Satellite Remote Sensing of Ground-Level NO2 for New Brunswick

Randall Martin and Lok Lamsal

Dalhousie University

Major Nadir-viewing Space-based Measurements Major Nadir-viewing Space-based Measurements of AQHI Speciesof AQHI Species

Sensor MISR MODIS SCIA-MACHY

TES OMI PARA-SOL

GOME-2

IASI S-5 Precursor

Platform (launch)

Terra Aqua

(1999) (2002)

Envisat (2002)

Aura

(2004)

PARA-SOL

(2004)

MetOp

(2006, 2011, 2016)

2014?

Equator Crossing

10:30 1:30 10:00 1:45 1:30 9:30 1:30

Typical Res (km)

18x18 10x10 60x30 8x5 >24x13 18x16 80x40 12x12 7x7

Global Obs

(w/o clouds)

7 2 6 n/a 1 1 1 0.5 1

Aerosol X X X

NO2 X X X X

Ozone X X X X X X

Solar Backscatter & Thermal Infrared

Proposed: MCAP (CSA), GEO-CAPE (NASA)

Use Satellite Observations to Improve Emissions Use Satellite Observations to Improve Emissions Inventories, and In Turn Simulations Inventories, and In Turn Simulations

Tropospheric NOTropospheric NO22 Column Proxy for Surface Concentration Column Proxy for Surface Concentration

NO/NO2

with altitude

OMI Tropospheric NO2 Column (1015 molecules cm-2) for 2005

Daily Retrieval Uncertainty: 1x1015 molec cm-2 + 30% of trop column

Data from Lamsal et al., JGR, in press

General Approach to Estimate Surface ConcentrationGeneral Approach to Estimate Surface Concentration

Daily Observed Column

S → Surface Concentration

Ω → Tropospheric column

In Situ

GEOS-Chem

Coincident Model Profile

OM

MO S

S

Significant Correlation Between In Situ and OMI-derived Significant Correlation Between In Situ and OMI-derived Surface NOSurface NO22; ; Less Clear for New BrunswickLess Clear for New Brunswick

Correlation with Coincident “Corrected” Observations over 2005

DOMINO

Lamsal et al., JGR, 2008

Annual mean in early afternoon ~13:45 for 2005

New Brunswick Generally Has Low NONew Brunswick Generally Has Low NO22 Concentrations Concentrations

OMI-derived Surface NO2 Concentration (ppbv)

... However There are Transient Events... However There are Transient EventsEarly Afternoon (13:00 – 14:00) NO2 Concentration

Mean OMI-derived NO2 for New Brunswick

More Analysis Needed for Direct ComparisonMore Analysis Needed for Direct ComparisonCollocated measurements (OMI Black x 5)

Different spatial scalesNo NOz interference correction

Local sources?

Interference in Molybdenum Converter Interference in Molybdenum Converter Measurements in Southeast US (YRK)Measurements in Southeast US (YRK)

Lamsal et al., JGR, in press

Photolytic / Molybdenum

Modeled (GEOS-Chem)

~NO2 / 0.1*ΔO3 [14:00 – 10:00] (Boersma et al., ACP, 2009)

OMI Observes During Minimum NOOMI Observes During Minimum NO22

Observations from EPA air quality networkObservations from EPA air quality network

Lamsal et al., JGR, 2008

mean

median

Possible StrategyPossible Strategy

Use satellite to monitor for extreme events

(i.e. when partial AQHI from NO2 exceeds a threshold)

IssuesIssues• Examine wintertime spikes; caution over snow

• Interference in ground-based NO2 measurements

• Assess diurnal variation with in situ

• Cloud-free: test clear sky bias

• “Row Anomaly” restricts OMI Coverage; may need to consider GOME-2