A1262160008aAVPi

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THE GLOBAL NETWORK OF ISOTOPES IN
PRECIPITATION GNIP
Pradeep Aggarwal Luis Araguás International
Atomic Energy Agency Water Resources Programme
Isotope Hydrology Section
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Main objective of the Water Resources Programme
of the IAEA

• To improve the management of water resources by
  Member States with the use of isotope
  technologies
• Improve understanding of the water cycle
• Sustainable exploitation of water resources
• Improved hydrogeological and hydrogeo-
  chemical data.
• Capacity for monitoring the quantity and quality
  of water resources

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Isotopes in the Global Water Cyclescientific
background of isotope hydrology

• Isotope fractionation of 18O and 2H occurs
  during evaporation, condensation, and vapor
  transport
• Stable isotopes are fingerprints of water ?
  excellent tracers of the origin of water, and of
  changes in the hydrological cycle

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GNIP
Oxygen and hydrogen isotopes as tracers in the
Water cycle and climate Joint activity IAEA/WMO
since 1961 GNIP programme in hydrology,
climatology and related fields
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Main objective of GNIP
Systematic collection of basic data on isotopic
content in precipitation (monthly basis) on a
global scale to determine temporal and spatial
variations of environmental isotopes in
precipitation
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1990s New monitoring needs, besides classical
input function for hydrology Global climate
modelling requires broader spatial coverage
?AGCM Interest in High latitudes and altitude
areas Climate-sensitive areas Tropical zones
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GNIP STATIONS
1953-2006, about 830 stations
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GNIP STATIONS / Record gt 2 years
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ACTIVE GNIP STATIONS
18O and 2H RECORDS (in years)
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Contents of the GNIP database

• Monthly values
• Total amount of precipitation (mm)
• Type of precipitation (rain, snow, both)
• Mean air temperature (ºC)
• Mean water vapour pressure (hPa)
• Stable Isotope contents (O-18, H-2) ()
• Tritium content and uncertainty (TU)

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Status of the network   About 210 active
stations in 53 countries The IAEAs Isotope
Hydrology Laboratory is currently performing
isotope analyses of about 40 of the collected
precipitation samples
30 other laboratories are analysing GNIP samples
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• Structure of the GNIP network
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• The network is composed of
• IAEA/WMO stations situated in climatically
  relevant locations
• National Networks composed of stations and labs
  operated by national authorities
• affiliated stations which are stations resulting
  from hydrological studies, often of short-term in
  nature

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Operation of GNIP

• International Atomic Energy Agency
• Isotope Hydrology Section
• Isotope Hydrology Laboratory
• World Meteorological Organization
• Link to the stations
• Meteorological information
• Cooperating institutes and laboratories
  (voluntary basis)
• Scientific Steering Committee

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Operational Problems

• Collaboration with Member States is on voluntary
  basis
• Sampling/storage protocols not always properly
  followed
• Access to meteorological information
• Insufficient communication with stations
• Partial or incomplete isotope records
• Uneven spatial coverage of stations
• Need for data in remote areas
• Automatic weather stations

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Operational problems (cont.)

• Difficulties to create new stations in remote and
  climate-sensitive areas
• Identify national co-ordinators
• Statistics Incomplete records
• Quality control of isotope analysis?
  inter-laboratory exercises

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Latest developments

• GNIP data distributed into 3 categories
• GNIP- monthly 100.000 records 780 st
• GNIP- event 25.000 records 100 st
• GNIP- vapour 700 records 6 st
• Completion of ISOHIS-Map
• Easier visualization to GNIP, GNIR, IGLASS
• Statistical treatment of data
• Yearly, monthly, long-term weighted means

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Creation of National focal points

• Link with national institutes coordinating
  activities related to isotope monitoring
• Data compilation and quality control at national
  level ? submission to the GNIP database

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Contact

• Luis Araguas (IAEA) L.Araguas_at_iaea.org

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Initiatives to correct negative trend

• Involvement of other groups/organizations
• Collection ? Met. Services (WMO)
• Analysis ? IH labs
• Creation/continuity of National Networks
• Long/term operation - GNS stations (?)
• Remote or climate-sensitive areas
• Links with other projects/programmes
• (AMMA, TRACE, etc)

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GCOS - CLIMAT reports by ca. 1000 monitoring
reference stations
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GNIP link to GCOS - GSN

• Advice on operational aspects
• IAEA request to stations to participate in the
  GNIP programme endorsed by WMO (GCOS)
• Reactivation/establishment of long-term GNIP
  stations
• Ensure availability of meteorological information

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Isotopes help to define groundwater origin,
dynamics and flow patterns
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Santiago de Chile Isotopes help to define
sources of recharge, groundwater origin, flow
patterns and pollutant transport
Oxygen-18
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(No Transcript)
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Modelling isotope contents over the Andes
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Links of GNIP with intern. programs

• GTN-H Global Terrestrial Networks Hydrology
• GCOS Global Climate Observing System
• UNESCO-IHP
• UNEP-GEMS Global Env Monitoring System
• IGBP-PAGES Past Global Changes
• World Data Centre-A for paleoclimatology
• WMO - WCRP (GEWEX, CLIVAR)

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GNIP/WMO stations
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National networks   Argentina, Australia,
Austria, Canada, China, Chile, Croatia, France,
Germany, Morocco, Netherlands, Portugal, South
Africa, Spain, Switzerland, Turkey, USA One
station maintained in Algeria, Egypt, Indonesia,
Israel, Jordan, New-Zealand, Poland,
Slovenia, U.K.