AHCCD
From variable 3.5
Summary of observation-based historical datasets with total precipitation available.
- reference Mekis and Vincent (2011)
- source
- CRD/ECCC
- data type
- Station data
- spatial domain
- Canada
- spatial resolution
- Point data
- temporal coverage
- Variable (1950 to present)
- time step
- Daily; Monthly; Seasonal; Annual
- data format
- ASCII; CSV; GeoJSON
- comments
- In-situ data with adjustments (derived from statistical procedures) to the original record for total precipitation, rain and snowfall. The data accounts for a number of known errors in precipitation measurements, specific to different types of rain gauges. Daily precipitation amounts below a minimum measurable amount were set to a value of zero in the past. However, the accumulated impact of these trace amounts can become significant, especially in areas like the Arctic where precipitation amounts are low. Adjustments were applied to account for this underestimation by assigning a value to these days: 0.1 mm was applied for rain, whereas for snow the adjustment factor ranged from 0.03 to 0.07 mm depending on the station location. Nearby observations were sometimes joined and adjustments were applied based on a simple ratio computed using available periods of overlapping data.