Complementary Ground-based and Space-borne Profile Measurements for Air Quality

presented at

1st WorkshopSatellite and Above-boundary-layer Observations for

Air-Quality Management

9-10 May, 2011Boulder, CO

Michael J. Newchurch1, Guanyu Huang1, John Burris2, Shi Kuang1, Wesley Cantrell1, Lihua Wang1, Patrick I. Buckley1, Brad Pierce3

1 Atmospheric Science Department, University of Alabama in Huntsville 2Goddard Space Flight Center, NASA3University of Wisconsin

Outline

1. Satellite kernels2. The effect of initial and boundary conditions3. Sondes and lidars and laminar structures4. Birmingham ozone/aerosol plume5. STE of ozone6. Ozone lamina climatology7. Modeling of laminar structures

Introduction

• Satellite observations of trace gases have progressed significantly in the last decade from total ozone column measurements by TOMS to ozone profiles by OMI and NO2, HCHO, CHOCHO by OMI, Gome, and SCIMACHY.

• Balloon borne ozone soundings at weekly intervals are now complemented by ground-based ozone DIAL measurements at sub-hourly intervals.

• Several intensive campaigns integrating space-borne, air-borne, balloon-borne, and ground-based in-situ campaigns and remote sensing techniques have significantly enhanced our understanding of the chemistry and physics controlling surface ozone and aerosol amounts.

• The next level of understand will derive from diagnosing the processes involved in forming and transporting the ubiquitous tropospheric layers we observe in the boundary layer and in the free troposphere.

• These tropospheric ozone layers have significant potential implications for a variety of dynamic, chemical atmospheric processes and energy budgets (Newell et. al,. 2001).

• However, we have little understanding of the mechanisms controlling ozone layers and the models don’t reproduce the laminae very well. (Zhang and Rao, 1999, Stoller et al., 1999, Newell et al., 2001, Thouret et al., 2001, Colette et al., 2005a and 2005b,).

• We present the climatology of ozone laminar structure and its applications to models, satellite retrievals, and ground-level ozone amounts.

Courtesy of Owen Cooper/CU, ESRL

IR and UV Averaging Kernels

High-resolution PBL lidar observation suggests both UV and Vis radiances required to capture significant PBL signal for satellite

Huntsville lidar observation on Aug. 4, 2010

Lidar obs. convolved with OMI UV averaging kernel---- unable to capture the highly variable ozone structure in PBL

Lidar obs. Convolved with OMI UV-Vis averaging kernel----Captures the PBL ozone structure. X. Liu et al.

True

A priori

UV retrieval

Vis retrieval

TIR retrieval

UV + Vis

UV + TIR

UV + Vis + TIR

Theoretical retrievals from multi-spectral measurementsCourtesy of Natraj, Liu, et al.

Ozone boundary conditions for CMAQ

HCHO boundary conditions for CMAQ

Lateral boundary transport is important

CMAQ/sonde at 5 sites. No boundary conditions

CMAQ/sonde at 5 sites. OMI Initial & boundary conditions

J O U R N A L O F A P P L I E D M E T E O R O L O G Y VOLUME 38

The Role of Vertical Mixing in the Temporal Evolution of Ground-LevelOzone Concentrations

JIAN ZHANG AND S. TRIVIKRAMA RAODepartment of Earth and Atmospheric Sciences, University at Albany, State University of New York,

Albany, New York(Manuscript received 15 July 1998, in final form 19 February 1999)

…The results reveal that a greater reduction in the ground-level ozone concentration can be achieved by decreasing the concentrations of ozone and precursors aloft than can be achieved from a reduction of local emissions…

Typical, large diurnal variabilityin the Boundary LayerZhang and Rao, 1999

Laminar structure analyzed by CWT and the gradient method

16

Seasonal Variations Occur in Altitudinal Distributions- Layer Height WRT to Tropopause Height

Gradient Wavelet

Spring

Summer High frequency of layers below tropopause

Low frequency of layers near tropopause

Trinidad Head

1717

Layer B ThicknessMax: 4.8 km Min: 3.0 km

Mean Thickness: 0.3 km /10min

+0.9 km /10min

-0.3 km /10min

Layer A Max-MinMax: 50.1 ppbv Min: 36.6 ppbv

Mean max-min : 2.5 ppbv / 10min

+7.9 ppbv / 10min

-2.4 ppbv / 10min

A

B

•Temporal variability from other layer attributes can be similarly quantified.

•For example: O3 peak altitude, mixing ratio at peak.

Fine structure in the temporal variations of layer attributes can be quantified by Wavelet and Gradient methods from Lidar observations.

17

P(R^2>0.5)= 10% 15% 19% 12%

Ozone in the free troposphere is not correlated with surface ozoneSeasonal correlation of surface w/ ozone aloft

Huntsville 1999-2010 Ozonesonde Data

Laminar structures cause anomalous behavior in correlationsHuntsville Lidar Data

EPA Surface Data

Correlation LengthsDefinition: the altitude over which R^2 decreases from 1 to 0.5.

•Each line is a regression through the correlations of at least 0.5.

•Correlations >0.5 above the first occurrence of a statistically insignificant value (<0.5) are not considered.

Conclusion:

•Measurements of ozone above correlation length carries no info about surface ozone.

Corollary: To determine surface ozone concentration, a measurement must contain info from within the correlation length.

Two clusters

1/28/2011

18-25 25-30 30-35 ppbv

UAHuntsville Campus OzoneMeasured with ozonesonde

Percent difference reaches ~30% for measurements away from buildings.

Inside

Horizontal Variability

June 19

Surface ozone of 24 sonde profiles compared with local EPA site: The variance in the surface ozone amounts at the ozonesonde/lidar site seen in the EPA HSV-Airport Rd. site (~10 km distant; Summer 2010) is about 75%. The other 25% is the HORIZONTAL variance.

22

•$800/ ozonesonde launch•No more than 6 launch per 24 hours = 4-hour resolution•$800/launch*6launch/day*365days/year=$1,752,000/year

4-hour temporal resolution vs. 10-minute resolution

sonde

Apr. 17 Apr. 23

Apr. 27May 1

What We Missed with the Weekly Ozonesonde Measurements?

24

Additional sonding on Tue. after the lidar detection of Stratosphere-troposphere exchange (STE)

Dry air

10min resolution

O3 lidar retrieval

sonde

500ppbv

CloudCloud Cloud

Tropospheric ozone variability due to STE captured by the HSV lidar

26

Different variation structures for ozone and aerosol suggest local photochemistry dominates the production

Ozone mixing ratio, August 4, 2010

Aerosol ext. coeff. at 291nm from O3 DIAL

O3 diurnal variation

The rapid aerosol variation in the PBL suggests the importance of a collocated aerosol measurement.

27

Nocturnal ozone enhancement associated with low-level jet

Aerosol ext.coeff. at 291nm from O3 lidar

Co-located ceilometer backscatter

(a)

Low-level jet

Co-located wind profiler

Positive correlation of ozone and aerosol due to transport

Oct. 4, 2008

Kuang et al. submitted to Atmospheric Environment

Aerosol

Lidar

May 01 May 02 May 03 May 04 May 05 May 06 May 07 May 08

May 3, 2010

Daytime PBL top collapsed

RAQMS misses ozone layer at 2-4km

over estimates depth of6-8km layer

shows collapse of PBL

May 01 May 02 May 03 May 04 May 05 May 06 May 07 May 08

O3 AQ eventSaharan dust event

May 7RAQMS shows diffuse freeTropospheric ozone

Does not resolve thin filaments observedBy lidar

Ozone Lidar Network1. EPA/Las Vegas recognized value of ozone lidar in 1977 and began

instrument research.2. Technology developed to produce a/c instruments (Browell/NASA,

Hardesty/NOAA) and ground-based (McDermid/NASA/TMF, Newchurch/UAH&NASA). A few other ozone lidars operate in Europe and Asia.

3. NASA has formed a working group to identify a pathway in science and technology to eventually create a network of ground-based ozone lidars.

4. Such an ozone lidar network would be very complementary to the NASA GEO-CAPE geostationary AQ/Ocean satellite planned for ~2020.

31

H. Volten et al. 2009 JGR

S. Berkhoutet al., 2006 ILRC

Interior of the mobile laboratory

The mobile lidar system while measuring

An example of NO2 lidar -RIVM mobile NO2 lidar in the Netherland

Conclusions

1. Satellite observations of trace gases provide good spatial coverage with limited vertical resolution. These satellite obs are helpful for model ic/bc constraints.

2. Ozonesonde and lidar observations identify ubiquitous laminar structures.

3. Laminar transport from STE and NBL transport can be important for AQ.

4. Current regional models often do not resolve laminar structures of importance to surface AQ.

5. An ozone lidar network is a potential solution to acquire the vertical ozone information needed by AQ practitioners.

Formaldehyde/NO2 RatioDuncan et al.

IONS ozonesonde networkThompson et al.

Continuous Wavelet Transform (CWT)

•The CWT coefficient is defined as:

•a is the spatial extent or dilation of the function.•b is the location at which the wavelet function is centered—the translation of the function. •f(z) is the signal of interest, in this case, an ozone profile. • and are the top and the bottom of the profile. is the wavelet function.

t

b

z

zf dza

bzzf

abaW )()(

1),(

tZ bZ

)(z

IONS06 Sonde/EPA surface comparisons

Correlating EPA surface ozone with the sonde measurements at 500m causes a 25% decrease in correlation.

Using EPA surface data as the origin in the lidar case is not useful or accurate.

IONS06 Sonde/EPA surface comparisons

The variance in the surface ozone amounts at the ozonesonde/lidar site seen in the EPA HSV-Airport Rd. site is about 75%. The other 25% is the HORIZONTAL variance.

Using difference quotients to find extreme points of ozone profiles

•Difference quotients are used to find extreme points of the mixing ratio.

• Local minima and maxima are filtered (max-min > 15%) to distinguish significant layers based on the threshold percent difference value.

•A 3-point boxcar average is applied to data before difference quotients are applied.

Huntsville Ozonesonde Data

Same profiles as previous slide with correlation origin at 500m. (No EPA sfc data)

•Correlation improves when EPA data isn’t used.

•Ozone at 500m is still very uncorrelated with aloft ozone

Correlations of EPA surface ozone with ozone aloft measured by Huntsville DIALTime Period: May, Jul, Aug

88 hours of data ~ 500 profiles

Std Err of mean: All correlations are in 2 hours intervals and then are averaged over the entire data set.

Random Distribution

Ozone in FT is not correlated with surface.

May 01 May 02 May 03 May 04 May 05 May 06 May 07 May 08

May 4, 2010Timing of low upper tropospheric ozone minimum seems delayed(note RAQMS only every 6hrs)

doesn’t show surface O3 enhancement

May 01 May 02 May 03 May 04 May 05 May 06 May 07 May 08

O3 AQ event

May 5RAQMS is in good agreementwith Huntsville Lidar above ~3km

under estimates low level ozone enhancement

May 01 May 02 May 03 May 04 May 05 May 06 May 07 May 08

O3 AQ eventSaharan dust event

May 6 (high PBL O3)RAQMS is in good agreementwith Huntsville Lidar above ~3km

under estimates low level ozone enhancement