Assessment of Satellite Precipitation Products in the Philippine Archipelago

Abstract

ABSTRACT:Precipitation is the most important weather parameter in the Philippines. Made up of more than 7100 islands, the Philippine archipelago is an agricultural country that depends on rain-fed crops. Located in the western rim of the North West Pacific Ocean, this tropical island country is very vulnerable to tropical cyclones that lead to severe flooding events. Recently, satellite-based precipitation estimates have improved significantly and can serve as alternatives to ground-based observations. These data can be used to fill data gaps not only for climatic studies, but can also be utilized for disaster risk reduction and management activities. This study characterized the statistical errors of daily precipitation from four satellite-based rainfall products from (1) the Tropical Rainfall Measuring Mission (TRMM), (2) the CPC Morphing technique (CMORPH) of NOAA and (3) the Global Satellite Mapping of Precipitation (GSMAP) and (4) Precipitation Estimation from Remotely Sensed information using Artificial Neural Networks (PERSIANN). Precipitation data were compared to 52 synoptic weather stations located all over the Philippines. Results show GSMAP to have over all lower bias and CMORPH with lowest Mean Absolute Error (MAE) and Root Mean Square Error (RMSE). In addition, a dichotomous rainfall test reveals GSMAP and CMORPH have low Proportion Correct (PC) for convective and stratiform rainclouds, respectively. TRMM consistently showed high PC for almost all raincloud types. Moreover, all four satellite precipitation showed high Correct Negatives (CN) values for the north-western part of the country during the North-East monsoon and spring monsoonal transition periods. Corresponding author

Assessment of Satellite Precipitation Data Sets for High Variability and Rapid Evolution of Typhoon Precipitation Events in the Philippines

“…The mean annual precipitation of the Philippines ranges between 965 and 4,064 mm per year (PAGASA, n.d.). Precipitation in many areas of the Philippines is also influenced by typhoons (Ramos et al., 2016). Particular areas in the northern Philippines can receive approximately 50%–60% of their annual precipitation from passing typhoons (Kubota & Wang, 2009).…”

“…The Philippines is an archipelago with more than 7,100 islands of complex topography (Bagtasa, 2017; Ramos et al., 2016). Two of its islands, namely Luzon in the north and Mindanao in the south, have long chains of mountains, whereas the Visayas region, which is located in the center of the country, consists of small islands (Bagtasa, 2017; Ramos et al., 2016). The Philippines frequently experiences typhoons that form in the Northwestern Pacific Basin (Bagtasa, 2017; Weinkle et al., 2012).…”

“…Few studies have been conducted in the Philippines (e.g., Jamandre & Narisma, 2013; Ramos et al., 2016) to evaluate the performance of SPDs. These studies evaluated the skills of TRMM, CMORPH (Jamandre & Narisma, 2013; Ramos et al., 2016), GSMaP, and PERSIANN (Ramos et al., 2016) precipitation data sets at various rainfall intensities, spatial and temporal scales. The results of these studies demonstrate that the performances of SPDs diverse on the amount of rainfall, geographical location, and temporal distribution of rainfall.…”

“…Every year, approximately 19 typhoons cross the border of the Philippines, and half of these typhoons make landfall (Bagtasa, 2017; Cinco et al., 2016). Few studies have been conducted in the Philippines (e.g., Jamandre & Narisma, 2013; Ramos et al., 2016) to evaluate the performance of SPDs. These studies evaluated the skills of TRMM, CMORPH (Jamandre & Narisma, 2013; Ramos et al., 2016), GSMaP, and PERSIANN (Ramos et al., 2016) precipitation data sets at various rainfall intensities, spatial and temporal scales.…”