# Presentation: 518007

## Understanding Ozone Photochemistry in Siberian Boreal Fire Plumes using TES and OMI observations Sunita Verma1, John Worden1, Brad Pierce2, Dylan Jones3, Jassim Al-Saadi4, Kevin Bowman1, Folkert boersma5 and TES team

- 1 Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA-91109, USA
- 2 NOAA3 University of Toronto 4 NASA Langley Research Center
- 5 Harvard University
- AURA Science Meeting, 1-5 October, Pasadena, CA

## 
Dramatic increase in the size of Siberian fires in the last decade.

Quantify the impact of boreal fires on tropospheric ozone.

However, understanding how boreal fires impact tropospheric ozone is difficult  as the ozone production in smoke plumes is highly variable (Mauzerall et al., 1998, Lapina et al., 2006, Martin et al., 2006, Real et al., 2007).

- Dramatic increase in the size of Siberian fires in the last decade.
- Quantify the impact of boreal fires on tropospheric ozone.
- However, understanding how boreal fires impact tropospheric ozone is difficult  as the ozone production in smoke plumes is highly variable (Mauzerall et al., 1998, Lapina et al., 2006, Martin et al., 2006, Real et al., 2007).

- Introduction

***J. Crawford, LaRC***

## Tower Measurements of North American Smoke Plumes

- O3 / CO ratios
- M. Val Martin, 2006

- Black Dots show ozone and CO for “background” air
- Colored Dots show ozone and CO for different smoke plumes

- Ozone and CO not necessarily correlated in smoke plumes.
- Ozone in smoke plumes is highly variable ranging from 35 PPB to 75 PPB.

- To explore furthermore ozone photochemistry within smoke plumes, this study in the present context, uses satellite observations for Siberian boreal fires event 2006

## Satellite data

TES makes several observations of ozone and CO in the Siberian fire plume between July 15 and mid-August every other  day. 

- TES makes several observations of ozone and CO in the Siberian fire plume between July 15 and mid-August every other  day.

-     Ten-Day forward trajectories show plume stretches from Eastern Europe to across the Pacific

**10-day forward trajectories (red) from peak Siberian wildfire emissions on July 24th, 2006. Daily wild fire emissions (Tg/day) from RAQMS real-time emissions are shown as colored dots in Siberia.**

- The July 2006 Siberian forest fires presents a unique opportunity for studying the ozone photochemistry and evolution in boreal fires using space-based measurements.

## RAQMS chemical Analysis

- Significant photo-chemical production of ozone (>120  PPB) at fire source with additional production along the plume as well as mixing as we move away from fire source with time

- Real time biomass burning emissions based on MODIS
-  fire count data

- What do models expect for ozone production in Boreal Fires?

- R.H.S-The 10 day forward trajectories as shown in global map. The same trajectories are being shown as a function time in L.H.S.

**Notes:**
as air parcels dip into the boundary layer they accumulate CO from the smoke plume. We also see ozone production within the fresh part of the smoke plume

## Satellite Observations of Enhanced Ozone in Boreal Fire Plume

- TES observes a significant production of ozone with a related high CO and NOx emissions but in the presence of low aerosols amounts in both fresh and aged plume conditions.
- Enhanced ozone (> 90 PPB) in fresh and aged plume consistent with RAQMS model prediction

**O****3****, CO, aerosol and NO****2**** near Fire source**

**O****3****, CO, aerosol and NO****2**** in Aged Smoke Plume**

- TES

- OMI

- OMI

- TES

## Observations of Relatively Low Ozone in Boreal Fire Plume

- In contrast, TES also observes a relatively low ozone under similar conditions of high CO and NOx emissions but with optically thick aerosols amounts for both over fire and aged smoke plumes cases.
- Hypothesis: Are aerosols inhibiting the ozone photo-chemistry in the smoke plume ?

**O****3****, CO, aerosol and NO****2**** over Fire**

**O****3****, CO, aerosol and NO****2**** in Aged Plume**

- TES

- TES

- OMI

- OMI

## O3 drops from 140 PPBV to ~60 ppbv with aerosols inhibiting photolysis

- RAQMS Model With Significant Aerosol Emissions
- (Black Carbon plus Organic Carbon)

- However, current model does not replicate low ozone observations of about 30 - 40 PPB

## Summary

- Ozone production in smoke plumes is highly variable some plumes show strong ozone enhancement and others show relatively low ozone.
- Aerosols have a significant impact on the ozone photochemistry of boreal fires.
- Additional production along the plume plus mixing of air parcels also needed to characterize ozone in boreal fire plumes.

## Methodology

**          **
**     ****1) ****Identify aged and fresh **
**plume observations using **
**enhanced CO** **values**
** ****(CO > 120 PPB) **

**          **
**           ****2) Connect these enhanced **
**values to fire source using **
**back/ forward trajectories **

**           ****3)**** ****Examine ozone **
**chemistry, and **
**evolution in boreal **
**smoke plume.**

**Aerosol Optical depth and NOx**

**4) Use RAQMS model to describe evolution of ozone **
**production and loss in boreal smoke plume and relate **
**these processes to TES and OMI observations.**

**Analysis Data**
**Examine co-located observations**

**Ozone Monitoring Instrument (OMI)**

**Tropospheric Emission Spectrometer (TES) **

**CO ozone**

**  ****colocated observations**