Polar Ozone: Stratosphere-Troposphere Coupling and recent Changes
NOAA Climate Forecast System Reanalysis (CFSR) model-level ...€¦ · • Analysis of the Upper...
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NOAA Climate Forecast System Reanalysis (CFSR) model-level data Amy H. Butler 1,2 , Sean M. Davis 1,2 , Henry L. Miller 1,2 , Jeremiah Sjoberg 8 , Craig S. Long 3 , Gloria L. Manney 4,5 , Zachary D. Lawrence 5 , Brian W. Knosp 6 , Susann Tegtmeier 7 , Ioana Ivanciu 7 , and Karen H. Rosenlof 2 (1) CIRES, Boulder, CO (2) NOAA/ESRL/CSD, Boulder, CO (3) NOAA Climate PredicYon Center, College Park, MD (4) NorthWest Research Associates, Socorro, NM (5) New Mexico InsYtute of Mining and Technology, Socorro, NM (6) Jet Propulsion Laboratory, California InsYtute of Technology, Pasadena, CA (7) GEOMAR Helmholtz for Ocean Research, Kiel, Germany (8) UCAR/COSMIC, Boulder, CO Introduc<on • Analysis of the Upper Troposphere- Lower Stratosphere (UTLS) requires sufficient verYcal resoluYon in the region of the tropopause, but most reanalysis products are interpolated onto a limited number of pressure-levels. • Model-level output has much higher verYcal resoluYon and is available for most reanalyses, and has been useful for the SPARC Reanalysis Intercomparison Project (S-RIP; Fujiwara et al. 2017). • NOAA CFSR (Saha et al. 2010) model-level output was previously only provided in an undocumented binary file format using spectral coefficients, with different formats between CSFRv1 (1/1979-3/2011) and v2 (4/2011-12/2014). We have created a 6-hourly global CFSRv1/v2 reanalysis model level data set in CF-compliant netcdf format, provided on a regular laYtude-longitude grid (0.5° x 0.5°) instead of its naYve horizontal resoluYon of T382, from 1979-2014. • 64 model levels compared to 37 pressure levels. Methodology and Data Accessibility • Binary CFSR model-level data are available at NCEI/NOMADS: hips://nomads.ncdc.noaa.gov/data/ • We downloaded a subset of the data (Table 1). CFSRv2 (2011-2014) only includes category (1) and (2) data. • We regridded the data to a regular 0.5° x 0.5° lat/lon grid. • We converted the data to CF-compliant netcdf files with clear metadata. • We can share the data from our servers where the data is currently hosted at NOAA ESRL. Full dataset size is ~ 1TB/yr from 1979-2014. Contact [email protected] . Pressure levels Model levels (p0=1013 hPa) Table 1. The 3 categories of model-level data available in netcdf format. Names in black show currently available data. Advantages of CFSR Model-Level data for UTLS studies Improved detec<on of tropopause height/cold-point temperature Figure 1. For the date 2000-01-01-00Z, (leS) Difference in minimum ver<cal profile temperature between model- level and pressure-level CFSR at every grid point; (right) Ver<cal temperature profile over the 45-90W, 30S-Eq region (shown by black box on leS) for model-level and pressure-level CFSR. Conclusions Figure 3. CFSR frequency maps for SON 1980-2014, for (leS) model-level data and (right) model-level minus pressure-level. Top row shows the mapped frequency of mul<ple tropopauses; bo‘om row shows the la<tude- pressure frequency of single thermal tropopauses. Note, model and pressure-level data have the same horizontal resolu<on. Bold contours highlight model-level values on leS, pressure-level values on right. This figure is from: Manney, G.L. et al., Reanalysis comparisons of upper tropospheric/lower stratospheric jets and mul@ple tropopauses, ACPD, doi:10.5194/acp-2017-400, 2017. • Model-level data show many more mulYple tropopauses compared to pressure-level data, and also many fewer single tropopauses. • The single tropical tropopause shows a low alYtude bias in the pressure-level data. • AddiYonal biases in upper tropospheric and subvortex jets from using pressure-level data (not shown). Improved characteriza<on of single versus mul<ple tropopauses 1981-1997 2002-2010 Figure 2. (top) Reanalysis comparison of Cold Point Temperature, and (bo‘om) difference between reanalysis and observa<ons for (leS) 1981-1997 and (right) 2002-2010. RS = radiosondes; pressure- level CFSR is shown by the green dashed line. All other reanalyses are based on model-level data. • Model-level data are now available in a documented netcdf format for the NOAA Climate Forecast System Reanalysis product. • Biases in CPT/tropopause height substanYally reduced in model-level data compared to pressure-level data. • Modern reanalysis model-level products show a colder, higher tropical tropopause that more closely captures observed values compared to the pressure-level product. • Model-level data detect more frequent mulYple tropopauses. • This dataset will be useful for number of addiYonal analyses, including gravity wave characterizaYon (personal comm, James Anstey) and improved tropopause dynamics. (1) Analysis and (2) 6-hour forecast (3) 6-hour Ancillary Specific Humidity (hus), pressure on model levels (pfull), surface pressure (ps), RelaYve divergence of wind (reld), RelaYve vorYcity (relv), Air temperature (ta), Ozone mixing raYo (tro3), Eastward wind (ua), Northward wind (va), GeopotenYal height (zg), relaYve humidity (rh), stream funcYon (strm), velocity potenYal (vpot), cloud mixing raYo (clwmr) ConvecYve gravity wave drag zonal acceleraYon (cngwdu), ConvecYve zonal momentum mixing acceleraYon (tnmmuc), Gravity wave drag zonal acceleraYon (tnmmugwd), Longwave heaYng rate (tntlw), Shortwave heaYng rate (tntsw), VerYcal diffusion zonal acceleraYon (vdfua), verYcal diffusion heaYng (vdmr), deep convecYve heaYng (cnvhr), shallow convecYve heaYng (shahr), large scale condensaYon heaYng (lrghr), verYcal diffusion moistening (vdfmr), deep convecYve moistening (cnvmr), shallow convecYve moistening (shamr), large scale moistening rate (lrgmr), ozone verYcal diffusion (vdfoz), ozone producYon (poz), ozone tendency (toz), ozone producYon from T term (pozt), ozone producYon from column ozone term (pozo), verYcal diffusion meridional acceleraYon (gwdv), convecYve meridional momentum mixing acceleraYon (cnvv), convecYve gravity wave drag meridional acceleraYon (cngwdv), non-convecYve cloud (cdlyr) We acknowledge the NOAA Research and Development High Performance Compu?ng and Communica?ons Program for providing compu?ng resources via funding from a NOAA FY16 Informa?on Technology Incubator Proposal.
Transcript of NOAA Climate Forecast System Reanalysis (CFSR) model-level ...€¦ · • Analysis of the Upper...
NOAAClimateForecastSystemReanalysis(CFSR)model-leveldataAmyH.Butler1,2,SeanM.Davis1,2,HenryL.Miller1,2,JeremiahSjoberg8,CraigS.Long3,GloriaL.Manney4,5,ZacharyD.Lawrence5,BrianW.Knosp6,SusannTegtmeier7,IoanaIvanciu7,andKarenH.Rosenlof2
(1) CIRES,Boulder,CO(2)NOAA/ESRL/CSD,Boulder,CO(3)NOAAClimatePredicYonCenter,CollegePark,MD(4)NorthWestResearchAssociates,Socorro,NM(5)NewMexicoInsYtuteofMiningandTechnology,Socorro,NM(6)JetPropulsionLaboratory,CaliforniaInsYtuteofTechnology,Pasadena,CA(7)GEOMARHelmholtzforOceanResearch,Kiel,Germany(8)UCAR/COSMIC,Boulder,CO
Introduc<on• AnalysisoftheUpperTroposphere-LowerStratosphere(UTLS)
requiressufficientverYcalresoluYonintheregionofthetropopause,butmostreanalysisproductsareinterpolatedontoalimitednumberofpressure-levels.
• Model-leveloutputhasmuchhigherverYcalresoluYonandis
availableformostreanalyses,andhasbeenusefulfortheSPARCReanalysisIntercomparisonProject(S-RIP;Fujiwaraetal.2017).
• NOAACFSR(Sahaetal.2010)model-leveloutputwaspreviouslyonly
providedinanundocumentedbinaryfileformatusingspectralcoefficients,withdifferentformatsbetweenCSFRv1(1/1979-3/2011)andv2(4/2011-12/2014).Wehavecreateda6-hourlyglobalCFSRv1/v2reanalysismodelleveldatasetinCF-compliantnetcdfformat,providedonaregularlaYtude-longitudegrid(0.5°x0.5°)insteadofitsnaYvehorizontalresoluYonofT382,from1979-2014.
• 64modellevelscomparedto37pressurelevels.
MethodologyandDataAccessibility• BinaryCFSRmodel-leveldataareavailableatNCEI/NOMADS:hips://nomads.ncdc.noaa.gov/data/• Wedownloadedasubsetofthedata(Table1).CFSRv2(2011-2014)onlyincludescategory(1)and(2)data.• Weregriddedthedatatoaregular0.5°x0.5°lat/longrid.• WeconvertedthedatatoCF-compliantnetcdffileswithclearmetadata.• WecansharethedatafromourserverswherethedataiscurrentlyhostedatNOAAESRL.Fulldatasetsizeis~1TB/yrfrom
Pressurelevels
Modellevels(p0=1013hPa) Table1.The3categoriesofmodel-leveldataavailableinnetcdfformat.Namesinblackshowcurrentlyavailabledata.
AdvantagesofCFSRModel-LeveldataforUTLSstudiesImproveddetec<onoftropopauseheight/cold-pointtemperature
Figure1.Forthedate2000-01-01-00Z,(leS)Differenceinminimumver<calprofiletemperaturebetweenmodel-level andpressure-level CFSR at every grid point; (right)Ver<cal temperatureprofileover the 45-90W, 30S-Eqregion(shownbyblackboxonleS)formodel-levelandpressure-levelCFSR.
Conclusions
Figure 3. CFSR frequencymaps for SON 1980-2014, for (leS)model-leveldata and (right) model-level minus pressure-level. Top row shows themappedfrequencyofmul<pletropopauses;bo`omrowshowsthela<tude-pressure frequency of single thermal tropopauses. Note, model andpressure-level data have the same horizontal resolu<on. Bold contourshighlightmodel-levelvaluesonleS,pressure-levelvaluesonright.
Thisfigureisfrom:Manney,G.L.etal.,Reanalysiscomparisonsof upper tropospheric/lower stratospheric jets and mul@pletropopauses,ACPD,doi:10.5194/acp-2017-400,2017.
• Model-leveldatashowmanymoremulYpletropopausescomparedtopressure-leveldata,andalsomanyfewersingletropopauses.
• ThesingletropicaltropopauseshowsalowalYtudebiasinthepressure-leveldata.
• AddiYonalbiasesinuppertroposphericandsubvortexjetsfromusingpressure-leveldata(notshown).
Improvedcharacteriza<onofsingleversusmul<pletropopauses
1981-1997 2002-2010
F i g u r e 2 . ( t o p )Reanalysis comparisono f C o l d P o i n tTempera tu re , and(bo`om) differencebetween reanalysisand observa<ons for(leS) 1981-1997 and(right) 2002-2010. RS =radiosondes; pressure-level CFSR is shownbythe green dashed line.Allotherreanalysesarebased on model-leveldata.
• Model-leveldataarenowavailableinadocumentednetcdfformatfortheNOAAClimateForecastSystemReanalysisproduct.
• BiasesinCPT/tropopauseheightsubstanYallyreducedinmodel-leveldatacomparedtopressure-leveldata.
• Modernreanalysismodel-levelproductsshowacolder,highertropicaltropopausethatmorecloselycapturesobservedvaluescomparedtothepressure-levelproduct.
• Model-leveldatadetectmorefrequentmulYpletropopauses.• ThisdatasetwillbeusefulfornumberofaddiYonalanalyses,includinggravitywavecharacterizaYon(personalcomm,JamesAnstey)andimprovedtropopausedynamics.
(1)Analysisand(2)6-hourforecast (3)6-hourAncillarySpecificHumidity(hus),pressureonmodellevels(pfull),surfacepressure(ps),RelaYvedivergenceofwind(reld),RelaYvevorYcity(relv),Airtemperature(ta),Ozone
mixingraYo(tro3),Eastwardwind(ua),Northwardwind(va),GeopotenYalheight(zg),relaYvehumidity(rh),streamfuncYon(strm),velocitypotenYal(vpot),cloud
mixingraYo(clwmr)
ConvecYvegravitywavedragzonalacceleraYon(cngwdu),ConvecYvezonalmomentummixingacceleraYon(tnmmuc),GravitywavedragzonalacceleraYon(tnmmugwd),
LongwaveheaYngrate(tntlw),ShortwaveheaYngrate(tntsw),VerYcaldiffusionzonalacceleraYon(vdfua),verYcaldiffusionheaYng(vdmr),deepconvecYveheaYng(cnvhr),shallowconvecYveheaYng(shahr),largescalecondensaYonheaYng(lrghr),verYcaldiffusionmoistening(vdfmr),deepconvecYvemoistening(cnvmr),shallowconvecYvemoistening(shamr),largescalemoisteningrate(lrgmr),ozoneverYcaldiffusion(vdfoz),ozoneproducYon(poz),ozonetendency(toz),ozoneproducYonfromTterm(pozt),ozoneproducYonfromcolumnozoneterm(pozo),verYcaldiffusionmeridional
acceleraYon(gwdv),convecYvemeridionalmomentummixingacceleraYon(cnvv),convecYvegravitywavedragmeridionalacceleraYon(cngwdv),non-convecYvecloud
(cdlyr)
WeacknowledgetheNOAAResearchandDevelopmentHighPerformanceCompu?ngandCommunica?onsProgramforprovidingcompu?ngresourcesviafundingfromaNOAAFY16Informa?onTechnologyIncubatorProposal.
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