The role of topography in precipitation on the maritime continent
The topography and abundant moisture supply of the Maritime Continent (MC) combine to produce copious precipitation amounts as sea breezes converge and interact with mountains. Therefore, the MC is a good region to study the topographical effects on precipitation. To do this, two sources of monthly precipitation data from 1998-2007, were used for the MC: the Tropical Rainfall Measuring Mission (TRMM) satellite and the APHRODITE system of rain gauges (APHRODITE: Asian Precipitation –Highly Resolved Observational Data Integration Towards Evaluation of Water Resources). The highest density of rain gauges was on the relatively flat Indochina Peninsula (approximate maximum elevation of 1500 meters), while the lowest density was on the island of New Guinea (mountainous with approximate max at 4000 m). Because of this, rain gauge measurements showed minimal evidence of topographic influence, while the TRMM data showed significant evidence, especially over New Guinea, where patterns of sea breeze convergence along mountain slopes could be seen. By using the root mean square error and the correlation between TRMM and rain gauge measurements at different elevation intervals, a transition between topographic influence on precipitation and insufficient rain gauge density could be seen at the 1350-1500 meter interval. With these limitations in mind, several conclusions were made. Mountainous terrain receives higher precipitation amounts than flat land, and, in the case of the MC, mountains only enhance precipitation. The TRMM satellite gives higher precipitation values than rain gauge measurements, notwithstanding whether the rain gauge density is high or low, and, therefore, more rain gauges are needed, especially in the higher elevations, to improve climate models and forecasts.