Page 1 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 Monitoring of SCIAMACHY Total Column Ozone Using the DAO Ozone DAS Authors: N. Winslow, I. Stajner, R. Rood

Page 2 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 Outline  Overview of the DAO Ozone DAS  Monitoring of SCIAMACHY total column ozone (TOZ)  all data  data that passed a simple quality control  Summary

Page 3 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December Statistical Analysis 1. Tracer Transport Model Winds Assimilated O3 Data: TOMS SBUV MLS Forecast & Observation Error Models 4. HALOE Sondes Monitored Data: SCIAMACHY (MIPAS GOMOS) 3. Analysis Short term forecast 3a. Analysis Increments 3b. Observations-Forecast (O-F)

Page 4 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 Overview of the Ozone DAS  Tracer transport model (2x2.5) uses near real time fv-DAS winds with parameterized chemistry  SBUV profile and total column values are actively assimilated  SCIAMACHY total column values are monitored  Software to actively assimilate MIPAS, GOMOS and SCHIAMCHY is being developed

Page 5 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 Results with all SCIAMACHY TOZ data  Pds2Ascii v converts RV_2 to DAS format  Geolocation matched to observations using dsr time  Data screened with provided quality flag  Daily global RMS of O-F residuals are very large, typically over 200 D.U.

Page 6 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 Results with all SCIAMACHY TOZ data  Time series of the zonal daily RMS of O-F residuals (D.U.)  Large values concentrated in southern and northern high latitudes  Large values appear to be near the terminator of high solar zenith angles

Page 7 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002  Time series of the zonal daily mean of reported error of observations (%)  Larger and smaller values of precision follow a distribution similar to that seen in zonal daily RMS of O-F residuals Results with all SCIAMACHY TOZ data

Page 8 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002  Daily regional mean of reported error in observations (%)  Large values are concentrated in space  Most (>99%) large RMS values correspond to a reported error larger than 1.2% or equal to 0.0% Results with all SCIAMACHY TOZ data

Page 9 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 Results with quality controlled SCIAMACHY TOZ  Times series of the daily global RMS of O-F residuals  Quality control is a range check: 100DU <ozone< 1000DU  Daily global RMS between SCIAMACHY TOZ and DAO forecast of TOZ is between 30 and 40 D.U.

Page 10 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002  Time series of the zonal RMS of O-F residuals (D.U.)  Larger RMS O-F residuals concentrated in the northern and southern high latitudes  Pattern similar to data without quality control, but magnitudes are smaller Results with quality controlled SCIAMACHY TOZ

Page 11 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002  Time series of the zonal mean of O-F residuals (D.U.)  SCIAMACHY TOZ lower than DOA TOZ forecast by 25, 30, and 35 D.U in the northern mid latitudes, tropics, and southern mid latitudes respectively  Some evidence of the zonal pattern seen in data without quality control Results with quality controlled SCIAMACHY TOZ

Page 12 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002  Regional means of O-F residuals (D.U.)  Large values are concentrated in space  Most (>99%) large RMS values correspond to a reported error larger than 1.2% or equal to 0.0% Results with quality controlled SCIAMACHY TOZ

Page 13 Validation by Model Assimilation and/or Satellite Intercomparison - ESRIN 9–13 December 2002 Summary of SCIAMACHY TOZ Monitoring  Data without external quality control generates RMS O-F residuals larger than 200 D.U.  Simple quality control reduces the global RMS of O-F residuals to D.U.  Large O-F residuals are tightly concentrated in northern and southern high latitudes at what appear to be high solar zenith angles, but this information is not yet provided in the data  Reported errors show a similar spatial distribution  Quality controlled data tends to be smaller than forecasted total column ozone by about 35 D.U.