Land surface temperature (LST) is an important parameter to study in urban climate. The understanding of the influence of biophysical factors could improve the establishment of modeling urban thermal landscape. It is well established that... more
Land surface temperature (LST) is an important parameter to study in urban climate. The understanding of the influence of biophysical factors could improve the establishment of modeling urban thermal landscape. It is well established that climate hold a great influence on the urban landscape. However, it has been recognize that climate has a low priority in urban planning process, due to the complex nature of its influence. This study will focus on the relatively cloud free Landsat Thematic Mapper image of the study area, acquired on the 2nd March 2006. Correlation analyses were conducted to identify the relationship of LST to the biophysical factors; vegetation indices, impervious surface, and albedo to investigate the variation of LST. We suggest that the results can be considered by the stackholders during decision-making process to create a cooler and comfortable environment in the urban landscape for city dwellers.
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Abstract Excessive rainfall is one of the triggers for the flooding phenomenon, especially in the tropics with flat or concave areas. Some critical points in the South Tangerang region, which are currently one of the most rapidly... more
Abstract Excessive rainfall is one of the triggers for the flooding phenomenon, especially in the tropics with flat or concave areas. Some critical points in the South Tangerang region, which are currently one of the most rapidly developing cities, cannot be ignored from the flooding problem. Floods cause disturbing human activities, loss of life and property, and in turn affect the economic stretch in an area. This paper aimed to predict rainfall by exploring the application of artificial intelligence techniques such as ANFIS (Adaptive NeuroFuzzy Inference System). The proposed technique combines neural network learning abilities with transparent linguistic representations of fuzzy systems. The ANFIS model with various input structures and membership functions was built, trained, and tested to evaluate the capability of a model. Analyses of six-year rainfall data on a monthly basis in South Tangerang City, Banten found that rainfall prediction based on ANFIS time series is promising where 80% of data testing is well predicted.
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Enhancements of the mixing ratios of short-lived halogenated gases were observed in air samples collected at Bachok Marine Research Station (BMRS), Peninsular Malaysia during Northern Hemisphere winters in 2013/2014 and 2015/2016. This... more
Enhancements of the mixing ratios of short-lived halogenated gases were observed in air samples collected at Bachok Marine Research Station (BMRS), Peninsular Malaysia during Northern Hemisphere winters in 2013/2014 and 2015/2016. This study investigates the potential source regions and source types that influenced the variability in chlorinated very short-lived substances (Cl-VSLS) [dichloromethane, 1,2-dichloroethane, trichloromethane, tetrachloroethene] and methyl halides [methyl chloride and methyl bromide]. The UK Met Office’s Numerical Atmospheric Modelling Environment (NAME) dispersion model, was used for tracking the origin of air masses arriving at BMRS. For the purpose of identifying possible sources of these compounds, carbon monoxide (CO) emission data taken from the Representative Concentration Pathway 8.5 were used along with NAME footprints to calculate modelled CO mixing ratios. A correlation analysis between the mixing ratios of measured compounds and the modelled C...
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The ecosystem off the east coast of Peninsular Malaysia is controlled by multiple physical processes during the monsoons (winter and summer) , including the air-sea interaction (such as net heat and surface freshwater fluxes), the... more
The ecosystem off the east coast of Peninsular Malaysia is controlled by multiple physical processes during the monsoons (winter and summer) , including the air-sea interaction (such as net heat and surface freshwater fluxes), the small-scale eddies off the southern South China Sea (SSCS), and the monsoon wind induced coastal upwelling. Using high-resolution Regional Ocean Modeling System (ROMS), in-situ observations and remote sensing data, this paper attempts to study the hydrodynamics of the shelf and coastal processes as well as thermohaline circulation in response to changes in the hydrological seasonal cycle especially in the summer monsoon. In addition, we investigate its impacts on the spatial patterns of chlorophyll biomass which acts as a proxy for primary productivity in the SSCS. This study looks into not only the detailed small-scale-circulation such as localized eddies but also the link between the southern South China Sea and the Indian Ocean through the Straits of Malacca and the Java Sea. The flow through the Strait of Malacca and the Java Sea is not only important for navigational purpose but also has an influence on the seasonal spatial and temporal variations of primary productivity in the region.
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Land and sea breezes are formed due to differential heating between land and sea surfaces and are prominent local circulation in the tropical region. We present the first observational analysis of the overview of sea-breeze... more
Land and sea breezes are formed due to differential heating between land and sea surfaces and are prominent local circulation in the tropical region. We present the first observational analysis of the overview of sea-breeze characteristics based on Automatic Weather Station (AWS) data and radiosonde ascends at Bachok Marine Research Station in peninsular Malaysia. Onset criteria for sea breeze were defined based on the variations of Sea Breeze Component (SBC). Associated parameters such as surface wind direction, wind speed, humidity, and air temperature are analysed for 3 yrs (2015–2017) from the AWS. The radiosonde data taken during two field experiments during northeast monsoon and southwest monsoon are utilised to investigate the impact of monsoons on the sea breeze in greater detail. The influence of synoptic-scale motion on the sea breeze is also investigated using radiosonde and reanalysis data. Generally, the sea breeze sets in from the east at about 10:00 AM and occasionall...
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Abstract Excessive rainfall is one of the triggers for the flooding phenomenon, especially in the tropics with flat or concave areas. Some critical points in the South Tangerang region, which are currently one of the most rapidly... more
Abstract Excessive rainfall is one of the triggers for the flooding phenomenon, especially in the tropics with flat or concave areas. Some critical points in the South Tangerang region, which are currently one of the most rapidly developing cities, cannot be ignored from the flooding problem. Floods cause disturbing human activities, loss of life and property, and in turn affect the economic stretch in an area. This paper aimed to predict rainfall by exploring the application of artificial intelligence techniques such as ANFIS (Adaptive NeuroFuzzy Inference System). The proposed technique combines neural network learning abilities with transparent linguistic representations of fuzzy systems. The ANFIS model with various input structures and membership functions was built, trained, and tested to evaluate the capability of a model. Analyses of six-year rainfall data on a monthly basis in South Tangerang City, Banten found that rainfall prediction based on ANFIS time series is promising where 80% of data testing is well predicted.
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Enhancements of the mixing ratios of short-lived halogenated gases were observed in air samples collected at Bachok Marine Research Station (BMRS), Peninsular Malaysia during Northern Hemisphere winters in 2013/2014 and 2015/2016. This... more
Enhancements of the mixing ratios of short-lived halogenated gases were observed in air samples collected at Bachok Marine Research Station (BMRS), Peninsular Malaysia during Northern Hemisphere winters in 2013/2014 and 2015/2016. This study investigates the potential source regions and source types that influenced the variability in chlorinated very short-lived substances (Cl-VSLS) [dichloromethane, 1,2-dichloroethane, trichloromethane, tetrachloroethene] and methyl halides [methyl chloride and methyl bromide]. The UK Met Office’s Numerical Atmospheric Modelling Environment (NAME) dispersion model, was used for tracking the origin of air masses arriving at BMRS. For the purpose of identifying possible sources of these compounds, carbon monoxide (CO) emission data taken from the Representative Concentration Pathway 8.5 were used along with NAME footprints to calculate modelled CO mixing ratios. A correlation analysis between the mixing ratios of measured compounds and the modelled C...
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Research Interests: Geology and Oceanography
The advent of satellite-based elevation dataset acquired by Shuttle Radar Topography Mission (SRTM) made new and novel techniques possible to model hydrological process in midsize to large scale watersheds. This application is important... more
The advent of satellite-based elevation dataset acquired by Shuttle Radar Topography Mission (SRTM) made new and novel techniques possible to model hydrological process in midsize to large scale watersheds. This application is important in regions with poor photogrammetric coverage and land use in appropriate scale. Watersheds are natural integrators of hydrological processes and as such require an integrated approach in data analysis and modeling. The first task is to delineate watershed boundaries accurately using terrain dataset. This research assessed the effectiveness of satellite base Digital Elevation Model (DEM) with photogrammetric base DEM in the Upper Klang watershed which is a complex urban area located on peninsular Malaysia. Watershed parameters include slope, area, perimeters and mean elevation are derived from two sources of elevation data. The first set of parameters is derived from a 30 m gird DEM generated by the digital topo sheets at the scales of 1:25,000 and 1...
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Mahlon C. Kennicutt II, Steven L. Chown and colleagues outline the most pressing questions in southern polar research, and call for greater collaboration and environmental protection in the region.
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Research Interests: Environmental Engineering, Environmental Science, Atmospheric Science, Atmospheric Modeling, Biomarkers, and 14 moreAtmospheric Aerosols, Pergamon, Atmospheric sciences, Solvent Extraction, Fossil Fuels, Chemical Analysis, Haze, Qualitative Analysis, Biomass burning, Particulate Matter, Vascular Plants, Troposphere, Atmospheric Environment, and airborne particulate matter
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The current situation of environmental condition becomes an importance niche that is crucial to be understand by many researchers. This research attempts carried out an investigation on the temperature daytime measurement across different... more
The current situation of environmental condition becomes an importance niche that is crucial to be understand by many researchers. This research attempts carried out an investigation on the temperature daytime measurement across different land cover areas. These land cover types were selected for interrogating the temperature varies in different measurement that was conducted. The method used in this study by utilizing vehicle equipped with a surface and air temperature sensor and a global positioning system (GPS) receiver, and measuring temperature to the same location in a different day period. The finding of this study is the playing field shows a hot pocket of temperature compared to the other areas, including residential, roads and commercial. Another finding is a consistency of the heat island areas was found; Sungei Wang Plaza and Dataran Merdeka of POI (Point of Interest) as the main attraction area of people and tourists. This study leads to the propose for the land use map...
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Atmospheric measurements of the ozone depleting substance CFC-113a (CCl3CF3) are reported from ground-based stations in Australia, Taiwan, Malaysia and the United Kingdom, together with aircraft-based data for the upper troposphere and... more
Atmospheric measurements of the ozone depleting substance CFC-113a (CCl3CF3) are reported from ground-based stations in Australia, Taiwan, Malaysia and the United Kingdom, together with aircraft-based data for the upper troposphere and lower stratosphere. Building on previous work, we find that, since the gas first appeared in the atmosphere in the 1960s, global CFC-113a mixing ratios have been increasing monotonically to the present day. Mixing ratios of CFC-113a have increased by 40 % from 0.50 to 0.70 ppt in the Southern Hemisphere between the end of the previously published record in December 2012 and February 2017. We derive updated global emissions of 1.7 Gg yr−1 on average between 2012 and 2016 using a two-dimensional model. We compare the long-term trends and emissions of CFC-113a to those of its structural isomer, CFC-113 (CClF2CCl2F), which still has much higher mixing ratios than CFC-113a, despite its mixing ratios and emissions decreasing since the 1990s. The continued p...
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The Antarctic continent is known to be an unpopulated region due to its extreme weather and climate conditions. However, the air quality over this continent can be affected by long-lived anthropogenic pollutants from the mainland. The... more
The Antarctic continent is known to be an unpopulated region due to its extreme weather and climate conditions. However, the air quality over this continent can be affected by long-lived anthropogenic pollutants from the mainland. The Argentinian region of Ushuaia is often the main source area of accumulated hazardous gases over the Antarctic Peninsula. The main objective of this study is to report the first in situ observations yet known of surface ozone (O3) over Ushuaia, the Drake Passage, and Coastal Antarctic Peninsula (CAP) on board the RV Australis during the Malaysian Antarctic Scientific Expedition Cruise 2016 (MASEC'16). Hourly O3 data was measured continuously for 23 days using an EcoTech O3 analyzer. To understand more about the distribution of surface O3 over the Antarctic, we present the spatial and temporal of surface O3 of long-term data (2009-2015) obtained online from the World Meteorology Organization of World Data Centre for greenhouse gases (WMO WDCGG). Furt...
Research Interests: Environmental Monitoring, Air pollution, Climate, Biological Sciences, Environmental Sciences, and 15 moreCarbon Monoxide, CHEMICAL SCIENCES, South Pole, Surface Ozone, Antartica, Ozone, Antarctic Peninsula, Seasons, Drake Passage, Air Pollutants, Photochemical Processes, Ushuaia, Coastal Antarctic Peninsula, WDCGG, and depletion process of surface
Large and effective reductions in emissions of long-lived ozone-depleting substance (ODS) are being achieved through the Montreal Protocol, the effectiveness of which can be seen in the declining atmospheric abundances of many ODS. An... more
Large and effective reductions in emissions of long-lived ozone-depleting substance (ODS) are being achieved through the Montreal Protocol, the effectiveness of which can be seen in the declining atmospheric abundances of many ODS. An important remaining uncertainty concerns the role of very short lived substances (VSLS) which, owing to their relatively short atmospheric lifetimes (less than 6 months), are not regulated under the Montreal Protocol. Recent studies have found an unexplained increase in the global tropospheric abundance of one VSLS, dichloromethane (CH<sub>2</sub>Cl<sub>2</sub>), which has increased by around 60 % over the past decade. Here we report dramatic enhancements of several chlorine-containing VSLS, including…
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Excessive rainfall is one of the triggers for the flooding phenomenon, especially in the tropics with flat or concave areas. Some critical points in the South Tangerang region, which are currently one of the most rapidly developing... more
Excessive rainfall is one of the triggers for the flooding phenomenon, especially in the tropics with flat or concave areas. Some critical points in the South Tangerang region, which are currently one of the most rapidly developing cities, cannot be ignored from the flooding problem. Floods cause disturbing human activities, loss of life and property, and in turn affect the economic stretch in an area. This paper aimed to predict rainfall by exploring the application of artificial intelligence techniques such as ANFIS (Adaptive NeuroFuzzy Inference System). The proposed technique combines neural network learning abilities with transparent linguistic representations of fuzzy systems. The ANFIS model with various input structures and membership functions was built, trained, and tested to evaluate the capability of a model. Analyses of six-year rainfall data on a monthly basis in South Tangerang City, Banten found that rainfall prediction based on ANFIS time series is promising where 80% of data testing is well predicted.
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This research compares data from the Tropical Rainfall Measuring Mission 3B42 V6 with data obtained from 19 synoptic rain gauges during the period 1998–2010 over the semiarid climate of Khorasan Razavi, Iran. Validation was performed... more
This research compares data from the Tropical Rainfall Measuring Mission 3B42 V6 with data obtained from 19 synoptic rain gauges during the period 1998–2010 over the semiarid climate of Khorasan Razavi, Iran. Validation was performed using three spatial extents, including 1 TRMM grid face from the synoptic station (1PTRM), 3 TRMM points surrounding the synoptic station (3PTRM) and 5 TRMM points surrounding the synoptic station (5PTRM), using ArcGIS 10.2 software. The perfect and poor r were obtained at stations S08 and S19, with values of 0.92 and 0.26, respectively. According to the Nash–Sutcliffe efficiency coefficient, the TRMM satellite can predict the spatial variation of the mean annual rainfall by 0.23, 0.43 and 0.38 for 1PTRM, 3PTRM and 5PTRM, respectively, at 19 stations. The agreement significantly increases by 0.88, 0.83 and 0.80 for 1PTRM, 3PTRM and 5PTRM, respectively, when gauges S05, S07, S11 and S13 are excluded from the dataset, which may be associated with orographic or instrumental error at the stations.
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The current situation of environmental condition becomes an importance niche that is crucial to be understand by many researchers. This research attempts carried out an investigation on the temperature daytime measurement across different... more
The current situation of environmental condition becomes an importance niche that is crucial to be understand by many researchers. This research attempts carried out an investigation on the temperature daytime measurement across different land cover areas. These land cover types were selected for interrogating the temperature varies in different measurement that was conducted. The method used in this study by utilizing vehicle equipped with a surface and air temperature sensor and a global positioning system (GPS) receiver, and measuring temperature to the same location in a different day period. The finding of this study is the playing field shows a hot pocket of temperature compared to the other areas, including residential, roads and commercial. Another finding is a consistency of the heat island areas was found; Sungei Wang Plaza and Dataran Merdeka of POI (Point of Interest) as the main attraction area of people and tourists. This study leads to the propose for the land use map...
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The present study is focused on the intensity distribution of rainfall in different classes and their contribution to the total seasonal rainfall. In addition, we studied the spatial and diurnal variation of the rainfall in the study... more
The present study is focused on the intensity distribution of rainfall in different classes and their contribution to the total seasonal rainfall. In addition, we studied the spatial and diurnal variation of the rainfall in the study areas. For the present study, we retrieved data from TRMM ( ...
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... Manuscript Seasonal Variation of Rainfall Characteristics in Different Intensity Classes Over Peninsular Malaysia Hamza Varikoden, B. Preethi, AA Samah, CA Babu ... 6 April 2011 Accepted Date: 9 April 2011 Please cite this article as:... more
... Manuscript Seasonal Variation of Rainfall Characteristics in Different Intensity Classes Over Peninsular Malaysia Hamza Varikoden, B. Preethi, AA Samah, CA Babu ... 6 April 2011 Accepted Date: 9 April 2011 Please cite this article as: Varikoden, H., Preethi, B., S mah, AA, Babu ...
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A three-dimensional Regional Ocean Modelling System is used to study the tidal characteristics and their dynamics in the Sunda Shelf of the southern South China Sea. In this model, the outer domain is set with a 25 km resolution and the... more
A three-dimensional Regional Ocean Modelling System is used to study the tidal characteristics and their dynamics in the Sunda Shelf of the southern South China Sea. In this model, the outer domain is set with a 25 km resolution and the inner one, with a 9 km resolution. Calculations are performed on the inner domain. The model is forced at the sea surface by climatological monthly mean wind stress, freshwater (evaporation minus precipitation), and heat fluxes. Momentum and tracers (such as temperature and salinity) are prescribed in addition to the tidal heights and currents extracted from the Oregon State University TOPEX/Poseidon Global Inverse Solution (TPXO7.2) at the open boundaries. The results are validated against observed tidal amplitudes and phases at 19 locations. Results show that the mean average power energy spectrum (in unit m2/s/cph) for diurnal tides at the southern end of the East Coast of Peninsular Malaysia is approximately 43% greater than that in the East Malaysia region located in northern Borneo. In contrast, for the region of northern Borneo the semidiurnal power energy spectrum is approximately 25% greater than that in the East Coast of Peninsular Malaysia. This implies that diurnal tides are dominant along the East Coast of Peninsular Malaysia while both diurnal and semidiurnal tides dominate almost equally in coastal East Malaysia. Furthermore, the diurnal tidal energy flux is found to be 60% greater than that of the semidiurnal tides in the southern South China Sea. Based on these model analyses, the significant tidal mixing frontal areas are located primarily off Sarawak coast as indicated by high chlorophyll-a concentrations in the area.
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A three-dimensional Regional Ocean Modeling System is used to study the seasonal water circulations and transports of the Southern South China Sea. The simulated seasonal water circulations and estimated transports show consistency with... more
A three-dimensional Regional Ocean Modeling System is used to study the seasonal water circulations and transports of the Southern South China Sea. The simulated seasonal water circulations and estimated transports show consistency with observations, e.g., satellite altimeter data set and re-analysis data of the Simple Ocean Data Assimilation. It is found that the seasonal water circulations are mainly driven by the monsoonal wind stress and influenced by the water outflow/inflow and associated currents of the entire South China Sea. The intrusion of the strong current along the East Coast of Peninsular Malaysia and the eddies at different depths in all seasons are due to the conservation of the potential vor-ticity as the depth increases. Results show that the water circulation patterns in the northern part of the East Coast of Peninsular Malaysia are generally dominated by the geostrophic currents while those in the southern areas are due solely to the wind stress because of negligible Coriolis force there. This study clearly shows that individual surface freshwater flux (evaporation minus precipitation) controls the sea salinity balance in the Southern South China Sea thermohaline circulations. Analysis of climatological data from a high resolution Regional Ocean Modeling System reveals that the complex bathymetry is important not only for water exchange through the Southern South China Sea but also in regulating various transports across the main passages in the Southern South China Sea, namely the Sunda Shelf and the Strait of Malacca. Apart from the above, in comparision with the dynamics of the Sunda Shelf, the Strait of Malacca reflects an equally significant role in the annual transports into the Andaman Sea.
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My current and future objective job is in teaching and research development to enhance the visibility and establishing of a university. I am PhD in Electrical, Electronics and System Engineering with more than 17 years of teaching and... more
My current and future objective job is in teaching and research development to enhance the visibility and establishing of a university. I am PhD in Electrical, Electronics and System Engineering with more than 17 years of teaching and research experiences; targeting assignment as Full Professor.