Yulihastin, Erma
LIPI Press

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PRECIPITATION EVENT ANALYSIS USING IMAGE PROCESSING BASED ON THE RAINFALL DETECTION RADAR (RDR) OBSERVATION ON MARCH 9 2014 DURING LANDSLIDE EVENT IN WEST JAVA Nugroho, Ginaldi Ari; Satyawardhana, Haries; Yulihastin, Erma; Satiadi, Didi; Halimurrahman, Halimurrahman
Teknologi Indonesia Vol 39, No 2 (2016)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jti.v39i2.254

Abstract

A Rainfall Detection Radar (RDR) is a simple weather radar based on marine radar that able is to detect the rainfall within 40 km of range located in Bandung. This system is able to conduct continuous operation, with temporal resolution of 3 minutes with data analysis using an image processing method, to analyze the observation data on March 9, 2014 during the landslide event. The landslides are located 24.6 km southwest from the RDR site. According to observation data, there are 2 large rainfall areas distribution that appear near the landslide location. The second rainfall area is estimated to have initiated the landslide. This second area has two detected object. Object A showed first with maximum size of + 6.47 km 2 . From the image processing point of view, the object A contributesto the size area of object B. Object B is the second object detected soon after object A appears. Object B has three peaks of its estimated size area with the highest size of + 19.4 km 2 occuring in 16.14 LT, and will move towards the southeast affected by local wind leaving the landslide location in 16.37 LT. RDR mean rainfall intensity in radius of 1 km from landslide location on 9 March showed the range value from 0.5–2.5 mm/hour that is located in the east side of the landslide location with the duration over 1 hour.
Method of Delineate of the ITCZ for the ITCZ Monitoring System Related to Early Season Yulihastin, Erma; Fathrio, Ibnu; Cholianawati, Nani
Teknologi Indonesia Vol 35, No 3 (2012)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (16.051 KB) | DOI: 10.14203/jti.v35i3.190

Abstract

The ITCZ has dominant of role to control atmospheric tropic-equator that were described clearly by satellite band of cloud and rain from west to east around the world as a part of Hadley circulation. Study the ITCZ phenomenon is very important because monsoon onset can be identifi ed by ITCZ jump to the northern or southern relative to the equator. Moreover, understand the ITCZ dynamic is keys to understand other phenomena such as ElNino Southern Oscillation (ENSO), Indian Ocean Dipole Mode (IODM), Madden Julian Oscillation (MJO), monsoon circulation, and Tropical Cyclone (TC). Other phenomena will disturb to the ITCZ. Study the ITCZ also important to predict rain and extreme event related to natural disaster such as fl ood, slide, dryness using prediction model. In this applied research, we develop monitoring system of the ITCZ based on MTSAT satellite observation to define early season over IMC (IMC). Research outputs are early season information and real time of ITCZ position on LAPAN website. The ITCZ position will always updated by real time. The information used to operational concern at LAPAN and researcher at other institutes for investigate early season predict to raise paddy fi eld productivity and to encourage development of early warning natural disaster system. Results show that jumping of the ITCZ positioncan be used to identify early season over IMC by global scale. Whereas in regional scale, jumping of the ITCZ appropriate to insitu observation to detect early season for monsoonal, equatorial, and local rain type. Moreover, time series profi le of the ITCZ has symmetry pattern with zonal wind over southern IMC.
PENENTUAN INDEKS MONSUN INDONESIA BERDASARKAN ANGIN ZONAL Yulihastin, Erma
Teknologi Indonesia Vol 34 (2011)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jti.v34iKhusus.45

Abstract

The research defi ned monsoon index which represented Indonesia Maritime Continent. Indonesia monsoon index were calculated based on monthly mean zonal wind at 850 milibar over the north-east area (2-80N, 95-1180E) and south (2-100LS, 105-1500BT), mentioned as Index I and Index II, respectively. The choice of index area based on prevailing westerly(easterly) to easterly(westerly) wind in the annual cycle. Monthly mean wind data derived from NOAA Satellite (National Oceanic and Atmospheric Administration), NCEP/NCAR Reanalysis (National Center for Environmental Prediction/National Center for Atmospheric Research), which have 2.5 degree spatial resolution from 1948 to 2010. The results showed Index I and II have symmetry pattern. Maximum (> 5 m/s) of Index I occurred on August and minimum (<-4 m/s) occurred on January. Conversely, Index II reached maximum (> 5m/s) at February and the minimum (<-5 m/s) occurred on August. The Index I and AUSMI (Australia Monsoon Index) were symmetry, but have different in amplitude. Correlation between the Index I and AUSMI were 0.99. The Index II and Webster-Yang Index were symmetry but have different in phase and amplitude. Correlation between the Index II and Webster-Yang Monsoon Index were also 0.99. Correlation between index I(II) and precipitable water were 0.68(0.95), respectively.
Annual Migration of Monsoon Over Indonesia Maritime Continent Based on OLR Data Yulihastin, Erma; Hermawan, Eddy
Teknologi Indonesia Vol 35, No 3 (2012)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jti.v35i3.191

Abstract

Annual migration of monsoon over Indonesia Maritime Continent (IMC) were analysed by Outgoing Longwave Radiation (OLR) data. Global climatology of NCEP/NCAR Reanalysis II (National Center for EnvironmentalPrediction/National Center for Atmospheric Research) namely OLR, wind, and precipitable water were derived from 1975 to 2010 which have 2,5o spatial degree resolution. The results showed those the annual migration were described by annual cycle of OLR<220 W/m2 occurred almost over IMC related to the wet periods (DJF). Whereas, OLR>240 W/m2 occurred only over south of IMC (3-9o S) related to the dry periods (JJA). Zonal variation of OLR showed annual cycle occured in areas of 2-10oS and 5-10oN, respectively. On the other hand, meridional variation described annual cycle in areas 90-120o E and 90-150, which respectively mentioned as area I and area II. Annual cycle of OLR in area I was symmetry with area II. Also, in areas I and II, parameters of OLR and precipitable waterwere symmetry each other. Signifi cants anticorrelation between OLR and precipitable water were -0.89 and -0.95 in area I and II, respectively.
PENGARUH OSILASI TAHUNAN DAN ENSO TERHADAP VARIABILITAS OZON TOTAL INDONESIA Ambarsari, Novita; Yulihastin, Erma
Teknologi Indonesia Vol 34 (2011)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jti.v34iKhusus.44

Abstract

The global ozone data of TOMS (Total Ozone Mapping Spectrometer) from NASA (National Aeronautics and Space Administration) Satellite was used from 1997 to 2005 in Indonesia (90E-151.2E, 12.5S-12.5N). The results of time series total ozone concentration data showed that the concentration varied from 242 to 275.38 Dobson Units. The highest concentration occurred from September to October, which was period of transition season from dry to rainfall season in Indonesia. In that times occurred autumn in northern hemisphere. The lowest concentration occurred from December to February, which was period of peak rainfall season in Indonesia, besides winter in northen hemisphere. The spectral analysis used FFT (Fast Fourier Transform) method founded total ozone variability in Indonesia from 1997 to 2005 was dominant infl uenced by annual oscillation (period of 11.33 months), ENSO (25.5 months), and semiannual oscillation (5.67 months).