CLPP

1
Terrestrial Snow Two Perspectives NOAA Weather
and Water Operations NASA Earth Science Research
Don Cline
National Operational Hydrologic Remote Sensing
Center
Office of Climate, Water and Weather Services,
National Weather Service, NOAA
2
Operational Drivers NOAAs Four Mission Goals

• Protect, Restore, and Manage the Use of Coastal
  and Ocean Resources Through an Ecosystem Approach
  to Management
• Snowmelt is an important component of freshwater
  input to oceans
• Understand Climate Variability and Change to
  Enhance Societys Ability to Plan and Respond
• Terrestrial snow is a sensitive indicator of
  climate change, a significant storage component
  of the global water cycle, and affects weather
  and climate through several surface energy and
  mass exchange mechanisms
• Several socioeconomic sectors linked to
  terrestrial snow
• Serve Societys Needs for Weather and Water
  Information
• Snow is a major component of water resources and
  contributor to flooding
• Support the Nations Commerce with Information
  for Safe, Efficient, and Environmentally Sound
  Transportation
• Terrestrial snow directly impacts land
  transportation

3
Operational Drivers Snow Economics
The Value of Snow and Snow Information Services
(2004)
- Dr. Rodney Weiher, Chief Economist, National
Oceanic and Atmospheric Administration, U.S.
Dept. of Commerce
Economic Benefits of Snow
Economic Costs of Snow
4
Operational Drivers Snow Economics
The Value of Snow and Snow Information Services
(2004)
- Dr. Rodney Weiher, Chief Economist, National
Oceanic and Atmospheric Administration, U.S.
Dept. of Commerce
Economic Benefits of Snow
Economic Costs of Snow
improved snow information and services have
potential benefits greater than 1.3 billion
annually.
investments that make only modest improvements
in snow information will have substantial
economic payoffs.
5
Snow is critically important to the U.S.
Snowmelt flooding affects thousands of lives and
causes billions of dollars in damages.
Region Michigan Cause Rain on snow, Frozen
Soils Damage 1 Death, 40 Million
Region New England Cause Snowmelt, Rain on
snow Damage 150 Deaths, 3.9 Billion
Region Pacific Northwest Cause Rain on
snow Damage 47 Deaths, 2.4 Billion
Region Colorado River Basin Cause Record Snow
Packs Damage 1.1 Billion
Region Northeast U.S. Cause Rapid
Snowmelt Damage 33 Deaths, 1.7 Billion
1964 Oregon City, OR
1996 Harrisburg, PA
1904 Grand Rapids, MI
1936 Pittsburgh, PA
1983 Salt Lake City, UT
1907 Wheeling, WV
1927 Cairo, IL
1951 Mankato, MN
1979 Fargo, ND
1997 Grand Forks, ND
Region West Virginia Cause Heavy Rain on
Snow Damage 1.9 Billion
Region Mississippi River Cause Saturated Soils
Snowmelt Damage 2.4 Billion
Region Southern Minnesota Cause Rain on Snow,
Rapid Snowmelt Damage 21 Million
Region Red River of the North Cause
Snowmelt Damage 96 Million
Region Red River of the North Cause Snowmelt,
Frozen Soil Damage 5.1 Billion
(Damages in 2002 Dollars)
Major snow-related flood
6
Conceptual Evolution of Operational Observing
Systems
Comprehensive Analyses and Data Assimilation
(including quality control, multisensor
estimation and 4DDA)
Requirements
Evolutionary infusion of new observing systems,
data sources, science, and technology.
Products
Updated Requirements
Systematic Evaluation and Customer Feedback
Data and Information Gap Analysis
(e.g. high space-time resolution)
7
NOAA/NWS/NOHRSC National Snow Analyses (NSA)

• Product Generation and Distribution
• Elements
• Daily National Snow Analyses
• Water Equivalent
• Snow Depth,
• Snow Temperature
• Sublimation
• Condensation
• Snow Melt
• Formats
• Interactive Maps
• Time-series Plots
• Text Discussions
• Alphanumeric and Gridded products
• Distribution
• NOHRSC Web Site, AWIPS, direct FTP, NSIDC, NCDC

Data and Product Archive
NOHRSC Snow Data Assimilation System Energy-and-ma
ss-balance snow modeling and observed snow data
assimilation 1-km, Hourly Continental U.S.
8
User Interactive Mapping on Internet

• Comprehensive snow hydrologic information
  products
• Snow water equivalent, depth, wetness,
  temperature, melt, sublimation losses
• GIS-based interactive
  information
  distribution
  on the
  Internet
• Overlay administrative
  
  and basin boundaries,
  
  rivers, roads, cities
• Zoom to full 1-km resolution
• Query stations for time-
  
  series history
• Export text data summaries
  
  for each basin
• Up to 300,000 hits a day
  during
  peak season

9
Time-series History Queries on Internet
User can query any of 40,000 stations shown on
interactive map.

• SWE, Depth, Density, and Melt
• e.g. Washington DC (Reagan National Airport)
• Jan 15 - Feb 15, 2004
• Dark blue line show modeled SWE
• Light blue line shows modeled snow depth
• Light blue points show observed snow depth
• Assimilation of observed snow depth on Jan 27
  corrected for underestimated snow precipitation

10
Hourly SWE Analysis, Oct 1 2003 May 23 2004
11
Science Drivers for Improved Snow Observations

• We lack sufficient understanding of the magnitude
  and variability of snow water storage and of the
  fluxes and feedbacks that relate it to the
  atmosphere and climate necessary to reliably
  predict local-regional consequences of climate
  variability and change.

• Snow water content is poorly measured by sparse
  and inconsistent ground networks.
• Current remote sensing observing systems are
  unable to provide process-oriented measurements
  of snow hydrologic properties required to test
  and constrain todays predictive models.
• Fundamental questions such as how much water is
  stored locally,
  regionally, or globally in seasonal snow packs
  remain unanswered.

12
In Situ Snow Observations
13
Space-Time Scales of Snow Processes
10 Years
Interannual Variability in Snow
Accumulation (Variation in Synoptic Climate)
3 Years
2 Years
1 Year
Snow Metamorphism Effects on Structural
Proeprties and Radiative Transfer
Intraseasonal Variability in Snow
Accumulation (Variation in Individual Storm
Tracks)
1 Month
Snowmelt Floods
Snow Melt Effects on Water Balance, Surface
Energy Balance and Microwave Radiative Transfer
Temporal Scale
Temporal Scale (Hours)
1 Week
Orographic Precipitation Effects on Snow
Accumulation
Wind-redistribution of Snow Accumulation on the
Ground
3 Days
Synoptic Storm Systems (Snow Precipitation and
Accumulation)
1 Day
Enhanced Boundary-layer Stability over Snow
Effects of Snow Cover on Heat and Moisture
Exchanges with Advecting Airmasses
1 Hour
10m
100m
1km
10km
100km
1000km
Spatial Scale
14
Comparison of Continental-scale Water Storage
15
Conceptual Evolution of Operational Observing
Systems
Comprehensive Analyses and Data Assimilation
(including quality control, multisensor
estimation and 4DDA)
Requirements
Evolutionary infusion of new observing systems,
data sources, science, and technology.
Products
Updated Requirements
Systematic Evaluation and Customer Feedback
Data and Information Gap Analysis
(e.g. high space-time resolution)
16
NOAA Operational Observing Requirements

• Specified in NOAA Observing System Architecture
  (NOSA)
• http//nosa.noaa.gov
• Four snow observation requirements
• Snow Cover
• Snow Depth
• Shallow, Deep
• Snow Water Equivalent (on ground)
• Shallow, Deep
• Snowfall Water Equivalent (precip rate)
• Two spatial domains
• North America
• Global
• Two levels of requirements for each
• Threshold (Minimal acceptable requirement)
• Objective

17
NOAA Operational Observing Requirements
Snow Cover
Current Operational GOES and AVHRR (Neither
meets T spatial requirements)
Current Experimental MODIS (Meets T spatial and
measurement, but not temporal)
Planned Operational GOES-R, VIIRS (Will meet all
current T requirements)
18
NOAA Operational Observing Requirements
Snow Depth
Current Operational SSM/I (Doesnt meet T
spatial or measurement requirements)
Current Experimental AMSR (Doesnt meet T
spatial or measurement requirements)
Planned Operational CMIS (Wont meet T spatial
or measurement requirements)
19
NOAA Operational Observing Requirements
Snow Water Equivalent
Current Operational SSM/I, AMSU (Doesnt meet T
spatial or meas. requirements)
Current Experimental AMSR (Doesnt meet T
spatial or measurement requirements)
Planned Operational CMIS (Wont meet T spatial
or measurement requirements)
20
NOAA Operational Observing Requirements
Snowfall Water Equivalent
Current Operational None
Current Experimental Ground-based Doppler Radar
(Neither spatial or measurement)
Planned Experimental GPM (TBD)
21
Conceptual Evolution of Operational Observing
Systems
Comprehensive Analyses and Data Assimilation
(including quality control, multisensor
estimation and 4DDA)
Requirements
Evolutionary infusion of new observing systems,
data sources, science, and technology.
Products
Updated Requirements
Systematic Evaluation and Customer Feedback
Data and Information Gap Analysis
(e.g. high space-time resolution)
22
NASA Cold Land Processes Working Group

• Sponsored by Terrestrial Hydrology Program
• Identify and implement the relevant science,
  technology, and application infrastructure
  necessary to support a future remote sensing
  mission focused on Cold Land Processes.
• Snow on land, ice sheets and sea ice
• 15 workshops since 2000 (next Mar 23-24, 2005
  Seattle)
• Science framework for mission
• Technology development for experimental and
  operational missions
• Algorithm development
• Model development
• Land surface (snow)
• Radiative transfer (microwave)

23

• Full global measurement of snow water equivalent
  and snow wetness

Cold Land Processes Roadmap
Cold Land Processes Measurement (CLPM) Mission
OPER CLPM MISSION
CLP Measurement Technology Development
Funded
Unfunded

• Improved measurement accuracy and precision

• Various technology development needs detailed in
  ESTO database to support multi-frequency SAR,
  higher-resolution radiometers, larger data
  volumes, etc.

Field Campaign

• Higher spatial and temporal resolution to
  resolve precipitation from individual storms

• Quantification of high latitude precipitation,
  fresh water stored in seasonal snowpacks,
  controls on variability of storage, snowpack
  feedback effects on weather and climate

CLPX V Validation
CLPP Airborne Simulator
Cold Land Processes Pathfinder (CLPP) Mission
CLPP Technology Devel.
CLPP Education and Outreach
CLPP Proposal
CLPP Technology Development
Enterprise Goals Understand distribution
of snowpack water storage and melt state
(wetness) Models capable of predicting the
water cycle, including floods and
droughts, down to 10s of km Routine
probabilistic forecasts of snow water storage
and snowfall accurate enough to support economic
decisions Improve winter storm hazard
forecasting at local scales to support mitigation
CLPP MISSION
CLPP Applications Development
CLPX III

• Narrow-swath sampling of global snow water
  equivalent and snow wetness

Increased coordination and collaboration with
polar regions and sea ice communities

• Data collection as needed to support advanced
  CLPP preparations algorithm refinement, ground
  system testing, science data processing tests,
  etc.

Development of International Partnerships

• Test and refine new active/passive algorithms
  with augmented Ku-band AIRSAR

Knowledge Base

• Routine modeled estimates of global SWE and
  snow wetness, largely unconstrained by
  observations

Airborne Imaging Ku SAR
CLPX II

• Test and refine improved models and data
  assimilation

• Examine key questions unresolved by CLPX I
  e.g. dynamics, untested snowpack regimes, polar
  regions, sea ice, etc.

• New algorithms for active/passive SWE and
  wetness retrieval

CLPX I

• Improved strategies for assimilation of snow
  information in models

• Progress in microwave radiative transfer models
  for snow

Data Analyses

• Improved representation of fundamental cold land
  processes in regional-global models

• Evaluation of regional-global snow models,
  AMSR-E snow products

• Improved general understanding of cold land
  processes

Cold Land Processes Working Group

• Continuation of 30-year baseline of global
  monitoring of snow cover and depth (dry-snow
  only, coarse resolution passive microwave)

AMSR-E
SSM/I
CMIS (NPOESS)
NRA
NRA
NRA
NRA
NRA
NRA
NRA
NRA
NRA
NRA
NRA
GAPP
GAPP
GAPP
GAPP
GAPP
GAPP

• Global variations in areal extent of snow cover
  well quantified
• Poor understanding of how local-scale processes
  scale up
• Poor understanding of snow feedbacks to
  atmosphere

• Models dont account for sub-grid scale snow
  distributions
• Winter precipitation poorly observed, esp. in
  high latitudes
• Paucity of observations of snow water content or
  melt state

TODAY
24
CLPP Baseline Mission Concept

• Two-frequency Ku-band SAR
• Ku-Band (13 and 17 GHz)
• 100 m Resolution (60 looks)
• Swath 35km
• 100 W Peak Transmit Power
• Incidence angle 30 degrees
• Polarization VV, VH
• K/Ka-band Radiometer
• 7/4 km resolution
• Swath 45km (K-band), 40km (Ka-band)
• Polarization H
• Orbit/Launch/Spacecraft
• Sun-synchronous, 510km, 5-6 pm ascending
• 6-day repeat
• Ball 2000 or SA200HP or Equivalent
• Peacekeeper L/V

1.95 m pushbroom reflector with offset feeds
6-Day Repeat Swaths
Feb 2004 Snow Extent
25
CLPP Fills Important Gap in Observation of
Processes
30-Year Legacy of Passive Microwave Remote
Sensing of Snow
Cold Land Processes Pathfinder Measurements
10 Years
Interannual Variability in Snow
Accumulation (Variation in Synoptic Climate)
3 Years
2 Years
1 Year
Intraseasonal Variability in Snow
Accumulation (Variation in Individual Storm
Tracks)
Snow Metamorphism Effects on Microwave and
Optical Radiative Transfer
1 Month
Snow Melt Effects on Water Balance, Surface
Energy Balance and Microwave Radiative Transfer
Temporal Scale
Temporal Scale (Hours)
1 Week
Orographic Precipitation Effects on Snow
Accumulation
3 Days
Wind-redistribution of Snow Accumulation on the
Ground
Synoptic Storm Systems (Snow Precipitation and
Accumulation)
1 Day
Snowmelt Floods
Enhanced Boundary-layer Stability over Snow
Effects of Snow Cover on Heat and Moisture
Exchanges with Advecting Airmasses
1 Hour
10m
100m
1km
10km
100km
1000km
Spatial Scale
26
CLPP Investigation Pathway
Preparatory Science/Application Investigations
Preparatory Science Investigations
Major Science and Application Investigations
Building Block
Science Investigation
Building Block
Level 1 Products
Level 4 Products
Level 2 3 Products
Active Microwave Algorithm
Near Real Time During Flight Global (synoptic)
Snow Analyses (Uncoupled Modeling/Assim)
Radar FVV FHV Ku FVV FHV Ku
Analysis of Local-Global Snow Water Storage,
Fluxes, and Variability
Global SWE Wetness Depth Grain
Size Density Snowmelt Snow Temp Fluxes Runoff
CLPP Swaths Only SWE Wetness Depth Grain
Size Density Roughness (TBD)
Ancillary Data (Vegetation, Topography)
FUSION
Quantify Ice-Sheet Snow Accum. Melt
Characteristics
Uncertainty Assessment
Passive Microwave Model-based Estimation
Near Real Time and Post-flight
Snow/Land Modeling Assimilation (Coupled
Uncoupled)
Exploration of Snow Cover on Sea Ice
Radiometer TbH19 TbH37
Algorithm Validation
Model Validation
Operational Demonstration Hydrological Analysis
and Forecasting
Level 3 Gridded Backscatter and Brightness Data
Benefit NPOESS/CMIS Risk Reduction (Snow Cover
Depth and SWE EDRs)
27
Terrestrial Snow Two Perspectives NOAA Weather
and Water Operations NASA Earth Science Research
Don Cline
National Operational Hydrologic Remote Sensing
Center
Office of Climate, Water and Weather Services,
National Weather Service, NOAA
28
Science Drivers

• Snow is a significant storage component of the
  fresh water cycle1, affects weather and climate2,
  is a critical fresh water resource in many
  mountainous regions and surrounding lowlands3,
  and is frequently responsible for loss of life
  and property due to flooding4.
• Snow water storage is highly variable in space
  and time, but appears to be changing in
  significant ways, including increasing snow
  accumulation at different times and locations, in
  contrast to some climate change hypotheses.

• 1On one day in Feb 2004, NWS model analyses
  indicated the volume of water stored in snow
  across the CONUS was 11 of the U.S. total annual
  renewable fresh water resources (258 km3 59 of
  estimated U.S. total annual freshwater
  withdrawal).
• 2In addition to the well-known ice-albedo
  feedback, snow cover depresses overlying air
  temperatures, which decreases atmospheric
  thickness, and in turn steers cyclonic activity
  which affects subsequent snowfall. Persistence of
  these effects depends on mass of snow (water)
  present.
• 3E.g., in the western U.S between 80-90 of total
  annual streamflow originates as snow .
• 4Eight of the top 20 floods of the 20th century
  were related to snowmelt (USGS). Three caused
  over 1B each in damages (2002 dollars).