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Ken PickeringProject ScientistNASA GSFCKenneth.E.Pickering@nasa.gov

Gao ChenData ManagerNASA LaRCGao.Chen@nasa.gov

DISCOVER-AQ Update: First impressions from California and

upcoming plans for HoustonJim Crawford Principal InvestigatorNASA LaRCJames.H.Crawford@nasa.gov

Mary KlebProject ManagerNASA LaRCMary.M.Kleb@nasa.gov

Webpage: http://discover-aq.larc.nasa.gov/

Deriving Information on Surface Conditions from Column and VERtically Resolved Observations Relevant to Air Quality

A NASA Earth Venture campaign intended to improve the interpretation of current and future satellite observations to diagnose near-surface conditions relating to air quality

Objectives: 1. Relate column observations to surface conditions for aerosols and key trace gases O3, NO2, and CH2O

2. Characterize differences in diurnal variation of surface and column observations for key trace gases and aerosols

3. Examine horizontal scales of variability affecting satellites and model calculations

Investigation Overview

Deployments and key collaboratorsMaryland, July 2011 (EPA, MDE, UMd, UMBC, Howard U.)California, January 2013 (EPA, CARB, UC-Davis&Irvine)Texas, September 2013 (EPA, TCEQ, U. of Houston)Colorado, Summer 2014 (EPA, NSF, NOAA, CDPHE) 2

NASA P-3B

NASA King Air

NATIVE, EPA AQS, and associated Ground sites

Deployment StrategySystematic and concurrent observation of column-integrated, surface, and vertically-resolved distributions of aerosols and trace gases relevant to air quality as they evolve throughout the day.

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NASA King Air (Remote sensing)Continuous mapping of aerosols with HSRL and trace gas columns with ACAM

NASA P-3B (in situ meas.)In situ profiling of aerosols and trace gases over surface measurement sites

Ground sitesIn situ trace gases and aerosolsRemote sensing of trace gas and aerosol columnsOzonesondesAerosol lidar observations

Three major observational components:

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California Flight Strategy

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DISCOVER-AQ CaliforniaHSRL-2 on the King Air Maps the Spatial Distribution of Aerosol between ground monitors across the valley

Ten science flights documented the details of two successive PM2.5 episodes in the San Joaquin Valley

Bakersfield PM2.5(16 January - 7 February)

Fresno

Bakersfield

*Orange line (36 ug/m3) is the 24hr average threshold for violating National Ambient Air Quality Standards

Aerosol Scattering from the P-3B shows the build up of fine particles to be concentrated in a shallow layer below 2000 feet.

550 nm Scattering (Mm-1)

16 Jan 22 Jan

Bakersfield

Fresno

(Photo taken from ER-2 during PODEX flight on 20 January)

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PM2.

5 (u

g/m

3 )A

OD

(500 nm; level 1.5 data)

PM2.5 and AOD at Bakersfield during a build-up (16-24 Jan 2013)

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P-3B profiles of BL structure over Porterville on 20 Jan 2013

310300290280

Potential Temperature (K)

2.0 2.0

1.5 1.5

1.0 1.0

0.5 0.5

0.0 0.0

Pres

sure

Alti

tude

(km

)

3002001000

EXTdry532 (Mm-1)440430420410400

CO2 (ppmv)

Porterville: 2013012008:30:30 to 08:41:3110:43:04 to 10:54:2712:58:10 to 13:09:11

8

60

40

20

0

O3+

NO

2 [pp

bv]

12:00 AM1/21/2013

6:00 AM 12:00 PM 6:00 PM 12:00 AM1/22/2013

Local Time

60

40

20

0

NO

2 [pp

bv]

60

40

20

0

O3 [

ppbv

]

1-min ground site data Missed approach average

Lowest radar alt for Pass 1:86.5 feet AGL

How shallow is the boundary layer? (Bakersfield, 21 Jan 2013)

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• Increase in effective radius• Increase in scattering and absorption

Feb. 1 Afternoon Flight Feb. 4 Afternoon Flight

Changes in Aerosol Properties between Feb. 1 and Feb. 4

HSRL-2 Aerosol Microphysical Retrievals

Scat. Coeff (532nm):> 350 1/Mm

Abs. Coeff (532nm):20 – 30 1/Mm

Abs. Coeff (532nm):> 30 1/Mm

Scat. Coeff (532nm):250 – 300 1/Mm

Eff. Radius:0.15 - 0.20 µm

Eff. Radius:0.2 - 0.25 µm

Microphysical Properties From Inversion of Backscatter (355,532,1064nm) + Extinction (355,532nm)

Microphysical Properties:• effective radius, number, surface-area, and volume concentration

→ fine and coarse mode• complex refractive index

Optical Data Products (just a few examples):• scattering and absorption coefficients, single-scattering albedo

→ 355, 532, 1064nm• effective variance, phase function and asymmetry parameter in 2013

Software:• automated, unsupervised, fast• data products are delivered the day after a research flight

Specific Features:• vertically resolved profiles• data products reflect ambient atmospheric conditions

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Data Availability

Baltimore-Washington: Currently AvailableCalifornia: Available on 15 June 2013Texas: Available on 1 February 2014

Houston Plans (September 2014)

P-3B (red line; in situ trace measurements)King Air (blue line; remote sensing) 15 Aeronet sunphotometers14 Pandora spectrometers 2 ozone lidars 2 aerosol lidars 2 Ozonesonde sites 4 Radar profilersExtensive ground-based sampling from multiple teamsGEO-Cape ship in the Gulf of MexicoGeoTASO demonstration