# Presentation: 051949

## Stratospheric Aerosol and Gas Experiment (SAGE) III

- 17 February 1999

**Stratospheric Aerosol and Gas Experiment (SAGE) III**
**Validation Summary**

## Introduction

- SAGE III is a 4th generation satellite-borne instrument and a crucial element in the NASA Office of Earth Sciences Earth Observing System (EOS). Its mission is to increase our understanding of natural and human-derived atmospheric processes by providing accurate long-term measurements of the vertical structure in the upper troposphere and stratosphere of aerosols, O3, H2O, NO2,, temperature/pressure, NO3, and OClO.
- Like its predecessor instruments (SAM II, SAGE I, and SAGE II), SAGE III utilizes the occultation measurement technique. This technique is inherently self-calibrating and allows for reliable long-term trend analysis.
- Two SAGE III instruments will be placed in orbit. The first instrument will be flown upon the Russian Meteor-3M spacecraft as a joint effort between NASA and the Russian Space Agency, which is scheduled for launch in **September 1999**. The second instrument will be placed upon the International Space Station in **2002.**
- A description of the SAGE III mission is available at (http://www-arb.larc.nasa.gov/sage3/)

## SAGE III Science Objectives

*Provide near-global profiles* of aerosols, O3, H2O, NO2, temperature and pressure, NO3, and OClO.
*Investigate the spatial and temporal variability* of the measured species in order to determine their role in atmospheric chemistry, climatological processes, biogeochemical cycles, and the hydrologic cycle.
*Characterize tropospheric as well as stratospheric aerosols and upper tropospheric and stratospheric clouds*, and investigate their effects on the Earth’s environment including radiative, microphysical, and chemical interactions.
*Extend the SAM II, SAGE I, and SAGE II data sets*, enabling the detection of long-term trends.
*Provide atmospheric data essential for the calibration and interpretation or correction of other satellite sensors*, including EOS and ground-based networks.

## SAGE III Instrument

- The SAGE III instrument incorporates two new elements: a CCD linear array of detectors and a 16-bit A/D converter.
- Spectral coverage between 280 and 1550 nm, with continuous coverage between 280 and 1030 nm at    ~1 nm resolution by the CCD. Measurements at 1550 nm are by a discrete photodiode.
- 12 solar channels ( ~80 sub-channels) routinely utilized during solar occultation measurements
- 3 lunar channels ( ~340 sub-channels) utilized during lunar occultation measurements
- CCD linear detector array permits on-orbit wavelength and intensity calibration from exoatmospheric solar Fraunhofer spectrum.

- SAGE III instrument prior to integration on the Meteor 3M spacecraft

## SAGE III Data Products

## Validation Overview

- Examine internal instrument data and perform self-consistency checks. (e.g. comparison of solar and lunar events during overlap periods and comparison of different retrieval techniques for the same parameter).
- Intercomparison of inverse retrieval algorithms with a forward simulation model to evaluate and verify different retrieval algorithm systems. The simulator is based upon physical models of the instrument, spacecraft, and ambient atmosphere.
- Confirm accuracy of Oxygen-A Band spectroscopic database for temperature and pressure retrievals and obtain improved line intensity and half-width data for the SAGE III water vapor measurement region.

## Validation Overview (cont)

- Acquire global correlative measurements under varying atmospheric conditions and altitude regimes to assess SAGE III measurement accuracy and precision.
-  Focused correlative measurement programs to support validation activities
- The SAGE III Ozone Loss and Validation Experiment (SOLVE) measurement campaign (November 1999-March 2000).
- Leverage upon the European ENVISAT and Japanese ADEOS-II validation programs at Kiruna, Sweden (January-March 2001)
-  Routine correlative measurements with key ground-based instrument facilities on a 	measurement-of-opportunity basis
- Network for the Detection of Stratospheric Change (NDSC) sites
- World Meteorological Organization’s ozonesonde network sites
- Russian measurement sites
-  Satellite instrument intercomparisons
- e.g. SAGE II, HALOE, POAM III, ENVISAT, ADEOS II

## Meteor 3M/SAGE III Coverage

- Launch in September 1999
- Sun-synchronous orbit, ~99o inclination & ~9:15 am equatorial crossing
- Local satellite sunrise    (sunset) occultation events denoted by solid (dashed) lines
- Local satellite moonrise (moonset) occultation events denoted by red (blue) dots.

- Nominal annual SAGE III measurement coverage for a May 15, 1999 launch date

## SOLVE Overview

- The SAGE III Ozone Loss and Validation Experiment (SOLVE) is a combined airborne, balloon-borne, and ground-based field mission designed to support SAGE III validation and examine unresolved issues related to ozone loss during the arctic winter.
- The mission will take place between November 1999 and March 2000 and will be based at Kiruna, Sweden (67.9N, 20E) for the NASA DC-8 and ER-2 aircraft and from near-by Esrange, Sweden for the high altitude balloons.
- SOLVE is co-sponsored by NASA’s Upper Atmospheric Research Program (UARP), Earth Science Enterprise (ESE) SAGE III validation program, the Atmospheric Chemistry Modeling and Analysis Program (ACMAP), and the Atmospheric Effects from Aviation Program (AEAP). SOLVE is also supported through collaborative activities with other international groups.
- SOLVE mission homepage (http://cloud1.arc.nasa.gov/espo/solve)

## SOLVE Validation Objectives

- Obtain correlative profile measurements of SAGE III solar and lunar science products to examine relative accuracy and precision.
- Maximize time/space coincidence of correlative measurements with aircraft underflights and balloon flights to reduce uncertainties due to the sampling of different air masses.
- Improve statistical significance of measurement intercomparisons through larger aircraft instrument sampling rates and backtrajectory analysis techniques.
- Obtain measurements along the satellite/sun line-of-sight
- to assess the inhomogeneity of species and their impact on retrieved products (constituent gradients, cirrus, polar stratospheric clouds, & dirunally varying species)
- to determine altitude registration of transmission profile (< 100 m) through the identification of cloud or constituent gradient structures.

## SOLVE  Validation Objectives (cont)

- Obtain correlative measurements using similar observational techniques (e.g., balloon IR remote sensing instruments) for NO2, ozone, and water vapor for intercomparisons with other instrument techniques.
- Link SAGE III observations with tracer distributions and other ground-based instruments to enhance its scientific interpretation and trends analysis.
- Acquire measurements under varying atmospheric conditions to examine the representativeness of the SAGE III measurements.

##   Team Lead	     Measurement
B. Anderson 	particle samplers, O3
C. Brock	particle samplers
E. Browell	O3 and H2O lidars
B. Brune	ClO, BrO, Hox
Burris/Hostetler	aerosol/ O3/temp. lidar
Y. Kondo	HNO3
K. Kunzi	microwave radiometer
Mankin/Coffey	solar FTS
M. Mahoney	temperature profile
G. Sachse	CO, N2O, CH4,CFCs
Shetter	photodissociation rates
A. Viggiano	HNO3

- B. Anderson 	particle samplers, O3
- C. Brock	particle samplers
- E. Browell	O3 and H2O lidars
- B. Brune	ClO, BrO, Hox
- Burris/Hostetler	aerosol/ O3/temp. lidar
- Y. Kondo	HNO3
- K. Kunzi	microwave radiometer
- Mankin/Coffey	solar FTS
- M. Mahoney	temperature profile
- G. Sachse	CO, N2O, CH4,CFCs
- Shetter	photodissociation rates
- A. Viggiano	HNO3

- SOLVE  DC-8 Payload

- The NASA DC-8 aircraft will be deployed in three two-week periods (1-15 December 1999, 15-30 January 2000, and 1-15 March 2000) to observed the evolution of ozone loss and provide intercomparison flights with SAGE III observations.

- DC-8 Mission Scientists:  M. Schoeberl and B. Toon

##   Team Lead	     Measurement
J. Anderson 	ClO, ClONO2, OH, OH2,
		NO2, H2O, BrO, BrOHO2
E. Atlas	whole air sampler
D. Baumgardner	particle samplers
T. Bui	T, P, and wind
J. Eisele	HNO3
J. Elkins	CFCs, CH4, N2O,SF6
D. Fahey	O3, Noy
H. Jost	N2O, CH4
M. Mahoney	temperature profile
C. Webster	CO, HCl, N2O, CH4
P. Wennberg	NHO3
C. Wilson	particle samplers

- J. Anderson 	ClO, ClONO2, OH, OH2,
- 		NO2, H2O, BrO, BrOHO2
- E. Atlas	whole air sampler
- D. Baumgardner	particle samplers
- T. Bui	T, P, and wind
- J. Eisele	HNO3
- J. Elkins	CFCs, CH4, N2O,SF6
- D. Fahey	O3, Noy
- H. Jost	N2O, CH4
- M. Mahoney	temperature profile
- C. Webster	CO, HCl, N2O, CH4
- P. Wennberg	NHO3
- C. Wilson	particle samplers

- SOLVE  ER-2 Payload

- The NASA ER-2 aircraft will be deployed in two three-week periods (15 January -5 February 2000 and 25 February - March 15, 2000) to observed the evolution of ozone loss and provide intercomparison flights with SAGE III observations.

- ER-2  Mission Scientists:  J. Anderson and P. Newman

##                     OMS Payload
Team Lead	     Measurement
J. Elkins 	CFCs, N2O, SF6
J. Margitan	O3
D. Toohey	ClO, BrO, Cl2O2
C. Webster	CH4, HCl, N2O
S. Wofsy	CO2
                Remote Sensing Payload
Team Lead	     Measurement
S. Oltmans	H2O, O3
R. Stachnik	ClO, O3, HCl, HNO3
G. Toon	Mark IV (many species)

- _Team Lead_	     _Measurement_
- J. Elkins 	CFCs, N2O, SF6
- J. Margitan	O3
- D. Toohey	ClO, BrO, Cl2O2
- C. Webster	CH4, HCl, N2O
- S. Wofsy	CO2
*                **Remote Sensing Payload*
- _Team Lead_	     _Measurement_
- S. Oltmans	H2O, O3
- R. Stachnik	ClO, O3, HCl, HNO3
- G. Toon	Mark IV (many species)

- SOLVE  Balloon Payloads

- Two different payloads will be flown during SOLVE that complement aircraft and ground-based observations for SAGE III validation. The first deployment will be in November 1999 with a flight of both payloads. A flight of the remote sensing payload will take place in mid January 2000, and a flight of the OMS payload will occur in late February 2000.

- High Altitude Balloon Mission Scientist: B. Brune

## Leverage with Existing Ground-based Networks

## Schedule

- Begin spectroscopic database studies		Oct 1998
- Initiate algorithm verification studies		Oct 1998
- Meteor 3M / SAGE III Launch		Sep 1999
- Begin data comparisons with NDSC and 	Sep 1999
-    other ground-based measurement sites
- SOLVE field mission 			Nov 1999 - Mar 2000
- Validation Workshop			Nov 2001
- ENVISAT/ADEOS II validation activities	Jan - Mar 2001