Transcript PRISM and SNOTEL - Irrigation ToolBox

Climate and Weather Projects at
the NWCC to Support
USDA-NRCS Activities
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Climate Mapping
Time Series Development
– Weather Generator Research (GEM)
– Serially Complete Dataset
Snow Climate Monitoring & Analysis
Soil Climate Monitoring & Analysis
Internet Technologies for Climate Delivery
Climate Mapping
Collaborative effort between NRCS
National Water and Climate Center
(NWCC) and the Spatial Climate
Analysis Service (SCAS) at Oregon State
University
 Goal is to produce new maps and
digital GIS layers of climate elements
needed by the NRCS and others
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A Spatial Climate Modeling
System
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PRISM (Parameter-elevation Regressions on
Independent Slopes Model)
Statistical/Dynamical/Topographic approach
Uses point data, a DEM and a coordinated set
of rules, decisions and calculations, designed to
mimic an “expert” climatologist
For good reference see PRISM Guide Book
under Technical Papers at the OSU PRISM
web site
PRISM
Originally developed for precipitation
only, now expanded to temperature,
dewpoint, solar radiation and many
derived variables such as HDD’s/CDD’s,
GDD’s, frost dates, snowfall, snow water
equivalent, etc.
 Most commonly applied in monthly or
annual time increments, but also applied
to events
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PRISM Model from OSU’s
Spatial Climate Analysis Service
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Funded primarily by the NRCS-NWCC since
1993 for development of spatial climate
products for the U.S.
4 km horizontal resolution raster data, and
ARC polygon coverages both available
Most commonly applied in monthly or annual
time increments, but also applied to events
PRISM
Any given grid cell value is determined
by a linear regression of station values
against elevation
 Stations assigned weights
 Combined weight of a station is a
function of many factors
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PRISM-derived Products
Mean Mon. and Ann. Precipitation
 Mean Mon. and Ann. Temps (mx/mn)
 Frost Dates and Freeze-free Season
 Extreme Winter Min. Temps & Probs.
 Growing, Heating, Cooling degree days
 Snow-Water Equivalent & Snowfall
 Rainfall Erosivity (‘R-factor’ for
RUSLE), Intensity-Duration-Frequency
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Other PRISM-derived Climate
Map Products for the NRCS:
New Soil Climate Maps, including mean
annual soil temperature, soil taxonomic
regions
 Precipitation Efficiency, Climatic Index,
and other “older” Thornthwaite products
 New Plant Hardiness Map of the U.S.
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Cartographic-quality
Map of Mean Annual
Precipitation for
Idaho Produced at the
USDA-NRCS NCGC
Annual
Precipitation
Map of Elmore
County, Idaho
Produced by the
NRCS NCGC
“Cut-out” of
State Map
July normal
precipitation
(top)
vs.
July 1993
precipitation
(bottom)
PRISM - SWE Map - Oregon
New Precipitation Frequency
Maps Needed in the NRCS
TP-40 100 Yr 24-hour pcpn. (in.) from SCS TR-55, 1986
100 Year, 24-hour NOAA Atlas 2 Values (inches)
Northwest Colorado (1973)
Ft. Collins CO Rainfall (in.), 5:30 -11 pm, July 28, 1997
PRISM Product Dissemination
Web Sites:
OSU www.ocs.orst.edu/prism/prism_new.html
(Raster and polygon coverages of practically
everything produced to date (Arc, GRASS);
documentation; metadata; DEM’s)
NRCS www.ftw.nrcs.usda.gov/prism/prism.html
(U.S., Regional and State mean annual
precipitation cartographic products)
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http://www.ftw.nrcs.usda.gov/prism/prism.html:
 Cartographic state mean annual precipitation maps
 Full repository of “official” NRCS PRISM layers
PRISM Product Dissemination
Compact Discs:
All precipitation layers for all of the U.S.
3 CD’s (East, Central, West) of the lower 48
states. Includes Arc Explorer viewing
software, and all documentation.
Available from the NRCS-NCGC:
800-672-5559
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PRISM Product Dissemination
Hardcopy maps:
Cartographic-quality, walls-size maps of mean
annual precipitation for each state
Available from the NRCS Climate Data
Liaison in each state
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Wind Mapping to Support
NRCS Air Quality Program
Need high resolution mean and event
wind speeds and directions for whole
U.S.
 Atmospheric model needed for this:
Sue Ferguson at USFS Research Seattle
 Mean monthly winds of U.S. at 5 km
resolution now nearly complete
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Time Series Development:
Weather Generator Research
and Integration
Ultimate Question:
What is really needed?
(for applications needing point-serial data)
A continuous time series of weather data of
sufficient length to make reasonable assessments
for planning decisions, of sufficient temporal
resolution to match the time step in process
models, and of sufficient spatial resolution and
accuracy to have confidence in its application in
any location in the U.S.
What are our choices?
Observed data
-orModel-generated data
Observed data: Point, “truth”, missing values,
limited record, one realization, only 1 or 2
elements at many stations
Generated data: Point, only an approximation of the
“true” climate, serially-complete, easy to generate
Why Stochastic Weather
Generation Programs?
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Easily accessible, serially-complete data sets are
produced
Easily modified outputs to match other modeling
requirements
Weather/Climate scenarios for locations with
limited or no observed data
Ability to adjust model parameters for playing
“What If ?” games; risk assessments
ARS-NRCS Weather
Simulation Team (WST)
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Formed in response to need for updated, more
dynamic weather simulation tool
Comprised of 5-10 ARS and NRCS scientists
Major focus areas include storm generation
(generating sub-daily time steps), GEM as a
predictive tool (linkage to large-scale forcings),
generation of all needed weather elements, and
spatial distribution of generator parameters
GEM: Generation of weather
Elements for Multiple applications
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Known as WGEN (Richardson, 1984) and
USCLIMATE (Hanson et al., 1994)
Preservation of serial and cross correlations
Basic version is a point model, and delivers daily
time series of precipitation, max/min temperature,
solar radiation, average dewpoint and average
wind speed
Distributing GEM Model Parameters
Using the PRISM (Parameter-elevation
Regressions on Independent Slopes
Model) system at Oregon State University
Goal:
To generate accurate climatic time series at any
point in the U.S., regardless of the availability
of historical climate information, for input to
models, scenario development, and many other
uses
Annual mean of Tmin for wet/dry days from
PRISM
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Time Series Development:
Serially Complete Dataset Project
To produce accurate historical
climate time series, with no
missing records, from NOAA
climate stations nationwide
(precipitation and temperature)
Serially Complete Dataset
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40+ years of daily pcpn. and max/min temps (19511993)
Approximately 11,000 precipitation and 7,300
temperature station records now available for all 48
conterminous states
Generating an ASCII file of estimates for NCDC and
UCAN
Unique flags for estimates
Journal of Applied Meteorology paper Sept. 2000
Snow Climate Monitoring &
Analysis: SNOTEL
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Large Automated Climate Network
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Began in 1978
Over 650 remote site
Generally in high elevation areas
Located in the 12 Western States and
Alaska
– Utilizes meteor burst communication
technology to telemeter data
SNOTEL Coverage
SNOTEL
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Typical Remote Site Sensor Array
– Snow Pillow used to measure snow water
content
– Snow Depth
– All Season Precipitation Gage
– Air Temperature
• Includes current, 24 hour: maximum,
minimum, and average
SNOTEL
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Other Sensor
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Relative Humidity
Solar Radiation
Wind Speed and Direction
Barometric Pressure
Water Level
Soil Moisture and Temperature
Typical SNOTEL Site
Soil Climate Monitoring and
Analysis: SCAN
SCAN (Soil Climate and
Analysis Network)
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Nationwide Soil Moisture &
Temperature Network
– Background
• A pilot project was started in 1991
• Pilot project objectives were to:
– Develop technical expertise in monitoring
Soil-Climate interface
– Demonstrate the technical feasibility for a
nationwide system
– Precursor to SCAN
SCAN
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Currently 42 SCAN sites, located in 30 states
Uses meteor burst or cellular telephone
technology to transmit data
Data are delivered to the National Water and
Climate Center in Portland, Oregon
Real-time data validation
Data are computer accessible in near real-time
Danger of losing 20+ SCAN sites without
additional funding
SCAN USA as of August 2000
Typical SCAN Site
Internet Technologies for
Climate Delivery
Unified Climate Access Network
Climate Data Now for the 21st Century
UCAN Goals
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Make climate data and analyses available to a
broad user community
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Tailor products to the needs of users
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Provide a flexible interface to satisfy
programmatic needs
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Integrate climate resources across agencies