past california air quality observations by hsrl · pm2.5 concentrations over california and...

Past California Air QualityObservations by HSRL

SacramentoFresno

Bakersfield

• Airborne HSRL aerosol backscatter measurements Feb. 15, 2007• Highest AOT and PBL heights between Bakersfield and Fresno• Low aerosol backscatter, extinction, AOT and PBL height in Sacramento region

NASA Langley Airborne HSRL Aerosol Backscatter Profiles Acquired on February 15, 2007 During Flight over San Joaquan Valley (SJV)

BakersfieldFresno

Sacramento


Backscatter

Extinction

Extinction/Backscatter

Aerosol Depol (532 nm)

Ratio of Aerosol Depol (532 nm/1064 nm)

Backscatter WavelengthDepend (1064/532)


Backscatter

Extinction

Extinction/Backscatter

Aerosol Depol (532 nm)

Ratio of Aerosol Depol (532 nm/1064 nm)

Backscatter WavelengthDepend (1064/532)Aerosol Type

Highest AOT in SJV region; little AOT observed over or near Sacramento

NASA Langley Airborne HSRL Aerosol Optical Thickness (AOT) Acquired on Several Flights During February 2007 over SJV

• Sacramento, California• June 3 - 28• 23 science flights (~68 hours)

• 19 with DOE G1 • 1 with NOAA R/V Atlantis• 2 with NOAA P3• 6 with NOAA Twin Otter• 11 with MODIS and/or MISR

B200/HSRL Deployment during DOE CARES Mission June 2010

AOT June 28, Flight 2

• Sacramento, California• June 3 - 28• 23 science flights (~68 hours)

• 19 with DOE G1 • 1 with NOAA R/V Atlantis• 2 with NOAA P3• 6 with NOAA Twin Otter• 11 with MODIS and/or MISR

AOT was low!

B200/HSRL Deployment during DOE CARES Mission June 2010

From Al-Saadi et al. AMS Meeting Presentation 2008

High PM2.5 Concentrations

NASA/GSFC Giovanni visualization of AirNow data

Jan-Feb 2007

Jun-Aug 2007

PM2.5 (ug/m^3)

Average PM2.5 Concentrations During 2007

• Monthy median PM2.5 levels for locations of interest (7/2002-4/2010)

SAC

SJV

LA

SLCPIT

DC

ATL

HOU

Data provided by NASA/GSFC Giovanni site

Selected Regions of Interest

Box Plots Showing Monthly PM2.5 Concentrations for Selected Regions of Interest

• Monthy median PM2.5 levels for locations of interest (7/2002-4/2010)

SAC

SJV

LA

SLCPIT

DC

ATL

HOU


Monthly Median PM2.5 Concentrations for Selected Regions of Interest

• January-March PM2.5 levels for locations of interest (7/2002-4/2010)• SJV has highest median values, followed by SLC

SAC

SJV

LA

SLC


Box Plots Showing Monthly PM2.5 Concentrations During January-March for Selected Regions of Interest

• SJV region has highest values

SAC

SJV

LA


PM2.5 Concentrations Over California During January-February 2007 March for Selected Regions of Interest

• June- August PM2.5 levels for locations of interest (7/2002-4/2010)• LA has highest median values, followed by DC, PIT, ATL• HOU has relatively low values

PIT

DC

ATL

HOU


Box Plots Showing Monthly PM2.5 Concentrations During June-August for Selected Regions of Interest

PM2.5 Concentrations Over California and Eastern U.S. During June-August 2007 for Selected Regions of Interest

NASA/GSFC Giovanni visualization of AirNow data

• June- August PM2.5 levels for locations of interest (7/2002-4/2010)• LA has highest median values, followed by DC, PIT, ATL• HOU has relatively low values

• Ontario, California• May 13-25• 8 science flights (~29.5 hours)

• 6 with CIRPAS Twin Otter• 2 with NOAA P3• 6 with MODIS and/or MISR

B200/HSRL Deployment over Los Angeles during NOAA CALNEX Mission May 2010

HSRL data over Los Angeles during May 19, 2010 CALNEX flight

Extinction (532 nm)

Lidar Ratio (532 nm)

Aerosol Depol. (532 nm)

Ratio of Aerosol Depol. (532/1064 nm)

Backscatter Wave. Depend (1064/532)

Backscatter (532 nm)

Aerosol depolarization (532 nm)

Aerosol scattering ratio (532 nm)Aerosol Type

AOD apportioned by type

HSRL data over Los Angeles during May 19, 2010 CALNEX flight

Aerosol Backscatter (532 nm) Aerosol Optical Thickness

HSRL Measurements over Los Angeles - May 19, 2010

Aerosol Backscatter (532 nm) Aerosol Type

HSRL Measurements over Los Angeles - May 19, 2010

HSRL Depolarization Ratio

HSRL Aerosol Backscatter


B200/HSRL Deployment over Houston during NOAA CALNEX Mission May 2010


B200/HSRL Deployment over Houston during NOAA CALNEX Mission May 2010

Presenter

Presentation Notes

Need to insert google earth map that shows where boxes are

Presenter

Presentation Notes

Make this for California Jan-Feb and average June-Aug average

HSRL data used to:• define PBL height• evaluate MODIS research AOT retrievals• determine AOT above/below PBL

Airborne Aerosol Lidar Measurements for Air Quality Research

Aqua MODIS AOT research retrieval(Allen Chu, GSFC)

HSRL aerosol backscatter profiles and PBL height

Science Questions: What is the relationship between

satellite AOT and measured surface PM2.5?

Can satellite measurements be used to adequately characterize PM2.5 spatial gradients/distributions in SJV?

What are the effects of PBL height and vertical aerosol distributions on the relationship between column AOD and surface PM2.5?

San Joaquin Valley, California

Normalizing AOT with PBL height (zi) significantly improves correlation with surface PM2.5

(r2 increases from 0.36 to 0.75)

Very good correlation between MODIS and HSRL AOT when MODIS retrievals restricted to large (>132 deg) scattering angles – reduces dependence of MODIS AOT on surface reflectance

Airborne Aerosol Lidar Measurements for Air Quality Research

AOT/PBL Height (HSRL) AOT (MODIS)

Assessment of Model Aerosol Simulations and Using Aerosol Model Simulations to Interpret HSRL

Measurements

Mixing & Transport over Terrain

18:00

17:00

16:30

17:30

19:00

MODIS “hotspots”

19:30

Backscatter measured by airborne HSRL NASA/LaRC B200/HSRL March 12, 2006

mountain venting

venting from plateau

• Airborne HSRL data:– reveal complexity of mixing and

transport of particulates– used to indirectly evaluate

meteorological predictions• Model can reproduce most aspects of

PBL in vicinity of Mexico City• Model requires smaller vertical grid

spacing to resolve shallow layering observed by lidar

Backscatter predicted by WRF-Chem model

Airborne HSRL Measurements used to Evaluate WRF-Chem Model

WRF-Chem (Jerome Fast – PNNL)

Mexico City

Mexico City

Mexico City

Mexico City

Presenter

Presentation Notes

These slides show some measurements and analyses of data acquired by the NASA Langley Research Center airborne High Spectral Resolution Lidar (HSRL). This slide shows HSRL measurements acquired over and around Mexico City during the Megacity Initiative: Local and Global Research Observations (MILAGRO) experiment in 2006. (The NASA portion of this experiment was Intercontinental Transport and Chemical Evolution Experiment (INTEX-B)). The figure on the right shows the NASA Langley B200 King Air aircraft on which the HSRL was deployed and the “curtain” of aerosol backscatter profiles measured by the HSRL during the flight. The figure on the top left shows the aerosol backscatter profiles measured by the HSRL during the flight; the bottom left figure shows the aerosol backscatter profiles predicted by the Weather Research and Forecast (WRF) model coupled with Chemistry (WRF-Chem) model. (Model runs were performed by Dr. Jerome Fast – Pacific Northwest National Laboratory). This is a high resolution (3-12 km horizontal resolution) mesoscale model. Comparison with the HSRL measurements shows the model does well over most of the region, and can resolve most aspects of the Planetary Boundary Layer (PBL) in the Mexico City region. However, the model does not do as well at high altitudes where the model vertical resolution is too coarse to capture the fine detail revealed by the HSRL measurements. The HSRL measurements are being used to evaluate other models (e.g. GOCART, GEOS-5) also.

HSRL/WRF-Chem Example – March 13, 2006

HSRL WRF-Chem

High resolution WRF-Chem shows much of the small scale structure shown in HSRL data

COOIN (coarse) - dust

NO3 (fine) SO4 (fine)

HSRL Aerosol Classification – Comparison to WRF-Chem

HSRL WRF-Chem

- In the vicinity of Mexico City, WRF-CHEM compositions qualitatively agree with aerosol types inferred from HSRL measurements

High concentrations of NO3, SO4, EC -> urban High concentrations of dust (other inorganics, OIN, in the model) -> mix of dust and urban

- Outside of Mexico City, dust and urban pollutants mix together

WRF-Chem (Jerome Fast – PNNL)

March 7 March 8 March 9

March 10 March 12 March 13

HSRLWRF-Chem

WRF-Chem aerosol extinction profiles in very good overall ageement with HSRL

HSRLWRF-Chem

HSRLWRF-Chem

AverageExtinction Profiles

Slope=0.97int=0.002R=0.86Bias diff ~ 2%

HSRL/WRF-Chem Aerosol Extinction Comparison

March 7

March 8

March 9

March 10

March 12

March 13

WRF-Chem aerosol optical thickness in very good overall ageement with HSRL

Overall Summary

• Performance varies with location WRF-chem overestimates backscatter and extinction over Gulf and coast -perhaps too much model dust?

• Some fine scale layers only crudely represented by model

• Some differences between measured and modeled PBL growth rate

HSRL/WRF-Chem Aerosol Optical Thickness Comparison

Spatial Variability in AOD based on HSRL observations

CALIPSO Validation flights encountered substantially higher AODs. Structure functions (q=1) were performed for each set of flights as well as for the CALIPSO validation flights only for AOD > 0.5 (roughly the upper quartile of data).

Results shown on following slide.

Long range transport of aerosols depends on whether aerosols injected above PBLHSRL data used to determine:• PBL height• Upper and lower limits of the

backscatter transition (i.e. entrainment) zone

• Fraction of aerosol optical thickness within PBL

• PBL heights over water significantly lower than PBL heights over land

• Large fraction (40-50%) of AOT above PBL during MILAGRO, GoMACCS, CHAPS

• Most (80-90%) of AOT within PBL during San Joaquin Valley Mission

• HSRL PBL heights now routinely requested by other investigators

Planetary Boundary Layer (PBL) Height Retrievals and AOT from High Spectral Resolution Lidar (HSRL)

Aerosol Backscatter (532 nm)Sept. 26, 2006 (GoMACCS)

PBL heightSept. 26, 2006 (GoMACCS)

Water Vapor Mixing RatioAerosol Backscatter

Aerosol ExtinctionRelative Humidity

DOE SGP Raman Lidar PBL Height Retrievals

June 12, 2001 June 12, 2001

Sunset Sunrise

• DOE SGP Raman Lidar (Oklahoma) operates 24/7 measuring water vapor and aerosols• Raman lidar data used to determine PBL height and aerosol and water vapor distributions

Boundary Layer Height (1998-2003)Median; Box: 25%, 75%; Whisker: 5%, 95%

Time (UT)

Alt

itu

de

(m

)

0

500

1000

1500

2000

2500

3000

2 4 6 8 10 12 14 16 18 20 22 24

Aerosol Backscatter (Lidar)Potential Temperature (Sonde)

Box Plot (copy of 01011998-12312003_aot_addv5.sta 59v*35976c)

• PBL Height Methods:• Radiosonde - Potential temperature -(Heffter, 1980) • Raman Lidar - Aerosol backscatter, water vapor via Haar wavelet – (Brooks, 2003)

• Best agreement during afternoon, early evening

Percentage of AOT below BL Height Median; Box: 25%, 75%; Whisker: 5%, 95%

Time (UT)

Pe

rce

nta

ge

0102030405060708090

100

2 4 6 8 10 12 14 16 18 20 22 24

WinterSummer

Box Plot (copy of 01011998-12312003_aot_addv5.sta 60v*35976c)

• Amount of AOT within PBL- varies with time of day- does not vary significantly with season or AOT

• Significant fraction of AOT (>25%) is above PBL

DOE SGP Raman Lidar PBL Height Retrievals

Presenter

Presentation Notes

See 1998-2010 files in G:\carl\seasonal images\nobe\05072010\avg_aot_Summer_1998-2010_nobe_3.gif

Winter

SummerAe

roso

l Ext

inct

ion

(km

-1)

Average Diurnal Variation of Aerosol Extinction Profiles and AOT

• Large changes in vertical profile• Smaller changes in AOT

(st. dev ~ 10%)Sunrise

Sunrise

Sunset

Sunset

Terr

a

0 2 4 6 8 10 12 14 16 18 20 22 240.0

0.1

0.2

0.3

0.4

0.5

0.6

Aqu

aA

qua

Terr

a Fall (day) Fall (night) Winter (day) Winter (night)

Aer

osol

Opt

ical

Thi

ckne

ss (35

5 nm

)

Time (UT)

Summer (day) Summer (night) Spring (day) Spring (night)

Aqua

AOT

0 2 4 6 8 10 12 14 16 18 20 22 240

10

20

30

40

50

60

Aqu

a

Terr

a

Fall (day) Fall (night) Winter (day) Winter (night)

Inte

grat

ed W

ater

Vap

or (a

rb. u

nits

)

Time (UT)

Summer (day) Summer (night) Spring (day) Spring (night)

Wat

er V

apor

Mix

ing

Rat

io (g

/kg)

Winter

Summer

Sunrise

Sunrise

Sunset

Sunset

Terr

a

Average Diurnal Variation of Water Vapor Profiles

• Smaller diurnal changes in profiles and integrated water vapor (st. dev ~ 3-5%)

Aqua

Integrated water vapor

HSRL Measurements used to evaluate satellite retrievals of aerosol optical depth – August 4, 2007

AOT Over land:• Terra and Aqua MODIS, HSRL, and

AERONET agreeAOT over water:• Terra MODIS , PARASOL, and HSRL

agree• Aqua MODIS AOT about 0.2 (33%)

low

WaterLand

Presenter

Presentation Notes

Overland: AERONET, MODIS (Aqua and Terra), PARASOL, and Airborne HSRL all agree nicely!! Over water: MODIS Aqua has a problem. MODIS over water measures AOT at 7 wavelengths. PARASOL at ~650? and ~870?, we use their wavelength dependence to extrapolate to 532 nm. Using MODIS collection 5. Lorraine first thought this was a scattering angle issue. However, we have looked at a variety of scattering angles with HSRL and seem to have the same problem. Jens may complain about graph on bottom right: not all points are independent. Used 25-km radius circle around each lidar profile to get MODIS values to average for the comparison. Not each of the blue points is independent (MODIS has 10 km resolution).

Extinction; AOT (532 nm) Depolarization (532 nm)

Extinction/Backscatter Ratio (532 nm)

Backscatter λDependence (1064/532 nm)

Characterizing aerosol optical properties/typeProviding vertical context for G-1 in situ measurements

NASA King Air & DOE G-1 coordinated fight – March 9, 2006

Presenter

Presentation Notes

For sacramento, use 39, -122 to 38, -120.5 For LA, use 34.5, -119 to 33.5, -117

Presenter

Presentation Notes

For sacramento, use 39, -122 to 38, -120.5

Presenter

Presentation Notes

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Presenter

Presentation Notes

SJV

Presenter

Presentation Notes

DC area 39.6, -77.6 38.8 -76

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Presentation Notes

Atlanta 34.3 -85.25, 33.3 -83.25

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Presentation Notes

pitt

Presenter

Presentation Notes

Jan-feb average, june-aug average

past california air quality observations by hsrl · pm2.5 concentrations over california and...

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