Readme file for: SnowClim: Pre-industrial Snow Data
(https://www.hydroshare.org/resource/fc621d75985c4695b6758ade312241c6/)


This .txt file was generated on 4 Nov 2021 by A.C. Lute.


Summary:
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This directory contains snow metrics for the pre-industrial period and
represents a subset of the SnowClim Dataset
(https://www.hydroshare.org/resource/acc4f39ad6924a78811750043d59e5d0/).
The SnowClim Dataset was developed following the methods presented in
Lute et al., (in prep). The pre-industrial snow data was created by
first downscaling 4 km climate forcings from the Weather Research and
Forecasting (WRF) model (Rasmussen and Liu, 2017) over a thirteen year
period (1 Oct 2000 to 30 Sep 2013) and then perturbing the downscaled
data using multi-model mean deltas from CMIP5 to create climate forcing
data that reflects conditions during 1850-1879. This climate data was
then used to force the SnowClim snow model. Snow model outputs were
summarized into snow metrics at ~210 m spatial resolution for the
western US. Additional details about forcing data preparation, model
physics, model calibration, and application to the western US domain can
be found in Lute et al., (in prep).


File Organization:
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Snow metrics are available in separate files. For accessibility, metrics
are available in both GeoTiff and netCDF format. The suffix '_PRE'
indicates that the data represents conditions under pre-industrial
climate. Metrics with values for each year use snow years, which we
define as September 1 - August 31. For example, snow year 2001 is the
year starting on September 1, 2000 and ending on August 31, 2001.
Metrics with values for each month have values for January through
December.


Metrics:
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- annual maximum SWE

	units: meters (m)

	Annual maximum snow water equivalent (m), averaged across years.

- date of annual maximum SWE

	units: Julian day of year

	Julian day of annual maximum snow water equivalent (m), averaged
	across years.

- largest snowfall event

	units: meters (m)

	Liquid water equivalent thickness of the largest three consecutive
	day snowfall total each year (m).

- date of largest snowfall event

	units: Julian day of year

	Julian day of the largest three consecutive day snowfall total each
	year.

- snow cover days

	units: days

	Monthly number of days with snow depth greater than 10 mm, averaged
	across years.

- snow duration

	units: days

	Number of days between the start and end of snow cover, averaged
	across years. The start of snow cover is defined as the first day of
	the first period of 5 consecutive days with snow depth greater than
	10 mm, and day of snow cover end is defined as the last day of the
	last period of 5 consecutive days with snow depth greater than 10
	mm.

- snow free days

	units: days

	Annual number of days with snow depth less than 10 mm between the
	start and end of snow cover, averaged across years. The start of
	snow cover is defined as the first day of the first period of 5
	consecutive days with snow depth greater than 10 mm, and day of snow
	cover end is defined as the last day of the last period of 5
	consecutive days with snow depth greater than 10 mm.

- date of snow cover start

	units: Julian day of year

	Julian day of beginning of snow cover, averaged across years. The
	day of beginning of snow cover is defined as the first day of the
	first period of 5 consecutive days with snow depth greater than 10
	mm.

- date of snow cover end

	units: Julian day of year

	Julian day of end of snow cover, averaged across years. The day of
	the end of snow cover is defined as the last day of the last period
	of 5 consecutive days with snow depth greater than 10 mm.

- min snow depth:

	units: meters (m)

	Monthly minimum snow depth (m), averaged across years.

- mean snow depth

	units: meters (m)

	Monthly mean snow depth (m), averaged across years.

- max snow depth

	units: meters (m)

	Monthly maximum snow depth (m), averaged across years.

- min SWE

	units: meters (m)

	Monthly minimum snow water equivalent (m), averaged across years.

- mean SWE

	units: meters (m)

	Monthly mean snow water equivalent (m), averaged across years.

- max SWE

	units: meters (m)

	Monthly maximum snow water equivalent (m), averaged across years.

- snowfall

	units: meters (m)

	Monthly total snowfall water equivalent (m), averaged across years.


Sharing and access information:
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1. Licenses/restrictions placed on the data: 
This resource is shared under the Creative Commons Attribution CC BY.

2. Links to publications that cite or use the data: 
none yet

3. Links to other publicly accessible locations of the data: 
none

4. Links/relationships to ancillary data sets: 
SnowClim Model and Dataset
(https://www.hydroshare.org/resource/acc4f39ad6924a78811750043d59e5d0/)
SnowClim Model Code
(https://www.hydroshare.org/resource/dc3a40e067bf416d82d87c664d2edcc7/)
SnowClim Pre-industrial Climate Data
(https://www.hydroshare.org/resource/0c852b12f668438fb9f0188a1cc6e8a9/)
SnowClim Present Climate Data
(https://www.hydroshare.org/resource/7e3678f00ad74bfd881f91d6f6f81494/)
SnowClim Present Snow Data
(https://www.hydroshare.org/resource/2dbd6e849a754c0981b99ee7c09031eb/)
SnowClim Future Climate Data
(https://www.hydroshare.org/resource/36895c3a2c53409893f5ba02ee142767/)
SnowClim Future Snow Data
(https://www.hydroshare.org/resource/96cba44cd74843639f855d7c9e22024b/)

5. Was data derived from another source? 
yes. Climate forcing data was downscaled from the dataset of Rasmussen
and Liu, 2017.

6. To cite this data, please reference both of the following: 
Lute, A., J. Abatzoglou, T. Link (2021). SnowClim Model and Dataset, 
	HydroShare, 
	http://www.hydroshare.org/resource/acc4f39ad6924a78811750043d59e5d0
Lute, A.C., John Abatzoglou, and Timothy Link (in prep), SnowClim:
	high-resolution snow model and data for the Western United States. 
	In preparation for submission to Geoscientific Model Development.


Authors:
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A.C. Lute, University of Idaho 
John Abatzoglou, University of California, Merced 
Timothy Link, University of Idaho


Contact Information:
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Please contact A.C. Lute with questions, concerns, or comments. Current
contact information is available on the webpage this file was downloaded
from.


References:
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Lute, A.C., John Abatzoglou, and Timothy Link (in prep), SnowClim:
	high-resolution snow model and data for the Western United States. 
	In preparation for submission to Geoscientific Model Development.
Rasmussen, R., and C. Liu. 2017. High Resolution WRF Simulations of the
	Current and Future Climate of North America. Research Data Archive 
	at the National Center for Atmospheric Research, Computational and
	Information Systems Laboratory. https://doi.org/10.5065/D6V40SXP.
	Accessed 24 Sep 2018.