PENINGKATAN KETERAMPILAN MEMBACA PEMAHAMAN TEKS EKSPLANASI SISWA KELAS XI TKR 1 SMK MERDEKA SOREANG

This class action education is aimed to find out (1) The improvement of reading comprehension students of class XI TKR 1 after being given REAP method, and (2) to know the student's response to the implementation of REAP method in reading comprehension. The subjects of this study were 36 students of class XI TKR 1 SMK Merdeka Soreang. The Data collection in this research is done by giving test, collecting questionnaires, interviews and field observation. The data gathering instruments used include students questionnaires, test results, observation sheets, and interview guidelines. The data obtained were analyzed descriptively quantitative and qualitative. The first research result is the implementation of REAP method can improve students' comprehension of class XI TKR 1 SMK Merdeka Soreang in reading text. The average score of the pre test gain was 62.47, increased to 69.78 in the post test 1, and 75.67 in the post test 2. The second study result is the student's response to the REAP method in this reading comprehension is very positively. Students feel helped by the use of this REAP method

ANALISIS CURAH HUJAN PANTAI BARAT SUMATERA BAGIAN UTARA PERIODE 1994-2007

Dari data curah hujan di pantai barat Sumatera bagian utara dilakukan analisis spektrum daya untuk mengetahui pola curah hujan di daerah tersebut, selanjut dilihat hubungannya dengan intensitas monsun,  Indian Ocean Dipole Mode (IODM) dan El-Nino Southern Oscillation (ENSO). Hasil analisis menunjukkan bahwa pola curah hujan di pantai barat Sumatera bagian utara memiliki dua puncak dan sangat dipengaruhi oleh faktor cuaca dengan dengan osilasi satu tahunan (annual oscillation), dan setengah tahunan (semi-annual oscillation) dan ditemukan hubungan yang kuat antara variabilitas monsun dan IODM. Pola hujan didaerah ini tidak memperlihatkan pengaruh ENSO.   The data of Rainfall in the west coast of northern Sumatera were analyzed through power spectrum analyzer to find out the rainfall pattern in that area and to look at the relationship between rainfall pattern and monsoon intensity, Indian Ocean Dipole Mode (IODM) and El-Nino Southern Oscillation (ENSO). The result of this analysis shows that the main rainfall pattern in the west coast of northern Sumatera has two peaks and is very much influenced by the factor of weather with annual oscillation and semi-annual oscillation, there is a strong relationship between monsoon variability and IODM, and the influence of ENSO on the rainfall in this region is not significant

AKURASI PREDIKSI CURAH HUJAN HARIAN OPERASIONAL DI JABODETABEK : PERBANDINGAN DENGAN MODEL WRF

Akurasi prakiraan curah hujan harian operasional yang dibuat oleh Badan Meteorologi Klimatologi dan Geofisika (BMKG) dikaji dengan cara diverifikasi berdasarkan kategori hujan dikotomi, lebat dan sangat lebat terhadap data dari 25 titik pengamatan di Jakarta. Prosedur yang sama juga diterapkan pada prakiraan curah hujan model Weather Research and Forecasting (WRF) dengan teknik multi-nesting yang di-downscale dari keluaran Global Forecast System (GFS). Hasilnya memperlihatkan bahwa kedua metode prediksi tersebut memiliki akurasi yang baik untuk prediksi dikotomi tetapi hampir gagal dalam memprediksi curah hujan lebat dan sangat lebat. Khususnya, kegagalan prediksi operasional dalam mendeteksi tiga kejadian hujan sangat lebat dalam periode kajian. Dalam hal ini, model WRF yang cenderung menghasilkan false alarm memperlihatkan prospek yang bagus untuk pengembangan sistem prediksi cuaca skala lokal/regional yang lebih akurat di Indonesia.   The accuracy of daily rainfall forecasts produced operationally by the Meteorological, Climatological, and Geophysical Agency (BMKG) has been assessed by verifying the prediction of dichotomous, heavy, and very heavy rain events against observed data at 25 stations in Jakarta. Similar procedure was applied to raw hindcasts performed  using the Weather Research and Forecasting (WRF) model with multi-nesting technique up to 3 km resolution downscaled from NOAA global forecast system (GFS) outputs.  The results show that both forecasts have quite favorable accuracy for dichotomous rain events but almost no meaningful score for the predictions of heavy and very heavy rain events was obtained. Particularly, none of as many as three observed very heavy rain events was predicted by the operational forecast. In this case, WRF tend produce false alarms indicating a better prospect for future development of more accurate local/regional weather forecasting system in Indonesia

Using 3D-Var Data Assimilation for Improving the Accuracy of Initial Condition of Weather Research and Forecasting (WRF) Model in Java Region (Case Study : 23 January 2015)

Weather Research and Forecasting (WRF) is a numerical weather prediction model developed by various parties due to its open source, but the WRF has the disadvantage of low accuracy in weather prediction. One reason of low accuracy  of model is inaccuracy initial condition model to the actual atmospheric conditions. Techniques to improve the initial condition model is the observation data assimilation. In this study, we used three-dimensional variational (3D-Var) to perform data assimilation of some observation data. Observational data used in data assimilation are observation data from basic stations, non-basic stations, radiosonde data, and The Binary Universal Form for the Representation of meteorological data (BUFR) data from the National Centers for Environmental Prediction (NCEP) , and aggregate observation data from all stations. The aim of this study compares the effect of data assimilation with different data observation on January 23, 2015 at 00.00 UTC for Java island region. The results showed that changes root mean square error (RMSE) of surface temperature from 2° C to 1.7° C - 2.4° C, dew point from 2.1o C to 1.9o  C - 1.4o C, relative humidity from 16.1% to 3.5% - 14.5% after the data assimilation

Prediksi Curah Hujan Jangka Pendek Dengan Assimilasi Data Reflektivitas Radar Doppler C band Di Wilayah Jakarta

Syarat awal untuk model cuaca numerik skala-meso dapat diperbaiki dengan asimilasi data pengamatan pada keluaran model global , seperti data reflektivitas dan kecepatan radial radar cuaca Doppler. Hal ini diharapkan mampu memberikan pengaruh positif terhadap kurasi prakiraan cuaca, khususnya curah hujan. Dalam penelitian ini dilakukan asimilasi data reflektivitas radar untuk memperbaiki keluaran model global forcas system (GFS) sebelum digunakan sebagai syarat awal dan syarat batas dalam prediksi cuaca di Jakarta, khususnya untuk prediksi curah hujan.Verifikasi keluaran model dalam memprediksi curah hujan di Jakarta dengan menggunakan data reflektivitas pengamatan radar dan hasil pengamatan curah hujan dari beberapa stasiun pengamatan di wilayah tersebut memperlihat prospek positif asimilasi data radar dalam meningkatkan akurasi prakiraan presipitasi kuantitatif (Quatitative Precipitation Forecast, QPF).Hlm. 158-16