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ANALISIS DATA EQUATORIAL ATMOSPHERE RADAR(EAR) PADA GEMPA PADANG PARIAMAN 30 SEPTEMBER 2009 Kusmita, Tri; Astuti, Dwi Puji; Hermawan, Eddy
Jurnal Fisika Unand Vol 1, No 1: Oktober 2012
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jfu.1.1.%p.2012

Abstract

Telah dilakukan analisis data EAR pada gempa PadangPariaman untuk melihat ada atau tidaknya anomali kecepatan angin pada kasus gempa bumi Padang Pariaman 30 September 2009.Dalam penelitian ini digunakan software xygraph untuk pengolahandata kecepatan angin yang terekam oleh EAR dalam orde 2,3 menit menjadi sebuah grafik vektor angin. Analisis yang dilakukan merupakan analisis kualitatif yang berdasarkan pada hasil plot grafik vektor angin. Hasil analisis menunjukkan bahwa untuk kasus gempa bumi Padang-Pariaman tidak ditemukan adanya anomali kecepatan angin. Namun,gangguan konstan yang terekam oleh EAR pada rentang waktu pengamatan dari puluk 16:00 WIB (30 September 2009)-03:00 WIB 1 Oktober 2009) kemungkinan disebabkan oleh adanya gangguan cuaca yang terjadi pada lapisan tropopause.
ESTIMASI PARAMETER TURBULENSI UNTUK JASA PENERBANGAN BERBASIS HASIL ANALISIS BEBERAPA DATA RADIOSONDE DI KAWASAN BARAT INDONESIA Hermawan, Eddy; Abidin, Zainal
Jurnal Sains Dirgantara Vol 3, No.2 Juni (2006)
Publisher : Lembaga Penerbangan dan Antariksa Nasional

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Abstract

The one of an important thing related to the aviation is the correct information of aviation meteorology, especially about bad weather condition such as turbulence that often disturb the plane during their flight. There are many parameters to estimate the turbulence parameter. One of them is called the Richardson Number (Ri) such as already investigated by Waco (1970). We continued hos study by applying the radiosonde data distributed at five stations in the Western part of Indonesia region, especially during the Coupling Processes Equatorial Atmoephere I (CPEA I) Campaign started from April 10 to May 10, 2004. We defined the turbulence when Ri less more 0.25 as described by Killer (1981). We found initial turbulence occurrence indication, even though we have found significant indication yet, related with less of locations and data observations which is only one month observation. Turbulance in the plane is described as the changes of vertical gravitation in the plane and observed by vertical accelerometer which is installed in the plane. After making some validations with the vertical accelerometer data, we found only a few good correlation between Ri and turbulence. We suspect it caused by the less of data observation. But initial indication based on data analysis shows that light turbulence occurrence a long Eastern Coast of Malacca Peninsula on 19th April 2004.
HOLT-WINTERS DALAM PREDIKSI ANOMALI OLR Hermawan, Eddy
Jurnal Sains Dirgantara Vol 9, No. 1 Desember (2011)
Publisher : Lembaga Penerbangan dan Antariksa Nasional

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Abstract

One of the pivotal study when analyzing the impact of the Madden-Julian Oscillation (MJO) phenomenon on rainfall anomalies in the Western part of Indonesia region is knowing the characteristics and the prediction of Outgoing Longwave Radiation (OLR) as the main parameter. This paper, focused to develop a predictive model OLR using the Box-Jenkins (ARIMA) method, which compared by the Holt-Winters method. This analysis focused on the average five days (pentad) OLR data in the Western part of Indonesia region, precisely at the position of 120oE for period of January 2007 to December 2009. Based on the comparison of the MSE (Mean Squares of Errors), and the MAPE (Mean Absolute Percentage Error) obtained from the Box-Jenkins (ARIMA) and Holt-Winters methods can be concluded that appropriate to predict the value of pentad OLR data on the position 120oE is the Box-Jenkins (ARIMA) method, because it has smaller value of MSE and MAPE comparing with the Holt-Winters method. Box-Jenkins model is the model ARIMA (1.0.1)(0.1.1)9 according to the results of significance analysis, autocorrelation in the residuals (white noise), also normality of residuals, where the process is repeated until model is really suitable and best meet the assumptions of model selection. The models can be assessed by the signal tracking value at each forecasting model. This assessment showed two of models in accepted boundary value, i.e ±5. This shows forecasting model can still be used to predict the 4 periods of the OLR pentad anomaly. Keywords: Box-Jenkins (ARIMA), Holt-Winters, OLR, and Prediction Model ABSTRAK Salah satu kajian penting ketika menganalisis dampak dari fenomena Madden-
VARIASI KANDUNAGN UAP AIR DI ATAS KOTOTABANG, SUMATERA BARAT HASIL ANALISIS DATA RADIO ACOUSTIC SOUNDING SYSTEM (RASS) SELAMA KEGIATAN CPEA-CAMPAIGN 2004 Hermawan, Eddy; Muhammad Abdul Wahab, Fikri
Jurnal Sains Dirgantara Vol 4, No.1 Desember (2006)
Publisher : Lembaga Penerbangan dan Antariksa Nasional

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Abstract

As we know since June 2001, the National Institute of Aeronautics and Space (LAPAN) and Research Institute for Sustainable Humanosphere (RISH) of Kyoto University, Japan has already stared to make a joint research at LAPAN-Kototabang under the Coupling Processes Equatorial Atmosphere (CPEA) project. There are many research activities have already been dano by both institutes. One of them is the estimation of Total Precipitable Water (TPW) in the lower troposphere at Kototabang, West Sumatera (0.2˚S; 100.32˚E) during the CPEA I Campaign stared from April 10 to May 9, 2004 using many instruments. The main purpose of this paper is we would like to show how the TPW parameter can be estimated from the Radio Acoustic Sounding System (RASS) and radiometer and their correlation with the surface rainfall data. We applied the Wiesner (1970) technique when we estimated the TPW with specific humidity and air density taken from RASS and radiomater, respectively. Then, we analyzed the Cross-Correlation Function (CCF) when we compared the TPW and Optical Rain Gauge (ORG) data. In the same time, we analyzed the Boundary Layer Radar (BLR) data also to investigate the updraft and downdraft air mass activities from surface up to 5 km. We can see here the consistency of BLR, RASS and radiomater data when we investigated the vertical profile of water vapor over Kototabang. We found also a time variation of TPW, especially on April 24 and May 5, 2005 are about 0.43 and 0.35, respectively. Although both values look small relatively, but they are inough significant statistically.
CLIMATE PROJECTION OVER INDONESIA BASED ON THE TOTAL FOSSIL FUEL CO2 EMISSION PREDICTION USING THE BOX-JENKINS ARIMA MODEL (PROYEKSI IKLIM WILAYAH INDONESIA BERDASARKAN PRAKIRAAN EMISI CO2 DARI PENGGUNAAN BAHAN BAKAR FOSIL MENGGUNAKAN MODEL ... Hermawan, Eddy
Agromet Vol. 23 No. 1 (2009): June 2009
Publisher : PERHIMPI (Indonesian Association of Agricultural Meteorology)

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (419.231 KB) | DOI: 10.29244/j.agromet.23.1.1-10

Abstract

This paper mainly discusses about the development of estimation models raising the rate of gas emissions of carbon dioxide (CO2) as the main parameters of global warming in Indonesia. This is important to remember not many comprehensive scientific study which shows that the impact of global warming has actually experienced by Indonesia. Using Box-Jenkins method and the stage of identification, assessment, and testing, then the best prediction model obtained for the above data, the model of ARIMA (8,1,3). This means that the predicted value for the next year depending on the data before and 8 years 3 years earlier error. In the validation data with predicted results, the MAD (Mean Absolute Deviation) is relatively high. However, the pattern of results followed the pattern predicted almost the original data with a correlation value of 99%. Based on this result, we can estimate the climate projection over Indonesia, especially during 2012-2014.
HUBUNGAN AIR TERKANDUNG DENGAN REFLEKTIFITAS RADAR Hermawan, Eddy; Handayati, Yuanita
Jurnal Sains Dirgantara Vol 5, No.1 Desember (2007)
Publisher : Lembaga Penerbangan dan Antariksa Nasional

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30536/j.jsd.2007.v5.a660

Abstract

This paper is mainly concentrated to the correlation between Total Precipitable Water (TPW) on one single column of the vertical air mass and radar reflectivity (Z) over Kototabang (0.2˚S; 100.32˚E), Bukittinggi, West Sumatera based on to the analysis of Radio Acoustic Sounding System (RASS) and Boundary Layer Radar (BLR) data during the Coupling Processes of Equatorial Atmosphere (CPEA) Campaign I from April 10 to May 9, 2004 was going on. wWe firstly reviewed yhe basic concept of TPW using the Weisner method ti estimate the TPW value from the radiosonde data. We reviewed the basic concpt of RASS and BLR system also, especially on the Z data analysis. By arranging the mean value of RASS data every 10 minutes and 150 meter in height, respectively, we estimated the TPW values from the RASS data. By analysing the Cross Cirrelation Function (CCF) of both values taken from SPSS software version 13, we found a good agreement between TPW and Z parameter, especially on 5 May 2004. The correlation values are 0.05, and 0.61 at around 2.7 and 2.25 km, repectively. Although, the maximum correlation value in only 0.61, but this is still good enough to describe the correlation between TPW and Z.
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.
PENGGUNAAN METODE ASPECT SENSITIVITY DALAM PENENTUAN TINGGI LAPISAN TROPOPAUSE DI SAAT MJO AKTIF MELINTAS KAWASAN KOTOTABANG DAN SEKITARNYA Hermawan, Eddy; Nurlela, Irma; Wahyu Hadi, Tri
Jurnal Sains Dirgantara Vol 5, No.1 Desember (2007)
Publisher : Lembaga Penerbangan dan Antariksa Nasional

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Abstract

This paper is mainly concerned to the utilization of aspect sensitivity (Pv/Po) method to define the tropopause height variation over the equatorial Indonesia, nearby Kototabang (0,2˚S; 100,32˚E), Bukittinggi, West Sumatera using the Equatorial Atmosphere Radar (EAR), especially during the Coupling Processes Equatorial Atmosphere (CPEA) Campign I in 2004 is already done. It is very important to be done since the tropopause is the buffer layer between troposphere and stratosphere (and also contrary) that usually called as the Stratosphere-Troposphere Exchanged (STE) (Holton, 1996). Validation's results with the radiosonde data shows that (Pv/Po relatively higher that radiosonde data. They are about 712 meter and 961 meter for Cold Point Tropopause (CPT) and Lapse Rate Tropopause (LRT) version, respectively. The mean difference between CPT and LRT itself is about 248 meter. This is enough valid considering to the maximum difference between of them not more 500 meter ( Haynes and Shepherd, 2001). This result then be applied in determining of tropopause height variation over Kototabang especially when the Madden-Julian Oscillation (MJO) passed over this region from November to December 2001. It shown that there are no significant differences between MJO active and no active on the tropopause height determination about 17.98 km and 17.73 km, respectively. The most interest is the tropopause height variation is larger during the MJO active than non active.To get the better understanding of tropopause height variation, especially with good time and spatial height resolution, the utilization of ERA and other instruments Kototabang are very needed.
PEMANFATAAN DATA EQUATORIAL ATMOSPHERE RADAR (EAR) DALAM MENGKAJI TERJADINYA MONSUN DI KAWASAN BARAT INDONESIA(THE VALUABLE OF EQUATORIAL ATMOSPHERE RADAR (EAR) DATA TO STUDY MONSOON IN THE WEST AREA INDONESIA) Azteria, Veza; Effendy, Sobri; Hermawan, Eddy
Agromet Vol. 22 No. 2 (2008): December 2008
Publisher : PERHIMPI (Indonesian Association of Agricultural Meteorology)

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (992.783 KB) | DOI: 10.29244/j.agromet.22.2.160-173

Abstract

Kototabang, Padang Panjang and Sicincin city are area in the West part of Indonesia and they are relative in the equator line. Otherwise, three of these cities have difference of behaviors of rainfall for Monsoon. In this study, we were used EAR Data, which were including the rainfall Kototabang, Padangpanjang, and Sicincin. Base on this data (i.e EAR data) in Kototabang, there is monsoon in 8-18 km layer and the higher monsoon is in 14 km layer during the April 2002-April 2006 period. Analisis Power Spectral Density (PSD) and Transformasi wavelet were shown that Monsoon oscillation around 12 months. While vertical profile was presented that the stronger monsoon will be in the wet weather on January. The domination of wind in Kototabang city is South Wind, it is because the wind took water vapor mass from South to North. According to analysis of rainfall in Kototabang, Padangpanjang and Sicincin City, meridional wind in the the Sicincin has rainfall pattern the same as with monsoon. Its was indicated that there were local indicator which can cause the monsoon. From the cross correlation between meridionial wind speed with rainfall in Kototabang, Pontianak and Sicincin, they were shown that three of these cities have significant correlation.
PENGEMBANGAN MODEL PREDIKSI MADDEN JULIAN OSCILLATION (MJO) BERBASIS PADA HASIL ANALISIS DATA REAL TIME MULTIVARIATE MJO (RMM1 DAN RMM2) (PREDICTION MODEL DEVELOPMENT MADDEN JULIAN OSCILLATION (MJO) BASED ON THE RESULTS OF DATA ANALYSIS ... Evana, Lisa; Effendy, Sobri; Hermawan, Eddy
Agromet Vol. 22 No. 2 (2008): December 2008
Publisher : PERHIMPI (Indonesian Association of Agricultural Meteorology)

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (829.212 KB) | DOI: 10.29244/j.agromet.22.2.144-159

Abstract

Background of this research is the importance of study on the Madden Julian Oscillation, the dominant oscillation in the equator area. MJO cycle showed by cloud cluster growing in the Indian Ocean then moved to the east and form a cycle with a range of 40-50 days and the coverage area from 10N-10S. Method that used to predict RMM is Box-Jenkins based on ARIMA (Autoregressive Integrated Moving Average) statistical analysis. The data used RMM daily data period 1 Maret 1979?1 Maret 2009 (30 years). RMM1 and RMM2 is an index for monitoring MJO. This is based on two empirical orthogonal functions (EOFs) from the combined average zonal 850hPa wind, 200hPa zonal wind, and satellite-observed Outgoing Longwave Radiation (OLR) data. The results in form of the Power Spectral Density (PSD) graph Real Time Multivariate MJO (RMM) and long wave radiation (OLR = Outgoing Longwave Radiation) at the position 100° BT, 120° BT, and 140°BT that show the wave pattern (spectrum pattern) and clearly shows the oscillation periods. There is a close relation between RMM1 with OLR at the position 100oBT that characterized the PSD value about 45 day. Through Box-Jenkins method, the prediction model that close to time series data of RMM1 and RMM2 is ARIMA (2,1,2), that mean the forecasts of RMM data for the future depending on one time previously and the error one time before. Prediction model for Zt = Zt = 1,681 Zt-1 ? 0,722 Zt-2 - 0,02 at-1 - 0,05 at-2.. Prediction model for RMM2 is Zt = 1,714 Zt-1 ? 0,764 Zt-2 - 0,109 at-1 - 0,05 at-2.. The flood case in Jakarta January-February 1996 and 2002 are one of real evidence that made the MJO prediction important. MJO with active phase dominant cover almost the entire Indonesia west area at that moment.