# Presentation: 186995

## Instrument Possibilities for Planetary Boundary Layer O3 Measurements from Space

- Aura Air Quality Working Group
*27 October 2008*

- Kelly Chance
- Harvard-Smithsonian Center for Astrophysics

## Background 1: UV (visible) O3 profiling from SCIAMACHY, GOME-n, OMI (e.g., Chance et al., 1997; Liu et al., 2005) 

**Ozone hole**

**Biomass burning over Indonesia**

- Background 1: UV (visible) O3 profiling from SCIAMACHY, GOME-n, OMI (*e.g*., Chance et al., 1997; Liu et al., 2005)

## Background 2: Combining UV + Infrared (OMI + TES, GOME-2 + IASI) (e.g., Worden et al., 1997) 

- Background 2: Combining UV + Infrared (OMI + TES, GOME-2 + IASI) (*e.g*., Worden et al., 1997)

## Slide 4

## N.B. cross sections!

- Background 3: Spectroscopic and scattering information on ozone

**Hartley & Huggins bands (~245-355 nm)**

**Huggins band (~318-340 nm)**

**Chappuis band (~380-750 nm)**

- Sensitivity down
- to the surface

**+ Polarization information**
**	****Polarization affected most strongly by ozone at scattering altitude (Hasekamp and Landgraf, *****JGR*****, 2002)**
**+ Infrared bands**
**3.3 and 3.6 ****μ****m (backscatter)**
- 9.6 μm (emission)
***N.B. cross sections!***

## Proposed GEO-CAPE Study

**Proposed GEO-CAPE Study**

**Genesis: 2008 GEO-CAPE Workshop**
**Participants: SAO, Harvard, UMD, NASA (GSFC, LaRC, JPL, ARC), UAH, NCAR**
- 1. Determine a minimal set of atmospheric scenarios, including gas and aerosol loading, pressure/temperature profile, and geolocations through which to fly instrument and measurement combinations. 4 days spanning the annual variation is likely enough, at least to start.
- 2. Select instrument parameters. Proposed channels:
- UV Hartley-Huggins bands at ~ GOME resolution: 290-340 nm @ 0.09 nm sample, 0.36 nm resolution (FWHM);
- UV Huggins band and slightly beyond. 5 discrete polarization-resolved channels, 1 nm FWHM wide, placed from 311 to 360 nm;
- Chappuis band at ~ GOME resolution: 500-650 nm @ 0.1 nm sample, 0.4 nm resolution (FWHM);
- 3.3 or 3.6 μm, as specified by Chatfield;
- 9.6 μm, as specified by Eldering and Irion.

## Proposed GEO-CAPE Study, cont’d

- 3. Calculate averaging kernels for the various scenarios and instrument parameters, starting with the case of negligible measurement and spectroscopic errors.
- 4. Evaluate linear combinations of averaging kernels to identify the most promising combinations of measurements.
- 5. Perform GEOS-Chem adjoint studies to determine the sensitivity of the surface ozone concentration to the concentrations at different altitudes and earlier times from the most promising combinations.
- The ability to improve AQ forecasts using data assimilation is likely outside the scope of this study, but certainly should remain central to
- GEO-CAPE mission studies.
- 6. Refine the most promising measurement techniques to include more realistic measurement and instrument calibration errors (***including those achieved to date as well as reasonable projections***), as well as spectroscopic errors. Refining spectroscopic needs and evaluating realistic expectations for them are included in this step.

## Proposed GEO-CAPE Study, cont’d

- Success this far will be a good beginning and a good point from which to consider air quality forecasts using data assimilation, field experiments, and directed laboratory studies.