Identification

Title

A comparison of statistical and dynamical downscaling of winter precipitation over complex terrain

Abstract

Statistical downscaling is widely used to improve spatial and or temporal distributions of meteorological variables from regional and global climate models. This downscaling is important because climate models are spatially coarse (50-200km), and often misrepresent extremes in important meteorological variables such as temperature and precipitation. However, these downscaling methods rely on current estimates of the spatial distributions of these variables, and assume that the small-scale spatial distribution will not change significantly in a modified climate. Here we compare data typically used to derive spatial distributions of precipitation (PRISM) to a high-resolution (2km) weather model (WRF) under current climate. We show that there are regions of significant difference in November-May precipitation totals (>300mm) between the two, and discuss possible causes for these differences. We then present a simple statistical downscaling based on the 2km WRF data applied to a series of regional climate models (NARCCAP), and compare the downscaled precipitation data to observations at 65 SNOw TELemetry (SNOTEL) sites throughout Colorado for the winter seasons from 1988 to 2000. Finally, we compare statistically downscaled precipitation from a 36km model under an imposed Pseudo Global Warming (PGW) scenario to dynamically downscaled data from a 2km model using the same forcing data. While the statistical downscaling improved the domain average precipitation compared to the original 36km model, the changes in the spatial pattern of precipitation (PGW-current) did not match those of the changes in the dynamically downscaled 2km model. This study illustrates some of the uncertainties in applying statistical downscaling to future climate.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d7w66n29

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

Keyword set

keyword value

Text

originating controlled vocabulary

title

Resource Type

reference date

date type

publication

effective date

2016-01-01T00:00:00Z

Geographic location

West bounding longitude

East bounding longitude

North bounding latitude

South bounding latitude

Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

publication

effective date

2012-01-01T00:00:00Z

Frequency of update

Quality and validity

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Conformity

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Use constraints

Copyright 2012 American Meteorological Society (AMS). Permission to use figures, tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be "fair use" under Section 107 or that satisfies the conditions specified in Section 108 of the U.S. Copyright Law (17 USC, as revised by P.L. 94-553) does not require the Society's permission. Republication, systematic reproduction, posting in electronic form on servers, or other uses of this material, except as exempted by the above statements, requires written permission or license from the AMS. Additional details are provided in the AMS Copyright Policies, available from the AMS at 617-227-2425 or amspubs@ametsoc.org. Permission to place a copy of this work on this server has been provided by the AMS. The AMS does not guarantee that the copy provided here is an accurate copy of the published work.

Limitations on public access

None

Responsible organisations

Responsible party

contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact

contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

Metadata date

2023-08-18T18:58:41.501133

Metadata language

eng; USA