Documenting the instrumentally observed precipitation climate record presents many challenges because scientists must rely on data from stations that undergo many changes in the course of their operation. Detecting changes from such networks is essential for adequate understanding of climate and global change. As an illustrative example, we review the history of the instrumentally observed precipitation in the USSR. In the USSR, similar to other countries, numerous problems must be addressed before reliable estimates of precipitation can be made. The types of problems range from inadequate and changing exposures of raingages to varying sampling periods used to measure precipitation. Using information about measurement procedures, instrument intercomparisons, and field studies, various methods have been devised to overcome biases in the measurements.
*State Hydrological Institute, 23, Second Line, Leningrad, 1999053, USSR. Current address: National Climatic Data Center, Federal Building, Asheville, NC 28801
+State Hydrological Institute, 23, Second Line, Leningrad, 199053, USSR
**All-Union Research Institute of Hydrometeorological Information, 6, Korolyov Street, Obnink, Kaluga Region 249020, USSR
++NOAA/NESDIS/National Climatic Data Center, Federal Building, Asheville, NC 28801