evaluating the mmf using high resolution data
DESCRIPTION
Evaluating the MMF Using High Resolution Data. Thomas Ackerman Roger Marchand University of Washington. The Question. As we move towards higher resolution models with more realistic simulations of cloud processes and cloud properties, how do we evaluate model cloud properties? - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Evaluating the MMF Using High Resolution Data](https://reader035.vdocuments.site/reader035/viewer/2022062323/5681668e550346895dda62d9/html5/thumbnails/1.jpg)
Evaluating the MMF Using High Resolution Data
Thomas AckermanRoger Marchand
University of Washington
![Page 2: Evaluating the MMF Using High Resolution Data](https://reader035.vdocuments.site/reader035/viewer/2022062323/5681668e550346895dda62d9/html5/thumbnails/2.jpg)
As we move towards higher resolution models with more realistic simulations of cloud processes and cloud properties, how do we evaluate model cloud properties? What are the metrics? How do know we are improving those
metrics?
The Question
![Page 3: Evaluating the MMF Using High Resolution Data](https://reader035.vdocuments.site/reader035/viewer/2022062323/5681668e550346895dda62d9/html5/thumbnails/3.jpg)
Occurrence in space and time – cloud fraction
Cloud top height Optical depth – an optical (radiation)
measure of the total condensed water and ice in a cloud
Statistical distributions of these quantities
The Metrics
![Page 4: Evaluating the MMF Using High Resolution Data](https://reader035.vdocuments.site/reader035/viewer/2022062323/5681668e550346895dda62d9/html5/thumbnails/4.jpg)
The tools
CloudSat – 3 mm radarNASA A-Train, launched
2006Profiles of cloud reflectivity
MISR – multi-angle radiometer
NASA Terra, launched 1999
Cloud height and optical depthARM sites – multiple instruments
Established 1996 – 1998Cloud profiles and integrated properties
![Page 5: Evaluating the MMF Using High Resolution Data](https://reader035.vdocuments.site/reader035/viewer/2022062323/5681668e550346895dda62d9/html5/thumbnails/5.jpg)
Cyclone Nargis in the Bay of Bengal before landfall in Myanmar
MODIS image
CloudSat curtain along red line
CloudSat data – an example
![Page 6: Evaluating the MMF Using High Resolution Data](https://reader035.vdocuments.site/reader035/viewer/2022062323/5681668e550346895dda62d9/html5/thumbnails/6.jpg)
B
Simulator Simulator
Synthetic Signals
In situ Observations Model Cloud
Properties
Remote Sensing Signals
Retrieved Model Cloud Properties Retrieved
Cloud Properties
Cloud M odel
D
A
C
Retrieval Algorithms
CloudSat Instrument Simulator
MMF August Composite
![Page 7: Evaluating the MMF Using High Resolution Data](https://reader035.vdocuments.site/reader035/viewer/2022062323/5681668e550346895dda62d9/html5/thumbnails/7.jpg)
MAM (Diff = MMF – CS)
![Page 8: Evaluating the MMF Using High Resolution Data](https://reader035.vdocuments.site/reader035/viewer/2022062323/5681668e550346895dda62d9/html5/thumbnails/8.jpg)
JJA (Diff = MMF – CS)
![Page 9: Evaluating the MMF Using High Resolution Data](https://reader035.vdocuments.site/reader035/viewer/2022062323/5681668e550346895dda62d9/html5/thumbnails/9.jpg)
SON (Diff = MMF – CS)
![Page 10: Evaluating the MMF Using High Resolution Data](https://reader035.vdocuments.site/reader035/viewer/2022062323/5681668e550346895dda62d9/html5/thumbnails/10.jpg)
DJF (Diff = MMF – CS)
![Page 11: Evaluating the MMF Using High Resolution Data](https://reader035.vdocuments.site/reader035/viewer/2022062323/5681668e550346895dda62d9/html5/thumbnails/11.jpg)
What have we learned MMF captures general cloud structure and
seasonal movement MMF generally overproduces convective
cloud Too much high cloud and too optically thick
MMF underpredicts BL cloud (Stratus, Trade Cu)
Produces too much precipitation Simulated Radar reflectivity values are too high Too much drizzle
![Page 12: Evaluating the MMF Using High Resolution Data](https://reader035.vdocuments.site/reader035/viewer/2022062323/5681668e550346895dda62d9/html5/thumbnails/12.jpg)
CloudSat has limited temporal coverage ARM radar has limited spatial coverage Combine them to provide detailed
regional data Work in progress
Detailed comparison ofradar signals
Apply to simulations inTWP
CloudSat and ARM
![Page 13: Evaluating the MMF Using High Resolution Data](https://reader035.vdocuments.site/reader035/viewer/2022062323/5681668e550346895dda62d9/html5/thumbnails/13.jpg)
MISR measures stereo cloud-top height and cloud optical depth
Plot as 2D joint histogram
MISR simulatorincorporated into MMF
Using MISR Joint Histograms
![Page 14: Evaluating the MMF Using High Resolution Data](https://reader035.vdocuments.site/reader035/viewer/2022062323/5681668e550346895dda62d9/html5/thumbnails/14.jpg)
64 or 128 Columns
2°
2.5°
Multi-scale Modeling Framework (MMF)Testing the effect of increasing resolution3-month MMF runs Increasing resolution•Control run
• 4 km horizontal• 64 columns• 26 vertical layers
• Test A• 1 km horizontal• 64 & 128 columns• 26 vertical layers
• Test B• 1 km horizontal• 64 columns• 52 vertical layers
Run on SDSC Datastar with support from CMMAP
![Page 15: Evaluating the MMF Using High Resolution Data](https://reader035.vdocuments.site/reader035/viewer/2022062323/5681668e550346895dda62d9/html5/thumbnails/15.jpg)
Sensitivity of low cloud amount to CRM resolution
![Page 16: Evaluating the MMF Using High Resolution Data](https://reader035.vdocuments.site/reader035/viewer/2022062323/5681668e550346895dda62d9/html5/thumbnails/16.jpg)
Hawaiian Trade Cumulus
![Page 17: Evaluating the MMF Using High Resolution Data](https://reader035.vdocuments.site/reader035/viewer/2022062323/5681668e550346895dda62d9/html5/thumbnails/17.jpg)
Summary of Low Cloud Response
Going from 4 km to 1 km reduced low cloud amount. Much (but not all) due to dissipation of “stratofogulus” Generally, little change in amount of low cloud with optical
depths less than 10.
Going from 4 km to 1 km and vertical resolution to 52 levels (50 in CRM) resulted in …
Small increase in the amount of low-level cloud relative to the simulations with 4 km horizontal resolution.
Increase in cloud with optical depths less than 10 (better agreement with MISR observational data)
Stratocumulus zones show a significant improvement in cloud top height.
BUT Total amount of model low cloud remains too low Too much low cloud with optical depths larger than 23 (the
largest two optical-depth bins).
![Page 18: Evaluating the MMF Using High Resolution Data](https://reader035.vdocuments.site/reader035/viewer/2022062323/5681668e550346895dda62d9/html5/thumbnails/18.jpg)
New instruments well suited to evaluating MMF Model spatial resolution matches
sensors Simulator approach easy to implement
in MMF Provide new metrics
Profiles of cloud occurrence Optical depth – cloud top height joint
histograms Test model improvements against
these same metrics
Concluding thoughts
![Page 19: Evaluating the MMF Using High Resolution Data](https://reader035.vdocuments.site/reader035/viewer/2022062323/5681668e550346895dda62d9/html5/thumbnails/19.jpg)
Thank you for your attention!
![Page 20: Evaluating the MMF Using High Resolution Data](https://reader035.vdocuments.site/reader035/viewer/2022062323/5681668e550346895dda62d9/html5/thumbnails/20.jpg)
Mace, G. G., Q. Zhang, M. Vaughan, R. Marchand, G. Stephens, C. Trepte, and D. Winker (2009), A description of hydrometeor layer occurrence statistics derived from the first year of merged Cloudsat and CALIPSO data, J. Geophys. Res., 114, D00A26, doi:10.1029/2007JD009755.
McFarlane, S. A., J. H. Mather, and T. P. Ackerman, 2007: Analysis of tropical radiative heating profiles: A comparison of models and observations, J. Geophys. Res., 112, D14218, doi:10.1029/2006JD008290
Marchand, R. T., J. Haynes, G. G. Mace, T. P. Ackerman, and G. Stephens, 2009: A comparison of CloudSat cloud radar observations with simulated cloud radar output from the Multiscale Modeling Framework global climate model, J. Geophys. Res., 114, D00A20, doi:10.1029/2008JD009790
Marchand, R. T., and T. P. Ackerman, 2009: Analysis of the MMF global climate model using ISCCP and MISR histograms of cloud top height and optical depth, manuscript in preparation
Marchand, R. T., T. P. Ackerman, M. Smyth, P. Hubanks, S. Platnick, and W. Rossow, 2009: A comparison of cloud top height and optical depth histograms from MISR, ISCCP, and MODIS, manuscript in preparation
References
Research supported by DOE ARM, NASA, and CMMAP