Meteorological Modeling In Klang Valley Region Malaysia Environmental Sciences Essay

It has been widely kno(prenominal)n that distortations of the defeat surface from flora sylvan to urban countrified can well impact the environing meteoric spatial relation. Meteorologic supposed fib was utilize to measure meteoric status for line of credit tonicity mold and prediction. One of the inputs for the meteoric and line of credit quality hypothetical account is earthly concern usance and kingdom screen of the terrain. In this survey, we examined the sensitiveness of cut back function and impart screen on the predicted meteoric conditions. A meteoric air utilizing 5th coevals mesoscale hypothetical account ( MM5 ) by Penn State/NCAR was utilize to compare the set up of primer customs from two dissimilar old ages on meteoric status. The predicted meteoric conditions are so compared with the several monitoring station onsite. Consequences showed change of surface wind amphetamine and temperature simulated utilizing change pour down example repre sent. Findingss suggest disgrace consumption map should be taking into rumination in historical meteoric Fieldss to entree future air quality if the hoidenish of survey expects big alterations in land use form.Keywords Meteorologic mold shore up usage MM5 urban.IntroductionIt has been widely known that alterations of the land surface from flora country to urban country can well impact the environing meteoric status. Urbanization of an country could take to alterations of meteoric parametric quantities much(prenominal) as boundary bed deepness, perpendicular diffusivity, wind stableness category, etc. These meteoric parametric quantities play an of import function in most of the air quality theoretical accounts that predicts the concentration at severally grid. Harmonizing to Jacobson ( 2002 ) , one of the factors that affect air pollution is the local air current which ensuing from tetchy land warming, variable topography and others. In another word, different land usage fibre may take to uneven land warming, because land screen affects ground temperature, which affects pollutant concentration finally ( Jacobson, 2002 ) . Meteorologic and air quality theoretical accounts require land usage and surface feature that differ by their land usage and land screen forms ( Civerolo et. at. , 2000 ) . Another survey carried out by Jazcilevich et Al. ( 2002 ) suggested that alterations of the land usage type could impact its environing meteoric status and strewing of air pollutant. Much of the current apprehension of the urban clime and meteoric status in Malaysia resulted from the research on Kuala Lumpur and Petaling Jaya country begins from 1970s ( Sham, 1973a, 1973b, 1979a, 1979b and 1987 ) . These researches focused on the description of the climatology and meteoric scene such as air current and temperature parametric quantities associated with urban heat island. The meteoric facets of the Kuala Lumpur and the environing metropoliss may alter due to t he change of land usage and land screen by urbanisation and development of the metropolis. However, no survey had been done to entree the meteoric status of Klang Valley part with current land usage and land screen.The meteoric theoretical account used in this survey was the Fifth Generation Mesoscale manikin ( MM5 ) from PSU/NCAR ( Grell et al. , 1994 ) . In this theoretical account the land usage was simulated from the planetary flora dataset from USGS which available at 1 grade, 30 min, 10 min, 5 min, and 30 unsweet announcement. However, the entropys were derived from satellite observations over a purpose 1992-3 and the flora shed light ons were out of day of the month and non relevant to the country of survey. The aim of the survey is to find to the effects of the land usage and land screen alterations on the meteoric mold system. solid ground usage map of twelvemonth 2000 obtain from the Town and Country be after Department ( JPBD ) will be used to repair 1992-3 USGS l and usage dataset.The Modeling SystemPSU/NCAR Fifth Generation Mesoscale Model ( MM5 ) was selected as the meteoric computer simulation patterning system in this survey. The MM5 theoretical account is non-hydrostatic with terrain following co-ordinates, multi-scale, capable of interface with existent conditions prognosis theoretical accounts ( Global Circulation Model ) , contains expressed cloud strategies and dirt parameterization. MM5 is widely used by the meteoric biotic community and its end product could be coupled together with the Sparse Matrix Operation Kernel procession ( SMOKE ) theoretical account and Community Multiscale Air Quality ( CMAQ ) theoretical account to imitate the scattering of the air pollutants that take in considerations of the meteoric Fieldss and emanation beginnings. MRF Planetary Boundary Layer ( PBL ) parameterization strategy was selected in this survey. The 4-dimensional in initializeions assimilation ( FDDA ) option was non used was selected in this survey because the purpose of the survey is to analyze the effects of modify land usage on the theoretical account end product. For inputs of informations, land usage datasets from USGS will be used as the default land usage, and land usage map from Town and Country mean Department as the improved land usage and NCEP FNL ( Final ) Operational Global Analysis information was used in this survey. theatre of operations SetupFour cranial orbits are used as shown in numeral 1 for this survey. The female parent sphere with the declaration 27km covers the most of the Peninsular Malaysia 2nd sphere with the 9km declaration screens Selangor province 3rd sphere with 3km declaration screens finest sphere with 1km declaration will covers the survey country which is Klang Valley. catch 1 MM5 domain apparatus.Processing of Land Use and Land CoverIn the MM5 mold system, separately grid cell was assigned one land usage based on the dominant mob in the grid cell. 24 classs of Vegetati on type by USGS was used in categorization of land usage in MM5. Each land usage categories consists of six surface parameterization, which includes, reflective power, wet handiness, emissitivity at 9 Am, raggedness length, thermic inactiveness, and surface heat capacity per unit volume tolerant together with the MM5 theoretical account. Since Malaysia is a tropical state, summertime values are used. Out of 24 land usage types in the MM5 theoretical account ( Guo and Chen, 1994 ) , 14 classs was used to to the full depict the full sphere ( design 2 ) , with 22 % classified as H2O organic structures, 0.4 % as urban country and the largest non water-based class is Irrigated Cropland and Pasture ( 39 % ) in sphere 3 and as for sphere 4, 10 % classified as H2O organic structures, 1 % as urban country and the largest non water-based class besides class is Irrigated Cropland and Pasture ( 37 % ) ( disconcert 1 ) . mannikin 2 USGS land usage dataset sphere 3 and domain 4.Since the Land usage dataset from USGS was generated from the twelvemonth 1992/3 orbiter image, the development of the Klang Valley country for the other(prenominal) 15 old ages decidedly changed the land usage and land screen of the survey country. To better the land usage type, updated land usage map from the Town and Country Planning Department was referred in this survey. The updated land usage map was preprocessed from polygon to gridded land usage map based on the categorization of the 24 USGS land usage classs ( Figure 3 ) .The per centum differences of the land usage in the midst of the default land usage and the update land usage are shown in ( Table 1 ) .Table 1 fortune of landuse class for USGS and JPBD land usage earth 3 and Domain 4.Land usage codificationLand usage classUSGSLand usage Domain 3 ( % )USGSLand usage Domain 4 ( % )JPBDLand usage Domain 3 ( % )JPBDLand usage Domain 4 ( % )1Urban and Built -Up Area0.41.025.140.62Dryland Cropland and Pasture12.117.00.00.03Irrigated Cro pland and Pasture40.237.40.00.04Mixed Dryland/Irrigated Cropland and Pasture0.00.020.428.05Cropland/Grassland Mosaic0.00.30.00.06Cropland/Woodland Mosaic1.01.00.00.07Grassland0.71.70.00.08Shrubland3.77.60.00.010Savanna0.10.20.00.011 broad-leaved Broadleaf Forest13.416.50.00.013Evergreen Broadleaf Forest2.81.10.00.014Evergreen Needleleaf Forest0.30.50.00.015Assorted Forest2.75.334.425.016Water Bodies22.410.317.86.5Figure 3 Gridded JPBD land usage in 3km and 1km declaration.An ASCII type of input file was generated based on the reclassified land usage map into specific format. This ASCII file contains column, row, land usage type, latitude, longitude, flora fraction, and H2O fraction ( Figure 4 ) .Figure 4 Example of ASCII format input.The FORTRAN codification named replace_lulc.f is used to replace the land usage type, flora fraction and H2O fraction in the TERRAIN_DOMAINx file based on the co-ordinates of the reclassified grid cells and the several land usage type, and other param etric quantities provided in the ASCII file. The FORTRAN codification is compiled utilizing run book run.replace which besides determines the input and end product files to treat, and parametric quantities to be updated ( Figure 5 ) .Figure 5 Example of run.replace book.MM5 Simulation ResultsMM5 simulation was performed from 1st July 2005 ( 1800 ) to 3rd July 2005 ( 1700 ) with entire simulation clip 48 hours utilizing USGS flora dataset for 27km, 9km, 3km and 1km spheres as base instance. The 3km and 1km sphere will be compared with the end product of MM5 simulation using JPBD land usage dataset during for same period. All the physical options used were indistinguishable for both simulations. Observation from the Continuous Air Quality Monitoring ( CAQM ) station from Alam Sekitar Malaysia Sdn. Bhd. ( ASMA ) and Malayan meteoric Department ( MMD ) was used to formalize MM5 commonplace presentation from the both USGS and improved land usage dataset. one-third CAQM site was sele cted to formalize the MM5 public presentation, which are the monitoring station in Klang and Shah Alam that maintained by ASMA and inadvertence station in Subang that operated by MMD.The simulations that utilized USGS land usage dataset showed overestimate of the air current speed and produces sudden extremum at certain hr in the simulation. The improved land usage dataset utilizing JPBD land usage informations reduces the air current hurrying and frequence of the sudden extremum, yet still over estimated the boilers suit air current velocity compared to the observation informations ( Figure 6 ) . However, the improved land usage dataset utilizing JPBD do increase the correlativity between the ascertained air current velocity and simulated air currents velocity from all CAQM site ( Table 2 ) . The lowered air current velocity due to the improved land usage informations set could take to increased stableness and decreased perpendicular commixture. This could increase the air poll ution concentration in certain country.The temperature profile simulated by both utilizing USGS and JPBD land usage dataset able to imitate the afternoon temperature near surface when comparison with the onsite observation temperature informations. However, both USGS and JPBD land usage dataset tends to overrate the temperature near surface during the dark ( Figure 7 ) . The correlativity between ascertained temperature and fraudulence temperature somewhat increases when use JPBD land usage dataset in the simulation for the all monitoring site ( Table 2 ) .The consequences suggest that improved land usage dataset utilizing JPBD land usage dataset could better the overall simulation consequence ( Table 2 ) . The alterations of the meteoric parametric quantities could impact scattering of air pollutant, energy convey that could impact anthropogenetic emanations. The alterations of the MM5 end product could besides impact the computation of the air pollution patterning package such as CMAQ.Figure 6 Time series comparing of windspeed at 1km sphere for Shah Alam.Figure 7 Time series comparing of 1.5m temperature at 1km sphere for Shah Alam.Figure 8 Correlation between observed and predicted informations at Shah Alam.Table 2 Summary of correlativity between observed and predicted informations for all the attitude. parametric quantitySphereMonitoring StationKlang, ASMAShah Alam, ASMASubang, MMDWind speed 10mDomain 3 USGS0.0340.0820.176Domain 3 JPBD0.3110.3180.214Domain 4 USGS0.0150.0830.169Domain 4 JPBD0.2770.2730.254Temperature 1.5mDomain 3 USGS0.6730.6720.410Domain 3 JPBD0.7740.7880.537Domain 4 USGS0.6660.6570.411Domain 4 JPBD0.7900.7590.544DiscussionThe land usage is merely one of many factors that take in consideration by the meteoric mold system. The consequences showed betterment of the fake air current velocity and temperature near surface. The public presentation of the MM5 on simulation could be improved by modifying the MM5 physical options and strategi es depending on the declaration and location of the survey country. Since the land usage and land screen alterations affects the close surface meteorological, it should be included as one of the cardinal factors in the air pollution patterning particularly future air quality scenario. The alterations of the temperature that slip away by land usage could increase downwind, and potentially affects the air quality simulation. The alterations of the air current velocity besides affect the dispersion of air pollutants and blending in the ambiance, alterations of the air pollutant concentration are expected. changing in the land usage and land screen forms due to the urban conurbation, altering of agricultural forms, forestation and disforestation are expected to affects to landscape. The change of landscape will take to alterations in population, energy ingestion, anthropogenetic and biogenic emanations. The consequences suggested that land usage should be taken into consideration when utilizing air quality calculating theoretical account to predicts and measure the air quality.RecognitionThe writers thank the Ministry of Science and Technology ( MOSTI ) Malaysia for back uping this research, under undertaking no. 04-01-04-SF0674. We besides thank Department of Environment ( DOE ) Malaysia, Malaysian Meteorological Department ( MMD ) and Town and Planning Department ( JPBD ) Malaysia for informations providing. The Positions expressed by the authours do non neccesarily reflect those of the bureau.