NACP

On network design for the detection of urban greenhouse gas emissions: Results from the

Indianapolis Flux Experiment (INFLUX)

Natasha Miles1, Thomas Lauvaux1, Kenneth Davis1, Scott Richardson1, Laura McGowan1, Daniel Sarmiento1, Colm Sweeney2, Anna Karion2, Michael

Hardesty2, Jocelyn Turnbull2,3, Laura Iraci4, Kevin Gurney5, Igor Razlivanov5, Paul Shepson6, M. Obiminda Cambaliza6, James Whetstone7

1. The Pennsylvania State University, 2. NOAA/ESRL, 3. GNS Science4. NASA/JPL, 5. Arizona State University, 6. Purdue University, 7. NIST

AGU Fall Meeting A44F-01 San Francisco, CA 12 December 2013

INFLUX motivation• Emissions mitigation will happen at local and regional scales.

• Validation of emissions mitigation will(?) require (independent) measurements

• Atmospheric GHG measurements have the potential to provide such independent emissions estimates.

• Develop improved methods for determination of urban area-wide emissions, and spatially and temporally-resolved fluxes of greenhouse gases, specifically, CO2 and CH4.

• Determine and minimize the uncertainty in the emissions estimate methods.

INFLUX objectives

• Inventory estimates of sector-by-sector emissions at high spatial resolution

• Periodic aircraft flights with CO2, CH4, and flask samples • Periodic automobile surveys of CH4 • 12 surface towers measuring CO2, 5 with CH4, and 5 with CO &

Mesoscale atmospheric inversion • 6 automated flask samplers from NOAA

– Identify sectoral emissions– Intensive study of diurnal cycle planned

• TCCON-FTS for 4 months (Sept - Dec 2012)• 4 eddy-flux towers – model assessment (installed Nov 2013)• Doppler lidar (installed Apr 2013)• Tracer release experiment (?)

INFLUX methodology: Simultaneous application of multiple methods

Vulcan and Hestia Emission Data Products

Vulcan – hourly, 10km resolution for USA

Hestia: high resolution emission data for the residential, commercial, industrial, transportation and electricity production sectors.

http://hestia.project.asu.edu/

A53E-0216. Gurney et al, Friday afternoon

250m res - Indy




Aircraft mass balance approach: 1 June 2011 Flight path

Cambaliza et al 2013 (ACPD)

8 ppm CO226,000 moles s-1

50 ppb CH4197 moles s-1

1 June 2011 Results

Cambaliza et al 2013 (ACPD)

A53E-0225. Quantification of the methane emission flux from the city of Indianapolis, IN: identification and contribution of sources, Cambaliza et al., Friday afternoon

NG leak

CH4 enhancement (ppb)

North

Observed CH4 enhancements directly downwind of SSLF landfill and a natural gas TRS on Harding St. obtained during a surface mobile measurement on Jan. 21, 2013. Note that a NG leak was also observed on Oliver Ave. Bridge just outside the city center. Courtesy of M. O. Cambaliza (Purdue Univ).

Drive-arounds: Separation/quantification of CH4 sources

Instrumentedvehicles used to identify and quantify individual sources.

Marion CountyKey: Drive Path

Data shown:• Total INFLUX

drive paths and methane enhancements (CSU 2013, Purdue 2012-2013)

***Threshold set to show CH4 data > 3 stdev above average background

Courtesy of M. O. Cambaliza (Purdue Univ)

Marion County

Key: Drive Path x40 x9 x29

Data shown:• Total

INFLUX drive paths and methane enhancements (CSU 2013, Purdue 2012-2013)

Panhandle

TRS #2

Oliver Ave Bridge

SSLF

Residential Leak

See also: A53E-0213. Quantification of Methane Emissions From Street Level Data, Prasad et al, Friday afternoon; Courtesy of M. O. Cambaliza (Purdue Univ)

Pic

arro

, CR

DS

sen

sors

; NO

AA

auto

mat

ed fl

ask

sam

pler

s;

Com

mun

icat

ions

tow

ers

~100

m A

GL

10 km

Results to date: Tower flask and in-situMesoscale atmospheric inversion

CO2WMO recommendation:

0.1 ppm

CADS (first generation) systems (circled): -0.18 to 0.1 ppm average site error

Checks of network intercalibration:

In-situ – flask comparison at 5 INFLUX sites (ongoing)

• NOAA 1 hour integrated flask samples• Mean value in-situ - flask:

CO2: 0.09 ppm CH4: 0.6 ppb CO: -4.1 ppb• Within WMO recommendations (urban)

Round-robin testing using 3 NOAA-calibrated tanks (Nov 2013)

Flask results: C14

Turnbull et al., in prep

Flask analysis: fossil fuel CO2

Sector-by-sector atmospheric CO2 mole fractions, in percentage contribution for each site

• Winter mean daytime [CO2]

• Hestia emissions combined with footprint analysis

CommercialIndustrial

MobileResidential

Power Plant

• Afternoon [CO2] with 21-day smoothing

• Site 03 (downtown): high [CO2]

• Site 01 (background): low [CO2]

• Seasonal and synoptic cycles are evident

Comparison of [CO2] at INFLUX sites

2011 2012 2013

• Afternoon [CO2] with 21-day smoothing

• Site 03 (downtown): high [CO2]

• Site 01 (background): low [CO2]

• Seasonal and synoptic cycles are evident



2011 2012 2013

Afternoon daily [CO2]

Range = 10 ppm

3 ppm


CO2 range as a function of wind speedObservations: CO2 range amongst INFLUX sites


Increased residence time (at low winds) tends to increase the CO2 range

10% of ranges are > 10 ppm

29% of ranges are < 3 ppm


Model: Difference along domain-averaged wind direction

Increased residence time (at low winds) tends to increase the CO2 range

• Site 09 measures 0.3 ppm larger than Site 01

• Site 03 (downtown site) measures larger [CO2] by 3 ppm

Spatial Structure of Urban CO2Average [CO2] above background site

East

of c

ity

Dow

ntow

n

Afternoon daily values, 1 Jan – 1 April 2013

East

ern

edge

of c

ity

• Backward model results using footprints and Hestia 2002 fluxes

• Agreement in terms of the ordering of the sites

• Observations are 25% higher than modeled values, on average

Average [CO2] above background site

Spatial structure: Model-data comparison

Jan – Apr 2013 AFTERNOONSite 02 – Site 01 CO2, ppm

Urban [CO2] enhancement

Eastern edge of city - backgroundAverage over all wind dir: 1.5 ppmDownwind of city: 2.4 ppm** Arrows point to sources

Jan – Apr 2013 AFTERNOONSite 02 – Site 01 CO2, ppm

Site 30 km east of edge of city - background siteAverage over all wind dir: 0.3 ppmDownwind of city: 1.1 ppm** Arrows point to sources** Black: Site 01 larger than Site 09

Urban [CO2] enhancementJan – Apr 2013 AFTERNOONSite 09 – Site 01 CO2, ppm

Eastern edge of city - backgroundAverage over all wind dir: 1.5 ppmDownwind of city: 2.4 ppm** Arrows point to sources

Site Description Sample height(s), m AGL

Site 01 Background 10/40/121

Site 02 East 10/40/136

Site 03 Downtown 10/20/40/54

Site 04 South 60

Site 05 NorthWest 125

Site 06 NorthEast 39

Site 07 West 58

Site 08 NorthEast (20 km from I-465)

41

Site 09 East (30 km from I-465)

10/40/70/130

Site 10 South 40

Site 11 North 130

Site 13 SouthEast (10 km from I-465)

87

How high do in-situ measurements need to be?

What is the vertical structure of urban CO2 mole fractions?

Vertical profiles of daytime CO2, compared to top level

-0.6 0.2 0.9 1.0

Background site Downtown siteMixed site

3.41.3-1.0 0.3

Vertical CO2 (Daytime) DifferencesSite 02 – Mixed site

CO2 at 10 m – CO2 at 136 m

Arrows point to sources

Mixed Site

Vertical CO2 (Daytime) DifferencesSite 02 – Mixed site

CO2 at 10 m – CO2 at 136 m

Arrows point to sources Source area varies for various heights

Mixed Site

Vertical CO2 (Daytime) DifferencesSite 03 – Downtown site

CO2 at 10 m – CO2 at 54 m


Downtown Site

Vertical CO2 (Daytime) DifferencesSite 03 – Downtown site

CO2 at 10 m – CO2 at 54 m


• “Spaghetti bowl” • How well does the model do for

this site?

Downtown Site

Conclusions• Whole city flux estimates achieved via aircraft mass balance. Drive-

arounds used for source identification.

• Flask: Winter, CO2 = CO2ff. Summer, not true.

• Tower observations detect a clear urban signal in both CO2 (buried amid lots of synoptic “noise”). Differences vary greatly with weather conditions.

• Model-data comparisons show similar spatial structure.

For more information, see http://influx.psu.edu

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