The Impact of Observational data p on Numerical Weather Prediction - PowerPoint PPT Presentation

The Impact of Observational data p on Numerical Weather Prediction Hirokatsu Onoda Numerical Prediction Division, JMA

Outline • Data Analysis system of JMA in Global Spectral Model (GSM) and Meso-Scale Model (MSM) p ( ) ( ) • • The impact of assimilated observations The impact of assimilated observations global view of the impact of observations on the quality of the forecast • Quality Control and inappropriate observation for NWP system NWP system • Gl b l D t Global Data Monitoring Report M it i R t 27-30 July, 2010 JMA/WMO Workshop on Quality Management in Surface, Climate and Upper-air Observations in RA II

Specification of NWP Models JMA operates the following NWP deterministic models: 1) Th 1) The Global Spectral Model (GSM) for the short and medium range forecast Gl b l S l M d l (GSM) f h h d di f up to nine days ahead to cover the entire globe, 2) The Mesoscale Model (MSM) for warnings and the very short-range forecast of precipitation to cover Japan and its surrounding areas. Grid size and/or Domains and Forecast hours Initial number of grid, topography (Initial time) condition Vertical levels/top Vertical levels/top 0.1875 deg. 84 hours (TL959) (TL959), (00,06,18 UTC) (00 06 18 UTC) 4D Var 4D-Var GSM analysis 216 hours 60 / 0.1hPa (12 UTC) Globe Globe 15 hours (00,06,12,18 5km / 721x577, 5km / 721x577, UTC) 4D-Var MSM analysis 33 hours Japan and its 50 / 21,800m (03 09 15 21 (03,09,15,21 surrounding surrounding UTC) areas 27-30 July, 2010 JMA/WMO Workshop on Quality Management in Surface, Climate and Upper-air Observations in RA II

Details of data use on NWP system Ob Observation ti I nstrument Global Analysis Mesoscale Analysis 650,000 820,000 type SYNOP Pressure Pressure AMeDAS* Rain (Analyzed Rain) 20% Ship, Buoy Pressure Pressure Importance is still high Conventional Pressure, Wind, Temperature, Pressure, Wind, Temperature, RAOB RAOB Relative Humidity Relative Humidity Aircraft Wind, Temperature Wind, Temperature Wind profiler Wind Wind Radar reflectivity (Analyzed Rain), Ground based Radar Doppler velocity remote sensing GPS GPS Total precipitable water Total precipitable water 80% VIS IR radiometer AMV , Radiance (clear sky) AMV IR MW sounder Radiance (clear sky) Radiance (Temperature) Satellite MW imager Radiance (clear sky) Radiance (TPW, Rain rate) Scattrometer Surface wind Surface wind GPS-RO* * GPS RO Refractivity Refractivity * Automated Meteorological Data Acquisition System * * GPS radio occultation 27-30 July, 2010 JMA/WMO Workshop on Quality Management in Surface, Climate and Upper-air Observations in RA II

Outline • Data Analysis system of JMA in Global Spectral Model (GSM) and Meso-Scale Model (MSM) p ( ) ( ) • • The impact of assimilated observations The impact of assimilated observations global view of the impact of observations on the quality of the forecast • Quality Control and inappropriate observation for NWP system NWP system • Gl b l D t Global Data Monitoring Report M it i R t 27-30 July, 2010 JMA/WMO Workshop on Quality Management in Surface, Climate and Upper-air Observations in RA II

Departure of observation and background Definition of words Background : forecast from previous analysis i.e. in GSM, 12UTC’s background is 06UTC’s 6 hour forecast 12UTCs background is 06UTCs 6-hour forecast. O ‐ B : ( O bservation) – ( B ackground) ( ) ( g ) usable for an index of the precision of the forecast or the observation 27-30 July, 2010 JMA/WMO Workshop on Quality Management in Surface, Climate and Upper-air Observations in RA II

Basis of Data Analysis system Schematic view of data analysis system (mean sea-level pressure) In data analysis system In data analysis system, observation revise the error of the model Time sequence of observation based on departure of White line : Background (input) White line : Background (input) observation and Red point : Observation (input) background (O-B). Red line : Analysis (output) Colored area : Increment (output) Colored area : Increment (output) *quantity of revision by analysis 27-30 July, 2010 JMA/WMO Workshop on Quality Management in Surface, Climate and Upper-air Observations in RA II

Experiment without ground ‐ based conventional observation (SYNOP, Radiosonde) #1 ( , ) OPERATIONAL Mean Sea-Level pressure O-B at SYNOP stations. T Term of experiment: f i t from 20 th Dec 2009 to 09 th Feb 2010 1 day 7 days later Difference of O ‐ B increased through the analysis ‐ forecast cycle. Continuous observation Continuous observation is important for forecast field. EXPERIMENT 27-30 July, 2010 JMA/WMO Workshop on Quality Management in Surface, Climate and Upper-air Observations in RA II

Experiment without ground ‐ based conventional observation (SYNOP, Radiosonde) #2 ( , ) Large difference b t between OPERATIONAL and EXPERIMENT Small difference between OPERATIONAL and EXPERIMENT 27-30 July, 2010 JMA/WMO Workshop on Quality Management in Surface, Climate and Upper-air Observations in RA II

Experiment without ground ‐ based conventional observation (SYNOP, Radiosonde) #3 ( , ) 3 • Density of the observation point may be important may be important. • Satellite observation makes the Satellite observation makes the land a weak point. 27-30 July, 2010 JMA/WMO Workshop on Quality Management in Surface, Climate and Upper-air Observations in RA II

DFS (Degrees of Freedom for Signal) Which type of data had the greater influence? Which type of data had the greater influence? Langland and Baker suggest to estimate the observation impact. to estimate the observation impact Investigated by JMA All conventional Scatterometer Scatterometer AMV Large DFS means large Aircraft impact to forecast. impact to forecast RAOB RAOB Small DFS means small All radiance Imager impact to forecast. AMSR AMSR TMI Conventional data still SSM/I plays important roll plays important roll. AMSU B AMSU-B AMSU-A DFS values of each observation type (%) 27-30 July, 2010 JMA/WMO Workshop on Quality Management in Surface, Climate and Upper-air Observations in RA II

Outline • Data Analysis system of JMA in Global Spectral Model (GSM) and Meso-Scale Model (MSM) p ( ) ( ) • • The impact of assimilated observations The impact of assimilated observations global view of the impact of observations on the quality of the forecast • Quality Control system and inappropriate observation for NWP system for NWP system • Gl b l D t Global Data Monitoring Report M it i R t 27-30 July, 2010 JMA/WMO Workshop on Quality Management in Surface, Climate and Upper-air Observations in RA II

Quality Control (QC) of observational data Observational data includes false report or deviating from a background. Used N t Not used d Δ u for Wind Profilers, 1 ～ 10 October 2009, 900 ～ 800hPa To reject these data, JMA perform Quality Control (QC) . Real-time QC (automatic) Non real-time QC (manual) 27-30 July, 2010 JMA/WMO Workshop on Quality Management in Surface, Climate and Upper-air Observations in RA II

Real ‐ time QC First Step Second Step • climatologically check • Gross error check • Gross error check • ship/flight path check Reject rough error • bias correction human error • • wind correction ind correction instrumental malfunction l lf • T lapse rate communication error etc. • interpolation (T,RH,wind) interpolation (T,RH,wind) • hydrostatic check • Spatial consistency check • ice (freezing) Compare with surrounding Compare with surrounding • wind shear observations • sea ‐ level correction Etc. Etc. 27-30 July, 2010 JMA/WMO Workshop on Quality Management in Surface, Climate and Upper-air Observations in RA II

Non real ‐ time QC Sometimes, data of low quality pass real–time QC. → real ‐ time QC is not perfect. p Blacklist is managed for these case. • Blacklist needs careful monitoring, and is updated when [ add ] [ add ] Platforms (stations, airplanes, ships, etc.) found to report biased or erratic observations [ remove ] The quality has returned to an accepted standard • Blacklisted observations are rejected before real ‐ time QC procedures. p 27-30 July, 2010 JMA/WMO Workshop on Quality Management in Surface, Climate and Upper-air Observations in RA II

Examples SYNOP,SHIP,BUOY : trouble of instrumentation Observation, Background Observation, Background continuously large difference blacklisted O-B O-B: used passed rejected O-B: used, passed, rejected Time sequence of Mean Sea-Level Time sequence of Mean Sea-Level pressure of SYNOP (WMO-ID:38944) pressure of Buoy (Call sign:17525) from 22 nd June to 8 th July 2010. from January to June 2010. Easy case to reject in real-time QC. Difficult case to reject in real-time QC. Inappropriate data were used in operational. 27-30 July, 2010 JMA/WMO Workshop on Quality Management in Surface, Climate and Upper-air Observations in RA II

Radiosonde : Quality of Indian Radiosonde observations has improved Term of blacklisted Improved Some other stations already Some other stations already unlisted. Time sequence of temperature O-B vertical profile e seque ce o te pe atu e O e t ca p o e from Jan 2008 to Dec 2009 at WMO-ID:43192 . At spring 2009, O-B became small suddenly. S Supplier of instrument has changed. li f i t t h h d 27-30 July, 2010 JMA/WMO Workshop on Quality Management in Surface, Climate and Upper-air Observations in RA II