Presentation on theme: "MOPITT CO Louisa Emmons, David Edwards Atmospheric Chemistry Division Earth & Sun Systems Laboratory National Center for Atmospheric Research."— Presentation transcript:
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, hPa
Operational Retrievals Make use of MODIS cloud mask product, so are not available until that is received (at least 2 days) April 20, hPa
MOPITT CO Retrievals MOPITT CO retrievals are determined by maximum likelihood (optimal estimation), incorporating a priori information. The retrieved profile x' can be expressed as a linear combination of the true profile x and the a priori profile x a. x' = A x + (I-A) x a The Averaging Kernel A represents 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) x a For example, x' (700 hPa) = A 700 x + (I-A 700 ) x a +
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
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 Expedited MOPITT NRT data within a few hours of overpass NCAR processing within 9 hours in ‘Rapid Response’ mode Plots posted on MOPITT website 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 Forecasting Pollution Plumes
Plume Origins 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 MOZART 500 hPa 36 hr Fx 1000 UTC 24 Apr. SE Asia bb China ffbf MOPITT 700 hPa CO April ‘06 This was fairly ‘typical’ cf. the same month during other MOPITT years
MOPITT/MOZART CO Forecast for HI Flight Planning 04/23/06 Reduced contribution of SE Asia BB in forecast Lower 30N primarily Chinese ffbf Upper 40N has a bb component though is still primarily Chinese ffbf
Forecast Comparison with Flight Data Data: Teresa Campos, NCAR Flight 1 min Obs Points CO, ppbv Flight 1 min Obs Points DC-8 CO Flights 10 to 14 OBS WITH MOPITT ASSIM (R=0.69) W/O MOPITT ASSIM (R=0.62) Data: Glen Sachse, NASA LaRC C-130 CO Flights 17 to 22 OBS WITH MOPITT ASSIM (R=0.72) W/O MOPITT ASSIM (R=0.63) EKF assimilation of U,V, T and MOPITT CO in CAM-Chem Out of Seattle WA 04/17-05/01 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