International Centre for Theoretical Physics Regional Climate Model (RegCM4) driven by three CMIP5 Global Climate Models (GCMs) is used at 25 km grid spacing over West Africa to investigate the impact of lateral boundary forcings on the simulation of monsoon precipitation and its relationship with regional circulation features. We find that the RegCM4 experiments along with their multimodel ensemble generally reproduce the location of the main precipitation characteristics over the region and improve upon the corresponding driving GCMs. However, the provision of different forcing boundary conditions leads to substantially different precipitation magnitudes and spatial patterns. For instance, while RegCM4 nested within GFDL-ESM-2M and HadGEM2-ES exhibits some underestimations of precipitation and an excessively narrow Intertropical Convergence Zone, the MPI-ESM-MR driven run produces precipitation spatial distribution and magnitudes more similar to observations. Such a superior performance originates from a much better simulation of the interactions between baroclinicity, temperature gradient and African Easterly Jet along with an improved connection between the Isentropic Potential Vorticity, its gradient and the African Easterly Waves dynamics. We conclude that a good performing GCM in terms of monsoon dynamical features (in this case MPI-ESM-MR) is needed to drive RCMs in order to achieve a better representation of the West Africa summer monsoon precipitation.

PEMODELAN DINAMIKA ARUS PERAIRAN INDONESIA YANG DISEBABKAN OLEH ANGIN

Research on current dynamics modelling in Indonesian waters with wind employed as independent variable has been observed. The purpose of this study was to model the hydrodynamic equations due to the influence of the wind in Indonesia waters in the form of visualization described consisting of wind circulation pattern and pattern of current movement in the west and east monsoon season. To analyze the data obtained during the study, researchers used a descriptive approach. The results showed that the west wind season (December, January, and February) blow from the northeast to the southwest then turning southeast. Whereas the east wind season (June, July, and August) blows from the southeast to the northwest and then turn to the northeast. On the surface layer shows the current movement in general follows the movement of the wind direction in which the current speed is very dominant occurred in some waters, such as the Karimata Strait, the Java Sea, the South China Sea, and the Arafuru Sea. The dominant current velocity in the layer of 100-200 m in the water of eastern equator and the South China Sea in the west season has recorded a current speed reaches 20 cm / s. while in the east monsoon which occurs in the equatorial waters of the eastern part, in the Maluku Sea, the Seram Sea and nearby the Arafuru Sea current velocity reaches 40cm / s.

Impact of spectral nudging on the downscaling of tropical cyclones in regional climate simulations

This study investigated the simulations of three months of seasonal tropical cyclone (TC) activity over the western North Pacific using the Advanced Research WRF Model. In the control experiment (CTL), the TC frequency was considerably overestimated. Additionally, the tracks of some TCs tended to have larger radii of curvature and were shifted eastward. The large-scale environments of westerly monsoon flows and subtropical Pacific highs were unreasonably simulated. The overestimated frequency of TC formation was attributed to a strengthened westerly wind field in the southern quadrants of the TC center. In comparison with the experiment with the spectral nudging method, the strengthened wind speed was mainly modulated by large-scale flow that was greater than approximately 1000 km in the model domain. The spurious formation and undesirable tracks of TCs in the CTL were considerably improved by reproducing realistic large-scale atmospheric monsoon circulation with substantial adjustment between large-scale flow in the model domain and large-scale boundary forcing modified by the spectral nudging method. The realistic monsoon circulation took a vital role in simulating realistic TCs. It revealed that, in the downscaling from large-scale fields for regional climate simulations, scale interaction between model-generated regional features and forced large-scale fields should be considered, and spectral nudging is a desirable method in the downscaling method.

Climatic Impacts and Reliability of Large Scale Wind Farms in Tamil Nadu

Objective: The main objective of this paper describes how the large scale windfarms affect the climate of south west monsoon region. Methods/Analysis: Method used for analysing climatic parameters of before and after installation of wind farms is Gaussian mixture model. ArcGIS and QGIS software is used for image and geo-information analysis. Data from the commercial wind turbine of south west monsoon region like temperature, relative humidity, precipitation, wind speed is used to find the climatic variation. Findings: Large scale wind farms significantly affect the various climatic parameters. These impacts depends on the static stability, increase or decrease in the climatic parameters. Conclusion/ Application: Improvements can be made by taking the ground temperature measured by satellite image and identify the warming effect of night and day time warming effect of large scale wind farm area of southwest monsoon regions.

Indo-western Pacific ocean capacitor and coherent climate anomalies in post-ENSO summer: A review

Abstract ENSO induces coherent climate anomalies over the Indo-western Pacific, but these anomalies outlast SST anomalies of the equatorial Pacific by a season, with major effects on the Asian summer monsoon. This review provides historical accounts of major milestones and synthesizes recent advances in the endeavor to understand summer variability over the Indo-Northwest Pacific region. Specifically, a large-scale anomalous anticyclone (AAC) is a recurrent pattern in post-El Ni˜no summers, spanning the tropical Northwest Pacific and North Indian oceans. Regarding the ocean memory that anchors the summer AAC, competing hypotheses emphasize either SST cooling in the easterly trade wind regime of the Northwest Pacific or SST warming in the westerly monsoon regime of the North Indian Ocean. Our synthesis reveals a coupled ocean–atmosphere mode that builds on both mechanisms in a two-stage evolution. In spring, when the northeast trades prevail, the AAC and Northwest Pacific cooling are coupled via wind–evaporation–SST feedback. The Northwest Pacific cooling persists to trigger a summer feedback that arises from the interaction of the AAC and North Indian Ocean warming, enabled by the westerly monsoon wind regime. This Indo-western Pacific ocean capacitor (IPOC) effect explains why El Ni˜no stages its last act over the monsoonal Indo-Northwest Pacific and casts the Indian Ocean warming and AAC in leading roles. The IPOC displays interdecadal modulations by the ENSO variance cycle, significantly correlated with ENSO at the turn of the 20th century and after the 1970s, but not in between. Outstanding issues, including future climate projections, are also discussed.

PROSES PENCIPTAAN A’BIRING BONE DI KAMPUNG KUNYI’ DESA BAHOREA KECAMATAN BONTOSIKUYU KABUPATEN KEPULAUAN SELAYAR SULAWESI SELATAN Bau Salawati

A’biring Bone is the name of a dance work which is performed in Kampong Kunyi’ in the Village ofBahoreain the Sub-District of Bontosikuyuin the Kepulauan Selayar District of the South Sulawesi Province.The way in which the A’biring Bone dance – whichin the Selayar language means “scouring the coastline” –isconstructed is closely connected to the local community, as it involves the people who live along the coast ofKampong Kunyi’. A’biring Bone is a work which tells about the lives of the people in the fishing communitywho move from Kampong Tile-Tile to Kampong Kunyi’ when the west monsoon season arrives, and hold aritual before going out to sea and a communal celebration to give thanks for an abundant harvest. This workalso presents a traditional dance that is found in the Sub-District of Bontosikuyu in the KepulauanSelayarDistrict of the South Sulawesi Province, namely the Pakarena BallaBulo dance.Keywords: Form, Creation, A’biring Bone

Effect of Non-Genetic Factors on Body Weight and Body Measurements at Birth in Konkan Kanyal Goats

A present study was conducted at Dr. BSKKV, Dapoli (Maharashtra) to evaluate the birth weight and body measurements viz., height at wither, body length and heart girth of Konkan Kanyal goats were 2.093±0.009 kg and 27.93±0.052, 26.65±0.045 and 25.96±0.045 cm, respectively. Significantly heaviest birth weight (2.24±0.04 kg) and body measurements viz., height at wither (28.75±0.24 cm), body length (27.45±0.22 cm) and heart girth (26.66±0.20 cm) were observed in the year 2005. The kids born in South west monsoon season was observed significantly higher in birth weight (2.2±0.02 kg) and body measurements viz., height at wither, body length and heart girth as 28.41±0.14, 27.14±0.09 and 26.30±0.11 cm, respectively. The least square means of type birth weight and body measurements viz., height at wither, body length and heart girth of single born kids were 2.15±0.01 kg, 28.17±0.07, 26.92±0.06 and 26.17±0.06 cm, respectively. The sex showed significant effect on birth weight and body measurements, the male goat was 2.15±0.01 kg heavier than the female 2.03±0.01 kg. The higher body measurements of 28.32±0.08 cm height at wither, 27.08±0.07 cm body length and 26.30±0.07 cm heart girth were found in male than the body measurements of female as 27.48±0.07 cm wither height, 26.31±0.06 cm body length and 25.63±0.05 cm heart girths, respectively. It was concluded that the significant effect of non-genetic factors on birth weight and body measurements at birth.

Short Term Prediction of PM10Concentrations Using Seasonal Time Series Analysis

Air pollution modelling is one of an important tool that usually used to make short term and long term prediction. Since air pollution gives a big impact especially to human health, prediction of air pollutants concentration is needed to help the local authorities to give an early warning to people who are in risk of acute and chronic health effects from air pollution. Finding the best time series model would allow prediction to be made accurately. This research was carried out to find the best time series model to predict the PM 10 concentrations in Nilai, Negeri Sembilan, Malaysia. By considering two seasons which is wet season (north east monsoon) and dry season (south west monsoon), seasonal autoregressive integrated moving average model were used to find the most suitable model to predict the PM 10 concentrations in Nilai, Negeri Sembilan by using three error measures. Based on AIC statistics, results show that ARIMA (1, 1, 1) × (1, 0, 0) 12 is the most suitable model to predict PM 10 concentrations in Nilai, Negeri Sembilan.