Modelling Climate Changes, Biogenic Emissions and Tropospheric Chemistry in Southeast Asia.

A regional climate model (PRECIS) and a biogenic emission model (BVOCEM) were used to investigate the impact of climate changes on biogenic emissions during northeast monsoon (Dec-Jan-Feb, DJF) and southwest monsoon (Jun-(July)-Aug, JJA) in both the A2 and B2 transient climate scenarios of the IPCC in Southeast Asia. The investigation also explored the regional climate change and biogenic emissions response to future landcover changes, both alone and in combination with atmospheric forcing. Consequently, a tropsopheric chemistry model (CiTTyCAT) was used to investigate the relative impact of climate changes and biogenic emissions on tropospheric chemistry, particularly ozone in both seasons and climate scenarios. A warming across the region occurred, with the largest temperature increase apparent over land areas during DJF and JJA in both the A2 (3.0°C and 3.1°C) and B2 (2.6°C and 2.1°C) climate scenarios. These temperature changes were statistically significant at the 95% level in both climate scenarios across the domain with the exception during DJF (B2 scenario) in some areas over the South China Sea and the Philippines Sea. The increase in solar radiation was also reflected in the increase of surface temperature and decreased cloud fraction in both seasons in the A2 and B2 scenarios. Future changes in other climatic variables, such as precipitation and boundary layer, have shown a high degree of variability. The combined effect of atmospheric forcing and landcover forcing was observed to increase the surface temperature significantly in both climate scenarios. However, the effects of future landcover forcing alone in both seasons in the A2 and B2 climate scenarios were observed to be small and produced cooling temperatures. Projected climate changes in the present-day landcover scenario in both A2 and B2, with the exclusion of the CO2 activity factor, showed an increase in isoprene emissions by 27% (A2) and 13% (B2) in 2100 relative to 2008. In the same scenario, but with the inclusion of future CO2 concentrations of 560 ppm, isoprene emissions were found to be inhibited by 8% (A2) and 19% (B2) respectively. The inhibitory effects of elevated CO2 on isoprene emissions was much larger than that of climate change alone. Meanwhile, the combined effects of climate change and future landcover forcing with the inclusion of the CO2 activity factor accounted for the decrease of future isoprene emissions by 66% (A2) and 60% (B2) respectively. Landcover forcing alone accounted for the decrease of isoprene emissions by 5% (A2) and 6% (B2) with the CO2 activity factor, and conversely the increase of isoprene emissions by 9% (A2) and 5% (B2) without the CO2 activity factor. The CO2 inhibitory effect was more important than the combined effects of climate changes and landcover forcings on isoprene emissions. These results suggest that future emissions of isoprene in the region is largely buffered by a number of competing factors, which is certainly an important consideration when estimating the global isoprene budget. In the present-day landcover scenario, the combined impact of climate changes and biogenic emissions (with the CO2 activity factor) in 2100, surface O3 concentrations in urban (Bangkok) and remote (Danum) areas increased in both climate scenarios. In Bangkok, in the A2 scenario, the surface O3 increased by 16% ((January) and 21% (July); while in the B2 scenario, O3 increased by 15% (January) and 18% (July) respectively. In Danum, in the A2 scenario, the O3 increased by 43% (January) and 28% (July); while in the B2 scenario, O3 increased by 13% (January) and 27% (July). In the future landcover scenario, the combined impact of climate changes and biogenic emissions resulted in a further increase in surface O3 concentrations in both seasons in the A2 and B2 climate scenarios in Danum (between 38% and 77%) and Bangkok (between 12% and 21%). In both locations, biogenic emissions accounted for a larger effect on the increase of surface O3 concentrations in both seasons in the A2 and B2 climate scenarios than that of climate changes. In Bangkok, the combined impact of climate changes and biogenic emissions in the present-day and future landcover scenarios were found to decrease OH concentrations in both seasons in A2 and B2 climate scenarios. The OH suppression was largely due to the oxidation of isoprene by OH radicals. (Abstract shortened by ProQuest.)

Preliminary studies on Odour pollution from Fishmeal factory

Complaints from the public have been reported frequently to the respective authorities concerning odour emission from the fis1uneal factory at Sepangar Bay Kota Kinabalu. PreIiminaty study has been carried out at the fishmeal factory to determine the point sources of odour emission and to assess the pollution control facilities to abate odour pollution. It was found that the major sources of odour pollution were from the cooking and drying processes. From the observation, the pollution control facilities to abate odour pollution, physically capable to minimize the odour pollution. However, the efficiency of the pollution control was not studied in detail

Impact of school traffic on outdoor carbon monoxide levels

This paper aims to determine the relationship between carbon monoxide levels with vehicles, including types and motions of vehicles in a school traffic environment. Children are more vulnerable as they spend most of their time in school and their still-developing respiratory system makes them more susceptible to air pollution compared to adults. The research was carried out by direct measurement of carbon monoxide using MultiRAE Lite PGM-6208 and counting of vehicles manually using tally counter with different traffic flow scenarios, type of vehicles, school days, locations and in schools. From the findings, it is found that the measurements of carbon monoxide exposures were significantly greater in town schools compared to rural area; weekdays recorded much higher carbon dioxide levels compared to weekends; moving vehicles had stronger effects compared to idle vehicles; and light-duty vehicles (LDV) had highest among other types of vehicles. The results show a large impact of traffic management and transport mode on carbon monoxide exposures to school children in the schools

Surface ozone variations at the Great Wall Station, Antarctica during austral summer

Surface ozone (O3) is a secondary pollutant harmful to human health and a greenhouse gas which is one of the prime climate forcers. Due to the clean atmospheric environment of the Antarctic region and given the complexity of O3 chemistry, the observation of surface O3 variability in this region is necessary in the quest to better understand the potential sources and sink of polar surface O3. In this paper, we highlighted our observations on O3 variability at the Great Wall Station (GWS) during austral summer in December 2018 and January 2019. The continuous surface O3 measurement at the GWS, Antarctica was carried out using the Ecotech Ozone analyzer. To understand the roles of the meteorological conditions on the temporal variations of O3, meteorological data was obtained from the conventional auto-observational station at the GWS. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model was employed to investigate the air mass transport over the region. The observed austral summer surface O3 concentrations at the GWS exhibited variability and were significantly lower than those previously observed at other permanent coastal stations in Antarctica. The surface ozone variability at the GWS was strongly influenced by the synoptic change of air mass origin although the roles of photochemistry production and destruction were still uncertain. Marine characteristics and stable surface O3 characterized the air masses that reached the GWS. The unique characteristic of surface O3 at the coastal site of GWS was emphasized by its synoptic air mass characteristics, which displayed a significant influence on surface O3 variability. Air mass that traveled over the ocean with relatively shorter distance was linked to the lower O3 level, whereby the marine transport of reactive bromine (Br) species was thought to play a significant role in the tropospheric chemistry that leads to O3 destruction. Meanwhile, the diurnal variation indicated that the O3 background concentration levels were not strongly associated with the local atmospheric conditions

Satellite imagery system in malaria transmission resulting from the land use/land cover change

This study analyzed the changes in land use and land cover trends and their implication on malaria transmission using satellite imagery applications. Deforestation or human land use activity related to water and development has expanded the ideal habitats for malaria-carrying mosquitoes, resulting in an upsurge of malaria transmission. The presence of these habitats and breeding increased the contact between humans and mosquitoes, thus increasing the number of malaria cases. The decrease of canopy and forest cover has increased the temperature, resulting in the shortening of aquatic stages and sporogony development of the mosquitoes. This study aims to provide an understanding of the relationship between the topography effect over the land-use factor and land cover change on malaria for more than ten years from 2005 to 2019 of transmission. Malaria case data obtained were analyzed for the trends, incidence rate, and spatial distribution. Remote Sensing and geographic information system were used to determine the land use and land cover change in selected districts of North Borneo in Sabah, as the study areas. The malaria incidence rate shows an increase from 2005 to 2019, with 149.64%. The transmission of the malaria vector dynamics and abundance with topography changes has changed with time, including with forest declination at 8.38%, and cropland change decreased at 16.61%. However, an expansion of 33.6% was observed for oil palm plantations. Overall, the results have shown that the range of incidence rate was found` highly viable from 0.29/1000 persons to 4.09/1000 people. In conclusion, using geographic information system remote sensing with malaria integrated topography transmission information will be targeted by zoning most affected areas or the most productive larval habitat for remedial measures. This study can help to reduce the malaria vector population through environmental management related to the mosquito larval cycle in different land-use settings and change by minimizing the transmission by the targeted malaria control program

Rainwater chemistry of acid precipitation occurrences due to long-range transboundary haze pollution and prolonged drought events during southwest monsoon season: climate change driven

The purposes of this research were to study the characteristics chemistry of pH, anions and cations in rainwater, and to identify the possible sources that contributing to the acid precipitation during southwest monsoon season with occurrence of extreme drought event. During the southwest monsoon season, it normally occurs along with haze phenomenon that every year will hit Southeast Asia. This condition will aggravate with high acidic particles in the atmosphere due to the prolonged drought. The analysed parameters which involved pH, anions (NO3 -, SO4 2- and Cl-) and cations (Ca2+, Mg2+, Na+ and K+) were analysed using pH meter, Hach DR 2800, argentometric method and ICP-OES. From the findings, it showed that acid rain occurred during the southwest monsoon season with the range of pH values from 4.95 ± 0.13 to 6.40 ± 0.03 and the total average of pH 5.71 ± 0.32. Anions NO3 -, SO4 2- and Cl- were found to be the dominant compositions of the acid rain occurrences with higher concentrations detected. In overall, rural area recorded with higher acidity of precipitation at total average of pH 5.54 ± 0.39 compared to urban area at pH 5.77 ± 0.26. Rural area surprisingly recorded higher frequency occurrences of acid rain with pH lesser than 5.6 and below compared to urban area. As for public health and safety, all rainwater samples during the acid rain event were found exceeded the allowable limits of NWQS and WHO standards, that shown not suitable for skin contact, recreational purposes even for drinking purposes

Variability of the PM10 concentration in the urban atmosphere of Sabah and its responses to diurnal and weekly changes of CO, NO2, SO2 and Ozone

This paper presents seasonal variation of PM10 over five urban sites in Sabah, Malaysia for the period of January through December 2012. The variability of PM10 along with the diurnal and weekly cycles of CO, NO2, SO2, and O3 at Kota Kinabalu site were also discussed to investigate the possible sources for increased PM10 concentration at the site. This work is crucial to understand the behaviour and possible sources of PM10 in the urban atmosphere of Sabah region. In Malaysia, many air pollution studies in the past focused in west Peninsular, but very few local studies were dedicated for Sabah region. This work aims to fill the gap by presenting the descriptive statistics on the variability of PM10 concentration in the urban atmosphere of Sabah. To further examine its diurnal and weekly cycle pattern, its responses towards the variations of CO, NO2, SO2, and ozone were also investigated. The highest mean value of PM10 for the whole study period is seen from Tawau (35.7±17.8 μg m-3), while the lowest is from Keningau (31.9± 18.6 μg m-3). The concentrations of PM10 in all cities exhibited seasonal variations with the peak values occurred during the south-west monsoons. The PM10 data consistently exhibited strong correlations with traffic related gaseous pollutants (NO2, and CO), except for SO2 and O3. The analysis of diurnal cycles of PM10 levels indicated that two peaks were associated during the morning and evening rush hours. The bimodal distribution of PM10, CO, and NO2 in the front and at the back of ozone peak is a representation of urban air pollution pattern. In the weekly cycle, higher PM10, CO, and NO2 concentrations were observed during the weekday when compared to weekend. The characteristics of NO2 concentration rationed to CO and SO2 suggests that mobile sources is the dominant factor for the air pollution in Kota Kinabalu; particularly during weekdays

Combined climate impacts and vulnerability index on coastal ecosystems in prediction of future scenarios: extended sustainable indicator tool for adaptive strategy

This study presents the coastal vulnerability due to the forecasted climate change impact on the marine environment, including the sea level rise physical trait of risk impact. A combined methodology using Representative Concentration Pathways (RCPs), which corresponds to the greenhouse gas emissions scenarios, is used in this research; combined with Climate Change Vulnerability Index (CCVI) to rank the relative risk for each of the marine ecosystem zones in relation to the potential hazard exacerbated by climate change and sea-level rise. This method presents vulnerability in numerical data, which cannot be calculated directly based on their physical properties. From the results, it shows that the coastal areas of the study area of Marudu Bay would experience a warmer atmosphere both under RCP 4.5 and RCP 8.5 with an increment of 1.0 °C and 1.7 °C; meanwhile, the climate projection for total exhibits of increase in total precipitation by 2.6 mm/day and 1.6. mm/day under RCP 4.5 and RCP 8.5 at the regional measure. At the same time, the projection simulates an increase of sea level by 0.21 m and 0.27 m over the northern region of Marudu Bay under RCP 4.5 and RCP 8.5, respectively. In addition, 43.84 ha and 57.02 ha of land estimated would be potentially inundated by the mid-century year 2050 under RCP 4.5 and RCP 8.5. By the end of the century 2100, the sea level is projected to increase locally at about 0.32 m under RCP 4.5 and 0.38 m under RCP 8.5, consequently resulting in a total of 66.84 ha and 79.78 ha of additional inundation coverage. Therefore, the result from this study can be used when making effective adaptive strategies and conservation planning despite its inherent uncertainties

Visualising point source pollutant concentration level dispersion using the gaussian model

In this study, we examined the usage of the Gaussian air dispersion model to visualise point source pollutant concentration levels and implemented it in MASPLUME, a newly developed computer software which functioned as an estimation tool application for measuring the concentration level (at ground zero) of a selected pollutant dispersed from a single point source. The identified pollutants were carbon monoxide, nitrogen dioxide, and sulphur dioxide. MASPLUME was able to show a two-dimensional static air pollution dispersion and concentration level, as well as graphical data for different scenario analysis. Although MASPLUME is in its initial development stage as a comprehensive software, it would still be sufficient as a current teaching and learning aid