Sea Surface Height

1
Sea Surface Height
97
98
99
00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
2-f MR 66-deg, 10-day, 315-km
OSTM (Jason-2)
TOPEX-Poseidon
JASON
Jason
Jason-3
Advanced Alt.
AltiKa on TBD
98-deg, 35-day, 80-km

ERS-2
GMES Sentinel 3
ENVISAT
HY-2 series
X
108-deg, 17-day, 160-km
98-deg, 17-day, 130-km
NPOESS C-3
GEOSAT Follow-on
In orbit
Approved
Planned/Pending Approval
2
Sea Surface Height

• Continue Jason series
• New start needed for a NOAA/EUMETSAT Jason-3 in
  FY09, and/or
• New start for NASA Advanced Altimeter Mission
• CNES has funding for AltiKa is negotiating for
  a ride on Indian satellite
• Prospects for ESA/GMES funding for Sentinel-3,
  while not approved, look good
• Timely access to altimeter data from now-approved
  Chinese HY-2A (launch in 2009) is at an impasse

3
Surface Vector Winds
97
98
99
00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
895 km
1700 km
X
WINDSAT
500 km
2 x 550 km w/ 768-km nadir gap
AMI/ERS-2
ASCAT/METOP 3-satellite series
SeaWINDS/ADEOS-II
HY-2 series scatterometer
1600 km
Seawinds/QuikSCAT
OceanSat-2 scatterometer
In orbit
Approved
Planned/Pending Approval
No CMIS on NPOESS C-1 a less capable CMIS is
planned beginning with C-2 in 2016.
4
Surface Vector Winds

• QuikSCAT is entering its 8th year with no
  follow-on identified
• Passive polarimetry does not meet operational
  needs for SVW
• An ASCAT on 3 METOPs is approved, but has 2/3rds
  of QuikSCAT coverage nadir gap
• Timely access to data from QuikSCAT-like
  scatterometers on approved Indian OceanSat-2
  (2007) Chinese HY-2A (2009) is at an impasse

5
WCRP Workshop onUnderstanding Sea-levelVariabili
ty and Change

• Stan Wilson
• Senior Scientist, NOAA/NESDIS
• GSOP-2
• Scripps
• 8-9 Dec 2006

6
WCRP Workshop onUnderstanding Sea-level Rise
Variability

• Organized by the WCRP, in concert with ICSU, to
• Identify the uncertainties associated with
  sea-level rise and variability, as well as the
  research needed to narrow these uncertainties
• Support the Global Earth Observation System of
  Systems by helping develop international
  scientific consensus for the observations needed
  to address these uncertainties
• Co-chairs John Church, Phil Woodworth, Thorkild
  Aarup Stan Wilson

7
WCRP Workshop onUnderstanding Sea-level Rise
Variability

• Hosted by the IOC and held at UNESCO June
  6-9, 2006
• 163 scientists from 29 countries participated
• 35 co-sponsors 16 participating programs
• A Summary Statement with Recommendations is
  available and will serve as the Executive Summary
  of a book due in mid-2007 http//copes.ipsl.jussi
  eu.fr/Workshops/SeaLevel/Reports/Summary_Statement
  _2006_1004.pdf

8
WCRP Workshop onUnderstanding Sea-level Rise
Variability

• Global mean sea levels have been rising
• Since 1992, at a rate of 3.2 /- 0.4 mm/yr based
  on tide gauges and satellite altimeters
• For the previous century, 1.7 /- 0.3 mm/yr based
  on tide gauges

9
Global Mean Sea Level
Seasonal variations removed GIA correction
applied (0.3 mm/year)
Rate 3.2 0.4 mm/year
http//sealevel.colorado.edu
10
Monthly Averages of Global Mean Sea Level
reconstructed from Tide Gauges (Black,
1870-2001) and Altimeters (Red,
1993-2004) Seasonal Cycle had been removed
Courtesy of Church White
11
Sea level rising at the very upper limit of the
IPCC TAR projections (i.e. 88 cm rise by 2100)
Rahmstorf et al.
12
WCRP Workshop onUnderstanding Sea-level Rise
Variability

• Global mean sea levels have been rising
• Since 1992, at a rate of 3.2 /- 0.4 mm/yr based
  on tide gauges and satellite altimeters
• For the previous century, 1.7 /- 0.3 mm/yr based
  on tide gauges
• Current estimates of thermal expansion over the
  1st decade of altimetry account for about half of
  the observed rise, but only about a quarter over
  the previous half century

13
WCRP Workshop onUnderstanding Sea-level Rise
Variability

• Melting glaciers and ice sheets are a significant
  contributor
• Terrestrial glaciers are shrinking worldwide
  during the past decade they have been melting at
  about twice the rate of the previous decades
• There is observational evidence of accelerating
  flow in outlet glaciers in southern Greenland and
  critical locations in Antarctica
• The largest uncertainties in contributions to
  sea-level rise are in terrestrial water storage
• Additional factors include changes in mass
  loading (such as GIA) and deteriorating reference
  systems

14
RecommendationsSome Research Themes

• Extend the present record of sea-level change
  back several hundred years
• Reconcile differences between observed changes in
  sea-level with the ability of different models to
  depict same
• Quantify the contribution of the cryosphere to
  sea-level rise using a combination of aircraft,
  in-situ, altimetry, gravity, and interferometric
  SAR
• Estimate changes in lake/reservoir/river levels
• Utilize tide gauges, altimetry, gravity, and GPS
  to improve estimates of changes in surface mass
  loading on sea-level rise

15
Recommendations Existing Observing Systems to
Sustain

• Sea level
• Extend series with a Jason-3
• GLOSS tide gauge network with co-located absolute
  positioning
• Ocean volume
• Argo
• Ocean, terrestrial water ice mass
• GRACE
• Ice sheet glacier topography
• GFO, ENVISAT, CryoSat-2, Sentinel-3, IceSat
• Aircraft in-situ observations
• Reference frame
• International Terrestrial Reference Frame
• GOCE

16
Recommendations Improved Observing Systems to
Develop

• Ocean volume
• Argo under ice
• Deep-ocean complement to Argo
• Ice sheet glacier volume
• Improved radar/laser altimetry
• Ice velocity
• Interferometric SAR satellite
• Sea terrestrial water levels
• Advanced wide-swath altimeter

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What was my motivation for the workshop?

• Concern about lack of progress in implementing
  observing systems

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Observing System Requirements

• 1999 Ocean Observations Conference in St
  Raphael
• 2001 IGOS Ocean Theme Team Report
• 2003 US Climate Change Science Program
  Strategic Plan
• 2004 GCOS Implementation Plan
• 2006 15 Years of Progress in Satellite
  Altimetry Symposium

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What was my motivation for the workshop?

• Concern about lack of progress in implementing
  observing systems
• NOAA Administrator
  You need to be able to make a business
  case
• We ought to be able to make a case for rising sea
  levels

20
John Churchs Summary

• Sea-level rise is an issue for
• Here and now, The 21st C and The long term
• Need to adapt
• Impacts will be felt through extreme events
  more frequent and more severe
• LDCs and the poor most at risk, Require local and
  regional planning, Planning to avoid the impacts
  of severe events
• Need to narrow uncertainties
• Need to mitigate to avoid the most extreme
  scenarios
• Will we pass a major tipping point during the
  21st C?
• Environmental refugees a here and now issue
• Not if but when and where and how will we
  respond
• Science/government/business/community partnership
  essential appropriate strategies can lead to
  significant amelioration of impacts

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Impacts exacerbated by subsiding Coastal
Megacities (during the 20th Century)
Tianjin (2 m)
Dhaka
Seoul
Osaka (3 m)
Istanbul
Tokyo (5 m)
New York
Shanghai (3 m)
Los Angeles
Manila
Lagos
Bangkok (2 m)
Bombay
Nicholls, in prep.
Lima
Karachi
Madras
Jakarta
Rio de Janeiro
Buenos Aires
Calcutta
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What was my motivation for the workshop?

• Concern about lack of progress in implementing
  observing systems
• NOAA Administrator
  You need to be able to make a business
  case
• We ought to be able to make a case for rising sea
  levels
• First, develop international consensus for
  observing systems required
• Then, use the political visibility of GEOSS to
  sell them

23
GEO FOCUS BENEFITS OF OBSERVATIONS

• NINE AREAS OF SOCIETAL BENEFIT
• Disasters Reducing loss of life and property
  from natural and human-induced disasters
• Health Understanding environmental factors
  affecting human health and well being
• Energy Improving management of energy resources
• Climate Understanding, predicting, mitigating
  and adapting to climate variability and change
• Water Improving water resource management
  through better understanding of the water cycle
• Weather Improving weather information,
  forecasting and warning
• Ecosystems Improving the management and
  protection of terrestrial, coastal and marine
  resources
• Agriculture Supporting sustainable agriculture
  and combating desertification
• Biodiversity Understanding, monitoring, and
  conserving biodiversity

24
Current Challenge Connecting Sea Level with GEO

• Disasters Weather
• How is the combined impact of subsidence, storm
  surge, tides, and flooding rivers exacerbated by
  global sea-level rise?
• How will coastal erosion in the Arctic continue
  to impact coastal erosion?
• Energy
• To what extent is energy infrastructure,
  especially offshore platforms, vulnerable to
  storm surge?
• Climate
• To the extent that the rate of global sea-level
  rise accelerating, what is its impact on coastal
  development?
• Water
• How are changes in terrestrial water storage
  estimated by lake and reservoir levels
  impacting global sea-level rise?

25
A Question-based Approach

• Identify an easily understandable,
  policy-relevant, science-based question
• Use the question as a basis to order and link
  required observing systems
• This also provides a basis for identifying a set
  of actions required for implementation
• Those who will pay the public and its
  representatives need to be able to easily
  understand the objective, what is needed to meet
  it, and its current status, as well as
  balance the required investment with the
  impacts

26
Other Possible Questions

• How is heat storage in the oceans changing?
• How is carbon storage in the oceans changing?
• How is decadal variability in the oceans
  changing?
• Others?

27
For each question

• Heat storage
• Carbon storage
• Decadal changes
• Others?

• What observations are required?
• What are the impacts?
• Why is it important?
• What exists what is missing?
• What data systems, assimilation modeling are
  needed?