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MOPITT CO. Louisa Emmons, David Edwards Atmospheric Chemistry Division Earth & Sun Systems Laboratory National Center for Atmospheric Research. MOPITT CO 700 hPa CO Zonal Average Mixing Ratio. The Northern Hemisphere winter maximum occurs March-April
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MOPITT CO Louisa Emmons, David Edwards Atmospheric Chemistry Division Earth & Sun Systems Laboratory National Center for Atmospheric Research
MOPITT CO 700 hPa CO Zonal Average Mixing Ratio • The Northern Hemisphere winter maximum occurs March-April • The peak of the Southern Hemisphere biomass burning maximum occurs each year in September-October with variable intensity • Most monthly anomalies can be attributed to sporadic wildfires and variations in annual biomass burning
Near-Real-Time MOPITT CO Retrievals For field campaigns (e.g., INTEX-B) we can request expedited data within a few hours of overpass for region of interest
Rapid Response Data As part of our standard procedure we produce retrievals within 1 day based only on MOPITT measurements (60S-60N) April 20, 2006 - 700 hPa
Operational Retrievals Make use of MODIS cloud mask product, so are not available until that is received (at least 2 days) April 20, 2006 - 700 hPa
MOPITT CO Retrievals MOPITT CO retrievals are determined by maximum likelihood (optimal estimation), incorporating a priori information. The retrieved profilex' can be expressed as a linear combination of the true profile x and the a priori profile xa. x'= A x + (I-A) xa The Averaging Kernel Arepresents the measurement sensitivity to the true profile. I is the identity matrix. Averaging kernels depend on the contrast between air and surface temperature and surface emissivity.
+ Transformation of in situ Profiles The averaging kernels and a priori CO profile are used to calculate x' from in situ CO (x): x'= A x + (I-A) xa For example, x'(700 hPa) = A700x + (I-A700) xa
MOPITT x x'
MOPITT/MOZART in INTEX-B Investigating the transport and transformation of gases and aerosols from Asia on trans-Pacific scales and assess their impact on air quality and climate • Campaign flight planning is aided by the ability to forecast the occurrence of pollution plumes • For the Spring 2006 NSF/NCAR MIRAGE and NASA INTEX-B campaigns, a pollution plume predictive capability was provided by the assimilation of near-real-time MOPITT CO data into the MOZART CTM NASA DC-8 from NCAR C-130
During: Fire emissions model (Wiedinmyer) & NRT Terra/MODIS fire counts • After: GFED-v2 (van der Werf et al.) emissions scaled by MODIS 8-day fire counts • Expedited MOPITT NRT data within a few hours of overpass • NCAR processing within 9 hours in ‘Rapid Response’ mode • Plots posted on MOPITT website Forecasting Pollution Plumes For each day of MIRAGE & INTEX-B: • MOZART with assimilation of MOPITT CO and full chemistry (2.8°x2.8°) run for past 3 days • CO forecasts initialized with assimilation • 3 day forecast CO and tags run at 0.7°x0.7° for flight planning
Plume Origins MOPITT 700 hPa CO April ‘06 This was fairly ‘typical’ cf. the same month during other MOPITT years MOZART Tracer @ 500 hPa 36 hr Fx 1000 UTC 24 Apr. SE Asia bb • CO emissions from different regions and sources were tagged to identify different contributions to the observations • Chinese emissions dominated and BB plumes contributed less than expected • Dynamics played a large role in mixing plumes China ffbf
MOPITT/MOZART CO Forecast for HI Flight Planning 04/23/06 • Reduced contribution of SE Asia BB in forecast • Lower plume @ 30N primarily Chinese ffbf • Upper plume @ 40N has a bb component though is still primarily Chinese ffbf
C-130 CO Flights 17 to 22 Data: Teresa Campos, NCAR CO, ppbv Flight 1 min Obs Points DC-8 CO Flights 10 to 14 Data: Glen Sachse, NASA LaRC CO, ppbv OBS WITH MOPITT ASSIM (R=0.69) W/O MOPITT ASSIM (R=0.62) Flight 1 min Obs Points Forecast Comparison with Flight Data EKF assimilation of U,V, T and MOPITT CO in CAM-Chem Out of Seattle WA 04/17-05/01 OBS WITH MOPITT ASSIM (R=0.72) W/O MOPITT ASSIM (R=0.63) Out of Honolulu HI 04/17-05/01
MOPITT CO Interannual variability 2006 appears to have an average amount of CO over the Pacific during April-May Gabriele Pfister
MOPITT Validation - INTEX-B Very few spirals were performed coincident with Terra overpasses, but many along-track profiles were roughly coincident Within 200 km and 13 hours: DC-8: 11 C-130: 16 As seen previously, MOPITT shows a positive bias compared to in situ observations The MOPITT team continues to investigate the cause of the bias (instrument, a priori, retrievals, etc.) and hopes to reduce it in the next retrieval version Colored points: NOAA/GCD network profiles (P. Novelli) C130: Teresa Campos, NCAR DC8: Glen Sachse, NASA Langley