Historical Monthly and Derived Precipitation Products Downscaled from CRU TS data via the delta method - 2 km

This dataset includes downscaled historical estimates of monthly average, minimum, and maximum precipitation and derived annual, seasonal, and decadal means of monthly total precipitation (in millimeters, no unit conversion necessary) from 1901 to 2006 (CRU TS 3.0), 2009 (CRU TS 3.1), 2015 (CRU TS 4.0), 2020 (CRU TS 4.05), or 2023 (CRU TS 4.08) at 2km x 2km spatial resolution. CRU TS 4.0 is only available as monthly averages, minimum, and maximum files. CRU TS 4.05 and 4.08 data are only available as monthly averages. The downscaling process utilizes PRISM climatological datasets from 1961-1990.

Date (Revision): 2024-11-04

Presentation form: Digital map

Credit: Matthew Leonawicz

Credit: Michael Lindgren

Credit: Tom Kurkowski

Credit: Scott Rupp

Credit: John Walsh

Status: Completed

Point of contact

Scenarios Network for Alaska and Arctic Planning

Maintenance and update frequency: As needed

Theme

historical
precipitation

Use constraints: License

Other constraints: https://creativecommons.org/licenses/by/4.0/

Spatial representation type: Grid

Distance: 2 km

Metadata language: eng

Character set: UTF8

Topic category

Climatology, meteorology, atmosphere

Begin date: 1901-01-15

End date: 2020-12-15

Supplemental Information: This ISO record intends to serve as the official metadata for a somewhat heterogenous dataset. The dataset is heterogenous in the sense that data exist for multiple versions of the base data (CRU TS observation / interpolated data), and there is some inconsistency in the types of derived summaries present for across the versions. E.g., annual, seasonal, and decadal means of monthly averages are available for some versions and not others. The rest of this section provides information for working with these data:

File naming scheme:

Files are named according to the following pattern:

<variable>_<aggregation type>_<units>_<CRU TS version>_historical_<month>_<year>.tif

* <variable> is `pr`, corresponding to precipitation

* <aggregation type> is `total`, how the data is aggregated over time

* <units> is `C` for Celsius, as these data represent temperatures measured in degrees Celsius

* <CRU TS version> will vary depending on download chosen

* <month> will be the two-numbered code ranging from 01 (Jan) to 12 (Dec)

* <year> will correspond to the year of the observations

For seasonal means, the four seasons are referred to by the first letter of 3 months making up that season:

* `JJA`: summer (June, July, August)

* `SON`: fall (September, October, November)

* `DJF`: winter (December, January, February)

* `MAM`: spring (March, April, May)

Unique resource identifier: EPSG:3338

Number of dimensions: 2

Dimension name: Row

Dimension size: 1186

Resolution: 2 km

Dimension name: Column

Dimension size: 3218

Resolution: 2 km

Cell geometry: Area

Distribution format

GeoTIFF ( 1.0 )

OnLine resource: URL to web-accessible folder containing dataset ( WWW:LINK-1.0-http--link )

Hierarchy level: Dataset

Statement: SNAP downscaled data products are value added products that build off of other datasets that have been accepted by the scientific community as some of the highest quality climate data available. Please see https://uaf-snap.org/ to explore how our data is produced.