Evaluation of Tropical Upper Tropospheric Evaluation of Tropical Upper Tropospheric Ozone from ACE-FTS and MAESTRO; Ozone from ACE-FTS and MAESTRO;

Estimation of Ozone Production EfficiencyEstimation of Ozone Production Efficiency

Matthew Cooper, Randall MartinMatthew Cooper, Randall MartinDalhousie UniversityDalhousie University

Bastien SauvageBastien SauvageUniversitUniversitéé de Toulouse, CNRS de Toulouse, CNRS

Catherine WespesCatherine WespesUniversitUniversitéé Libre de Bruxelles Libre de Bruxelles

ACE TeamACE Team

Why look at OWhy look at O33 and HNO and HNO33??

Upper tropospheric HNO3, O3 highly influenced by lightning.

Lightning NOx source is poorly understood

High quality O3, HNO3 measurements could be used to reduce lightning emissions uncertainty

Satellite Observations Satellite Observations

ACE-FTS, MAESTROACE-FTS, MAESTRO Most validations done in stratosphereMost validations done in stratosphere

ACE-FTS typically 5% higher than other satellite ACE-FTS typically 5% higher than other satellite instruments (Dupuy et al, ACPD 2008)instruments (Dupuy et al, ACPD 2008)

MAESTRO-sondes within 5-10% 16-30 km, larger MAESTRO-sondes within 5-10% 16-30 km, larger difference below 16 km (Kar et al JGR 2007)difference below 16 km (Kar et al JGR 2007)

Less validation done in troposphereLess validation done in troposphere ACE-FTS biased high 18-25% compared to sondes ACE-FTS biased high 18-25% compared to sondes

and aircraft (Hegglin et al ACP 2008)and aircraft (Hegglin et al ACP 2008)

Ozone Observations for ComparisonOzone Observations for Comparison

SHADOZ ozonesondes launched 2x a month starting 1998

MOZAIC: instruments onboard passenger aircraft measure O3, H2O since 1994

In Situ Measurements

The “Truth”

Satellite Observations

Direct comparisons of satellite data to aircraft or sondes is difficult

•Sonde locations and flight paths limited in space

•Number of coincident observations small

Better to use a model as an intermediary step:

Compare in situ measurements with model, then compare model to satellite observations.

In Situ Measurements

The “Truth”

Satellite Observations

Finding the TroposphereFinding the Troposphere

Thermal tropopause Thermal tropopause (NCEP) best in (NCEP) best in tropicstropics

Dynamic tropopause Dynamic tropopause (ECMWF PV fields) (ECMWF PV fields) best at mid-latitudesbest at mid-latitudes

Used lowest of the Used lowest of the twotwo

Tropopause Height (km)

Tropospheric Ozone MapsTropospheric Ozone Maps

GEOS-Chem simulation for 2000

MOZAIC August 1994 – August 2006, SHADOZ Jan 1998- Dec 2004

ACE-FTS v2.2 Ozone Update March 2004-December 2008

Tropospheric Ozone MapsTropospheric Ozone Maps

GEOS-Chem simulation for 2000

MOZAIC August 1994 – August 2006, SHADOZ Jan 1998- Dec 2004

MAESTRO v1.2 March 2004-March 2008

Ozonesonde

MOZAIC

GEOS-Chem

ACE-FTS

MAESTRO

Number of observations used displayed on plots

Ozonesonde

MOZAIC

GEOS-Chem

ACE-FTS

MAESTRO

Model agrees well with ozonesondes and MOZAIC

Significant differences between satellites and in situ observations

Mean Profile BiasMean Profile Bias

ACE-FTS biased high on ACE-FTS biased high on averageaverage 15% from sondes15% from sondes 13% from MOZAIC13% from MOZAIC

MAESTRO MAESTRO 30% lower than MOZAIC 30% lower than MOZAIC

from 10-12 kmfrom 10-12 km 40% higher than sondes 40% higher than sondes

from 12-14 kmfrom 12-14 km

Model – Satellite ComparisonModel – Satellite Comparison

ACE-FTS and ACE-FTS and MAESTRO annual MAESTRO annual mean tropical (20N-mean tropical (20N-20S) profile20S) profile

GEOS-Chem GEOS-Chem simulation sampled at simulation sampled at satellite profile satellite profile locationslocations

ACE-FTS bias 12%ACE-FTS bias 12% MAESTRO biasMAESTRO bias

34% above 14km34% above 14km -40% below 14km-40% below 14km

ACE-ModelMAESTRO-Model

Future Work: HNOFuture Work: HNO33 evaluation evaluation

NASA Aura Validation Experiment

AVE-0410 AVE-0506 CR-AVE (0601)Z

(km

)

MOZAIC NOy measurements

Will study ACE-FTS HNO3 product in troposphere in similar manner

Ozone Production EfficiencyOzone Production Efficiency

Medium correlation expected due to additional HNO3 sources/sinks in upper troposphere

Value within range given by model (100-150 mol/mol, Sauvage et al JGR 2007)

First measurement of OPE using satellite data

Improvements in HNO3 and O3 data may reduce uncertainty

OPE = 120 ±11mol/mol

r = 0.58

ACE-FTS Data 20N – 20S 10.5 km

Longitude

SummarySummary

ACE-FTS OACE-FTS O33 biased high compared to MOZAIC biased high compared to MOZAIC and ozonesondesand ozonesondes ACE –sondes 15%ACE –sondes 15% ACE –MOZAIC 13%ACE –MOZAIC 13% ACE –GEOS-Chem 12%ACE –GEOS-Chem 12%

MAESTRO OMAESTRO O33 bias altitude dependant bias altitude dependant 30% lower than MOZAIC 10-12km30% lower than MOZAIC 10-12km 40% higher than sondes 12-14km 40% higher than sondes 12-14km

ACE-FTS measurements can be used to ACE-FTS measurements can be used to calculate ozone production efficiencycalculate ozone production efficiency