Ground-based Observing System for Climate Change Monitoring
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Transcript of Ground-based Observing System for Climate Change Monitoring
Ground-based Observing Ground-based Observing System for Climate Change System for Climate Change
Monitoring Monitoring
Tom AckermanTom Ackerman
Lecture II.6Lecture II.6
TopicsTopics
Why do we need ground-based Why do we need ground-based observations for climate and what observations for climate and what would we do with them?would we do with them?
What is measurement synergy all What is measurement synergy all about?about?
To be addedTo be added
Results from Monday discussionResults from Monday discussion
GCOS Position on Ground-based GCOS Position on Ground-based Observations for ClimateObservations for Climate
Primary tool is satellite(s)Primary tool is satellite(s) Surface and in situ observations only Surface and in situ observations only
needed forneeded for• Calibration and validationCalibration and validation• Measurement of parameters that cannot be Measurement of parameters that cannot be
measured by satellite (“biodiversity, measured by satellite (“biodiversity, groundwater, carbon sequestration, subsurface groundwater, carbon sequestration, subsurface ocean”)ocean”)
• Long time series for diagnosis of global change Long time series for diagnosis of global change (“surface temperature, precipitation and water (“surface temperature, precipitation and water resources, weather and other natural hazards, resources, weather and other natural hazards, … pollutants”)… pollutants”)
GCOS Position – Surface networksGCOS Position – Surface networks
GCOS surface network (GSN)GCOS surface network (GSN)• Measure in situ (surface) observations of Measure in situ (surface) observations of
surface temperature, humidity, wind speed and surface temperature, humidity, wind speed and directiondirection
• Mention “surface radiation (e. g., sunshine Mention “surface radiation (e. g., sunshine duration)”duration)”
• Approximately 1000 stations world wideApproximately 1000 stations world wide• Over ocean – volunteer ships, buoys (fixed and Over ocean – volunteer ships, buoys (fixed and
floating)floating)• Baseline Surface Radiation Network (BSRN) Baseline Surface Radiation Network (BSRN)
should be enhanced (currently a volunteer should be enhanced (currently a volunteer network of 39 stationsnetwork of 39 stations
BSRN LocationsBSRN Locations
GCOS Position – Surface networksGCOS Position – Surface networks
GCOS surface network (GSN)GCOS surface network (GSN) GCOS Upper Air Network (GUAN)GCOS Upper Air Network (GUAN)
• Radiosonde T, q, wind (~150 stations)Radiosonde T, q, wind (~150 stations)• Cloud properties from surface observerCloud properties from surface observer• Commercial aviation Commercial aviation
Global Atmospheric Watch (GAW)Global Atmospheric Watch (GAW)• CO2, CH4, O3, other GHGs, aerosolCO2, CH4, O3, other GHGs, aerosol• ~33 stations, some ship measurements~33 stations, some ship measurements
So, what’s wrong with this picture?So, what’s wrong with this picture?
A Minority Report and ProposalA Minority Report and Proposal
Acknowledgements to Acknowledgements to Jim Coakley (OSU) and Chuck Long (PNNL)Jim Coakley (OSU) and Chuck Long (PNNL)
Two underlying premisesTwo underlying premises
Understanding and addressing climate Understanding and addressing climate change will be a critical societal problem for change will be a critical societal problem for the next several decadesthe next several decades• The most important issues will be The most important issues will be water availabilitywater availability
and and energy production and useenergy production and use
Climate change is a global problem and must Climate change is a global problem and must be attacked with globally integrated models be attacked with globally integrated models and observationsand observations
Some Limitations of Satellite Some Limitations of Satellite ObservationsObservations
Surface fluxes of energy and Surface fluxes of energy and moisturemoisture
Properties of low-level clouds in Properties of low-level clouds in multi-layered systemsmulti-layered systems
Aerosols below and mixed with cloud Aerosols below and mixed with cloud layerslayers
Absorption of solar energy by Absorption of solar energy by aerosolsaerosols
More?More?
Role of ground-based observationsRole of ground-based observations
Continuous observations of cloud, aerosol and Continuous observations of cloud, aerosol and radiative properties at high temporal resolution radiative properties at high temporal resolution that facilitate the understanding of cloud and that facilitate the understanding of cloud and aerosol processes (aerosol processes (Improvement of atmospheric Improvement of atmospheric physicsphysics))
Alternative climatologies of radiation, cloud, and Alternative climatologies of radiation, cloud, and aerosol quantities crucial to climate change aerosol quantities crucial to climate change science (science (Model and satellite comparisonModel and satellite comparison))
Critical datasets to test the surface and cloud Critical datasets to test the surface and cloud properties retrieved from satellite observations properties retrieved from satellite observations ((EvaluationEvaluation))
A means for evaluating the performance of A means for evaluating the performance of satellite instruments over the lifetime of the satellite instruments over the lifetime of the satellite (satellite (CalibrationCalibration))
Level 1 stationsLevel 1 stations
Basic surface observation site – BSRN typeBasic surface observation site – BSRN type Measurements ofMeasurements of
• Surface energy fluxesSurface energy fluxes• Surface state variablesSurface state variables• Column aerosol propertiesColumn aerosol properties
Co-located with sonde sitesCo-located with sonde sites Order of 1000 to 2000 sites globallyOrder of 1000 to 2000 sites globally Site capital cost $75KSite capital cost $75K Site operational costs: $16K/yearSite operational costs: $16K/year
Level 2 SitesLevel 2 Sites
Includes Level 1 site instrumentsIncludes Level 1 site instruments Incorporates highly reliable remote Incorporates highly reliable remote
sensing instruments to measuresensing instruments to measure• Column water vaporColumn water vapor• Cloud base heightCloud base height• Aerosol backscatter profileAerosol backscatter profile• Cloud fraction and occurrenceCloud fraction and occurrence
Order of 100 to 200 sites globallyOrder of 100 to 200 sites globally Additional capital cost: $200KAdditional capital cost: $200K Additional site operational cost: $4KAdditional site operational cost: $4K
Level 3 SitesLevel 3 Sites Includes Level 2 site instrumentsIncludes Level 2 site instruments Like US ARM and European sitesLike US ARM and European sites High end remote sensing sites to measureHigh end remote sensing sites to measure
• Surface propertiesSurface properties• Vertical profiles of aerosol and cloud properties and Vertical profiles of aerosol and cloud properties and
thermodynamic variablesthermodynamic variables• Spectrally-resolved radiances and fluxesSpectrally-resolved radiances and fluxes
Focus on high spatial and temporal resolutionFocus on high spatial and temporal resolution Order of 10 to 20 sites globallyOrder of 10 to 20 sites globally Additional capital cost: $1.5MAdditional capital cost: $1.5M Additional site operational cost: UndeterminedAdditional site operational cost: Undetermined
CAP sitesProcess
Best obs possible
Augmented SitesClimatology
Measured cloud propertiesEnhanced meteorology
Basic surface radiation and meteorology sitesMonitoring
Sfc energy budget, aerosol OD, statistical cloud properties
IncreasingInstrument Complexity
Data volumeCost
Operator training
StrategyStrategy Integrate concept into climate observing system Integrate concept into climate observing system
plans such as GCOSplans such as GCOS Build on existing networksBuild on existing networks
• Sustained support for current sitesSustained support for current sites• Funding to expand observations to under-represented Funding to expand observations to under-represented
areas (oceans, southern hemisphere) => areas (oceans, southern hemisphere) => need much need much better geographical representationbetter geographical representation
Enable scienceEnable science• Shared and accessible data => archive!Shared and accessible data => archive!• Algorithm development and operational applicationAlgorithm development and operational application
From observations to science … From observations to science …
Three level plan implies a progression of Three level plan implies a progression of understanding and interpretationunderstanding and interpretation• More sophisticated measurements clarify what More sophisticated measurements clarify what
we can learn from less sophisticated we can learn from less sophisticated measurementsmeasurements
• Multiple measurements provide additional data Multiple measurements provide additional data that allow us to do more detailed comparisons that allow us to do more detailed comparisons with modelswith models
Top level sites are the key to making the Top level sites are the key to making the entire scheme work! entire scheme work!
The Atmospheric Radiation The Atmospheric Radiation Measurement ProgramMeasurement Program
Sites are prototypes of the Level 3 Sites are prototypes of the Level 3 sitessites
What have we learned from ARM? What have we learned from ARM?
Note: Sites in Europe (e. g., Cabauw, Lindenberg, Palaiseau, Chilbolton) are as well instrumented and scientifically useful as the ARM sites. ARM is a more operational program, so it offers the best model for us to consider here.
Atmospheric Radiation Measurement Atmospheric Radiation Measurement ProgramProgram
GoalGoal
Improve the treatment of cloud and radiation Improve the treatment of cloud and radiation physics in global climate models in order to physics in global climate models in order to improve the climate simulation capabilities of improve the climate simulation capabilities of these modelsthese models
Two fundamental science questionsTwo fundamental science questions
If we can specify the If we can specify the properties of a cloud field, properties of a cloud field, can we compute the can we compute the radiative fluxes?radiative fluxes?
Requires knowledge of cloud Requires knowledge of cloud properties (3D structure, water properties (3D structure, water path, phase, size, etc.)path, phase, size, etc.)
Two fundamental science questionsTwo fundamental science questions
If we can specify the large-If we can specify the large-scale atmospheric fields, scale atmospheric fields, can we predict the cloud can we predict the cloud field properties?field properties?
Requires 3D field of state Requires 3D field of state properties properties andand cloud field cloud field propertiesproperties
ARM Program ComponentsARM Program Components
Development of ground-based remote sensing Development of ground-based remote sensing facilitiesfacilities
Continuous data acquisition and archivalContinuous data acquisition and archival
Data analysisData analysis Physical modelingPhysical modeling Parameterization development and testingParameterization development and testing
Infrastructure
Science
ARM HistoryARM History Program initiated in 1990Program initiated in 1990
• initial science grantsinitial science grants
• Site planning and instrument selection Site planning and instrument selection
USA facility (SGP) data available since 1994USA facility (SGP) data available since 1994
Full instrumentation in 1996Full instrumentation in 1996 Tropical western Pacific site Tropical western Pacific site
• Manus 1996Manus 1996
• Nauru 1998Nauru 1998
• Darwin 2003Darwin 2003
North Slope of Alaska (Pt. Barrow) since 1998North Slope of Alaska (Pt. Barrow) since 1998 ARM Mobile Facility first deployment in 2005ARM Mobile Facility first deployment in 2005
Central Facility
Southern Great Plains Southern Great Plains
Southern Great Plains Central FacilitySouthern Great Plains Central Facility
North Slope of AlaskaNorth Slope of Alaska
North Slope of Alaska – Barrow facilityNorth Slope of Alaska – Barrow facility
Tropical Western PacificTropical Western Pacific
Darwin
Tropical Tropical Western Western
Pacific SitesPacific Sites
Nauru
Darwin
Manus, PNG
The ARM Mobile Facility at Pt. The ARM Mobile Facility at Pt. ReyesReyes
What have we learned in ARM about What have we learned in ARM about ……
Operating ground-based sitesOperating ground-based sites
Continuous measurementsContinuous measurements• Can be done but difficult in remote locationsCan be done but difficult in remote locations• Measurement synergy is key to science successMeasurement synergy is key to science success
Instrument improvement and developmentInstrument improvement and development• Interaction with science community is criticalInteraction with science community is critical
ExpensiveExpensive• But not when compared with science returnBut not when compared with science return
Data acquisition and archivingData acquisition and archiving
Science success depends on a good archiveScience success depends on a good archive Good => reliable, easy to use, responsiveGood => reliable, easy to use, responsive Best metric is Best metric is useruser satisfaction satisfaction Second best metric is data Second best metric is data outflowoutflow
Data analysis Data analysis
Data must be calibrated and quality-controlledData must be calibrated and quality-controlled Continuous dataContinuous data
• Multiple instrumentsMultiple instruments• Multiple sitesMultiple sites• Multiple seasons and yearsMultiple seasons and years
Scientists will find more things to do with the Scientists will find more things to do with the data than you ever imagineddata than you ever imagined
High-resolution atmospheric modelingHigh-resolution atmospheric modeling
Most profitable area of scientific investigationMost profitable area of scientific investigation• GEWEX Cloud System Studies (GCSS) linkGEWEX Cloud System Studies (GCSS) link• Weather forecasting centers (ECMWF, NCEP, etc.)Weather forecasting centers (ECMWF, NCEP, etc.)
Data used for Data used for • Model initializationModel initialization• Model evaluationModel evaluation• Model developmentModel development
Classification studiesClassification studies
Evaluating and improving climate Evaluating and improving climate modelsmodels
Most difficult problemMost difficult problem• Requires a lot of dataRequires a lot of data• Dependent on clever data analysis and understandingDependent on clever data analysis and understanding• Critical issues of spatial and temporal samplingCritical issues of spatial and temporal sampling
We are making significant progress!We are making significant progress!• Model evaluationModel evaluation• Cloud and convection parameterizationsCloud and convection parameterizations
(more about this later!)(more about this later!)
Retrievals, Synergy and RedundancyRetrievals, Synergy and Redundancy In the beginning, there was one measurement In the beginning, there was one measurement
and one retrieved propertyand one retrieved property Lidar backscatter => Cirrus optical depthLidar backscatter => Cirrus optical depth
Required closure assumptions!
Retrievals, Synergy and RedundancyRetrievals, Synergy and Redundancy
Then we added a Then we added a measurement of measurement of Window Window Radiance Radiance
Lidar + I(10 mic) Lidar + I(10 mic) => => and IWP and IWP
Synergy!
Retrievals, Synergy and RedundancyRetrievals, Synergy and Redundancy
Then we added Then we added an an InterferometerInterferometer
Lidar + I(Lidar + I() => ) => , IWP, Deff, IWP, Deff
Synergy!
Redundancy!
Retrievals, Synergy and RedundancyRetrievals, Synergy and Redundancy
Then we added a Then we added a mm radarmm radar
Radar + Lidar + I(Radar + Lidar + I() ) => multiple values => multiple values of of , IWP, Deff , IWP, Deff
Synergy!
Redundancy!
Choice!
Retrievals, Synergy and RedundancyRetrievals, Synergy and Redundancy
Multiple measurements allow us to Multiple measurements allow us to retrieve more pieces of informationretrieve more pieces of information
Observational redundancy allows us to Observational redundancy allows us to address issues of instrument noise address issues of instrument noise
Multiple measurements allow us to Multiple measurements allow us to perform complex retrievals that optimize perform complex retrievals that optimize information based on instrument information based on instrument operational characteristicsoperational characteristics
A priori information based on our A priori information based on our knowledge of atmospheric phenomena can knowledge of atmospheric phenomena can also be folded into the retrieval processalso be folded into the retrieval process