2Why is there a GAW world data centre at CCU? What does the World Data Centre for Aerosols do?What will it do in the future?
3Why is there a GAW world data centre at CCU? Some Acronyms……GEO: Group on Earth Observations (2002 World Summit on Sustainable Development & G8) co-ordinates efforts to build GEOSS.GEOSS: Global Earth Observation System of Systems: components covering Disasters; Health; Energy; Climate; Agriculture; Ecosystems; Biodiversity; WeatherGCOS: Global Climate Observing System established 1992 (WMO, IOC, UNEP, ICSU) = adopted as the climate observation component of GEOSS. GCOS calls for systematic observations of ECVs to serve needs of UNFCCC & IPCC.ECVs: Essential Climate Variables 44 variables plus soil moisture needed to describe the climate.WMO/GAW: World Meteorological Organisation Global Atmosphere Watch Aerosol Network is the GCOS network for Aerosol Properties ECV.WDCA is the World Data Centre for the WMO/GAW Aerosol Network. WDCA is one of principal direct actions by the European Commission (as opposed to indirectly supported through project funding) that supports GCOS.
4Why: Essential Climate Variables DomainEssential Climate VariablesAtmospheric(over land, sea and ice)Surface: Air temperature, Precipitation, Air pressure, Surface radiation budget, Wind speed & direction, Water vapour.Upper-air: Earth radiation budget (including solar irradiance), Upper-air temperature (including MSU radiances), Wind speed & direction, Water vapour, Cloud properties.Composition: Carbon dioxide, Methane, Ozone, Other long-lived greenhouse gases, Aerosol properties.OceanicSurface: Sea-surface temperature, Sea-surface salinity, Sea level, Sea state, Sea ice, Current, Ocean colour (for biological activity), Carbon dioxide partial pressure.Sub-surface: Temperature, Salinity, Current, Nutrients, Carbon, Ocean tracers, Phytoplankton.TerrestrialRiver discharge, Water use, Ground water, Lake levels, Snow cover, Glaciers and ice caps, Permafrost and seasonally-frozen ground, Albedo, Land cover (including vegetation type), Fraction of absorbed photosynthetically active radiation (fAPAR), Leaf area index (LAI), Biomass, Fire disturbance, Soil moisture. Including nitrous oxide (N2O), chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), sulphur hexafluoride (SF6), and perfluorocarbons (PFCs). Includes runoff (m3 s-1), ground water extraction rates (m3 yr-1) and location, snow cover extent (km2) and duration, snow depth (cm), glacier/ice cap inventory and mass balance (kg m-2 yr-1), glacier length (m), ice sheet mass balance (kg m-2 yr-1) and extent (km2), permafrost extent (km2), temperature profiles and active layer thickness, above ground biomass (t/ha), burnt area (ha), date and location of active fire, burn efficiency (%vegetation burned/unit area). ] Recognized as an emerging Essential Climate Variable (not part of the 44).
5Why: Global Atmosphere Watch (GAW) GAW established in 1989 by the Eleventh World Meteorological Congress (Cg-XI) as a major priority program. The mission of GAW is:make reliable, comprehensive observations of the chemical composition and selected physical characteristics of the atmosphere on global and regional scales;provide the scientific community with the means to predict future atmospheric states;organize assessments in support of formulating environmental policyComprises five measurement programs: Ozone & UV, GHGs & Reactive Gases, Precipitation Chemistry, Aerosols & Solar radiation.
6What: GAW SAG Aerosol, chairman (until 2009): Dr. Urs Baltensperger (PSI, CH)(WCC) for Physical Aerosol Instrumentation: Dr. Ali Wiedensohler (IfT, DE)GAWTEC IV, VI, VIII, Schneefernhaus, Zugspitze etc.WDC Aerosols (IES JRC, IT)
7What – GAW Aerosol Program The SAG Aerosol recommends that the GAW aerosol program include:for regional stations any one, or more of the following:optical depthmass (preferably in two size fractions)major chemical components in two size fractionslight scattering coefficientfor global stations as many as possible of the following:mass in two size fractionslight scattering & hemispheric backscattering coefficients at various wavelengthlight absorption coefficientaerosol number concentrationcloud condensation nuclei number concentration at 0.5% supersaturationdiffuse, global and direct solar radiationintermittently:aerosol size distribution; detailed size fractionated chemical composition; dependence of aerosol properties on relative humidity; CCN spectra at various supersaturations; LIDAR measurements and other altitude profiles.
8What: WDCA activities Data Submission Data and Metadata Format: NARSTO data exchange standard (DES) extended CSV.NARSTO DES includes all the file metadata. Additional files provide more detailed information.Submission:Data are sent by ftp orQuality Analysis at WDCA:NARSTO quality analysis system – checks conformity with the DES and internal integrity of the data.QA summary added to each file archived, only posted to ftp site when no errors/warnings.Data RetrievalProcedure:Data available online from WDCA server and ftp. Data also supplied byCatalogue:Static & map based catalogue on WDCA serverArchive:Both NARSTO and non-NARSTO archives accessible via ftp.Data:Data in NARSTO DES format.Data usage:free scientific use, acknowledgement of data originator for substantive use.
9What: NARSTO Data Exchange Standard WDCA uses the NARSTO Data Exchange Standard both for submission and distribution of data – extended comma separated value ASCII format:data files can either be prepared in a spreadsheet, e.g. using the free excel template, or by scripts/programs, depending on data management at a particular site.The NARSTO DES is used by EPA, MSC, & IMPROVE in the N. America, WDCA & is an output option for NILU/EMEP (Co-ordinated data submission for european sites).The Data Exchange Standard has been used for exchanging aerosol physical and chemical data from aerosol chemistry to single particle analysis.It is supported by a quality assurance science centre: and each user community has its own quality assurance centre, WDCA in the case of GAW.Attempts to ensure that ALL relevant meta-data for informed use of data now & in future are available together with the data – ideal for long term archive such as WDCA
11What: NARSTO FlagsEvery data record is required to have a quality flagOnly report valid (V1) or qualified valid (V2-V7) valuesInvalid values set to missing, avoids their inadvertent use
12What: Data sets available ParameterNumber of stations submitting dataPeriod coveredTotal N station years (files)Aerosol Optical Depth16133Aerosol Chemical Composition58290CCN18CN14217Light Absorption / EBC11119Light scattering & back scattering170Size distribution319
13What: Data sets available AODChem. CompositionCNSize dist.Lscat & BscatLabs
16from external addresses. What: UsersFile downloadsfrom external addresses.4x increase from summer 2007 to winter 2008 as a result of increased data availability.
17AOD metadata portal – Chryssa Doxani What NextAOD metadata portal – Chryssa DoxaniData products, not just data sets in first instance: NARSTO QA reportsEnhance data submission – for the ‘slower’ global stations, ‘twinning’ with an active station and or SAG member to get them to submit data regularly.
19What next: AOD Metadata portal Chryssa has:Collected metadata for GAW & non-GAW AOD networks – e.g. AERONET, Skynet.Built a relational database (Access).Cold fusion interface to web pages.Database structure is generic so it can accommodate non AOD-metadata (stage –II)Interface to the WDCA web pages – search for AOD data by criteria e.g. country, WMO region, latitude & longitude etc.Search returns details of data sets & their locations.