The MOPITT Instrument on Terra:

1
The MOPITT Instrument on Terra Mission and Data
Processing Status
David P. Edwards, John C. Gille, James R.
Drummond, and the NCAR University of Toronto
MOPITT Teams
2
Recent Developments

• Version 3 CO Profile Production
• Cloud detection algorithm is now using a
  combination of MOPITT measurements and
  MODIS cloud mask
• Improved coverage at high
  latitudes
• Improved noise characterization
• Recovery of 40 of data
  compared with Version 2 data product
• Improved calibration scheme for Length Modulated
  Radiometers (LMRs)
• Improved low altitude
  comparison with aircraft validation
• Phase 2 CO Data (.after the MOPITT Side B cooler
  failure)
• New retrieval channel configuration was necessary
  after MOPITT Side B loss
• Improved radiance characterization for the
  low-altitude-sensitive Channel 5
• Recovery of a Phase 2 retrieval vertical
  resolution similar to that of Phase 1

David Edwards, NCAR
3
The New MOPITT V3 Data 700 hPa 1-12 Nov. 2000
Improved global coverage Improved
calibration Provisional level of validation

• Improved global coverage
• Improved calibration
• Provisional level of validation

David Edwards, NCAR
4
Data Processing

• Prior to the Version 3 Algorithm, operations
  focused primarily on ensuring
  scientific validity
• Now with a stable Version 3 algorithm, MOPITT
  processing has shifted priorities to
  operational production
• Two main concerns at this stage
• Transfer of L0 data to NCAR still problematic
  but improving
• Use of the MODIS cloud mask in the operational
  processing has recently created a bottleneck
  also improving

MODIS data gets sent to LDAAC where it is
co-located to MOPITT pixels. The results are sent
to NCAR for L2 Production.
David Edwards, NCAR
5
The MOPITT CO Data Collection - 11/13/02
Feb. 21 - Apr. 10 TRACE-P
May - Aug.01 Off Line Cooler Failure, Chopper
Failure, Instrument Tests
David Edwards, NCAR
6
MOPITT Level 3Gridded CO Product

• We are currently examining a gridded Level 2 data
  product to be delivered at Level 3 in the near
  future
• Less prone to misuse than an assimilated product
  which requires users to understand the interplay
  between data and model, and use the analysis and
  error fields together in their work

Aug. 1, 2000 850 mb
MOPITT Science Team decided that 1x1 degree daily
maps for day and night separately along with the
corresponding mean averaging kernels would be
most useful
Aug 2000 850 mb Monthly Mean
David Edwards, NCAR
7
MOPITT Shortwave Channels

• Use of the signals from the shortwave solar
  reflectance channels,
  2 and 6 for CO, 4 and 8 for CH4, has proved
  problematic to date
• This has prevented delivery of a CH4 column
  product and optimization of the CO total column
  retrieval with sensitivity to the lower
  troposphere
• Progress is now being made on these issues, and
  problems associated with the CH4 channel signals
  in particular are being resolved
• The signals in these channels have been plagued
  by very high noise which has been identified with
  two effects, one geophysical and the other
  instrumental
• We are now using MODIS data to help characterize
  surface reflectivity and radiance variability

Comparison of MOPITT 4A and MODIS B7 collocated
normalized clear pixel radiances. N. Africa 1-1-01
David Edwards, NCAR
8
Averaging Kernels andVertical resolution

• MOPITT profiles have been compared with aircraft
  in situ measurements taken at CMDL sites and
  during major field campaigns such as SAFARI-2K
  and TRACE-P
• Applying the MOPITT averaging kernel removes fine
  scale vertical structure
• Agreement is generally very good for latest V3
  data version

MOPITT In-Situ Avg Kernel x In-Situ
TRACE-P Flt. 11 2001-03-17
TRACE-P Flt. 16 2001-03-30
David Edwards, NCAR
In situ data from G. Sachse, NASA Langley
9
Future Processing Plans

• Version 3 Processing
• L2 currently at a rate of 6 days/day
• Currently limited by the availability of the
  co-located MODIS cloud mask
• Optimistically, processing could be completed
  mission-to-date in about 4 months
• Algorithm Improvements for Version 4
• Implement new calibration scheme for Pressure
  Modulated Radiometers (PMRs)
• Implement improved forward model for the PMR
  channels
• Cloud Clearing Use MODIS cloud mask to help
  reconstruct a clear pixel signal in the presence
  of partial cloud cover - potentially double
  coverage
• Investigate the use of a variable (location and
  season) a-priori in the retrieval
• Overcome issues currently hindering the inclusion
  of the CO shortwave solar reflectance channel
  signals in the retrieval
• Improve CO measurement sensitivity to the lower
  troposphere
• Produce a reliable CH4 column product

David Edwards, NCAR
10
Future Plans

• Data Quality Assessment and Validation
• Promote Phase-1 CO data to validated after
  science use
• Continue validation of Phase-2 data
• Comparison with A/C profile measurements from
  Trace-P, CMDL, others
• Comparison with ground based FTIR column
  measurements
• Enhancement of MOPITT website with interactive
  browse tools http//www.eos.ucar.edu/mopitt/
• Science
• Use of data to investigate CO seasonal and
  regional distributions
• Use CO for tropospheric ozone chemistry and
  transport studies
• Examination of sources and budgets using inverse
  modeling
• MOPITT special issue Algorithm, validation, and
  data application science
• Possible Future Activities
• Involvement in ENVISAT/SCIAMACHY and Aqua/AIRS
  validation
• Interaction with TES on Aura
• Collaboration with experimental group and field
  campaigns
• Evaluation of other instrument/observational
  approaches
• MOPITT-2 ???

David Edwards, NCAR