# Presentation: 797944

## The Atmospheric Chemistry Experiment (ACE):  Current Validation Results

- Kaley Walker, Chris Boone, Randall Skelton, Daniel Markel, Sean McLeod
- and Peter Bernath, University of Waterloo,
- Tobias Kerzenmacher, Jay Kar and Kim Strong, University of Toronto,
- C. Thomas McElroy, Meteorological Service of Canada
- Cora Randall, LASP, University of Colorado
- Chip Trepte, NASA Langley
- November 10, 2005

## ACE Mission Status

- Satellite and instrument operations are nominal
- Both instruments have been acquiring as much data as possible
- ~7600 occultations recorded since January 2004
- Atmospheric profiles (for sunrises and sunsets) are being produced for all instruments
- ACE-FTS – O3, H2O, CH4, N2O, NO2, NO, HNO3, HCl, HF, CO, CFC-11, CFC-12, N2O5, ClONO2, plus 20 more molecules, temperature and pressure
- ACE-MAESTRO – O3 and NO2 (atmospheric extinction)
- IMAGERS – extinction profiles at 0.5 and 1.02 microns

**Notes:**
Both HCl and ClONO2 – no other satellite instrument (right now) measures both reservoirs at the same time

## All ACE measurements to Nov. 4

## 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 v1.0 (GRL paper)

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

- Up to 10% difference
- Between 10 and 40 km

## Version 2.2 – More Stable Process

- Differences slightly
- better than v1.0 ~5-7%

## ACE-FTS O3 - Version 2.2 Update

- Issue found with ACE-FTS microwindows
- Inconsistent results between the two microwindow ranges with HITRAN2004 (10 micron vs. 5 micron)
- New retrievals for ozone only – 2.2 “Ozone Update”
- Uses a consistent set at ~10 micron – the most well known region
- 36 between 985 – 1129 cm-1 (added 4 near 987 cm-1)
- (ones between 1803 – 2121 cm-1 have been removed)

## ACE-FTS Ozone Microwindows

## ACE-FTS Ver2.2 Ozone Update

- Differences within ±5%
- between ~10-40 km

## O3:  ACE-FTS vs. POAM III

- Profiles within 500 km and 2 hours; using POAM III version 4.0 data

- Average Latitude: 67.0

## ACE-FTS vs. ACE-MAESTRO O3

- FTS ozone higher than MAESTRO at sunrise but reverses at sunset
- MAESTRO uses T and p from FTS
- Sunrise and sunset having opposite offsets suggests that there is a residual timing discrepancy

**Jay Kar**

- ACE-FTS v2.2 Update; ACE-MAESTRO v1.1

## NO2: ACE-FTS – ACE-MAESTRO

- 1 year of Arctic occultations:  March 2004 – March 2005
- ACE-FTS v2.2; ACE-MAESTRO v1.1 – 447 profiles

**Tobias Kerzenmacher**

**Within 10%**
**22-40 km**

## ACE-FTS & Radiosonde - Eureka

**Tobias Kerzenmacher**

- Using 9 profiles:
- ACE-FTS temperatures within ±2 K of sonde to 30 km.
- No smoothing.
- Similar to results with MLS:
- FTS temperatures agree to within ±2 K from 15 – 60 km

- Coincidence criteria:  200 km and 3 hours of sonde launch

## Summary

- New ACE-FTS Ozone – version 2.2 Update uses more consistent set of microwindows
- Comparisons with SAGE III, POAM III (& ozonesondes)
- Will be put into AVDC soon (next week)
- ACE-FTS v2.2 and ACE-MAESTRO v1.1 are there now
- ACE-FTS and ACE-MAESTRO ozone and NO2 comparisons
- Difference between sunrise and sunset occultations show residual timing discrepancy between instruments
- ACE-FTS and radiosonde temperature comparisons
- ±2 K difference is consistent with comparisons to MLS and SABER

## ACE Validation Program

- Will be starting very, very soon!
- We would like to involve as many different groups as possible so if you would like to work with us, contact me:
- _[validate@acebox.uwaterloo.ca](mailto:validate@acebox.uwaterloo.ca)_
- Efforts are organized by subgroups:
- O3, H2O, CH4, CO, NOy+N2O, Cly/Fy, p/T, aerosols
- We will put you in contact with the appropriate subgroup