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Studies of columnar observations and model outputs

Studies of columnar observations and model outputs. Brian Mapes University of Miami with thanks to many data producers and sharers. Looking under the hood of monthly mean data “points”. Time sections: f(submonthly time x pressure) a vast, rich domain

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Studies of columnar observations and model outputs

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  1. Studies of columnar observations and model outputs Brian Mapes University of Miami with thanks to many data producers and sharers

  2. Looking under the hood of monthly mean data “points” • Time sections: f(submonthly time x pressure) • a vast, rich domain • complementary to typical climate model examination space (lat x lon x months) • Natural domain for observations • Sensible domain for physical processes

  3. Shortcomings • Free-running climate model time axis not directly comparable to observations • statistical comparisons of course • Models have climate-regime offsets in space, biasing comparisons at a fixed geo-location • non-meanstatistics that is • Submonthly variations (dynamics-driven) a poor proxy for climate sensitivity (thermo-driven) • tough luck, we do what we can • Eulerian viewpoint a perverse view of weather • you’re free to leave

  4. standard raw plots Common data format, variables, names, units, flux sign conventions, etc. standard stat plots inescapable programming tedium inescapable programming tedium • COARE obs • KWAJEX obs • LBA obs • EPIC, JASMINE • KWAJEX CRM • NCAR CAM • GFDL AM2 • NASA GMAO • (super-CAM soon?) • cross-forced SCMs • SCAM2 driven by CAM • SCAM driven by AM2

  5. All obs are from warm-wet tropics so far - what I have & know best Datasets • COARE obs • KWAJEX obs • LBA obs • EPIC, JASMINE • (more: ARM? etc?) • KWAJEX 3D CRM • NCAR CAM • GFDL AM2 • NASA GMAO • (more: CAM-SP?) • cross-forced SCMs • SCAM2 driven by CAM • SCAM driven by AM2 Cloud obs rare: satellite TOA rad in ~GCM-grid areas, but cloud profiles at only a few points (cloud radar) the most GCM-comparable cloud dataset Driving the whole exercise -- an AMIP, at the very least weird experiments, not done real carefully so far. Future?

  6. What variables? CLIMATE IMPACT SCALAR TOA radiation and cloud forcing cloud fraction and condensed water content (p) humidity (p) vertical motion (p) physical tendencies heating and drying (p) rain • COARE obs • KWAJEX obs • LBA obs • EPIC, JASMINE • KWAJEX CRM • NCAR CAM • GFDL AM2 • NASA GMAO • (super-CAM soon?) • cross-forced SCMs • SCAM2 driven by CAM • SCAM driven by AM2 structure within tropo-sphere SCALAR LINK TO HYD CYC

  7. IFA OBS CRF: LW+, SW-, net ~0 [obs needclear-sky assumptions] What plots? • COARE IFA obs • KWAJEX obs • LBA obs • EPIC, JASMINE • KWAJEX CRM • NCAR CAM • GFDL AM2 • NASA GMAO • (super-CAM soon?) • cross-forced SCMs • SCAM2 driven by CAM • SCAM driven by AM2 note: net <0 at rainiest times 100 RH cld frac [ crude f(RH) here ] % 0 rain Q1, CWC (no obs) wind divergence and vertical grid

  8. Lag regressions I: scalars vs. reference variable (here, ref = qbudget-derived IFA rain) What stats? TOA rad up: • COARE IFA obs • KWAJEX obs • LBA obs • EPIC, JASMINE • KWAJEX CRM • NCAR CAM • GFDL AM2 • NASA GMAO • (super-CAM soon?) • cross-forced SCMs • SCAM2 driven by CAM • SCAM driven by AM2 reflected SW net reduced OLR Other rain vars: (here, other obs. estimates models, other rain types)

  9. ~6am diurnal rain peak regressions vs. IFA rainfall What stats? ocean shading* ~ -20% of latent heat in rain • COARE IFA obs • KWAJEX obs • LBA obs • EPIC, JASMINE • KWAJEX CRM • NCAR CAM • GFDL AM2 • NASA GMAO • (super-CAM soon?) • cross-forced SCMs • SCAM2 driven by CAM • SCAM driven by AM2 net longwave atm heating ~ 15% of latent heating * straight regression incl. nocturnal zeroes - not really right approach ~1 mm/h x 1d ~24 mm rain

  10. II. lag-height regressions of profile fields vs. surface rain What stats? • COARE obs • KWAJEX obs • LBA obs • EPIC, JASMINE • KWAJEX CRM • NCAR CAM • GFDL AM2 • NASA GMAO • (super-CAM soon?) • cross-forced SCMs • SCAM2 driven by CAM • SCAM driven by AM2 44 km radius “MCS-resolving” ~1/2 day timescale at a point

  11. regressions vs. surface rainfall SYNOPTICSCALE (IFA) What stats? • COARE IFA obs • KWAJEX obs • LBA obs • EPIC, JASMINE • KWAJEX CRM • NCAR CAM • GFDL AM2 • NASA GMAO • (super-CAM soon?) • cross-forced SCMs • SCAM2 driven by CAM • SCAM driven by AM2 multiscale (incl. several-day timescales) but no cloud profile observations

  12. TOA: obs TOA: obs-forced CRM condensate can’t blow away What should areal cloud statistics look like? KWAJEX 3D CRMthanks Marat 4-8 units, vertical up to 16, vertical

  13. regressions vs. surface rainfall - AM2 What stats? july - 10 mm/d TOA about balanced, long time scales • COARE IFA obs • KWAJEX obs • LBA obs • EPIC, JASMINE • KWAJEX CRM • NCAR CAM - IFA • GFDL AM2 - IFA • NASA GMAO • (super-CAM soon?) • cross-forced SCMs • SCAM2 driven by CAM • SCAM driven by AM2 layers upward development time jitters sometimes zigzag layers

  14. AM2 - a different month What stats? nov - 11 mm/d TOA closely balanced, long time scale • COARE IFA obs • KWAJEX obs • LBA obs • EPIC, JASMINE • KWAJEX CRM • NCAR CAM - IFA • GFDL AM2 - IFA • NASA GMAO • (super-CAM soon?) • cross-forced SCMs • SCAM2 driven by CAM • SCAM driven by AM2 slow upward development zigzag layers

  15. regressions vs. surface rainfall - CAM What stats? jan - 7 mm/d CRF not well linked to rain events • COARE IFA obs • KWAJEX obs • LBA obs • EPIC, JASMINE • KWAJEX CRM • NCAR CAM - IFA • GFDL AM2 • NASA GMAO • (super-CAM soon?) • cross-forced SCMs • SCAM2 driven by CAM • SCAM driven by AM2 3-day waves vertical thanks to ‘convective’ fraction but… …condensed water not coherent in vertical

  16. regressions vs. surface rainfall - GMAO What stats? a bit stark but about like IFA • COARE IFA obs • KWAJEX obs • LBA obs • EPIC, JASMINE • KWAJEX CRM • NCAR CAM - IFA • GFDL AM2 - IFA • GMAO 140E/8N July • (super-CAM soon?) • cross-forced SCMs • SCAM2 driven by CAM • SCAM driven by AM2 upward development, zigzag layers 2xKwajCRM ice content freezing level schism

  17. rain event met fields - obs <-KWX IFA->

  18. rain event met fields - CAM-IFA <-Jan Dec->

  19. rain event met fields - 3 models AM2 CAM GMAO

  20. But are these brief rain-event fluctuations a Climate Process? • hypothesis Divergence profile in tropical rain events linked to profile of divergent winds linked to profile of total winds? ( -> coupling issues…climate by any standard) ? Let’s look

  21. GMAO CAM IFA AM2 All 3 GCMs have unrealistic surface-intensified div fluctuations Top- stats of div regression sections (lag-height) Bottom- stats of total wind speed (time-height)each curve shows 1 month of data mean stdev w/in 6-day lag section GMAO-midlevel swoop mean CAM-jangly wind profiles stdev but no near- surface enhancement of wind fluctuations KWAJEX is 3rd line; LBA 4 1000 vs 850 not right

  22. wind profile results • hypothesis too simplistic • BUT • Systematic windspeed profile differences from observations are clear at low levels!

  23. Regressions wrt TOA CRF “events”? • Weird idea: submonthly TOA CRF has ~no feedback to the weather that causes it, so there’s less expectation of a repeatable “life cycle” • Proxy for climate sensitivities? • ? Maybe, if tau << {days, years, decades, etc.} ? • Anyway, try it (but I have no obs yet) • use 24h smoothing to kill diurnal cycle

  24. SWup>0 Whiter w/clouds at 975 not 925 24h-smoothed TOA -CRF as base time series -- CAM 85W 20S CRF<0, big slow changes

  25. faster changes, polymodal pdf? SWup>0 CRF<0 Complicated mixture of events Another month at 85W 20S -- CAM

  26. AM2 - 85W 20S whiteness varies little; regression structure not stable steady -30ish CRF PBL-based clouds rise to ~550mb here !? Minghua’s AM2 “midlevel” cloud (ISCCP) (Q1 data missing)

  27. Cross-forced SCMs (CAM <-> AM2) • V. advection of SCM fields by prescribed vertical velocity from other GCM • H. advection prescribed (non-interactive) • Look at LBA (Amazon) just for fun

  28. LBA obs (via Minghua’s shop), & GCMs LBA obs CAM AM2 (warning: clear sky not careful) (sorry: Q1 missing)

  29. LBA obs CAM AM2

  30. LBA models SCAM driven by AM2 omega CAM AM2 Cloud style CAMlike

  31. LBA models SCAM2 driven by CAM omega CAM AM2 Cloud style AM2 ish

  32. standard raw plots Web standard stat plots MORE DATA in (p,t) space SCMs! CRMs! EXPERIMENTS! OBS! other people Future plans - team efforts? • COARE obs • KWAJEX obs • LBA obs • EPIC, JASMINE • KWAJEX CRM • NCAR CAM • GFDL AM2 • NASA GMAO • (super-CAM soon?) • cross-forced SCMs • SCAM2 driven by CAM • SCAM driven by AM2 Common data format, variables, names, units, sign conventions clickable from Bony index plot co-ra.com/~bem more to come publication strategy? informing param'z'n?

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