DOC PREVIEW
UI ECE 591 - Measuring Atmospheric Changes in the Arctic

This preview shows page 1-2-15-16-31-32 out of 32 pages.

Save
View full document
View full document
Premium Document
Do you want full access? Go Premium and unlock all 32 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 32 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 32 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 32 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 32 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 32 pages.
Access to all documents
Download any document
Ad free experience
Premium Document
Do you want full access? Go Premium and unlock all 32 pages.
Access to all documents
Download any document
Ad free experience

Unformatted text preview:

Christopher J Cox University of Idaho, GeographyAcknowledgmentsOutlineWhat is Climate Change? Scientific ConsensusWhat is Climate Change? The Greenhouse EffectSlide 6Slide 7Slide 8PowerPoint PresentationThe Arctic Climate SystemSigns of Arctic Climate ChangeSlide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18PAERISlide 20Slide 21Slide 22Slide 23Slide 24Slide 25Slide 26Slide 27Slide 28Slide 29Slide 30Slide 31Slide 32Measuring Atmospheric Changes in the ArcticChristopher J CoxUniversity of Idaho, GeographyAcknowledgments• Von Walden (UI), Penny Rowe (UI), Matt Shupe (UC, Boulder• Mike Town (UW), Ed Eloranta (U Wisconsin)• Funding by National Science Foundation (NSF)• NOAA SEARCH, CANDAC, ARM, SSEC, IGRA, NSIDCOutline• What is climate change?• The Arctic Climate System• Instrumentation• Preliminary research• ConclusionWhat is Climate Change?Scientific Consensus“Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice and rising global average sea level” (WGI 3.9, SPM)•Intergovernmental Panel on Climate Change (IPCC)Climate change no longer a scientific debate, but a societal issueWhat is Climate Change?The Greenhouse EffectWhat is Climate Change?The Greenhouse EffectGlobal atmospheric concentrations of carbon dioxide, methane, and nitrous oxide (all greenhouse gases) have increased markedly as a result of human activities since 1750.IPCC WG1.2 Figure 1What is Climate Change?The Greenhouse EffectB1 “Green” Scenario (550 ppm)A1B “Medium” Scenario (700 ppm)}Natural VariabilityPotentialHuman Contribution A1Fl “Aggressive” Scenario (850 ppm)What is Climate Change?The Greenhouse EffectSo what about Arctic?Primarily as a result of a strong ice-albedo postive feedback, the Polar Regions are very sensitive to a warming climate.But, they are also poorly quantified!Previous ResearchArctic atmosphereSurface Heat Budget of the Arctic (SHEBA)Intrieri et al (2002) An annual cycle of Arctic surface cloud forcing at SHEBAShupe et al (2005) Arctic mixed-phase cloud properties from surface-based sensors at SHEBAOtherKey et al (2004) “Cloud distributions over the coastal Arctic Ocean: surface-based and satellite observations”Shupe & Intrieri (2003) “Cloud Radiative Forcing of the Arctic Surface: The Influence of Cloud Properties, Surface Albedo, and Solar Zenith AngleTjernstrom et al (2004) “The Summertime Arctic Atmosphere: meteorological measurements during the Arctic Ocean Experiment 2001”Verlinde et al (2004) “Mixed-Phase Arctic Cloud Experiment (M-PACE)”Recent Sea Ice MeltDrobot et al (2008) “Evolution of the 2007-2008 Arctic sea ice cover and prospects for a new record in 2008”Kay et al (2008) “The contribution of cloud and radiation anomalies to the 2007 Arctic sea ice extent minimum”Perovich et al (2008) “Sunlight, water,and ice: Extreme Arctic sea ice melt during the summer of 2007”Schweiger et al (2008) “Did unusually sunny skies helpdrive the record sea ice minimum of 2007?”Zhang et al (2008) “What drove the dramatic retreat of arctic sea ice during summer 2007?”The Arctic Climate System•Cloud properties– not well known– climate models•Downwelling Infrared–Atmospheric properties–Temperature, Humidity•Upwelling Infrared–Surface prop (, Ts)–Satellite validationSigns of Arctic Climate ChangeNational Snow and Ice Data Center (NSIDC)Polar Atmospheric Emitted Radiance Interferometer Arctic High Spectral Resolution Lidar (AHSRL)Ed Eloranta (SSEC. U. Wisconsin-Madison)Millimeter Cloud Radar (MMCR)NOAA ERL, Boulder, COMicrowave Radiometer (MWR) - total column water vaporNOAA ERL, Boulder, CORadiosondes from the Eureka Weather Officehttp://lidar.ssec.wisc.edu/Instruments now in the ArcticArctic High Spectral Resolution Lidar (AHSRL) LIDAR – Light Detection and Ranging 40 ns pulse widthWavelength: 523 nm http://lidar.ssec.wisc.edu/Instrument SpecsAHSRLhttp://arm.gov/ http://lidar.ssec.wisc.edu/Instrument SpecsMMCRMillimeter Cloud RadarZenith pointing radarOperates at 35 GhzUsed to determine cloud boundarieswww.arm.govhttp://arm.gov/ http://lidar.ssec.wisc.edu/Instrument SpecsMWRMicrowave RadiometerMeasure microwave emission from water (liquid/vapor)Reports column integrated amountswww.arm.govhttp://lidar.ssec.wisc.edu/Instrument SpecsPAERIPolar Atmos. Emitted Radiance InterferometerSpectral infrared radiance from 3 to 20 m (1 cm-1)Two detectors: MCT - LW and InSb - SWVery accurate [1% (3) of ambient radiance]PAERIPAERICO2H2OCH4,N2OO3CloudPAERIWhat can we use PAERI output for?• Cloud fraction• Trace gas measurements• Scale radiosondes• Validate satellites• Longwave cloud radiative forcing• more…Instrument SitesEureka, Nunavut, Canada: Study of Environmental Arctic Change (SEARCH) Arctic Observing Network (AON) at Canadian Network for the Detection of Arctic Change (CANDAC) site79º59’N, 85º57’WBarrow, Alaska: Atmospheric Radiation Measurement (ARM) North Slope Alaska (NSA) site71º18’N, 156º44’WLongwave Downwelling Radiation and Arctic Sea Ice Melt• Preliminary experimental evidence for the importance of downwelling longwave radiation to the recent decrease in sea ice concentration over the Arctic Ocean.• Was shortwave downwelling radiation (SDW) the cause?Kay et al (2008) “The contribution of cloud and radiation anomalies to the 2007 Arctic sea ice extent minimum”Perovich et al (2008) “Sunlight, water,and ice: Extreme Arctic sea ice melt during the summer of 2007”• Was it longwave downwelling radiation (LDW)?Schweiger et al (2008) “Did unusually sunny skies helpdrive the record sea ice minimum of 2007?”Schweiger et al (2008)Surface TemperatureTropospheric TemperatureFractional Cloud CoverPrecipitable Water VaporCalculating DLW Flux and LWCRFAERI measurements made at zenithOut of band radiance was simulated as a black body using brightness T from 650-660 cm-1Assume isotropic radiance (fluxes within ~5%) Focusing on Eureka data onlyLW CRF = All – Clear (Ramanathan et al, 1989)FIR=π I (λ)d(λ)λ1λ2∫Differences in DLW and CRF• LWCRF depends on many variables• FCC• Optical thickness of clouds• AND Temperature of the near-surface air (in winter)Cloud ForcingInter-annual Variations at EurekaEureka Summer Average (JJA)Year LW-CRF (W m-2) All Sky Flux (Wm-2) FCC (%)2006 42 275


View Full Document

UI ECE 591 - Measuring Atmospheric Changes in the Arctic

Documents in this Course
SunSpiral

SunSpiral

34 pages

Contol

Contol

11 pages

Load more
Download Measuring Atmospheric Changes in the Arctic
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view Measuring Atmospheric Changes in the Arctic and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Measuring Atmospheric Changes in the Arctic 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?