# Presentation: 670980

## Tropical Tropospheric O3 and CO during the 2006 El Niño from TES observations and GEOS-Chem simulations

**Ray Nassar, **Jennifer Logan, Inna Megretskaia, Lin Zhang, Lee Murray & the TES Team
- Aura Science Team Meeting
- Pasadena, 2007-Oct-4

## El Niño

- Tropical Pacific SST anomaly induces changes in atmospheric convection, precipitation and composition
- Asymmetric Dipole Anomalies:
- Tropospheric ozone column residual
- MLS H2O at 215 hPa
- Outgoing Longwave Radiation

- http://ggweather.com/enso/nino_regions.gif

*Chandra et al.* (1998) GRL

**O****3**

**H****2****O**

**OLR**

**1997 – 1996 Anomalies**

## Modeling O3 from the 1997 El Niño

***Hauglustaine, Brasseur & Levine***** (1999) GRL**
- 	MOZART model
***Sudo & Takahashi***** (2001) GRL**
- 	CHASER model
- 	Trop Column Ozone 	from TOMS using 			Convective Cloud Differential technique
***Chandra et al.***** (2002) JGR**
- 	GEOS-Chem model
- 	TCO using CCD, TOMS
- 	TOMS Aerosol Index for biomass burning
**-> Biomass Burning component**
**-> Meteorology/Dynamics/Convection component**
***Duncan et al.***** (2003) JGR**
**	**GEOS-Chem: biomass burning and lightning

*Chandra et al.* (2002) JGR

**Observations**

**Model**

## TES Ozone and CO October 2006

**Ozone**

**CO**

- Well-characterized O3 with 2 DOFS in the troposphere

- TES has simultaneous coincident CO, a better proxy for biomass burning than TOMS Aerosol Index

## GEOS-Chem Simulations

- TES v02 O3 & CO filtered using data quality and O3 emission layer flags
- Removed cloudy TES profiles (effOD > 2.0, cloud top above 750 hPa)
- GEOS-Chem sampled at TES positions and times (t < 1.5 hr)
- TES AK and constraint (TES op) applied to GEOS-Chem
- TES averaged in 2ox 2.5o bins to match model
- TES averaged over 6 vertical levels: UT (464-287 hPa), LT (825-511 hPa)

**GEOS-Chem Simulations**

- 3-D global tropospheric Chemical Transport Model (CTM)
- Goddard Earth Observing System 4 (GEOS-4) meteorology
- 10 month spin-up, 15 month run from 2005-09 to 2006-12
- 2o latitude x 2.5o longitude resolution
- v7.04.10 with improved lightning parameterization
- Global Fire Emission Database 2 (GFED2) emissions

## TES & GEOS-Chem LT CO: October 2006

- Differences exceed TES CO bias of 10%, *Luo et al.* (2007)

## 2006–2005 CO Differences

**2006–2005 CO Differences**

**October**

**November**

**December**

**GEOS-Chem**

**TES Observations**

## 2006–2005 CO Differences

**2006–2005 CO Differences**

**October**

**November**

**December**

**GFED 2005 & 2006**

**GFED 2005 both years**

**TES Observations**

## TES & GEOS-Chem LT O3: October 2006

- Differences exceed 3-10 ppbv bias in TES ozone *Nassar et al.* (2007)

## 2006–2005 O3 Differences

**2006–2005 O****3**** Differences**

**October**

**November**

**December**

**GFED 2005 & 2006**

**GFED 2005 both years**

**TES Observations**

## CO and O3 Contribution due to Biomass Burning Changes2006 meteorology/emissions – 2006 meteorology with 2005 emissions 

**CO and O****3**** Contribution due to Biomass Burning Changes****2006 meteorology/emissions – 2006 meteorology with 2005 emissions **

**October**

**November**

**December**

**CO**

**O****3**

- Note: different color scale

## O3: Separating the Effects of Meteorology and Emissions

**O****3****: Separating the Effects of Meteorology and Emissions**

**October**

**November**

**December**

- Note: different color scale

**2006 - 2005**
**different emissions**
**same meteorology**

**2006 - 2005**

**2006 - 2005 **
**different meteorology **
**same emissions**

- =

- +

## GEOS-Chem & Lightning Imaging Sensor (LIS)

**GEOS-Chem & Lightning Imaging Sensor (LIS)**

**October**

**November**

**December**

**GEOS-Chem **
**2006 Lightning Flashrate**

**GEOS-Chem**
**2006-2005**

**2x2.5o**

**4x5o**

**LIS Observations**
**2006-2005**

- Note: Lightning values below a given absolute threshold were omitted

## 2006–2005 O3 DifferencesLightning Sensitivity

**2006–2005 O****3**** Differences****Lightning Sensitivity**

**October**

**November**

**December**

**Climatological Lightning flashrate**

**Lightning flashrate**
**Increased by 50%**

**TES Observations**

## Future Work 

- Further ozone sensitivity tests
- Run GEOS-Chem with LIS measured lightning distributions
- More quantitative assessment: GEOS-Chem vs. TES correlations, Ozone and CO budgets

- GEOS-Chem tropical O3 and CO are low relative to TES in some areas
- TES and GEOS-Chem both show elevated O3 and CO over Indonesia in late 2006
- October/November 2006 O3 anomalies clearly relate to increased Indonesian biomass burning during dry El Niño conditions, but also have a dynamical/convective component
- Persistent December O3 anomaly likely relates to lightning changes coupled with weaker convection both associated with the 2006 El Niño

**Conclusions**