QOS 2016 26 2016 Quadrennial Ozone Symposium of

QOS 2016 -26, 2016. Quadrennial Ozone Symposium of the International Ozone Commission QUALITY ASSESSMENT OF IASI/Metop-A AND OMI/Aura OZONE COLUMN AMOUNTS BY USING EUBREWNET GROUND-BASED MEASUREMENTS N. Peinado-Galán (1), X. Calbet (2), O. E. García (3), E. López-Baeza (1), A. Redondas (3), E. Sepúlveda (3), M. E. Koukouli (4), I. Zyrichidou (4), I. Fountoulakis (4), D. Balis (4), A. Bais (4), T. Karppinen (5), J. López-Solano (3), and B. Hernández-Cruz (3) (1) University of Valencia, Faculty of Physics, Earth Physics and Thermodynamics Dept, Climatology from Satellites Group, Valencia, Spain. , (2) State Meteorological Agency (AEMET), Madrid, Spain, (3) Izaña Atmospheric Research Center (IARC), State Meteorological Agency (AEMET), Santa Cruz de Tenerife, Spain, (4) Laboratory of Atmospheric Physics, Aristotle University of Thessaloniki, Greece, (5) Finnish Meteorological Institute (FMI), Arctic Research Centre, Sodankylä, Finland ABSTRACT This work addresses the comparison of IASI (Infrared Atmospheric Sounding Interferometer) on board Metop. A and OMI (Ozone Monitoring Instrument) on board Aura to several ground-based Brewer spectrophotometers belonging to the European Brewer network (EUBREWNET) for the period September 2010 to December 2015. The focus of this study is to examine how well the satellite retrieval products capture the total ozone column amounts (TOC) at different latitudes and evaluate the different levels of Brewer spectrophotometer data. On this comparison Level 1 and 1. 5 Brewer data will be used to evaluate satellite data, where: 1) Level 1 Brewer data are the TOC calculated with the standard Brewer algorithm from the direct sun measurements; and 2) Level 1. 5 Brewer data are Level 1. 0 observations filtered and corrected from instrumental issues. The IASI retrievals examined are operational IASI Level 2 products, version 5 from September 2010 to October 2014, and version 6 from October 2014 to December 2015, from EUMETSAT Data Centre, while OMI retrievals are OMI-DOAS TOC products extracted from the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC). FACTORS TO BE CONSIDERED IN THE COMPARISON IASI-BREWER-OMI: STUDY AREA A) Collocation criteria: - Temporal collocation criteria: 1, 2, 3, 4, and 6 hour time difference between the measurements of IASI and Brewer. IASI overpass times at 9: 30 local solar time. OMI overpass time over Europe: 12: 45 hours (GMT). • Sodankylä (Finland): highlatitude station (67. 42°N, 26. 59°E, 180 m a. s. l. ) - Spatial collocation: 5 collocation distances: 250 km, 200 km, 150 km, 100 km and 50 km between IASI and Brewer measurements. OMI spatial grid: 0. 25º lat, 0. 25º lon over station position. • Thessaloniki (North of Greece): mid-latitude station (40. 63º N, 22. 96º E, 36 m a. s. l). B) Vertical Sensitivity: IASI, OMI and Brewer techniques have different vertical sensitivity, what affects the comparison. IASI VERTICAL SENSITIVITY (from IASI v 6) • Izaña Atmospheric Observatory (IZO) (Tenerife, Canary Islands, Spain): sub-tropical station (28. 31º N, 16. 50º W, 2367 m a. s. l. ) Median of the sum along the row AVKS distinguishing for each season O 3 row AVKs for typical measurement conditions at IZO COMPARISONS Brewer 1. 0/1. 5 vs OMI-DOAS v 3 vs IASI L 2 v 5 : Comparison of total atmospheric integrated ozone from September 2010 to October 2014. Brewer 1. 0/1. 5 vs OMI-DOAS v 3 vs IASI L 2 v 6: Comparison of total atmospheric integrated ozone from October 2014 to December 2016. • The IASI’s response to real atmospheric O 3 variability strongly depends on its vertical sensitivity. • The vertical structures that are detectable by the IASI remote sensor are given by the AVKs. • Analysis based on the possible presence of clouds and the topography and the surface type (land/water) within the IASI v 6 IFOV is presented. IASI Sensitive to the max O 3 concentrations in the stratosphere and to the upper troposphere/lower stratosphere regions, but weak sensitivity in the lower troposphere. RESULTS IZO (28. 31º N, 16. 50º W, 2367 m a. s. l. ) Flag cldness=1 Flag Lansea=0 SUMMARY 3 STATIONS: TEMPORAL COLOCATION CRITERIA 1 h Colocation criteria: 100 km and 1 h • Mean and STD decreases for Brewer data L 1. 5 except in IZO • Differences are not independent of spatiotemporal criteria. • 100 km and 1 h spatiotemporal windows is a good compromision between the scatter and the nº of coincidences. • Corrected in Brewer Level 2. 0 p. e TOC Temporal Serie in IZO Thessaloniki (40. 63º N, 22. 96º E, 36 m a. s. l. ) Sodänkyla (67. 42°N, 26. 59°E, 180 m a. s. l. ) Flag cldness=1 Flag Lansea=0 Colocation criteria: 100 km and 1 h Mean differences decrease as space window increases systematicall y difference between IASI land ocean data Ocean +RD Land -RD SUMMARY TABLE: Spatial window 100 km. Temporal window +1 h IZO. 01/09/2014 – 31/12/2015 Cldness=[1, 2] Land/sea=0 R MEAN RD (%) STDV RD (%) BIAS (DU) IASI v 6 vs BREWER L 1. 5 0, 90 3, 6 3, 1 6, 5 IASI v 6 vs OMI 0, 83 2, 9 3, 7 3, 4 OMI vs BREWER L 1. 5 0, 92 0, 8 2, 4 2, 1 Thessaloniki. 01/09/2014 – 31/12/2015 N 484 484 IZO. 01/09/2010 – 31/08/2014 R MEAN RD (%) STDV RD (%) BIAS (DU) IASI v 6 vs BREWERL 1. 5 0, 90 0, 9 3, 4 9, 3 IASI v 6 vs OMI 0, 89 -0, 2 3, 1 -3, 6 OMI vs BREWER L 1. 5 0, 91 1, 2 3, 4 3, 3 N 620 620 Cldness=[1, 2] Land/sea=0 R MEAN RD (%) STDV RD (%) BIAS (DU) IASI v 6 vs BREWER L 1. 5 0, 94 3, 2 3, 1 3, 6 IASI v 6 vs OMI 0, 90 1, 9 4, 2 1, 6 OMI vs BREWER L 1. 5 0, 96 -1, 6 2, 4 -0, 8 Sodänkyla. 01/09/2014 – 31/12/2015 N 197 197 Cldness=[1, 2] Land/sea=1 R MEAN RD (%) STDV RD (%) BIAS (DU) N IASI v 6 vs BREWER L 1. 5 0, 97 3, 1 3, 9 10, 7 150 IASI v 6 vs OMI 0, 97 4, 2 4, 3 14, 2 150 OMI vs BREWER L 1. 5 0, 99 -1, 0 2, 6 -3, 4 150 Thessaloniki. 01/01/2013 – 31/08/2014 Sodänkyla. 01/09/2010 – 31/08/2014 R MEAN RD (%) STDV RD (%) BIAS (DU) N IASI v 6 vs BREWER L 1. 5 0, 93 -1, 9 3, 1 -6, 1 466 IASI v 6 vs OMI 0, 87 -0, 5 4, 2 -1, 8 466 OMI vs BREWER L 1. 5 0, 92 -1, 3 3, 3 -4, 4 466 R MEAN RD (%) STDV RD (%) BIAS (DU) N IASI v 6 vs BREWER L 1. 5 0, 97 2, 4 3, 4 7, 6 458 IASI v 6 vs OMI 0, 97 3, 4 4, 0 10, 3 458 OMI vs BREWER L 1. 5 0, 99 -0, 9 2, 2 -2, 8 458 CONCLUSIONS - The comparison of total ozone columns as retrieved by IASI v 6 and IASI v 5 to coincident ground-based ozone observations (Brewer) and other satellite-based sensor (OMI) show very consistent results at three stations. But IASI shows higher agreement with Brewer than with OMI at all locations. IASI overestimates TOC measurements registered with all sensors at three stations. The inter-comparison between IASI and Brewer results are shown to be dependent on the collocation criteria used: being the most ideal case the comparison between data with a max distance of 100 km and 1 hour of time difference between datasets (good scatter and high nº of coincidences). In addition, results show that differences between IASI and ground base measurements depend on cloud cover and topography. REFERENCES ACKNOWLEDGEMENTS - Balis, D. , Koukouli, M. , Loyola, D. , Valks, P. , and Hao, N. : O 3 M SAF second validation report of GOME-2 total ozone products, REF: SAF/O 3 M/AUTH/GOME 2 VAL/RP/02, 2008. - Clerbaux, C. , Boynard, A. , Clarisse, L. , George, M. , Hadji-Lazaro, J. , Herbin, H. , Hurtmans, D. , Pommier, M. , Razavi, A. , Turquety, S. , Wespes, C. , and Coheur, P. -F. : Monitoring of atmospheric composition using thermal infrared IASI/Met. Op sounder, Atmos. Chem. Phys. , 9, 6041– 6054, 2009. - Scarnato, B. , J. Staehelin, R. Stübi, and H. Schill (2010), Long‐term total ozone observations at Arosa (Switzerland) with Dobson and Brewer instruments (1988– 2007), J. Geophys. Res. , 115, D 13306, doi: 10. 1029/2009 JD 011908. We thank the European Brewer Network (http: //rbcce. aemet. es/eubrewnet/) for providing access to the data and the PI investigators and their staff for establishing and maintaining the sites used in this investigation.