Adventures with AIRS: continued Tim P. Barnett David W. Pierce - - PowerPoint PPT Presentation

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Adventures with AIRS: continued Tim P. Barnett David W. Pierce - - PowerPoint PPT Presentation

Apr 02, 2024 160 likes •430 views

Adventures with AIRS: continued Tim P. Barnett David W. Pierce Eric Fetzer Andrew Gettleman Amy Braverman Sam Iacobellis Outline/Summary Water Vapor: AIRS vs. Climate Models (models wrong AND error is important) . Cloud Issues (what

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Adventures with AIRS: continued

Tim P. Barnett David W. Pierce Eric Fetzer Andrew Gettleman Amy Braverman Sam Iacobellis

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Outline/Summary

  • Water Vapor: AIRS vs. Climate Models

(models wrong AND error is important)

. Cloud Issues

(what a mess…HELP!) . Moisture Flares (promising opportunities for AIRS?)

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Annual mean specific humidity: models systematically differ from AIRS

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Fractional difference 50-100% at 500 hPa

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Fractional differences: greater with height

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Seasonal variability: AIRS vs. AR4 models

Red: Specific humidity from AIRS. Whiskerplots: 5, 25, 50, 75, and 95 percentiles of AR4 models

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Temperature (K) in AIRS compared to AR4 models, 400 hPa

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Temperature (K) in AIRS compared to AR4 models, zonal average

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Relative humidity in AIRS compared to AR4 models, 400 hPa (Andrew Gettleman’s RH)

Note: Values are percentages, i.e., (model-AIRS)/AIRS*100. Using Andew Gettleman RH vals, not AIRS

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PDF of specific humidity error

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PDF of specific humidity error

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WHO CARES?

  • Is ‘q’ error important?
  • If so, how important?
  • Modeling community disinterest?
  • SCM work
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Forcing error, Single Column Model (upper troposphere)

SCM delta-OLR @ TOA

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Cloud issues

Compare: AIRS fractional clouds vs. CGCM fractional clouds

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Cloud fraction DJF climatology AIRS vs. AR4 models

Cloud fraction, 0 to 100%

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Cloud fraction DJF climatology AIRS vs. ISCCP

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ISCCP anomalies vs. AIRS

ISCCP (removed mean = 67%) AIRS (removed mean = 42%) Pattern Correlation=0.85

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Moisture flares

  • Associated with heavy rain events
  • Predictive skill
  • Physics=?
  • AIRS might give us their third dimension

and insight into how they work

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Moisture flare: el Nino event

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SoCAL moisture flare composite: el Nino

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Vertical structure of the Dec 25-29, 2004 moisture flare (contour taken along the black line) Relative humidity from A. Gettleman

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Conclusions

  • ‘q’ and ‘RH’ errors are real and large
  • Radiatively large w.r.t GHG forcing
  • Clouds: Expert help required but promising
  • AIRS can help understand moisture flare structure

and, maybe, physics

  • ASIDE: Quality flag adventures (for beginners)
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Absolute differences: central latitudes near surface

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PNW la Nina rain event (moisture field)

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Other Southwestern U.S. Moisture flares

Total cloud liquid water from AIRS; interpolated across missing values