# Presentation: 737530

## ACE Ozone Profiles

- Kaley Walker, Chris Boone, Randall Skelton and Peter Bernath, University of Waterloo
- Lucien Froidevaux and MLS team, JPL
- Marty McHugh, GATS,
- Cora Randall, LASP, University of Colorado
- Chip Trepte, NASA Langley,
- Svetlana Petelina and Ted Llewellyn, University of Saskatchewan
- September 21, 2005

## ACE Instruments

**ACE-FTS:**
- a high resolution (0.02 cm-1) infrared Fourier transform spectrometer operating between 2-13 microns
- 2-channel visible/near infrared imager operating at 0.525 and 1.02 microns
**MAESTRO:**
- dual UV / Visible / NIR spectrometer measuring from 0.285 to 1.030 microns, resolution ~1-2 nm
**Measurement modes:**  solar occultation, nadir (ACE-FTS) and backscatter (MAESTRO), calibration (sunscans)
**Instrument Pointing:**  suntracker located within ACE-FTS

## All ACE measurements to June 6

## Global Distribution of Occultations

## ACE Ozone Data

- ACE ozone profiles are available from three sources (occultation mode measurements):
- ACE-FTS v2.2
- Retrievals cover range from ~5 to 95 km
- Microwindows used:
- 32 between 1022 – 1168 cm-1
- 22 between 1803 – 2121 cm-1
- ACE-MAESTRO v1.1
- One profile produced from each spectrometer - UV and VIS
- Retrievals from <10 km up to ~100 km
- Currently, p and T profiles from ACE-FTS are used in MAESTRO retrieval

## ACE-FTS - POAM III:  O3

- Lower than POAM III by up to ~10% from 15 and 40 km.  Maybe due to difference in vertical resolution?

- ACE-FTS up to 25% higher than POAM from 40-60 km

- Profiles within 500 km and 2 hours; POAM III v 4.0 and ACE-FTS v1.0

**Thanks to Cora Randall**

- average latitude:  67°N

**Notes:**
large percent differences correspond to density differences that are only on the order of 5x109 cm-3 (at 55 km) 

## ACE-FTS - SAGE III comparison

- Profiles within 500 km and 2 hours; SAGE III v 3.0 and ACE-FTS v 1.0

- No indication of significant altitude registration errors but between 15-40 km, ACE-FTS lower than SAGE III by ~10%

- ACE-FTS up to 38% higher than SAGE III from 40-55 km

**Thanks to Chip Trepte**

- average latitude:  76°N

## O3:  ACE-FTS - HALOE

- ACE-FTS and HALOE are within ± 5% from 15 to 35
- ACE-FTS is ~ 0.4 ppmv higher from 35 to 70 km
- 29 Coincident Events in July 2004 at ~66 N (within 500 km and 3 hours) plus 2 on Jan 17 (60 S) and 1 on Feb 12 (48 N) in 2004
- ACE-FTS version 1.0, HALOE v19

**Marty McHugh**

## ACE-FTS vs ACE-MAESTRO

**Jay Kar**

- ACE-FTS v 1.0 and MAESTRO v1 data

## Improvements in ACE-FTS

- Between version 1.0 and later ones:
- Generally see similar behavior, ACE-FTS tends to be lower than comparison in region near peak in concentration
- In comparisons with UV-visible spectrometers,  discrepancy generally smaller with later versions:            ~5-7 % rather than 10%

## ACE-OSIRIS:  O3 comparisons

- Sunsets in March 2005 – Latitude range:  50° – 82° ACE-FTS v2.2, OSIRIS v2.4 data, using criteria 5° latitude, 10° longitude, 7 hours
- Between 15-30 km, ACE-FTS is within 5% (or better) of OSIRIS results – improvement over ACE-FTS v 1.0

**Svetlana Petelina**

## Further Improvements

- ACE-FTS microwindows
- Inconsistent results between the two microwindow ranges used (10 micron vs. 5 micron)
- Will use consistent set at 10 micron – most well known
- This may explain lower values near concentration peak
- Troposphere improvements
- Variability in v2.2 due to approximation used in code – fixed in new version
- Ozone isotopologues will be retrieved in next version of ACE-FTS data set
- O3 (668) and O3 (686) [and maybe O3 (667) and O3 (676)]

**Notes:**
Problem with low spectral information – does not work well for ozone

## ACE O3 data available

- Newest ACE data to be put into AVDC
- ACE-FTS v2.2 – will be in very soon
- ACE-MAESTRO v1.1 – sometime in future
- MAESTRO backscatter measurements
- New tables have been developed and command sequences are being implemented in planning system
- Expect first measurements to be taken within two weeks
- Looking forward to validation collaborations with other Aura instrument teams