Transcript No Slide Title

Status and needs of Sea level
Observing Systems in East and South
East Asia
GCOS Regional Meeting for East and South East Asia, Singapore , 16-18
September 2002
John Church, CSIRO Australia [email protected]
Philip Woodworth, POL (GLOSS Chairman) [email protected]
Thorkild Aarup, GLOSS Technical Secretary IOC [email protected]
C.K. Shum, Ohio State Univ. (GLOSS Asia-Pacific Regional Contact)
[email protected]
Contents of Presentation:
1. Rationale - Why monitor sea level changes and how?
2. The GLOSS programme
3. Status of sea level data availability from the Region
4. Recommendations
http://www.pol.ac.uk/psmsl/programmes/gloss.info.html
Why Measure Sea Level Changes?
•Coastal management requires understanding of past
and future changes in sea level and related ocean
conditions
• Practical applications – e.g. to predict flood risks,
coastal
Different Time-Scales
navigation
etc.
• Rapid changes due to tsunamis
• Daily changes due to tides and surges
• Seasonal changes
• Interannual changes e.g. due to ENSO
• Long term changes due to climate change
Causes of Sea Level Change
• Local processes in river/coastal regimes
• Ocean circulation changes
Maldives Int.
Airport
• Regional and global climate changes
• Geological processes
Sea level has risen by about 120 m
since the last glacial maximum
http://www.pol.ac.uk/psmsl/programmes/gloss.info.html
Over several hundred years there has been an
increase in the rate of sea-level rise.
http://www.pol.ac.uk/psmsl/programmes/gloss.info.html
Changes in Sea Level during the 20th
century
• Most records show evidence for
rising sea levels during the
past
century
• IPCC concluded that there has
been a global rise of
approximately 10-20 cm
during the past 100 years
http://www.pol.ac.uk/psmsl/programmes/gloss.info.html
Some E and SE Asia Long Records
Example records from
India, Malaysia,
Singapore, Thailand,
Vietnam, Hong Kong,
South Korea, Russia,
Japan and Philippines.
http://www.pol.ac.uk/psmsl/programmes/gloss.info.html
Sea level rise during the 20th century has had regional impacts.
Marsh Destruction at Blackwater, Maryland, Due to Sea Level Rise
Leatherman, 2001
“sea level is projected to rise by 0.09 to 0.88 m
between 1990 and 2100”
about 2 to 4 times the rate for the past 100 years
For the IS92a greenhouse
gas scenario
Thermal expansion
0.11 to 0.43 m
Glaciers and ice caps 0.01 to 0.23 m
Greenland
-0.02 to 0.09 m
Antarctica
-0.17 to 0.02 m
Return period of surge heights at Immingham (UK)
A reduction in the return period of extreme events.
Longer Term Projections
• Continued glacier melting
• East Antarctic Ice Sheet
• West Antarctic Ice Sheet
opinion not favouring catastrophic collapse
• Continued thermal expansion for centuries
• Greenland melting
greater than +3C then continued melting
+5C - 3m over 1000 years
Projected Coastal Megacities: 2010
By 2100, the number of people who will have to respond to coastal flooding will be tens
of millions/year; Most vulnerable regions are South and South-East Asia; Africa;
Carribean; Indian Ocean Islands; Pacific Ocean Islands.
Tianjin
Dhaka
Seoul
Osaka
Istanbul
Tokyo
New York
Shanghai
Los Angeles
Manila
Bangkok
Lagos
Bombay
Lima
Karachi
Buenos Aires
Rio de Janeiro
Madras
Jakarta
Calcutta
Measuring Sea Level Changes
Altimeter System
Tide Gauge (float)
Bottom Pressure
Gauge
http://www.pol.ac.uk/psmsl/programmes/gloss.info.html
Tide Gauges are still essential
in the “Age of Altimetry”
• Principle of continuity, relative low cost of
gauges
• Long
records
for
trend/acceleration
studies (e.g. for input to IPCC)
secular
• Higher frequency sampling important
• High latitude regions of ice coverage
• Altimeter
‘relative’)
Acoustic Gauge in
Australia
• Coastal
Module)
calibrations
applications
(‘absolute’
(GOOS
and
Coastal
http://www.pol.ac.uk/psmsl/programmes/gloss.info.html
•Vertical land motion (using GPS)
GLOSS - The Global Sea Level
Observing System
•For many years agencies have sent data to the PSMSL. GLOSS
aims to ensure the provision of high quality sea-level data for
regional and global applications.
•Establishment of high quality regional and global sea level
networks for application to climate, oceanographic and coastal
sea-level issues
•Coordinated by the Intergovernmental Oceanographic
Commission (IOC) for the JCOMM of WMO/IOC
• Major contributor to IOC’s Global Ocean Observing System
(GOOS)
http://www.pol.ac.uk/psmsl/programmes/gloss.info.html
The GLOSS Programme
• GLOSS Core Network
(GCN)
• Regional Densifications
of the GCN
• Long Term Trends (LLT)
• Altimeter calibration
(GLOSS-ALT set)
• Ocean Circulation
(GLOSS-OC set)
GLOSS Core Network (GCN) with approx. 280
stations
http://www.pol.ac.uk/psmsl/programmes/gloss.info.html
An effective regional and global system requires:
delayed mode original data (e.g. hourly values) be
sent to one of the GLOSS International Archiving
Centres (Most countries are now doing this but it remains a
problem for a few (e.g. national security, or cost recovery)).
IAC’s are PSMSL, Univ. Hawaii and National Tidal
Facility Australia.
fast sea level data to be sent from GLOSS Core
Network sites to the GLOSS Fast Centre (University of
Hawaii Sea Level Center) within one week.
GCN Status E. and S.E. Asia
GCN Status Category:
Measured by PSMSL
data receipts
•up-to-date
•a bit slow
•historical data only
•no data
http://www.pol.ac.uk/psmsl/programmes/gloss.info.html
Status of data submission
(see http://www.pol.ac.uk/psmsl/reports.national+regional/)
India – no hourly data, national security issues
Bangladesh – major investments needed in difficult
estuary environment
Myanmar – first contact for many years made in
2002
Thailand – MSL delivered promptly, but gauges
need upgrading
Malaysia – excellent tide gauge and GPS networks
Singapore – excellent tide gauge and GPS networks
Vietnam – new recent gauges for flood warning.
PR China – MSL delivered regularly if a bit
behind. More gauges are known to exist than
provide data to international data banks.
Hong Kong China – long standing data provision.
Japan – excellent networks of several agencies.
S. Korea – good gauges. MSL data behind.
N. Korea – contacts lapsed.
Russia – good formal contacts. Several gauges
destroyed by tsunami. Need for modernisation.
Philippines – long standing contacts lapsed.
Indonesia – large gauge networks, none of which
now work due to funding problems.
Major Issues for the Region
Comparatively few tide gauges in the region are equipped
with GPS for monitoring vertical land movements (major
exception of Japan), see
http://www.soest.hawaii.edu/cgps_tg
Need for major investment in upgrade of tide gauges (e.g.
for fast data provision as well as delayed-mode) and for
GPS alongside the gauges. (No plans as yet for bids, e.g. to
World Bank, for resources for the region, as for Africa.)
Historical data
GLOSS/IODE Data Archaeology Project
Agencies which have historical sea level data in
non-computer form (e.g. on paper charts, or
paper tape) are asked to inform IOC or PSMSL
which may be able to arrange for computerisation
of the information.
Ongoing Regional Activities
•Regional networks of gauges with greater spatial density, to
serve the particular oceanographic interests of those regions
- example: Asia-Pacific Space Geodynamics (APSG) activities
•Research in the measurement and characterization of AsiaPacific regional and global sea-level rise
•Data center to be established, potentially at NTF, or other sites
providing data products including sea-level measurements, wave
heights, wind speed, and integrated water vapor from multiple
satellites
• GLOSS contributes to the activities of national agencies by
improving the standards for sea level recording around the
world
•Annual training courses on the techniques of tide gauge
operations, and workshops on special interests e.g.
measurements
in environmentally hostile areas. Next course
http://www.pol.ac.uk/psmsl/programmes/gloss.info.html
Malaysia April 2003.
Recommendations
Establish a Regional Project, under the auspices of GLOSS, to further develop a
networks of modern tide gauges and geodetic instrumentation to serve regional
requirements.
Specific Recommendations
Employ a Regional Coordinator to pursue the Regional Project.
That historical data (hourly, delayed mode and fast data) be submitted to the
GLOSS data archives (including if necessary, conversion to computer
compatible form)
That tide gauge instrumentation at GLOSS sites be upgraded to allow efficient
quality control and submission of delayed mode and fast data.
That a subset of gauge sites be equipped with Continuous GPS (CGPS)
receivers and/or other geodetic devices, in order to monitor vertical land
movement.
That tide gauges suitable for ongoing calibration of satellite altimeter missions
(e.g. deep ocean islands) be included in international programs (GLOSS-ALT).
That the project also contribute to observations quantifying the causes of sea
level change.
That programs be established to study the social, economic and environmental
consequences of sea level change; including the impact and frequency of
GLOSS Data Availability
Data from GLOSS tide gauges
• Permanent Service for Mean Sea Level
http://www.pol.ac.uk/psmsl/
• University of Hawaii Sea Level Center
http://www.soest.hawaii.edu/UHSLC/
• National Tidal Facility (Australia) Southern Ocean Centre
http://www.ntf.flinders.edu.au
GLOSS sea level data and information on each gauge in the
GLOSS Core Network are also available from PSMSL on CDROM.
Further Information
GLOSS Technical Secretary
Intergovernmental Oceanographic
Commission (IOC), UNESCO
email: [email protected]
Permanent Service for Mean Sea Level
Proudman Oceanographic Laboratory
email: [email protected]
http://www.pol.ac.uk/psmsl/programmes/gloss.info.html