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| Dai Precipitation Data Set |
| Variable(s) | Precipitation |
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| Land or Ocean | Land |
| Current Period of Record | 1850-1996 |
| Resolution | Monthly, Global, 2.5ox2.5o |
| Description: | Gridded archive of precipitation based on land stations only. Empirical corrections applied for changes in instrumentation and station location. |
| Reference: | Dai et al. (1997) |
| Data Set Location: | The NASA Goddard Institute for Space Studies
(binary format) Aiguo Dai's Website (binary and netCDF format) |
| Technical Overview | Expert User Guidance | Relevant Articles | Coverage Maps |
| Technical Overview |
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This is an updated version of an earlier dataset and is a single 78-Mb file. The dataset uses the quality-controlled NOAA Baseline precipitation station data and latest station data from NOAA NCEP, covers the period from 1850 to 1995 (data for 1996 are incomplete). The same analysis procedure (including the discontinuity correlation) was used for the updated dataset (described below). Each record is a map of a monthly or annual precipitation anomalies (relative
to the 1951-1979).
Earlier data set information: The station data source of the earlier data set is the DOE precipitation data set, and the data cover the period from Jan. 1900 to Dec. 1988 (data for 1989 are incomplete). Five-sigma gross screening and discontinuity-correction were performed on the station data before the gridding. An inverse-distance weighted averaging was used during the gridding, which was carried out on the anomalies relative to the 1951-1979 mean. |
| Expert User Information |
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Brief commentary This data set contains only monthly precipitation anomalies (relative to the 1950-1979 mean) on a 2.5x2.5 grid. It was designed for studying the interannual (e.g., ENSO) to decadal variations. One unique feature of this dataset is that it limits the gridding radius to 300 km and grid boxes 300 km away from any raingauge stations were assigned a missing data code. This radius was derived based on the spatial correlation distance of monthly precipitation. The 1950-1979 period has the best spatial coverage. Many areas do not have data after the late 1980s. It is strongly recommended that the data be mapped out and examined for selected years before doing area-averaging. More specific information can be found online at http://www.giss.nasa.gov./data/adai/. For more recent years, it is recommended to use the Xie and Arkin data set. Dai and Wigley (2000, GRL) show that it is possible to combine the Xie and Arkin data set (for the 1990s) and this data set to create more updated monthly time series of precipitation over land (for 1900-present) and over ocean (for 1979-present only). Aiguo Dai |
| Relevant Arcticles |
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Dai et al. (1997) Dai, A., and T.M.L. Wigley, 2000: Global Patterns of ENSO-induced Precipitation. Geophys. Res. Lett., 27, 1283-1286. (.pdf version available at Aiguo Dai's Website) |
| Coverage Maps |
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Click on the links below to view data coverage maps for a particular time period. Percentage of non-missing data per time period is plotted.
(1861-1880, 1881-1900, 1901-1920) |
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Updated: 10/15/03 |