# Presentation: 177774

## Aura Science Team MeetingMicrowave Limb Sounder Overview

- Nathaniel Livesey on behalf of the MLS team

## New addition to the MLS team at JPL

- Last year, Joe Waters stepped down as MLS Principal Investigator
- However, we have since added a new key player to the MLS team...

## MLS data products

- Dashed lines indicate regions that are goals, or where averaging(e.g., zonal means) is required for useful signal to noise

- All MLS data are publicly available from GSFC DISC (formerly DAAC)
- The latest version of MLS data is v2.2

## MLS strat. observations, 16 Sep. 2007

## MLS version 2.2 data processing progress

- Green boxes show days processed to v2.2 to date
- Planning soon to upgrade to new ‘v2.22’ software (~2x faster)
- Reprocessing should finish around  Spring 2008

## MLS v2.2 val. papers & quality document

- _Manuscripts led by MLS team:_
**Froidevaux et al.:** HCl
**Froidevaux et al.:** Strat. / mes. O3
**Jiang, Y. et al.:** O3 sonde and lidar
**Kovalenko et al.:** BrO
**Lambert et al.:** Strat. / mes. H2O & N2O
**Livesey et al.:** UT/LS CO and O3
**Manney et al.:** Non-coincident validation
**Pickett et al.:** OH and HO2
**Pumphrey et al.:** Strat. / mes. CO
**Read et al.:** UT/LS H2O
**Santee et al.:** ClO
**Santee et al.:** HNO3
**Schwartz et al.:**  Temperature & GPH
**Wu et al.:** Cloud ice

- _Manuscripts led by others:_
**Barnes et al.: **Raman Lidar and MLS H2O
**Boyd et al.:** O3 and ground-based μwave
**Coffey et al.:** Airborne FTS
**Connor et al.:** ClO and grnd-based μwave
**Considine et al.:** Non-coincident validation
**Feng et al.:** O3 ECMWF assimilation
**Lary et al.:** Satellite HCl comparison
**Nedoluha et al.:** H2O, ground-based μwave
**Petropavlovskikh et al.:** O3 and CAFS
**Schoeberl et al.: **OMI – trajectory MLS O3
**Stajner et al.:** O3 assimilation
**Vömel et al.:** Sonde H2O
**Yang et al.:** OMI–MLS O3

- The v2.2 data quality document is a comprehensive reference for product-by-product screening rules, estimated accuracies and validation summaries
- http://mls.jpl.nasa.gov/

## MLS plans for ‘near-real-time’ data

- MLS O3 has been assimilated into several state-of-the-art models
- GMAO – Ivanka Stajner	NOAA – Craig LongECMWF – Liang Feng		UK Met. Office – David JacksonNRL – Karl Hoppel (also Temperature)

- Many of these organizations would like to include ‘near-real-time’ MLS data in operational systems
- Initial development of this is underway, with a goal of having a prototype in place for ARCTAS

- See Alyn Lambert’s poster for more information

## MLS observations during TC4 campaign

- MLS observations during TC4 campaign

- Maps show MLS 215-hPa observations during the 15 – 21 July phase of TC4
- Influences of convection and long-range transport on CO clearly seen
- During the TC4 campaign, part of the MLS 640-GHz subsystem shut down
- Probably due to a radiation-induced Single Event Upset
- The affected period was 14 July to 9 August
- During this time MLS did not measure HCl, BrO, HO2 or HOCl
- 190-GHz data are available for ClO and N2O, in lieu of 640-GHz products
- _All other products were unaffected_

## Impact of convection on upper trop. CO

- CO in the upper troposphere is influenced by a combination of surface emissions, convective lofting and horizontal transport
- Plot shows MLS 147 hPa CO for 09/04–09/06, binned by emissions and MLS cloud ice (indicating convection)

- From *Jiang (Jonathan) et al., GRL, in press*

- 1 – 6 June, 2006

## MLS cloud ice validation and science

- From *J.-L. (Frank) Li et al., GRL, 2007*

- Statistical approaches have been a major focus of MLS cloud ice validation
- Plot compares PDFs of July 2006 MLS and CloudSat cloud ice water content

- From *Wu et al., JGR, submitted*

## Stratospheric and mesospheric studies

- MLS data used to quantify Arctic chemical O3 loss, discounting changes in O3 due to transport
- Daily variations in MLS O3 compared to ‘passive O3’ tracer from SLIMCAT

- From *Singleton et al., JGR, 2007*

- MLS daily global US/LM temperature data give new insight into stratopause evolution during major warmings
- Analyses fail to capture stratopause reformation at ~0.01 hPa
- NOGAPS model, which assimilates MLS temperatures, shows better agreement than other analyses

- From *Manney et al., JGR, submitted*

## Summary and future plans

- The MLS instrument continues to operate well
- Version 2.2 reprocessing is expected to be complete in Spring 2008
- All MLS data are publicly available from the GSFC DISC
- The many validation papers and the v2.2 quality document provide important information for MLS data users
- A ‘near-real-time’ data processing capability is planned for selected products
- Goals for future product improvements include:
- Eliminating or reducing the factor of ~2 high bias in 215 hPa CO
- Extending O3, CO, H2O and HNO3 retrievals lower in the troposphere
- Better handling of cloud signatures and joint cloud / chemistry retrievals
- Retrievals of some new species (e.g., stratospheric CH3Cl)
- MLS data are being used in a wide variety of scientific studies
- ~75 peer reviewed papers published or in press to date