1. The Ozone ENSO Index (OEI) Skip Navigation (press 2) + NASA Portal + Text Only Site FIND IT @ NASA: HOME MEASUREMENTS TOOLS NEWS FAQ OMI Global Images 2012 February 2012 SunSun MonMon TueTue WedWed ThuThu FriFri SatSat 132132 233233 334334 435435 536536 637637 738738 839839 940940 10411041 11421142 12431243 13441344 14451445 15461546 16471647 17481748 18491849 19501950 20512051 21522152 22532253 23542354 24552455 25562556 26572657 27582758 28592859 29602960 March 2012 SunSun MonMon TueTue WedWed ThuThu FriFri SatSat 161161 262262 363363 464464 565565 666666 767767 868868 969969 10701070 11711171 12721272 13731373 14741474 15751575 16761676 17771777 18781878 19791979 20802080 21812181 22822282 23832383 24842484 25852585 26862686 27872787 28882888 29892989 30903090 31913191 April 2012 SunSun MonMon TueTue WedWed ThuThu FriFri SatSat 192192 293293 394394 495495 596596 697697 798798 899899 91009100 1010110101 1110211102 1210312103 1310413104 1410514105 1510615106 1610716107 1710817108 1810918109 1911019110 2011120111 2111221112 2211322113 2311423114 2411524115 2511625116 2611726117 2711827118 2811928119 2912029120 3012130121 May 2012 SunSun MonMon TueTue WedWed ThuThu FriFri SatSat 11221122 21232123 31243124 41254125 51265126 61276127 71287128 81298129 91309130 1013110131 1113211132 1213312133 1313413134 1413514135 1513615136 1613716137 1713817138 1813918139 1914019140 2014120141 2114221142 2214322143 2314423144 2414524145 2514625146 2614726147 2714827148 2814928149 2915029150 3015130151 3115231152 June 2012 SunSun MonMon TueTue WedWed ThuThu FriFri SatSat 11531153 21542154 31553155 41564156 51575157 61586158 71597159 81608160 91619161 1016210162 1116311163 1216412164 1316513165 1416614166 1516715167 1616816168 1716917169 1817018170 1917119171 2017220172 2117321173 2217422174 2317523175 2417624176 2517725177 2617826178 2717927179 2818028180 2918129181 3018230182 July 2012 SunSun MonMon TueTue WedWed ThuThu FriFri SatSat 11831183 21842184 31853185 41864186 51875187 61886188 71897189 81908190 91919191 1019210192 1119311193 1219412194 1319513195 1419614196 1519715197 1619816198 1719917199 1820018200 1920119201 2020220202 2120321203 2220422204 2320523205 2420624206 2520725207 2620826208 2720927209 2821028210 2921129211 3021230212 3121331213 August 2012 SunSun MonMon TueTue WedWed ThuThu FriFri SatSat 12141214 22152215 32163216 42174217 52185218 62196219 72207220 82218221 92229222 1022310223 1122411224 1222512225 1322613226 1422714227 1522815228 1622916229 1723017230 1823118231 1923219232 2023320233 2123421234 2223522235 2323623236 2423724237 2523825238 2623926239 2724027240 2824128241 2924229242 3024330243 3124431244 September 2012 SunSun MonMon TueTue WedWed ThuThu FriFri SatSat 12451245 22462246 32473247 42484248 52495249 62506250 72517251 82528252 92539253 1025410254 1125511255 1225612256 1325713257 1425814258 1525915259 1626016260 1726117261 1826218262 1926319263 2026420264 2126521265 2226622266 2326723267 2426824268 2526925269 2627026270 2727127271 2827228272 2927329273 3027430274 October 2012 SunSun MonMon TueTue WedWed ThuThu FriFri SatSat 12751275 22762276 32773277 42784278 52795279 62806280 72817281 82828282 92839283 1028410284 1128511285 1228612286 1328713287 1428814288 1528915289 1629016290 1729117291 1829218292 1929319293 2029420294 2129521295 2229622296 2329723297 2429824298 2529925299 2630026300 2730127301 2830228302 2930329303 3030430304 3130531305 Calendar Dates Dates in the calendar are formatted as follows: Upper #: Day of Month Lower #: Day of Year + Home Ozone and Air Quality Measurements Instruments Multimedia Tools News Archive FAQ Documentation Discussion Quality Assessment Known Issues Ozone Hole + Privacy Policy and Important NoticesPrivacy Policy and Important Notices NASA Official: Richard D. McPeters Website Manager: Arnold MartinArnold Martin Web Curator: David LarkoDavid Larko

2. The El Nino-Southern Oscillation Quasi-periodic variation in tropical Eastern Pacific SSTs and the associated atmospheric circulation.

3. Climatological conditions L H

4. El Nino conditions L H Southern Oscillation Index: pressure difference between Tahiti and Darwin. DarwinTahiti Southern Oscillation Index is negative for an El Nino

5. La Nina conditions LH Southern Oscillation Index is positive for an La Nina

6. Why do we care?

7. ENSO Indices  Nino 3.4 SSTs 5 month running means of monthly SST anomalies are 0.5C or more for at least 6 consecutive months  Southern Oscillation Index Darwin Tahiti Opposite sign to the Nino 3.4 SST index. Often used together with SSTs e.g. Japanese Met service

8. ENSO Indices  Precipitation in the tropical Pacific  OLR anomalies  Multi-variate ENSO index uses 6 of the main observed variables over the tropical Pacific: SLP, U, V, SST, SAT, Cloud fraction.

9. ENSO Indices Why do we need more? Motivation 1: All these ENSO indices rely on measurements of absolute fields at any point in time…instrument drift and calibration between different instruments could be a problem. Motivation 2: Devise a metric that could be used to test GCMs that are aiming to simulate variability and change in tropospheric ozone.

11. JANJUL Climatological Ozone UV + O 2  O, O + O 2  O 3 http://www.knmi.nl/research/climate_chemistry/Data/FKClimatology/ NO x from lightening. NO x and CO from biomass burning, soil. Strat-trop exchange. Anthropogenic NO x, CO and VOC emissions

12. http://acd-ext.gsfc.nasa.gov/Data_services/cloud_slice/#nd Climatological tropospheric ozone from OMI AURA/MLS from 2004 to 2009 Wavenumber 1 structure: more ozone in the Atlantic than the Pacific. Martin et al (2001) – Atlantic enhancement primarily due to combination of lightening NO x and dynamics. Climatological Tropospheric Ozone

14. Influence of Convection on tropospheric ozone Possibilities:  Mixing of ozone poor/rich air by the convective updrafts and downdrafts  Uplift of ozone precursors into the free troposphere.  Uplift of things that destroy ozone precursors into the free troposphere.

15. Influence of Convection on tropospheric ozone  Lelieveld and Crutzen (1994) – Suggest that globally convection reduces tropospheric ozone concentrations by 20%. Convective updrafts transport boundary layer air into the upper troposphere where O3 production is higher and destruction is lower. But, compensating down drafts transport ozone rich air downward to the surface where it can be more effectively removed. Balance between these two effects.  Lawrence et al (2003) – Globally convection increases tropospheric ozone concentrations by 12%. Convection lifting surface NOx emissions into the upper troposphere  more ozone production.  Doherty et al (2005) – Different chemistry scheme. Convection  lifts isoprene  reacts with NOx  less NOx BUT oxidation of isoprene  more HOx  more O3 production.  Argument used for the wave 1 in the climatology and the ENSO changes in these papers is that convective updrafts lift low ozone air from the boundary layer up into the free troposphere   Convection  Less ozone

16. ENSO Influence on Tropospheric Ozone Tropospheric TOC differences between October 1997 (big El Nino) and October 1996 (neutral conditions)  Drier Indonesia  more biomass burning  more NO x, CO  more O 3  Reduced convection  more total column ozone  Enhanced convection  less total column ozone Chandra et al (1998) DecreaseIncrease

18. They want to look at variability in tropospheric column ozone with ENSO from total column ozone measurements. Get the tropospheric ozone out from the measurements and derive the ENSO index and show that it works. Demonstrate that actually using total column ozone also works quite well given the zonal invariance of stratospheric column ozone  somewhat easier to calculate. Demonstrate their method for deriving tropospheric column ozone from total column ozone works well. Demonstrating that stratospheric column ozone is quite zonally invariant.

19. Satellite observations of Ozone  1979-1993 Nimbus 7 TOMS (Total Ozone Mapping Spectrometer)  1993-1996 SBUV/2 (Solar Backscatter Ultraviolet)  1996-2004 Earth Probe TOMS  2004-2009 OMI (Ozone Monitoring Instrument) and MLS (Microwave Limb Sounder) Polar Orbitting, Measures vertical profiles of stratospheric ozone as well as total column ozone using a variety of UV wavelengths. Daily global coverage. Using back-scattered UV in 6 wavelength bands. Like TOMS but on a different satellite Backscattered UV and Visible. Measures more constituents than TOMS. OMI MLS Limb sounding measurements of microwave emissions for vertical profiles

20. EARTH SURFACE Absorption/ scattering by Earth surface and atmosphere Observation by solar backscatter Total ozone column and surface reflectivity is derived by measuring the backscattered light from two wavelengths, one that is strongly absorbed by ozone and one that is absorbed very little. Radiative transfer calculation based on conditions of measurement e.g. viewing angle, latitude, surface reflectance with various different total ozone columns. Figure out which one gives you the reflectance you measure.  Gridded: they’ve already done all the calculation of total column ozone. Got rid of pixels where clouds are interfering etc.  Level 2 footprint measurements (nasa term). Levels describing how processed the data is. Level 2 has been processed to give you the ozone that the satellite sees. But they haven’t taken out e.g. measurements affected by clouds or put it on a uniform grid.

21. The Convective Cloud Differential (CCD) method Used to derive tropospheric ozone column under the assumptions….. (1) Deep convective clouds in the tropical pacific have physical cloud tops which often lie at or near the tropopause. (2) Zonal variability of stratospheric column ozone in these latitudes is small to within a few DU. Ziemke et al 1998

22. Testing the zonally invariance of stratospheric ozone using MLS ozone MLS provides vertical profiles of stratospheric ozone  can measure stratospheric ozone column directly. Using monthly means.

23. Testing the zonally invariance of stratospheric ozone using MLS ozone MLS provides vertical profiles of stratospheric ozone  can measure stratospheric ozone column directly Quite zonally invariant. At most 4DU (<2%).

24. Testing the zonally invariance of stratospheric ozone using MLS ozone MLS provides vertical profiles of stratospheric ozone  can measure stratospheric ozone column directly Quite zonally invariant. At most 4DU (<2%). Only small deviations from the zonal mean when you de- seasonalise.

25. Testing the zonally invariance of stratospheric ozone using MLS ozone Even zonally invariant using daily data. When there are sufficient numbers of deep convective clouds in the Pacific, the CCD method can be used to derive SCO and subsequently TCO on short timescales, even daily, to an accuracy of +/- 2DU.

26. Testing the zonally invariance of stratospheric ozone using GEOS-CCM GCM with interactive stratospheric Chemistry. Internally generated QBO.

27. MODEL MLS Why?  Strong zonal winds compared to meridional winds.  Weak meridional gradients of ozone in the tropics.  Very small zonal variations in the production and destruction of ozone in the tropics.

28. If you use the Convective Cloud Differential method to get stratospheric column ozone over regions with high cloud  you can get tropospheric column ozone at other longitudes.

29. MLS SCO and CCD derived SCO agree well  can use CCD derived TCO measurements to obtain a long term record of TCO

30. Zonal dipole anomalies in tropospheric column ozone associated with El Nino and La Nina events.

31. Deriving the Ozone ENSO Index  Temporal cross correlations of Nino3.4 and SOI ENSO indices Averaged TCO over these areas. Use West –East, monthly

32. Agrees well with Nino3.4 and SOI Index

33. Could also just use total column ozone measurements

34. Error associated with assumption of stratospheric zonal invariance

35. The Ozone ENSO Index Motivation 1: All these ENSO indices rely on measurements of absolute fields at any point in time…instrument drift and calibration between different instruments could be a problem. Motivation 2: Devise a metric that could be used to test GCMs that are aiming to simulate variability and change in tropospheric ozone.

36.  Goddard Earth Observing System (GEOS-5) GCM  Coupled to the Global GMI stratosphere-troposphere chemical mechanism (interactive chemistry in both troposphere and stratosphere).  117 chemical species, 322 chemical reactions, 81 photolysis reactions.  Includes the O 3 -NO x -Hydrocarbon chemistry necessary for the simulation of tropospheric ozone.  Simulation forced with observed SSTs. (1985-2009)

38. Obs Model

39. Model (25y)

40. Comparing the Ozone ENSO Index

41. Looking at the vertical structure of ozone anomalies using the model Regressed the de- seasonalised ozone onto the Nino 3.4 index averaged between 15S and 15N

42. The Latitudinal Structure

43. Comparing vertical profiles with ozonesondes The SHADOZ network.

45.  They used this to test whether a CCM can reproduce the observed tropospheric ozone variability  it does.  They plan to do a full budget analysis of the ozone changes in the future. Conclusions  A new ENSO index has been derived based on satellite measurements of total column ozone.  Because they are looking at differences between western and eastern Pacific it is self calibrating.  Further examination of the vertical, longitudinal and latitudinal variations in the ozone response demonstrate a relationship with changes in the atmospheric circulation.

46. Current Conditions http://cpc.ncep.noaa.gov http://www.temis.nl/protocols/o3col/ data/omi/o3doas_today.gif