Rainfall spatial and temporal variation analysis over Papua based on GSMAP during 1998-2006 and it‟s relation to the regional climate

Abstract

This study is focused on rainfall spatial and temporal variation analysis over Papua, Indonesia using GSMaP MWR (Global Satellite Mapping of Precipitation Microwave Radiometer) during 1998-2006. GSMaP MWR data was extracted and represented in time series and spatial format, and compared with other observation data such meridional (UWND) and zonal (VWND) surface wind from National Centers for Environmental Prediction (NCEP), Southern Oscillation Index (SOI) and NINO 3.4 Index. Continuous Wavelet Transform (CWT) and Empirical Orthogonal Function (EOF) analysis show that rainfall variation over Papua is effected by monsoon and topography factor, especially in the central and southern Papua. In the other hand, equatorial rainfall variation is very dominant in the northern Papua. The Cross Wavelet Transform (XWT) and Wavelet Transform Coherence (WTC) analysis indicate that El Nino-Souther Oscillation (ENSO) also give significant impact to the onset of rainy season during El Nino and La Nina years, even though it does not give much impact to the rainfall amount as the monsoon effect over Papua.

Penelitian ini membahas tentang analisis pola spasial dan temporal curah hujan di wilayah Papua, Indonesia menggunakan produk data GSMaP MWR (Global Satellite Mapping of Precipitation Microwave Radiometer) pada periode 1998-2006. Data GSMaP MWR diekstrak dan direpresentasikan kedalam deret waktu dan format spasial, serta dibandingkan dengan data observasi lainnya seperti data angin permukaan meridional (UWND) dan zonal (VWND) yang diperoleh dari National Centers for Environmental Prediction (NCEP), data Southern Oscillation Index (SOI) dan NINO 3.4 Index. Hasil analisis menggunakan Continuous Wavelet Transform (CWT) dan Empirical Orthogonal Function (EOF) menunjukkan bahwa variasi curah hujan di Papua sangat dipengaruhi monsun dan faktor topografi, khususnya di wilayah Papua bagian tengah dan selatan. Di sisi lain, variasi curah hujan ekuatorial sangat dominan di wilayah Papua bagian utara. Hasil analisis dengan Cross Wavelet Transform (XWT) dan Wavelet Transform Coherence (WTC) mengindikasikan bahwa El Nino Southern Oscillation (ENSO) juga memberikan pengaruh signifikan terhadap permulaan musim hujan pada tahun-tahun El Nino dan La Nina, walaupun tidak terlalu berpengaruh terhadap besarnya curah hujan seperti halnya efek monsun di Papua.