WatER: The proposed Water Elevation Recovery satellite mission

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WatER The proposed Water Elevation Recovery
satellite mission
Doug Alsdorf, U.S. WatER PI, alsdorf.1_at_osu.edu
Nelly Mognard, EU WatER PI, nelly.mognard_at_cnes.fr
Ernesto Rodriguez, JPL Engineer of KaRIN and
over 150 participants from more than 20
countries, world wide
We welcome everyone to join and participate in
WatER! Please feel free to attend an
informational meeting in this room at 615
Tonight.
Seed funding from Ohio State University, CNES,
JPL, and the Terrestrial Hydrology Program at
NASA
www.geology.ohio-state.edu/water
www.legos.obs-mip.fr/recherches/missions/water
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Three Key Points for this Talk

• One
• WatER will answer the question of Where is water
  stored on Earths land surfaces, and how does
  this storage vary in space and time?
• Two
• Opportunities and problems with profiling
  altimeters
• Three
• Other science and societal benefits from WatER

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OSTP OMB 2004
OSTP OMB 2005
OSTP 2004
UN 2004
The ability to measure, monitor, and forecast
the U.S. and global supplies of fresh water is
another high-priority concern.
Significant progress on this plan, including
stakeholder input, is expected during the next
two years.
Decides that the goals of the Decade should be a
greater focus on water related issues at all
levels and on the implementation of water-related
programmes and projects
Does the United States have enough water? We do
not know. What should we do? Use modern
science and technology to determine how much
water is currently available
Co-chair R. Hirsch, Director USGS Water Division
http//www.whitehouse.gov/omb/memoranda/fy04/m04-2
3.pdf
http//www.ostp.gov/NSTC/html/swaqreport_2-1-05.pd
f
http//www.un.org/Depts/dhl/resguide/r58.htm
http//www.ostp.gov/html/budget/2007/ostp_omb_guid
ancememo_FY07.pdf
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The WatER Mission
Submitted to NRC Decadal Review Panel Alsdorf,
D., D. Lettenmaier, J. Famiglietti, and C.
Vörösmarty, GEWEX News, 15, 6-7, August 2005.
Cazenave, A., P.C.D. Milly, H. Douville, J.
Benveniste, P. Kosuth, and D. Lettenmaier, EOS
Transactions AGU, 85, 59-60, 2004. Alsdorf, D.
and D. Lettenmaier, Science, 1485-1488,
2003. Alsdorf, D., D. Lettenmaier, C. Vörösmarty,
the NASA Surface Water Working Group, EOS
Transactions AGU, 269-276, 2003.
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WatER TechnologyKaRIN Ka-Band Radar
INterferometer
See Talk by Ernesto Rodriguez This Room 1745
Today

• Only method capable of producing images of high
  resolution water surface elevation measurements
• can provide h, dh/dx, and dh/dt
• Strong Heritage Is technology evolution, not
  revolution
• Radar altimetry has already been successfully
  used in space on a number of missions (e.g.,
  Topex/POSEIDON)
• SRTM was a radar interferometer
• Extensive JPL technology investment in WSOA
• Compared to SRTM
• Order of magnitude better vertical resolution
  over water sub-100 m size pixels
• Near nadir look angle, max 4.5º, not SRTMs 30º
  to 60º
• Water surface is highly reflective, thus is
  easily measured at near nadir

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Problems With Profiling Altimeters Global
Coverage
Does the United States have enough water? We do
not know. What should we do? Use modern
science and technology to determine how much
water is currently available
USGS Coverage 7000 gauges
0
5
10
15
Two somewhat similar sized areas
Even if multiple altimeters with optimal along
track resolutions are used, how will they answer
the question for the U.S. and the rest of the
world?
0
5
10
15

• Coverage from a pulse limited altimeter severely
  under samples rivers and especially lakes
• 16-day repeat (i.e., Terra) coverage misses 30
  of rivers and 70 of lakes in the data bases
  (CIA-2 UNH UH)
• 120 km swath instrument misses very few lakes or
  rivers
• 1 for 16-day repeat and 7 for 10-day repeat

Topex/POSEIDON 70 points
Birkett, C.M., L.A.K. Mertes, T. Dunne, M.H.
Costa, and M.J. Jasinski,Journal of Geophysical
Research, 107, 2003. Hirsch, R.M., and J.E.
Costa, EOS Transactions AGU, 85, 197-203, 2004.
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Problems With Profiling Altimeters Local Coverage
cm
SRTM DEM
m
Actual dh/dt
cm
dt 44 days
dt 44 days
dt 44 days
cm
Predicted dh/dt
Predicted dh/dt
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Targets are Global Russia's vast northern
wetlands A key player in global change
See talk on Friday by Larry Smith (H53i-01)
Arctic Change and The New Global Hydrology
Lake Water Surface Area North of 45.5N is 589,000
km2 Wetland area North of 45.5N is 4.5M km2
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Targets are Global
Congo River Basin 3.7M km2
Matthews, E. and I. Fung, GBC, 1, 61-86, 1987.
Ohio R.
Canada
Floods
Peace-Athabasca Delta 3200 km2
New Orleans
Costa Rica
Braided Rivers
Turkey
Reservoirs
Coastal Zones
New Zealand
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WatER Science Goals

• Primary
• To determine the spatial and temporal variability
  in freshwater stored in the worlds terrestrial
  water bodies.
• Potential Additional Goals (no particular order)
• Inundation area provides carbon fluxes at
  air-water boundary (e.g., CO2)
• Repeated topographic measurements for
  floodplains, glacial ice, etc.
• Global low-relief topography every 8 days and
  topographic change

Carbon Fluxes
Global Low-Relief DEMs
Floodplain Topography
3 cm s for a given pixel after 250 measurements
over 5 yrs
Vertical Component, Low Relief, Local
Deformation Only
Ice DEMs
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WatER Science Goals

• Potential Additional Goals (continued)
• High resolution h images allow plume and near
  shore studies
• Calculation of ocean water slopes and sea surface
  topography for bathymetry, ocean circulation, and
  climate.
• Differences between sea ice and water surface
  allow ice-freeboard calculations, thus thickness.

Plume off California
Jason-1
Sea Surface Anomalies
So, our acronym was carefully chosen WatER
Water Elevation Recovery can easily
become. WATER Water And Terrestrial Elevation
Recovery
Arctic Sea Ice Thickness
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Conclusions
www.geology.ohio-state.edu/water
www.legos.obs-mip.fr/recherches/missions/water
WatER is not a gauge replacement strategy. It is
an altogether new way of understanding water
storage and flow. Water fluxes and volume
changes are more than a 1D process. Profiling
altimeters repeat 1D, in-situ gauge approaches
whereas WatERs KaRIN will provide
two-dimensional h, dh/dt, and dh/dx about once a
week, thus yield ?S and Q globally. Free access
to data will enable all governments to know how
much surface water they have.
We welcome everyone to join and participate in
WatER! Please feel free to attend an
informational meeting in this room at 615
Tonight.