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Water Vapor Radiance Assimilation in the NCEP Global Data Assimilation System. James Jung Cooperative Institute for Meteorological Satellite Studies [email protected] In collaboration with NCEP/EMC, NASA/GMAO, NESDIS/STAR, NESDIS/JPSS, CAWCR, etc. Outline. Recent Projects - PowerPoint PPT Presentation
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Water Vapor Radiance Assimilation in the NCEP Global Data
Assimilation System
James JungCooperative Institute for Meteorological Satellite Studies
In collaboration with
NCEP/EMC, NASA/GMAO, NESDIS/STAR, NESDIS/JPSS, CAWCR, etc.
12th Annual JCSDA Review
Outline
• Recent Projects Supersaturation removal Using q instead of RH for background error Addition to Baseline Observing System Experiments
• Current Work 2014 Global Data Assimilation System transition
• Future Projects Water Vapor Radiance Assimilation Addition to Baseline Observing System Experiments
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12th Annual JCSDA Review3
Water Vapor Assimilation
12th Annual JCSDA Review
Background
• May 2012 version of the GDAS/GFS Hybrid (80 ensembles, T254) T574, NCEP operational resolution
• Summer and winter seasons• No changes to observations
Counts / fits differences due to atmosphere changes
• Forecast scores verified against own analysis
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12th Annual JCSDA Review
BackgroundSupersaturation removal
• NCEP Ticket #346 Supersaturation removal experiments
• Subversion branch r29873 with updates
• T574 hybrid (~May 2012 version ported to JIBB)
• No changes to observations
• Perturbations derived from the ensembles used RH
• Namelist variable added (clip_supersaturation=.true.)
• Factqmax=50.0 (penalize minimization for generating supersaturation)
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12th Annual JCSDA Review
Backgroundrelative humidity vs specific humidity
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• NCEP ticket #338 Use q instead of RH perturbations for the moisture component in the ensembles.
• Includes the changes from the supersaturation removal experiment.
• RH background error derived from ensemble specific humidityF RH perturbations are computed from q only (Removes
ΔT)
F From Daryl Kleist
F Namelist variable (q_hyb_ens=.true.)
12th Annual JCSDA Review
Supersaturation counts before each outer loop from the control
SUPERSAT RH COUNT,RMS= 770051 0.118376SUPERSAT RH COUNT,RMS= 1494196 0.103566SUPERSAT RH COUNT,RMS= 1585750 0.101427
Supersaturation counts before each outer loop from the experiment
SUPERSAT RH COUNT,RMS= 0 0.00000SUPERSAT RH COUNT,RMS= 235489 0.266668E-01SUPERSAT RH COUNT,RMS= 160906 0.716671E-02
Supersaturation counts accumulate with each outer loop in the control. Counts and RMS are an order of magnitude higher in the control
Effect on supersaturation counts
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12th Annual JCSDA Review
Latitude – Height Analysis DifferencesRelative Humidity
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About equally less relative humidity in both experiments
20120801 - 20120915 20130101 - 20130215
12th Annual JCSDA Review
Latitude – Height Analysis DifferencesCloud Water
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About equally less cloud water in both experiments
20120801 - 20120915 20130101 - 20130215
12th Annual JCSDA Review
Latitude – Height Analysis DifferencesGeopotential Height
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Lower heights in the enkf_q experiment
20120801 - 20120915 20130101 - 20130215
12th Annual JCSDA Review
Latitude – Height Analysis DifferencesTemperature
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Significantly colder over both poles
20120801 - 20120915 20130101 - 20130215
12th Annual JCSDA Review
Analysis DifferencesNear Surface Temperature
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Significantly colder over both poles
20120801 - 20120915 20130101 - 20130215
12th Annual JCSDA ReviewCourtesy A. Collard
North Pole Rawinsonde Comparisons
Black = control, green = experiment
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12th Annual JCSDA Review
South Pole Rawinsonde Comparisons
Courtesy A. CollardBlack = control, green = experiment
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12th Annual JCSDA Review
Analysis troposphere fit to rawinsondes
Experiment is generally cooler
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Control: solidExperiment: dash
Analysis: black6-hr guess: red
12th Annual JCSDA Review
Analysis troposphere fit to rawinsondes
Experiment generally drier
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Control: solidExperiment: dash
Analysis: black6-hr guess: red
12th Annual JCSDA Review
12 & 36 hr forecast fit to rawinsondes
Experiment remains cooler in troposphere but drifting back to control
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Control: solidExperiment: dash
12-hr: black36-hr: red
12th Annual JCSDA Review
12 & 36 hr forecast fit to rawinsondes
Experiment remains drier
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Control: solidExperiment: dash
12-hr: black36-hr: red
12th Annual JCSDA Review
Anomaly Correlations500 hPa Northern Hemisphere
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20120801 - 20120915 20130101 - 20130215
12th Annual JCSDA Review
Anomaly Correlations500 hPa Southern Hemisphere
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20120801 - 20120915 20130101 - 20130215
12th Annual JCSDA Review
Tropical Wind Vector RMSE
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20120801 - 20120915 20130101 - 20130215
12th Annual JCSDA Review
Summary
• Reduce supersaturation counts and RMS (wrt RH) by an order of magnitude
• Troposphere - drier / stratosphere – wetter
• Troposphere cooler, less drift in stratosphere temperature
• Less clouds at upper levels
• Convergence and penalty marginally worse (factqmax)
• Benchmarks / scores are mixed to postitive. ENKF_Q better than SUPERSAT.
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12th Annual JCSDA Review
Addition to baseline Observing System
Experiments
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12th Annual JCSDA Review
Background
• May 2012 version of the GDAS/GFS Hybrid (80 ensembles, T254) T574, NCEP operational resolution
• Summer and winter seasons
• Baseline is conventional data and GPS-RO
• Add single instruments ATMS (SNPP) AMSUA, MHS (NOAA-19) AIRS (Aqua)
• Verified against a control analysis with all operational data (including NOAA-19, SNPP, and Aqua)
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12th Annual JCSDA Review25
Latitude – HeightAnalysis Differences
All_Data SNPP-ATMS – All_Data
Aqua-AIRS – All_Data N19-AMSU/MHS – All_Data
Base – All_Data
Relative Humidity
00Z20120801 - 20120920
12th Annual JCSDA Review
Latitude – HeightAnalysis Differences
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All_Data SNPP-ATMS – All_Data
Aqua-AIRS – All_Data N19-AMSU/MHS – All_Data
Base – All_Data
Cloud Water
00Z20120801 - 20120920
12th Annual JCSDA Review27
Latitude – HeightAnalysis Differences
All_Data SNPP-ATMS – All_Data
Aqua-AIRS – All_Data N19-AMSU/MHS – All_Data
Base – All_Data
Temperature
00Z20120801 - 20120920
12th Annual JCSDA Review
500 hPa AC scores for 00Z 20120801-20120930
Base SNPP-ATMSAll_Data Aqua-AIRSN19-AMSU/MHS
Base SNPP-ATMSAll_Data Aqua-AIRSN19-AMSU/MHS
Northern Hemisphere Southern Hemisphere
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12th Annual JCSDA Review
1000 hPa AC scores for 00Z 20120801 – 20120930
Base SNPP-ATMSAll_Data Aqua-AIRSN19-AMSU/MHS
Base SNPP-ATMSAll_Data Aqua-AIRSN19-AMSU/MHS
Northern Hemisphere Southern Hemisphere
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12th Annual JCSDA Review
Tropical Vector Wind RMSE for 00Z 20120801 - 20120930
Base SNPP-ATMSAll_Data Aqua-AIRSN19-AMSU/MHS
Base SNPP-ATMSAll_Data Aqua-AIRSN19-AMSU/MHS
200 hPa 850 hPa
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12th Annual JCSDA Review
Hurricane Statistics20120801 - 20120915
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12th Annual JCSDA Review
Summary(WRT the control)
• Increased cloud water in the tropics. Baseline has the most clouds
• Higher geopotential heights at upper levels. Baseline and SNPP-ATMS are the highest
• Greater RH in Southern Hemisphere upper troposphere Except for Aqua-AIRS
• Anomaly correlation scores: SNPP-ATMS and Aqua-AIRS are generally equal N19-AMSU/MHS is slightly lower
• Tropical wind vector RMSE: Aqua-AIRS is best (first 24 hours) Baseline worst throughout
• Aqua-AIRS generally best hurricane stats
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12th Annual JCSDA Review
Future Projects
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12th Annual JCSDA Review
Water Vapor Radiance Assimilation • Build from previous work. Control will including these namelist
changes: clip_supersaturation=.true. factqmax=50.0 q_hyb_ens=.true.
• Due to all of the recent changes in both the analysis and forecast model, a review of the QC procedures for MW and IR water vapor channels currently used by GDAS is in order. Adjust gross error check Adjust assimilation weights
• Review water vapor channel selection for AIRS, IASI, and CrIS. Remove AIRS stratospheric channels ( ~11) Add tropospheric channels for IASI and CrIS.
• Two season impact tests. Operations resolution (T1534?)
• Wiki page for progress updates. Ticket #394 Branch jung_wv_chans
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12th Annual JCSDA Review
Observing System ExperimentsData Additions
• Control Lower resolution semi-Lagrangian (T670?) All available data
• Baseline Conventional data only (unless unstable)
• Experiments AIRS IASI CrIS
• If time permits ATMS SSMIS
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