QME AERI LBL: QME of AERI Spectra and Line-By-Line Calculations with Residuals
This quality measurement experiment (QME) was designed to facilitate the analysis of the residuals obtained from the observed minus the calculated downwelling radiances in the longwave regime.
Information Last Updated: June 2002
General Description
The observed radiances are measured by the Atmospheric Emitted Radiance Interferometer (AERI) and the calculated radiances are from the Line-by-line radiative transfer model (LBLRTM), a product of Atmospheric and Environmental Research, Inc (AER).
Three principle components of this study are 1) ground-based measurements of spectral radiances, 2) characterization of the atmospheric state associated with the radiating column, and 3) evaluation of the line-by-line radiative transfer model. The initial focus of this longwave study is on clear sky, which is currently being extended to clouds and aerosols. There are also plans to extend this approach to the shortwave regime.
In addition to providing statistics over the entire spectral band from 3.3 - 18 microns (the range of the AERI), and statistics for each channel, the entire spectrum is divided into 17 spectral regions called "bins." These bins are disjoint intervals such that the union of them covers the entire spectrum. The criteria used for selecting these spectral regions are similar to those used in selecting the spectral bands for rapid radiation models in general circulation models (GCMs).
To further facilitate analysis, each spectral element was associated with a specific physical process. To this end, a "spectral mapping" was done, where for each wavenumber the sensitivity of the element to changes in the column and the dominant physical process was determined (please see the references below for more information on how this was done). The processes are h2o, co2, o3, o2, n2o, ch4, co, the self and foreign water vapor continuum, the carbon dioxide continuum, and the nitrogen continuum. Click here to see the bin specifications, as well as the sensitivity and primary process in each bin.
The Algorithm and Methodology
Flow Chart
This information is currently unavailable
Input Data Sources
sgpaeri01ch1C1.a1 - AERI observed radiance data (5 - 18 microns)
sgpaeri01ch2C1.a1 - AERI observed radiance data (3.3 - 5 microns)
sgpaeri01summaryC1.a1 - AERI summary data
sgplblch1C1.c1 - LBLRTM calculated radiance data (5 - 18 microns)
sgplblch2C1.c1 - LBLRTM calculated radiance data (3.3 - 5 microns)
sgp30smosE13.a1 - Surface meteorology data
Output Products
Example #1 - 'typical' channel 1 observed - calculated residuals
Example #2 - 'typical' channel 2 observed - calculated residuals
Example #3 - integrated residuals for the transparent region (window region affected by the water vapor continuum, clouds, and aerosols), water lines, and ozone from channel 1
Data Quality Assessment Included
This information is currently unavailable
Known Algorithm Caveats
This information is currently unavailable
VAP History
Current Version
This information is currently unavailable
Reprocessing History
This information is currently unavailable
Compatibility of Results from Different Version
This information is currently unavailable
Plans for Future Modifications
This information is currently unavailable
Other
This information is currently unavailable
Output Products
Descriptions of Products
This information is currently unavailable
Examples of Output Data and Output Filename Structure
This VAP creates three platforms as output. The first platform contains the residuals between the observed and the calculated. For each LBLRTM run, which produces one spectrum for each sonde launch, residuals are calculated for up to four AERI observations around the launch time. Usually, the AERI observation directly before the launch and the three immediately following are used in the analysis.
The second platform contains the statistical information (means, integrals, standard deviations, etc.) of the residuals. These statistics are calculated for the entire spectral range, for each channel, for each bin, and then all of the above with respect to each spectral process. These statistics are not calculated over time.
The third platform contains statistics on the observed radiances measured by the AERI on a hourly window centered on the sonde launch time. These statistics are similar to the ones calculated for the residuals above.
Analysis of this data is facilitated by the VAP qmeaerilblclouds. Two primary products of this platform is a non-clear flag and the total precipitable water vapor in the column. The transparent_region_dq_flag in the platform sgpqmeaerilblC1.c1 is also useful in analyzing this data stream.
Output Platforms
sgpaerilbldiffC1.c1 - contains the observed minus calculated residuals
sgpqmeaerilblC1.c1 - contains the statistics on the residuals
sgpqmeaerimeansC1.c1 - contains the statistics on the AERI observations
Description of Data Quality Fields
This information is currently unavailable
Status and Location of Results
This information is currently unavailable
Notes for Data Users
This information is currently unavailable
Related Products Data and Links
Ordering Data
This information is currently unavailable
Links to Notification File
This information is currently unavailable
Link to Data Release History
This information is currently unavailable
Other
This information is currently unavailable
Frequently Asked Questions
This information is currently unavailable
Contacts
- Translator
- Chuck Long
Phone: 1 (509) 372-4917
Fax: 1 (509) 372-6168
Email: chuck.long@pnl.gov
VAP Specific Glossary and Acronyms
For ARM-wide acronyms, see the ARM Acronyms/Glossary.
Citable References
Clough, S.A., P.D. Brown, J.C. Liljegren, T.R. Shippert, and D.D. Turner. 1996. "Implications for Atmospheric State Specification From the AERI/LBLRTM QME and the MWR/LBLRTM QME." In Proceedings of the 6th Annual ARM Science Team Meeting, U.S. Department of Energy, Washington, D. C.
Brown, P.D., S.A. Clough, N.E. Miller, J.C. Liljegren, T.R. Shippert, D.D. Turner, R.O. Knuteson, and H.E. Revercomb. 1996. "Initial results of spectral analyses of residuals between observed downwelling radiance and model calculations." Proceedings of the Fifth Atmospheric Radiation Measurement (ARM) Science Team Meeting, pp 29-32. ONF-9503140, U.S. Department of Energy, Washington, D.C.
Clough, S.A., P.D. Brown, N.E. Miller, J.C. Liljegren, and T.R. Shippert. 1995. "Residual analysis of surface spectral radiances between instrument observations and line-by-line calculations." Proceedings of the Fourth Atmospheric Radiation Measurement (ARM) Science Team Meeting, pp 101-109. CONF-940277, U.S. Department of Energy, Washington, D.C.
