Scientific Objectives

Long-term, High-resolution, Daily datasets

A daily gridded precipitation dataset covering a period of more than 50 years was created by collecting and analyzing rain-gauge observation data across Asia through the activities of the Asian Precipitation?Highly Resolved Observational Data Integration Towards the Evaluation of Water Resources (APHRODITE) project. APHRODITE’s daily gridded precipitation is presently the only long-term continental-scale high-resolution daily product.

High quality dataset based on individual data collection via international collaboration and quality control algorithm

Develop long-term daily grid precipitation and temperature datasets from rain-gauge observation records over Asia by international collaborations with local meteorological/hydrological agencies and researchers.

Enhancement of quality control algorithm develops APHRODITE product the only Asian precipitation and temperature products highly resolved in time and space.

  • Assess and revise climatological mean precipitation and temperature by using APHRODITE products. Contribute to model analyses (climate, hydrology, agriculture and so on), and long-term climate change analyses. Contribute to climate model research, validate precipitation and its characteristics such as extreme events analyses by providing high resolution datasets.
  • Improve the quantification of orographic precipitation by combining rain-gauge data, remotely sensed data, and geographic information. Refine algorithms in collaboration with climate modelers and data users so that our products are useful to various environmental sciences.

Our Achievements

We developed and released daily precipitation data on a 0.25/0.5-degree grid for Asia (APHRO_MA/ME/RU_V1101R1) for the period 1951-2007 and daily mean temperature product (AphroTemp_V1204R1) for the period 1961-2007. They are the only long-term continental-scale daily grid precipitation and temperature data for Asia and include data from many rain-gauge stations.

We developed and released daily precipitation data on a 0.05-degree grid for Japan (APHRO_JP_V1207) for the period 1900-2011. A version that uses constant input data was also released, and this “Japan analysis” is used to study the long-term change of extreme events.

We give feedback to data providers by providing a 0.05-degree version of the dataset of each country/domain and we held a training seminar. We have received feedback from users through our website and an international session of the Japan Geophysical Union meeting held in May 2010.

Advantage of the APHRODITE product

APHRODITE’s daily gridded precipitation and temperature is the only long-term (1951 onward) continental-scale daily product that contains a dense network of daily rain-gauge data for Asia including the Himalayas, South and Southeast Asia and mountainous areas in the Middle East. Our number of valid stations was between 5000 and 12,000, representing 2.3 to 4.5 times the data available through the Global Telecommunication System network, which were used for most daily grid precipitation products. The product contributes to studies such as the diagnosis of climate changes, evaluation of Asian water resources, statistical downscaling, forecast improvements, and verification of numerical model simulation and satellite precipitation estimates.

The data are available free of charge and are easy for GrADS and netCDF users to handle. We attach information of the density of station data on each grid for each day with the daily precipitation and temperature product, so that users know whether a grid box is close to an observation point or has an interpolated value. Therefore, APHRODITE precipitation data can be used as a benchmark for various estimations of gridded precipitation.

Project History

  • Feasibility Study: May 2005~March 2006
  • APHRODITE first term: May 2006~March 2009
  • APHRODITE second term: April 2009~March 2011