Assimilation of ATOVS level1C radiance and MODIS polar winds at JMA
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Transcript of Assimilation of ATOVS level1C radiance and MODIS polar winds at JMA
July 19, 2005 EMC Sack Lunch Seminar
Assimilation of ATOVS level1C radiance and MODIS polar winds at JMA
Masahiro Kazumori
Japan Meteorological Agency / EMC Visiting scientist
July 19, 2005 EMC Sack Lunch Seminar
Introduction of JMA NWP modelsRSMGSM MSM
Global Model (GSM) Regional Model (RSM) Meso-scale Model (MSM)
3-7day forecastBoundary for RSM
1-2day forecastBoundary for MSM
Disaster prevention information
55km, 40levels (0.4hPa) 90 hours (00UTC)216 hours(12UTC)
20km, 40levels (10hPa) 51 hours (00,12UTC)
10km, 40levels (10hPa) 18 hours (00,06,12,18UTC)
4D-Var (Since 2003) 4D-Var (Since 2002) 4D-Var (Since Feb. 2005)
Purpose:
Resolution, Forecast time:
Assimilation system:
July 19, 2005 EMC Sack Lunch Seminar
Satellite data in JMA global data assimilation system
• Radiance AMSU-A(NOAA15/16, Aqua) AMSU-B(NOAA15/16/17)
• Wind GOES(9/10/12),METEOSAT(5/7) MODIS(Terra/Aqua) QuikSCAT
• Radiance AIRS (Aqua) SSMI,TRMM,AMSR-E GOES-9,METEOSAT,MTSAT-1R
• Wind METEOSAT(8),MTSAT-1R
• SSMIS(DMSP-16)
• HIRS,AMSU-A,HSB(NOAA-18)
• IASI (Metop)
• ASCAT(Metop)
Now using operationally Now testing
Planning
July 19, 2005 EMC Sack Lunch Seminar
Progress on global data assimilation in 2004-2005
• Dec. 2004 : – Direct assimilation of ATOVS level-1C data replaced that of lev
el-1D data– The radiative transfer model for the radiance assimilation was u
pgraded from RTTOV-6 to RTTOV-7• Feb. 2005 :
– Introduction of 4D-Var in operational system• March. 2005:
– Start of Aqua/AMSU-A radiance data assimilation
ATOVS level 1C radiance
MODIS polar winds• May 2004 : – Assimilation of polar winds from Terra/MODIS and
Aqua/MODIS in the north polar region started. • Sep. 2004 :
– Assimilation of polar winds from Terra/MODIS and Aqua/MODIS in the south polar region started.
4D-Var
July 19, 2005 EMC Sack Lunch Seminar
Assimilation of ATOVS level 1C radiance
Masahiro KazumoriHiromi OwadaKazuyo Fukuda
Numerical Prediction DivisionJapan Meteorological Agency
July 19, 2005 EMC Sack Lunch Seminar
ATOVS level 1C radiance data
Dec. 2004Dec. 2004
ATOVS data was changed from ATOVS data was changed from level-1D datalevel-1D data(NESDIS pre-processe(NESDIS pre-processed data) to d data) to level-1C datalevel-1C data(unmapped instrument data) (unmapped instrument data)
At the same time, RTM upgrade was performed.At the same time, RTM upgrade was performed.•JMA uses RTTOV (Saunders et al. 1998) as RTM
•The update was from RTTOV-6 to RTTOV-7
•RTTOV-7 treats each sensor separately
•RTTOV-7 has an ability to calculate AIRS radiance
Since May 2003, ATOVS radiance data have been assimilated Since May 2003, ATOVS radiance data have been assimilated directly into the global model with JMA 3D-Var system.directly into the global model with JMA 3D-Var system.
But…, it had been using ATOVS level 1D radiance data
July 19, 2005 EMC Sack Lunch Seminar
AAPP & MSC direct read out data
AAPPAAPP (( ATOVS and AVHRR Processing PackageATOVS and AVHRR Processing Package ))Direct broadcast data are received at JMA Meteorological Satellite Center.Direct broadcast data are received at JMA Meteorological Satellite Center.
Global level 1B data from NESDISGlobal level 1B data from NESDIS
Direct read out data (HRPT) at MSCDirect read out data (HRPT) at MSC AAPPLevel 1C radianceLevel 1C radiance
decodedecode
The limit of data receiving.The limit of data receiving.
Data coverage of ATOVS level 1c for early analysis.Data coverage of ATOVS level 1c for early analysis.Blue points are the global data from NESDIS and red points are Blue points are the global data from NESDIS and red points are direct read out data at MSC at JMA. 12UTC 31 July 2004.direct read out data at MSC at JMA. 12UTC 31 July 2004.
Level 1D radianceLevel 1D radiance
JMA
July 19, 2005 EMC Sack Lunch Seminar
Difference of ATOVS data between level 1C and level 1D
Level 1D dataLevel 1D dataNo high latitude data.No high latitude data.Thinned and removed by NESDISThinned and removed by NESDISNESDIS provide some quality flag for NESDIS provide some quality flag for observationobservation
Level 1C dataLevel 1C dataAll observation data are available.All observation data are available.thinning and quality check are needed.thinning and quality check are needed.
Level 1D dataLevel 1D data
Level 1C dataLevel 1C dataBlueBlue :: NOAA15NOAA15 RedRed ::NOAA16NOAA16
July 19, 2005 EMC Sack Lunch Seminar
Difference of ATOVS data between level 1C and level 1D
Level 1D dataLevel 1D dataNo high latitude data.No high latitude data.Thinned and removed by NESDISThinned and removed by NESDIS
Level 1C dataLevel 1C dataAll observation data are available.All observation data are available.Original data thinning and quality Original data thinning and quality check are needed.check are needed.
Level 1D dataLevel 1D data
Level 1C Level 1C datadata
July 19, 2005 EMC Sack Lunch Seminar
Mapping (computing sounder data to another sounder grid)
HIRS AMSU-A
In level 1D data,In level 1D data,
Mapping of AMSU-A FOV to Mapping of AMSU-A FOV to HIRS FOV are conducted.HIRS FOV are conducted.
In level 1C data,In level 1C data,
We can assimilative those We can assimilative those data in their original data in their original observation points.observation points.
FOVFOV
July 19, 2005 EMC Sack Lunch Seminar
Assimilation scheme of ATOVS 1C radiance
• Data thinning
– 240km for AMSU-A, 180km for AMSU-B
– Land sea decision: 0.25*0.25degree map and considering the maximum size of FOV for each sensor.
• Quality Control
– Rain detection ( based on scattering index)
– Cloud detection( based on amount of cloud liquid water)
• Observation error
– Remove the adjustment for each FOV
• Bias correction
– Scan bias correction ( fixed for each channel)
– Air mass correction (fixed for all season)
• Predictor: Calculated brightness temperature of AMSU-A Ch5,7,10, Surface temperature.
• Coefficient was calculated from collocated data set with RAOB
discontinued
July 19, 2005 EMC Sack Lunch Seminar
Land Sea Mask based on FOV
AMSU-A CH4 Departure(monthly mean)
[K]
Land sea grid
Land
Sea0.25degree
0.25degree
A Observation point
Field of View
Land sea mask are modified based on FOV size for each sensor.
Contamination by land
July 19, 2005 EMC Sack Lunch Seminar
Results of cloud, rain detection
Level 1C dataLevel 1C dataThere are many rain observationThere are many rain observation(( Level 1C have original all observation dataLevel 1C have original all observation data ))Many cloud around high latitude in winter.Many cloud around high latitude in winter.
For level 1C,For level 1C,
HIRS can not be used for HIRS can not be used for cloud detection (no mapping)cloud detection (no mapping)
Clear Clear →→Thin cloudThin cloud
Level 1DLevel 1D
Level 1CLevel 1C
Used Retrieval Algorithm for QC
CLW from AMSU-A (English et al. 1997) > 100g/m^2 rejectedRAIN (Scattering index method) AMSU-A (over ocean) SI = ETB15 – TB15 >10 rejected AMSU-B ( over ocean) SI = TB1-TB2>3 and Median filter QC for CH1
July 19, 2005 EMC Sack Lunch Seminar
Mean departure for each scan position
Level1C (AMSU-A)Level1C (AMSU-A) Level1D (AMSU-A)Level1D (AMSU-A)
Level 1D data has an effect of mapping to HIRS field of Level 1D data has an effect of mapping to HIRS field of viewview
RedRed :: W Bias correctionW Bias correctionBlueBlue :: W/O Bias W/O Bias correctioncorrection
Stop the use of Stop the use of Ch14Ch14
July 19, 2005 EMC Sack Lunch Seminar
Difference between level 1C and level 1D• Example: AMSU-A Channel 7 (2004/10/07/12UTC)
Level 1DLevel 1D
Level 1CLevel 1C
Level 1C dataLevel 1C dataNo high latitude data.No high latitude data.Thinned and removed by NESDISThinned and removed by NESDIS(NESDIS pre-processed data)(NESDIS pre-processed data)
Level 1C dataLevel 1C dataAll observation data are available.All observation data are available.Data thinning and quality check Data thinning and quality check should be done by ourselves.should be done by ourselves.
July 19, 2005 EMC Sack Lunch Seminar
Monthly mean O-B distribution (AMSU-A)
level1Dlevel1D
level1Clevel1C
The bias of level1C seems smaller than 1D The bias of level1C seems smaller than 1D It means the QC of level 1C works better.It means the QC of level 1C works better.
July 19, 2005 EMC Sack Lunch Seminar
Assimilation experiment of ATOVS 1C• Period:
– Summer : From July 13, 2004 To September 9, 2004
• Verification Period : From July 26, 2004 to August 31, 2004
– Winter: From December 27 2003 to February 2004
• Verification Period: From January 1,2004 to January 31 2004
• Setting of experiments
Analysis : Global 3D-Var, Forecast : T213L40 GSM0407 NAPEX R111
CNTL: same with operational ( For summer, with MODIS polar winds in the S.H.)
TEST:CNTL + replace of ATOVS data ( from 1D to 1C)
Update of RTM from RTTOV-6 to RTTOV-7
• Used level1C
NOAA15,16 AMSU-A,B, NOAA17AMSU-B
• Discontinued level 1D data
NOAA15,16AMSU-A,B, NOAA16 HIRS
July 19, 2005 EMC Sack Lunch Seminar
TEST GUESSTEST GUESS
TEST ANALTEST ANAL CNTL ANALCNTL ANAL
CNTL GUESSCNTL GUESS
TESTTEST--CNTLCNTL
TESTTEST--CNTLCNTL
ANALANAL--GUESSGUESS ANALANAL--GUESSGUESS
Summer Z500Summer Z500
July 19, 2005 EMC Sack Lunch Seminar
Impact on analysis
• TEST:
– ATOVS level 1C data
– RTTOV-7
• CNTL:
– ATOVS level 1D data
– RTTOV-6
Zonal mean difference of Temperature for August 2004
Change at the high latitudes in the troposphere Change at the high latitudes in the troposphere And large change in the stratosphere.And large change in the stratosphere.
TEST-CNTL
July 19, 2005 EMC Sack Lunch Seminar
level 1Clevel 1C
level 1Dlevel 1D
2004 Aug. N.H.2004 Aug. N.H. 2004 Aug.2004 Aug. S.H.S.H.
2004 Jan.2004 Jan. N.H.N.H. 2004 Jan.2004 Jan. S.H.S.H.
Improvement of RMSE of 500hPa GeImprovement of RMSE of 500hPa Geopotential heightopotential height
Z500RMSE
Impacts on forecast
Operational use of level 1C data started on 2 Dec. 2004
July 19, 2005 EMC Sack Lunch Seminar
Where can I find the improvements?
1day1day
3day3day
5day5day
summersummer winterwinterDifference of RMSE between TEST and CNTL (blue color means improvement)Difference of RMSE between TEST and CNTL (blue color means improvement)
S.H. and the polar S.H. and the polar region were improved.region were improved.
July 19, 2005 EMC Sack Lunch Seminar
• Target
The 11 typhoon in the summer test period ( maximum sample number 62 )
red : TEST, green : CNTL
Comparison of typhoon track prediction
T0409T0409 T0410T0410 T0411T0411 T0412T0412 T0413T0413
T0414T0414 T0415T0415 T0416T0416 T0417T0417 T0418T0418
T0419T0419
There are some difference between There are some difference between TESTTEST and and CNTLCNTL..But, statistically, the impact was almost neutral.But, statistically, the impact was almost neutral.
July 19, 2005 EMC Sack Lunch Seminar
Summary
JMA use ATOVS level-1C radiance since Dec. 2004 operationally.
The use of ATOVS level-1D radiance was discontinued.
– Land sea mask are modified for each sensor.
– Cloud, rain detection scheme are introduced.
– Use of direct read out data received at MSC/JMA
– Change of the RTM from RTTOV-6 to RTTOV-7.
– OSE showed the improvement of forecast score on 500hPa height.
July 19, 2005 EMC Sack Lunch Seminar
Plan for 2005 on ATOVS at JMA
KMA and JMA are going to exchange the direct received ATOVS data.
For Early analysis,These data make the data coverage expand.
Data will be available within 50 min. after the observation
Red: JMA(Tokyo)Blue:KMA(Seoul)
At present, data impact study is being conducted.
July 19, 2005 EMC Sack Lunch Seminar
Plan for 2005 on ATOVS at JMA
Japan has a ground station(ice station) in the Antarctic. SHOWA-kichi
JMA is getting the direct received ATOVS data in the Antarctic through National Institute of Polar Research (NIPR).
The data is available within 50 min. after observation.
The data is coming through International Mobile Satellite Organization.
Data acquisition is going well.
July 19, 2005 EMC Sack Lunch Seminar
Exchange of ATOVS Direct Broadcast Data in Eastern Asia
• JMA will contribute to establish a RARS together with the associated inter-regional data exchange mechanisms;
• - JMA is willing to perform its part of the re-transmission functions through the GTS and/or the Internet, in co-operation with CMA, ABoM and other centres;
• - The APSDEU forum should be used to co-ordinate the Asian RARS activities;
• - Responsibility for implementation of functions and operations to be shared between centres.
Reference:CGMS/WMO REGIONAL ATOVS RE-TRANSMISSION SYSTEM(RARS) WORKSHOP REPORT
July 19, 2005 EMC Sack Lunch Seminar
Data coverageEARS(EUMETSAT ATOVS Retransmission Service ) RARS(Eastern Asia)
If we use both, we will get much data in Early
analysis.
http://www.eumetsat.int/en/dps/atovs/images/coverage.gif
July 19, 2005 EMC Sack Lunch Seminar
Next…
July 19, 2005 EMC Sack Lunch Seminar
Assimilation of MODIS polar winds at JMA
Masahiro KazumoriYoshiyuki Nakamura
Numerical Prediction divisionJapan Meteorological Agency
July 19, 2005 EMC Sack Lunch Seminar
MODIS polar winds• AMVs from Geostationary Satellites have been used at JMA
• But, the polar regions have been remained as data poor regions because no winds from geostationary satellite for these regions. RAOB and Aircraft-network are also sparse. And ATOVS 1D data had no high latitude data.
• Since July 2002, CIMSS(Cooperative Institute for Meteorological Satellite) at Univ. of Wisconsin have been produced AMVs from MODIS on Terra and Aqua for the polar regions.
Orange TerraOrange Terra
Green AquaGreen Aqua
N.H.N.H. S.H.S.H.
Data distribution of AMVs from Satellite
MODIS polar winds fill the gap of observation and will improve the accuracy of MODIS polar winds fill the gap of observation and will improve the accuracy of analysis in the polar regions, and bring a better forecast in the mid-latitudes.analysis in the polar regions, and bring a better forecast in the mid-latitudes.
July 19, 2005 EMC Sack Lunch Seminar
Difference between CIMSS and NESDIS• Terra/MODIS WV 400hPa N.H. Wind Speed O-B and number
Period:Period:
From 27 December 2003From 27 December 2003
To 9 February 2004To 9 February 2004
Difference in QualityDifference in Quality
And CoverageAnd Coverage
O-BO-B
NumberNumber
CIMSSCIMSS NESDISNESDIS
JMA use CIMSS MODIS winds.
July 19, 2005 EMC Sack Lunch Seminar
Quality of MODIS Polar Winds• BIAS and RMSE of Wind Speed against first guess
ALL dataALL dataQC PassQC Pass
July 19, 2005 EMC Sack Lunch Seminar
MODIS polar winds data assimilation Experiments• Period of the experiments
– From 27 June 2003 to 9 August 2003– From 27 December 2003 to 9 February 2004
• ConfigurationsJMA Global Spectral Model (GSM)+ 3D-Var T213L40 CNTL the same as JMA operational run. MODIS polar winds were passively monitored. TEST CNTL+Terra/MODIS+Aqua/MODIS
• Used MODIS polar winds (Only in the Arctic) Over ocean IR: above 700hPa WV: above 550hPa Over land IR,WV: above 400hPa.
• Data thinning 150km(horizontal) 100hPa(vertical)• The data in the Antarctic have large bias. That degraded the
forecast scores in another experiment.
July 19, 2005 EMC Sack Lunch Seminar
Impacts on Analysis
• Mean field
– Temperature : Rise in the lower troposphere and fall in the upper troposphere ( about 0.5 degree in zonal mean)
– 500hPa height:Increase over ocean and decrease over land, especially over Siberia area.
• Comparison with Radiosonde observation(RAOB)
– Analysis and first guess in the TEST became close to RAOB, especially over Siberia
– Improvements on background bring better forecasts.
July 19, 2005 EMC Sack Lunch Seminar
Zonal mean difference of Temperature
• Rise in the lower troposphere and fall in the upper troposphere
( about 0.5 degrees in zonal mean)
Monthly mean for July 2003Monthly mean for July 2003 Monthly mean for January 2004Monthly mean for January 2004hPahPa
July 19, 2005 EMC Sack Lunch Seminar
Impacts on Analysis
• Mean field
– Temperature : Rise in the lower troposphere and fall in the upper troposphere ( about 0.5 degree in zonal mean)
– 500hPa height:Increase over ocean and decrease over land, especially over Siberia area.
• Comparison with Radiosonde observation(RAOB)
– Analysis and first guess in the TEST became close to RAOB, especially over Siberia.
– Improvements on background bring better forecasts.
July 19, 2005 EMC Sack Lunch Seminar
Change of 500hPa Z • Monthly mean error for July 2003
Analysis (TEST-CNTL)Analysis (TEST-CNTL)
First guess (TEST-CNTL)First guess (TEST-CNTL)
TEST first guess against RAOBTEST first guess against RAOB
CNTL first guess against RAOBCNTL first guess against RAOB
Analysis and first guess in the TEST became Analysis and first guess in the TEST became close to RAOB, especially over Siberia.close to RAOB, especially over Siberia.
(m(m))
(m(m))
(m(m))
(m(m))
July 19, 2005 EMC Sack Lunch Seminar
Impacts on Forecast
• Anomaly Correlation and RMSE at 500hPa– Large improvement for both seasons in the N.H.– Neutral for the Tropics and the S.H. (no MODIS assimilation in these regions in this test.)– Change in the Arctic spread to the lower latitudes.
• RMS forecast error of wind vectors were reduced.– Especially, improvements at 500hPa was remarkable. ( 500hPa was the level with maximum data number)
• Improvements on typhoon track prediction
– Small, but positive impacts were found at the later stage in the forecasts.
July 19, 2005 EMC Sack Lunch Seminar
Anomaly Correlation of 500hPa height
TEST:With MODISTEST:With MODISCNTL:Without MODISCNTL:Without MODIS
Large improvements were found for the forecast scoreLarge improvements were found for the forecast score..
MODIS polar winds assimilation in the Arctic
July 19, 2005 EMC Sack Lunch Seminar
Impacts on Forecast by MODIS polar winds• RMSE at 500hPa
– Large improvement for both seasons in the polar region
– Change in the polar regions spread to the lower latitudes.
RMS forecast error difference for 500hPa Z TEST minus CNTL
• Monthly mean difference for July 2003
1day forecast1day forecast 3day forecast3day forecast 5day forecast5day forecastPositive Impacts of MODIS (negative difference) spread to mid-latitudes with Positive Impacts of MODIS (negative difference) spread to mid-latitudes with procession of forecast.procession of forecast.
July 19, 2005 EMC Sack Lunch Seminar
Impacts on Forecast
• Anomaly Correlation and RMSE at 500hPa– Large improvement for both seasons by 9-day forecasts– Neutral for the tropics and the S.H. (no MODIS assimilation)– Change in the Arctic spread to the lower latitudes.
• RMS forecast error of wind vectors were reduced.– Especially, improvements at 500hPa were remarkable. ( 500hPa was the level with maximum data number)
• Improvements on typhoon track prediction
– Small, but positive impacts were found at the later stage in the forecasts.
July 19, 2005 EMC Sack Lunch Seminar
Zonal mean of RMSE of Wind Speed at 500hPa( 5-day forecasts,January2004 )
ImprovementImprovement
ImprovementImprovement
July 19, 2005 EMC Sack Lunch Seminar
Impacts on Forecast
• Anomaly Correlation and RMSE at 500hPa– Large improvement for both seasons by 9-day forecasts– Neutral for the tropics and the S.H. (no MODIS assimilation)– Change in the Arctic spread to the lower latitudes.
• RMS forecast error of wind vectors were reduced.– Especially, improvements at 500hPa was remarkable. ( 500hPa was the level with maximum data number)
• Improvements on typhoon track prediction
– Small, but positive impacts were found at the later stage in the forecasts.
July 19, 2005 EMC Sack Lunch Seminar
Mean positional error of typhoon track predictions
• 22 events in July 2003
• Neutral or slightly positive at the later stage in the forecast time.Neutral or slightly positive at the later stage in the forecast time.
July 19, 2005 EMC Sack Lunch Seminar
Summary• The MODIS polar winds assimilation experiments were performed at JMA
– Period:July 2003, January 2004
– Used data:Aqua/MODIS,Terra/MODIS in the Arctic
– QC
• Over land, above 400hPa for IR and WV
• Over ocean, above 700hPa for IR and 550hPa for WV
– Data thinning 150km(horizontal) 100hPa(vertical)
• Results
– Improvements on the analysis and first guess in the Arctic.
– Large positive impacts on forecasts for both seasons. ( height, temperature, wind fields)
– Improvements on the typhoon track prediction.
Since 27 May 2004, operational use in the Arctic
Since 16 Sep 2004, operational use in the Antarctic
July 19, 2005 EMC Sack Lunch Seminar
The change of Quality of MODIS polar winds
After June 2004, both data became similar.Same algorithm for retrieval, and same first guess for height assignment.
Wind speed comparison between CIMSS and NESDIS
CIMSS changed the first guess for height assignment from NAVY model to GFS in June 2004.
July 19, 2005 EMC Sack Lunch Seminar
Next…
July 19, 2005 EMC Sack Lunch Seminar
Improvement of operational forecast score
12-month averageForecast score of JMA global model is rapidly improving.
July 19, 2005 EMC Sack Lunch Seminar
RMSE of 500hPa height against initial
1day forecast 5day forecastN.H. N.H.
5day forecast S.H.1day forecast S.H.
July 19, 2005 EMC Sack Lunch Seminar
Conclusion
• ATOVS level 1C radiance data are used in JMA global data assimilation system operationally.
• MODIS polar winds data are used in JMA global data assimilation system operationally.
• In virtue of these data and 4D-Var system, operational forecast score of JMA global model is improving rapidly.
Filling data poor region(space) with satellite data make better analysis and better forecast.
Next step:
Effective data usage for 4D-Var. Intelligent data thinning and Quality control for 4D-Var time slot in the assimilation window.
Use of new satellite data (AIRS, SSMI, AMSR-E, SSMIS, etc…)
July 19, 2005 EMC Sack Lunch Seminar
Thank you.