Ozone Climate Data Records from Satellite Measurements

1
Ozone Climate Data Records from Satellite
Measurements
Ozone Climate Data Records from Satellite
Measurements

• Presented by
• Lawrence E. Flynn

Center for Satellite Applications and Research
(STAR) Review 09 11 March 2010
2
Requirement, Science, and Benefits

• Requirement/Objective
• Mission Goal Develop an integrated global
  observation and data management system for
  routine delivery of information on the current
  state of the climate
• Research Area Document and Understand Changes in
  Climate Forcings And Feedbacks, Thereby Reducing
  Uncertainty in Climate Projections
• Science
• Can we create a sufficiently accurate time series
  of global total columnn and ozone profiles to
  monitor long-term changes in the ozone layer for
  climate change and atmospheric composition
  studies?
• Benefits
• Provide accurate up-to-date information for
  national reports on the state of the ozone layer
• Provide a data resource for international
  assessments
• WMO Ozone Assessments for Montreal Protocol and
  Amendment participants
• Support the Planned National Climate Services and
  their customers
• Decision makers on climate change policies and
  anthropogenic chemical releases
• Research community studying atmospheric
  composition and climate change
• General public with ultraviolet radiation
  exposure concerns

3
Challenges and Path Forward

• Science challenges
• Instruments characterization and
  inter-calibration still need improvements
• Past record components have relied on occultation
  sensors and SSBUV under-flights for validation
• Ground-based validation sites must be maintained
• Researchers want improved vertical resolution
• Next steps
• Improve monitoring and evaluation/inter-calibratio
  n of existing components
• Include currently operating satellites in the CDR
• Transition Path
• Updated CDR with new and reprocessed data
  approximately every two years to extend state of
  the ozone layer studies
• Include additional monitoring in the ICVS
• Build a reprocessing system for JPSS OMPS (SDS)

4
Instrument and Measurement Principles

• Backscatter Ultraviolet (BUV) spectrometers on
  NOAA, NASA, and MetOp Polar Orbiting Satellites
• Eight SBUV(/2) on Nimbus-7 and POES,
  1978-present
• TOMS 1978-2003
• OMI EOS Aura 2002-present
• GOME-2 starting with MetOp-A 2005
• OMPS JPSS starting with NPP in 2011
• Measuring BUV from 250 to 380 nm
• Strengths
• Ratio of Solar irradiance to Earth radiance
• Absorbing and reflectivity pair method for total
  ozone
• Maximum likelihood retrievals for profiles
• Weaknesses
• Vertical resolution of 7 KM or greater.
• Sunlit Earth only

Typical mid-latitude Version 8 SBUV/2 Averaging
Kernel. The line styles cycle through three
selections from top to bottom.
5
Analysis of Instrument Degradation and Changes

• The record is composed of data from multiple
  SBUV/2 missions
• Measurement residuals are monitored
• Internal consistency is tested
• Analysis leads to improved characterization of
  time-dependent and relative calibration
• Reprocessing is performed for full record for
  satellite of interest.

Initial Measurement Residuals
5
Residual
Update to NOAA-18 Calibration
296 nm
Comparisons between B-pair and D-pair are used to
estimate calibration adjustments for total ozone
channels
2
6
/Calibrate/Reprocess/Validate/ Vicious Circle

• Solar Diffusers and on-board calibration
  lamps track instrument throughput
• Internal consistency methods are used to
  check results (e.g., B/D Pairs, Langley method,
  measurement residuals)
• Vicarious calibration is obtained by monitoring
  Antarctic and Greenland ice sheet reflectivity
• Frequent reprocessing using improved
  characterization and calibration analysis
• Satellite time series and trends are compared to
  those derived from other observing systems both
  ground-based
• Dobson and Umkehr Networks
• NDACC Network for LIDAR and MW instruments
• Ozonesondes collected at the WOUDC and in SHADOZ
• and satellite products
• Limb (MLS) and occultation (SAGE)
• Additional monitoring and comparisons are in the
  Integrated Calibration and Validation System
  (ICVS)

Figure from V. Fioletov et al. at the 2008 QOS
showing deseasonalized global mean ozone time
series from SBUV(/2) and other sources.
7
30-Year SBUV(/2) Atmospheric Ozone Climate Data
Record

• Intercalibrated 30-year (1979-2008) SBUV(/2) CDR
• DVD release (2004) and ftp update (2008)
• Total column ozone
• Ozone vertical profiles
• Path to Assessments
• NOAAs Composite time series
• NASAs Merged time series

Monthly average anomaly values (percent) of zonal
mean total ozone, as a function of latitude (80ºN
to 80ºS) and time (January 1979 to December
2009). The anomalies are derived relative to each
month's 1979 to 2008 average. Long-term ozone
variations may be readily seen. The largest
anomalies are found for the polar regions in each
hemisphere in winter-spring months, with positive
anomalies of more than 10 percent in the earlier
years changing to negative anomalies of greater
than -10 percent for the 1990s and beyond.
8
Challenges and Path Forward

• Science challenges
• Instruments characterization and
  inter-calibration still need improvements
• Past record components have relied on occultation
  sensors and SSBUV under-flights for validation
• Ground-based validation sites must be maintained
• Researchers want improved vertical resolution
• Next steps
• Improve monitoring and evaluation/inter-calibratio
  n of existing components
• Include currently operating satellites in the CDR
• Transition Path
• Updated CDR with new and reprocessed data
  approximately every two years to extend state of
  the ozone layer studies
• Include additional monitoring in the ICVS
• Build a reprocessing system for JPSS OMPS (SDS)

9
Backup Material
10
References

• Solar Backscatter Ultraviolet Instrument (SBUV/2)
  Version 8 Ozone Retrieval Algorithm Theoretical
  Basis Document (V8 ATBD), Edited by L. Flynn,
  2007, http//www.star.nesdis.noaa.gov/smcd/spb/cal
  ibration/icvs/sbuv/doc/SBUV2_V8_ATBD_020207.pdf
• Kondragunta, S., et al., 2005 Vertical Structure
  of the Anomalous 2002 Antarctic Ozone Hole. J.
  Atmos. Sci., 62, 801811. http//ams.allenpress.co
  m/perlserv/?requestget-abstractdoi10.11752FJAS
  -3324.1
• NOAA Bulletin Southern Hemisphere Winter
  Summary, 2008, Contributors Angell, J.K., Flynn,
  L.E., Hofmann, D., Johnson, B.J., Long, C.S.,
  Oltmans, S.J., Zhou, S. http//www.cpc.ncep.noaa.
  gov/products/stratosphere/winter_bulletins/sh_08/
• Flynn, L.E. et al., (2009) Measurements and
  products from the Solar Backscatter Ultraviolet
  (SBUV/2) and Ozone Mapping and Profiler Suite
  (OMPS) instruments, International Journal of
  Remote Sensing, vol. 30, issue 15, pp. 4259-4272.
• WMO (World Meteorological Organization),
  Scientific Assessment of Ozone Depletion 2006,
  Global Ozone Research and Monitoring
  ProjectReport No. 50, 572 pp., Geneva,
  Switzerland, 2007. http//www.esrl.noaa.gov/csd/as
  sessments/2006/
• Herman, J.R., et al., (1991), A New
  Self-Calibration Method Applied to TOMS and SBUV
  Backscattered Ultraviolet Data to Determine
  Long-Term Global Ozone Change, Journal of
  Geophysical Research, 96(D4), 75317545.
• Bhartia, P.K., et al. (1995), Application of the
  Langley plot method to the calibration of the
  solar backscattered ultraviolet instrument on the
  Nimbus 7 satellite, J. Geophys. Res., 100(D2),
  29973004.
• Hilsenrath, E., et al. (1995), Calibration of the
  NOAA 11 solar backscatter ultraviolet (SBUV/2)
  ozone data set from 1989 to 1993 using in-flight
  calibration data and SSBUV, J. Geophys. Res.,
  100(D1), 13511366.

11
SBUV/2 Timeline and Equator Crossing Times
12
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13
D-Pair Total Ozone Pair Justification Method
Physics
14
Langley Method(Ascending/Descending) Physics
15
Time Chart for some BUV Missions
Instrument Sat. 19 70 72 78 80 82 84 86 88 90 92 94 96 98 20 00 02 04 06 08 10 12 14 16
BUV Nimbus4                                            
SBUV Nimbus7                                            
SBUV/2 NOAA-9                                            
SBUV/2 NOAA-11                                            
SBUV/2 NOAA-14                                            
SBUV/2 NOAA-16                                            
SBUV/2 NOAA-17                                            
SBUV/2 NOAA-18                                            
SBUV/2 NOAA-19                                            
GOME-1 ERS-2                                            
GOME-2 MetOP-A                                            
GOME-2 MetOP-B                                            
SCIAMACHY EnviSat                                            
OMI EOSAura
OMPS NPP                                            
OMPS JPSS-1                                            

Table 1. Timeline of some BUV instruments.
Nadir instruments only, no Limb Profiler.