The Pacific Rainfall Project (PACRAIN) at the University of Oklahoma is collaborating with the Pacific Islands Global Climate Observing System (PI-GCOS) to install a series of tipping bucket rain gauges throughout the islands and atolls of the tropical Pacific. PACRAIN procures the rain gauges and provides software and technical assistance to the local meteorological services, and in return the data are sent to Oklahoma for assimilation into the PACRAIN database. To date, 50 gauges have been sent to The Cook Islands, Guam, Kiribati, Niue, Samoa, Tonga, Tuvalu, and Vanuatu.

PACRAIN data have traditionally been fixed interval (e.g. daily) observations from manual gauges, so the PACRAIN database is structured around this paradigm. Tipping bucket gauge data (TBG) can be converted to fixed interval accumulations at virtually any temporal resolution. While this is a seemingly straightforward process, there are some subtleties involved. The optimum techniques for converting TBG data to the existing PACRAIN format are currently being explored. New quality assurance techniques applicable to TBG data must also be developed.

For many applications, fixed interval data are not sufficient. For example, quantities like rainfall intensity and storm total precipitation cannot be readily obtained from fixed interval accumulations. These values can be approximated using sufficiently small fixed intervals, but data storage requirements can become prohibitive as the interval size decreases. With access to TBG data, the PACRAIN database no longer needs to be limited to the fixed interval paradigm. Raw TBG data more naturally occupy a time/frequency domain that is very useful for applications requiring rate and duration information. A new data model will be developed that allows the PACRAIN database to efficiently store and present TBG data while preserving its inherent information content.