MOPITT CO

Louisa Emmons, David EdwardsAtmospheric 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 profile x' 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 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) xa

For example, x'(700 hPa) =

A700 x + (I-A700) xa

+

MOPITTx 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 CTMNASA DC-8 from NCAR C-130NASA 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 Tracer @ 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 plume @ 30N primarily Chinese ffbf•Upper plume @ 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

, ppb

vC

O, p

pbv

Flight 1 min Obs Points

DC-8 CO Flights 10 to 14DC-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 22C-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, NCARDC8: Glen Sachse, NASA Langley