Sopia Lestari, Sopia
Environmental Science Study Program, Graduate Program, University of Indonesia

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ANALISIS VARIABILITAS CURAH HUJAN DI SUMATERA BARAT DAN SELATAN DIKAITKAN GENGAN KEJADIAN DIPOLE MODE Hermawan, Eddy; Lestari, Sopia
Jurnal Sains Dirgantara Vol 4, No.2 Juni (2007)
Publisher : Lembaga Penerbangan dan Antariksa Nasional

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Abstract

The rainfall variability over the Western and Southern part of Sumatera Island related to te Dipole Mode (DM) event for period of twenty years (1980-1999) based on the monhly mean of rainfall, Dipole Mode Index (DMI), Sea Surface Temparature (SST), and Outgoing Longwave Radiation (OLR) data analysis have already investigated. By applying the spectral analysis technique Fast Fourier Transform (FFT), the most predominant peak ascillation of rainfall and DMI data has been identified. They are Semi Annual Oscillation (SAO) for Bukit Tinggi, Maninjau, and Sicincin sation, and Annual Oscillation (AO) for Padang-panjang, Padang, Batu Sangkar, Solok, Tabing, Bengkulu, Kotabumi, Jambi, and Palembang station, respectively. While the other predominant peak oscallation in period of 1.5 to 3 years are also found , especially on the DMI data analysis. It indicates that the rainfall variability over these areas could be related to the DM event, especially during DM (+) when the high pressure covers most of Indonesia region. When DM (+) occured, especially on JJA (June-July-August) and SON (September-October-November), the rainfall intensity over those area become less intil below normal condition. Conversely, when DM (-) occured, the amount of rainfall intensity is more than normal condition. Compared to DM (-), DM(+) looks more giving a significant influence to the rainfall in both areas.
Study on Heat Island Effect Induced by Land Use Change Increased Temperature in Metropolitan Jakarta Lestari, Sopia; Moersidik, Setyo S.; Syamsudin, Fadli
Journal of Mathematical and Fundamental Sciences Vol 47, No 2 (2015)
Publisher : ITB Journal Publisher, LPPM ITB

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Abstract

The heat island (HI) effect in metropolitan Jakarta was studied using air temperature measurements at 9 meteorological stations in Jakarta, Tanjung Priok, Serang, Halim, Cengkareng, Pondok Betung, Curug, Bogor, Citeko during 1986-2008 and Serpong during 2008-2011 and 2013; land use for forest, industry, water, settlement, open/cleared land in 1997, 2004, 2009, 2012; and total number of industries and total number of vehicles during 1986-2011. Harmonic analysis was used to remove the seasonal component from the temperature time series data, which was filtered with the 30-day moving average technique to capture trends whose significance was tested with the Mann-Kendall method. The results show that industry was a major factor in land use change over Jakarta with an increasing growth/year of 502 ha (9.76%) concentrated in the eastern part of Jakarta from 1997 to 2012. Industry had a spatial cover change similar to deforestation and open/cleared land expansion, especially in Jakarta from 2009 to 2012: 38.8%/year (industry), 8.3%/year(deforestation), and 13.8%/year (open/cleared land). The HI effect increased the temperature trend rate/year in Jakarta, Tanjung Priok, Serang, Halim, Pondok Betung, Cengkareng, Curug, and Bogor about 0.051°C, 0.021°C, 0.018°C, 0.012°C, 0.006°C, 0.006°C, 0.005°C, and 0.004°C from 1986 to 2008, respectively, equivalent to average warming in the city, suburban, and mountainous areas of around 2.5°C, 0.6°C, and 0.4°C, respectively within 100 years from 2009.
DAMPAK PEMANASAN PULAU PERKOTAAN (URBAN HEAT ISLAND) PADA PENINGKATAN TREN CURAH HUJAN EKSTREM DAN AEROSOL DI MEGAPOLITAN JAKARTA SEJAK TAHUN 1986 Syamsudin, Fadli; Lestari, Sopia
Jurnal Teknologi Lingkungan Vol 18, No 1 (2017)
Publisher : Center for Environmental Technology - Agency for Assessment and Application of Technology

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Abstract

Dampak pemanasan pulau perkotaan (urban heat island (UHI)) pada curah hujan ekstrem dan aerosol telah dikaji dalam penelitian ini menggunakan data curah hujan harian dan konsentrasi aerosol bulanan (NO2, SO2, dan SPM) di stasiun Badan Meteorologi Klimatologi dan Geofisika (BMKG) pada megapolitanJakarta dan wilayah pegunungan Bogor dan Citeko dari 1986-2012. Analisis harmonik dilakukan untuk menghilangkan pengaruh musiman pada hasil tren data curah hujan dan selanjutnya signifikansi tren tersebut diuji dengan metoda statistik Mann-Kendall. Hasil penelitian menunjukkan dampak pemanasanpulau perkotaan (UHI) telah terjadi secara nyata dengan tren peningkatan curah hujan ekstrem dari indikator total hari hujan 40, 50 dan 100 mm/tahun dan konsentrasi aerosol di wilayah megapolitan Jakarta dan sekitarnya dengan laju tren masing-masing sebesar 0.17 hari/tahun, 0.17 hari/tahun, dan 0.04 hari/tahun, dan 3.7e-004 ppm/tahun (NO2) dan 0.148 ppm/tahun (SO2). Namun sebaliknya terjadi tren penurunan di wilayah pegunungan Bogor dan Citeko. Hasil penelitian ini menunjukkan ada indikasi peningkatan UHI menyebabkan kenaikan konsentrasi aerosol di megapolitan Jakarta dan kondisi ini menjadi trigger peningkatan curah hujan ekstrem yang berdampak pada intensitas banjir yang semakin meningkat sejak tahun 1986.Kata kunci: Pemanasan pulau perkotaan, curah hujan ekstrem, aerosol, tren