Alberth’s Digest

I dedicate this page for sharing of my paper. Well, it’s really nice if you can give your opinion after you read it. Who knows, someday you can read my name in Elsevier By the way, I use an English abstract as it is a requirement for making an article in my station, but the content is written in Bahasa Indonesia.

Analisis Konsentrasi Metana Atmosferik di Stasiun Pemantau Atmosfer Global Bukit Kototabang
Over the past decades, global atmospheric methane (CH4) concentration as one of the greenhouse gases had increased dramatically. However, in the 1990’s, CH4 concentration began to decrease and in the period of 1998-2002, the growth rate of CH4 is nearly zero. Several factors had been suggested as the cause of this stability, such as the change of chemical composition in the troposphere, decrease of the wetland areas, and the collapse of former Soviet Union industry in the early of 1990. Similar trend is shown from the CH4 concentration measurement in Global Atmosphere Watch Station Bukit Kototabang, West Sumatera. The measurement that had been conducted from 2004, showed the stability of CH4 concentration which has similar trend with global CH4 concentration. From the measurement, it’s found that there is seasonal variation on CH4 emission which the high concentration occurred in December-January-February while the low at May-June-July.
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Distribusi Global Persistent Organic Pollutants (POPs)
Persistent Organic Pollutants (POPs) become one of the major problems for the environment in the last years. Their properties that can resist in the atmosphere for several years and easy moving over the long area make this problem become more serious. Concentration of POPs in the atmosphere was measured by using passive air sampling method with PUF disk sampler deployment. The data was collected from the result of measurement in 53 sites which are classified into 5 categories: background, agricultural, rural, urban, and polar. The study showed that POPs was found in all type of sampling site across the world, even in the polar region where there is small chance of using any kind of POPs that could trigger the emission on that area. The study also showed that agricultural areas emitted more POPs in term of concentration compare to the other kind of areas. Latest result of POPs measurement in Bukit Koto Tabang showed the decreasing of concentration for most of compounds measured. However, more research on this area have to be conducted because it is still difficult to observe the trend of POPs distribution due to their independence from meteorological impacts since no pattern found on POPs’ emission observed in Bukit Koto Tabang and the period of measurement is relatively too short.
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Korelasi Antara Indeks Kecerahan (K_T) dengan Parameter Meteorologi di Bukit Kototabang Menggunakan Pendekatan Regresi Multi Linier terhadap Persamaan Ångstrom Termodifikasi
A study of the correlation between solar radiation and several meteorological parameters had been done. Solar radiation was represented by the clearness index (K_T), the ratio of the global solar radiation on the surface and global solar radiation on the top of atmosphere or extraterrestrial solar radiation. K_T was correlated with meteorological parameters which are taking from Campbell-Stock observation for relative sunshine duration, and from Automatic Weather Station (AWS), for ratio of minimum and maximum temperature, average temperature, and relative humidity. All of the data were collected from February 2008 to March 2009 using daily average. Multi linear regression method was used to determine the best correlation between the parameters, based on Ångstrom equation which already used for correlating the global solar radiation and relative sunshine duration. The values of correlation coefficient (r), Root Mean Square Error (RMSE), Mean Bias Error (MBE), and Mean Percentage Error (MPE) were used to determine which equation had the strongest correlation. The result suggested that the relation of clearness index and 4 meteorological parameters provides the best correlation among the others. The modified Ångstrom equation for this relation is H/H₀=0.3709 + 0.2577 (S/S₀) – 0.2744 (T_min/T_max ) + 0.0339 T_ave - 0.0060 RH, where H/H₀ is the clearness index, S/S₀ is the relative sunshine duration, T_min/T_max is the ratio of daily minimum and maximum surface temperature, T_ave is the daily average surface temperature, and RH is the relative humidity. The modified Ångstrom equation can be used to determine the impact of several meteorological parameters on the clearness index.
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