Field Results from BEARPEX 2009 and the First Deployment of the Madison FILIF HCHO Instrument Josh...
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Transcript of Field Results from BEARPEX 2009 and the First Deployment of the Madison FILIF HCHO Instrument Josh...
![Page 1: Field Results from BEARPEX 2009 and the First Deployment of the Madison FILIF HCHO Instrument Josh DiGangi, Josh Paul, Sam Henry, Aster Kammrath, Erin.](https://reader033.fdocuments.us/reader033/viewer/2022061603/56649ef25503460f94c04230/html5/thumbnails/1.jpg)
Field Results from BEARPEX 2009 and the First Deployment
of the Madison FILIF HCHO Instrument
Josh DiGangi, Josh Paul, Sam Henry,
Aster Kammrath, Erin Boyle, Frank Keutsch
University of Wisconsin – Madison
06/21/10
![Page 2: Field Results from BEARPEX 2009 and the First Deployment of the Madison FILIF HCHO Instrument Josh DiGangi, Josh Paul, Sam Henry, Aster Kammrath, Erin.](https://reader033.fdocuments.us/reader033/viewer/2022061603/56649ef25503460f94c04230/html5/thumbnails/2.jpg)
2
Volatile Organic Compound (VOC) Oxidation
Processed via HOx/NOx
cycles
Results in O3 and CO2
production
HCHO is a major tracer of
VOC oxidation
![Page 3: Field Results from BEARPEX 2009 and the First Deployment of the Madison FILIF HCHO Instrument Josh DiGangi, Josh Paul, Sam Henry, Aster Kammrath, Erin.](https://reader033.fdocuments.us/reader033/viewer/2022061603/56649ef25503460f94c04230/html5/thumbnails/3.jpg)
3
HOx in Forest Canopies
Likely due to fast, in-canopy oxidation of unknown BVOCs Need a method of probing VOC oxidation in canopy…HCHO!!
Adapted from: DiCarlo et al., Science, 304, 722 (2004).
- Observed
- Modelled
![Page 4: Field Results from BEARPEX 2009 and the First Deployment of the Madison FILIF HCHO Instrument Josh DiGangi, Josh Paul, Sam Henry, Aster Kammrath, Erin.](https://reader033.fdocuments.us/reader033/viewer/2022061603/56649ef25503460f94c04230/html5/thumbnails/4.jpg)
HCHO Gradient & Flux Measurements
Multiple sampling heights allow measurement of vertical HCHO distribution (gradient)
4
![Page 5: Field Results from BEARPEX 2009 and the First Deployment of the Madison FILIF HCHO Instrument Josh DiGangi, Josh Paul, Sam Henry, Aster Kammrath, Erin.](https://reader033.fdocuments.us/reader033/viewer/2022061603/56649ef25503460f94c04230/html5/thumbnails/5.jpg)
HCHO Gradient & Flux Measurements
Multiple sampling heights allow measurement of vertical HCHO distribution (gradient)
Colocation of an inlet with a sonic anemometer allows calculation of mass transport (flux)
5
Eddy
![Page 6: Field Results from BEARPEX 2009 and the First Deployment of the Madison FILIF HCHO Instrument Josh DiGangi, Josh Paul, Sam Henry, Aster Kammrath, Erin.](https://reader033.fdocuments.us/reader033/viewer/2022061603/56649ef25503460f94c04230/html5/thumbnails/6.jpg)
HCHO Gradient & Flux Measurements
Multiple sampling heights allow measurement of vertical HCHO distribution (gradient)
Colocation of an inlet with a sonic anemometer allows calculation of mass transport (flux)
Combined, measurements provide insight into VOC oxidation above & inside canopy
6
Eddy
![Page 7: Field Results from BEARPEX 2009 and the First Deployment of the Madison FILIF HCHO Instrument Josh DiGangi, Josh Paul, Sam Henry, Aster Kammrath, Erin.](https://reader033.fdocuments.us/reader033/viewer/2022061603/56649ef25503460f94c04230/html5/thumbnails/7.jpg)
HCHO Gradient & Flux Measurements
Instrumental challenges– Field capable– High selectivity– High sensitivity– Fast time resolution (10 Hz)
No reported technique can meet all of these requirements
7
Eddy
![Page 8: Field Results from BEARPEX 2009 and the First Deployment of the Madison FILIF HCHO Instrument Josh DiGangi, Josh Paul, Sam Henry, Aster Kammrath, Erin.](https://reader033.fdocuments.us/reader033/viewer/2022061603/56649ef25503460f94c04230/html5/thumbnails/8.jpg)
8
LIF of HCHO
21
~
AA
11
~
A
353 nm vibronic
absorption
ν4
0
1
2
3
:
.
0
1
:
.
![Page 9: Field Results from BEARPEX 2009 and the First Deployment of the Madison FILIF HCHO Instrument Josh DiGangi, Josh Paul, Sam Henry, Aster Kammrath, Erin.](https://reader033.fdocuments.us/reader033/viewer/2022061603/56649ef25503460f94c04230/html5/thumbnails/9.jpg)
9
Absorption Spectrum of HCHO
Spectrum: J.D. Rogers, J. Phys. Chem., 94, 4011 (1990).
Assignment: Clouthier & Ramsay, Ann. Rev. Phys. Chem, 34, 31 (1983).
20
041
0 band
λ ≈ 353 nm
![Page 10: Field Results from BEARPEX 2009 and the First Deployment of the Madison FILIF HCHO Instrument Josh DiGangi, Josh Paul, Sam Henry, Aster Kammrath, Erin.](https://reader033.fdocuments.us/reader033/viewer/2022061603/56649ef25503460f94c04230/html5/thumbnails/10.jpg)
10
Dissociation of HCHO
1.0
0.8
0.6
0.4
0.2
0.0
Quantu
m Y
ield
360350340330320310300
Wavelength (nm)
(H + HCO)(H
2 + CO)
Total
* Data for plot from Finlayson-Pitts & Pitts, Chemistry of the Upper and Lower Atmosphere, Academic Press (2000).
† Möhlmann, G.R. App. Spectr. 39, 98 (1985).
No strong electronic absorption features at λ > 353 nm
~27% dissociation expected at 353 nm
![Page 11: Field Results from BEARPEX 2009 and the First Deployment of the Madison FILIF HCHO Instrument Josh DiGangi, Josh Paul, Sam Henry, Aster Kammrath, Erin.](https://reader033.fdocuments.us/reader033/viewer/2022061603/56649ef25503460f94c04230/html5/thumbnails/11.jpg)
11
LIF of HCHO
21
~
AA
11
~
A0
1
2
3
:
.
0
1
:
.
Radiative
De-excitation
(fluorescence):
~ 390 – 510 nm
ν4
![Page 12: Field Results from BEARPEX 2009 and the First Deployment of the Madison FILIF HCHO Instrument Josh DiGangi, Josh Paul, Sam Henry, Aster Kammrath, Erin.](https://reader033.fdocuments.us/reader033/viewer/2022061603/56649ef25503460f94c04230/html5/thumbnails/12.jpg)
12Selectivity throughRotational Transitions
Spectrum: Co et al., J. Phys. Chem. A, 109, 10675 (2005).
Assignment: Emery et al., J Chem. Phys., 103, 5279 (1995).
404 ← 413
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13Selectivity throughRotational Transitions
Spectrum: Co et al., J. Phys. Chem. A, 109, 10675 (2005).
Assignment: Emery et al., J Chem. Phys., 103, 5279 (1995).
Online
Offline
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Narrow Bandwidth UV Pulsed Fiber Laser14
• Bandwidth: < 300 MHz
• Fast tuning range: 1.5 cm-1
• Slow tuning range: 60 cm-1
• Repetition Rate: 300 kHz
• Power: ~ 13.5 mW
• Size/Weight: < 1 ft3
, < 10 lbs
• Power consumption: < 100 W
• Rugged and turnkey operation
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15
FILIF Field Instrument
Based on design using Ti:Sapphire laser *
Compact design– < 4 ft3, ~ 250 lbs
High time resolution & low detection limit (3σ)– < 200 pptv / 1 s– < 1 ppbv / 0.1 s
* Hottle et al., Environ. Sci. & Tech., 43, 790 (2009).
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BEARPEX 2009
Well-established meteorological pattern
> 10 research groups
16
Wind blows uphill
during day
Wind blows
downhill at night
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BEARPEX 2009
Well-established meteorological pattern
> 10 research groups
17
Wind blows uphill
during day
Wind blows
downhill at night
17.8 m
8.7 m
3.3 m
2.4 m
![Page 18: Field Results from BEARPEX 2009 and the First Deployment of the Madison FILIF HCHO Instrument Josh DiGangi, Josh Paul, Sam Henry, Aster Kammrath, Erin.](https://reader033.fdocuments.us/reader033/viewer/2022061603/56649ef25503460f94c04230/html5/thumbnails/18.jpg)
Warm/Cold Diurnal Averages
8.7 m inlet
3.3 m inlet
17.8 m inlet
2.4 m inlet
warm
cold
18
* Isoprene + MBO and temperature measurements courtesy of the Goldstein group (UC-Berkeley)
![Page 19: Field Results from BEARPEX 2009 and the First Deployment of the Madison FILIF HCHO Instrument Josh DiGangi, Josh Paul, Sam Henry, Aster Kammrath, Erin.](https://reader033.fdocuments.us/reader033/viewer/2022061603/56649ef25503460f94c04230/html5/thumbnails/19.jpg)
Conc. Differential Diurnal Averages19
![Page 20: Field Results from BEARPEX 2009 and the First Deployment of the Madison FILIF HCHO Instrument Josh DiGangi, Josh Paul, Sam Henry, Aster Kammrath, Erin.](https://reader033.fdocuments.us/reader033/viewer/2022061603/56649ef25503460f94c04230/html5/thumbnails/20.jpg)
Conc. Differential Diurnal Averages20
Shows an inverted profile during daytime hours
Suggests in canopy production of HCHO
More HCHO in canopy during
day
![Page 21: Field Results from BEARPEX 2009 and the First Deployment of the Madison FILIF HCHO Instrument Josh DiGangi, Josh Paul, Sam Henry, Aster Kammrath, Erin.](https://reader033.fdocuments.us/reader033/viewer/2022061603/56649ef25503460f94c04230/html5/thumbnails/21.jpg)
21
HCHO Eddy Flux Measurements
Laser tunes from on to off peak in ≤ 10 ms
Slow/fast duality suggests improvements may make faster
Can measure @ 10 Hz with 90% duty cycle
Combined with high sensitivity should be capable of HCHO flux measurements
![Page 22: Field Results from BEARPEX 2009 and the First Deployment of the Madison FILIF HCHO Instrument Josh DiGangi, Josh Paul, Sam Henry, Aster Kammrath, Erin.](https://reader033.fdocuments.us/reader033/viewer/2022061603/56649ef25503460f94c04230/html5/thumbnails/22.jpg)
HCHO Eddy Flux Measurements HCHO Flux
measurements performed for ~10 days
22
![Page 23: Field Results from BEARPEX 2009 and the First Deployment of the Madison FILIF HCHO Instrument Josh DiGangi, Josh Paul, Sam Henry, Aster Kammrath, Erin.](https://reader033.fdocuments.us/reader033/viewer/2022061603/56649ef25503460f94c04230/html5/thumbnails/23.jpg)
HCHO Eddy Flux Measurements HCHO Flux
measurements performed for ~10 days
Covariance calculations result in no significant flux
Measurements believe to have failed due to incorrect air sampling
Will repeat measurements during BEACHON-ROCS: August 2010
23
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Preliminary CalNex 2010 Flux24
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25
Summary Successful first deployment of Madison FILIF
Instrument
Observed nighttime deposition of HCHO and daytime in-canopy HCHO production
New class of laser offers new opportunities in applied molecular spectroscopy
Interest in instrument reproduction by:– NASA (has already begun)– Max Planck Institute– University of Leeds
![Page 26: Field Results from BEARPEX 2009 and the First Deployment of the Madison FILIF HCHO Instrument Josh DiGangi, Josh Paul, Sam Henry, Aster Kammrath, Erin.](https://reader033.fdocuments.us/reader033/viewer/2022061603/56649ef25503460f94c04230/html5/thumbnails/26.jpg)
26
Acknowledgements
Keutsch Group NSF NASA Sierra Pacific Industries UW-Madison Chemistry NovaWave Technologies University of California System BEARPEX 2009 Science Team Blodgett Forest Research Station Wisconsin Alumni Research Fund The Camille & Henry Dreyfus Foundation, Inc.
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28
Dispersed Emission of HCHODispersed Fluorescence of HCHO
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
350 400 450 500 550 600
Wavelength(nm)
Inte
nsi
ty (
A.U
.)
![Page 29: Field Results from BEARPEX 2009 and the First Deployment of the Madison FILIF HCHO Instrument Josh DiGangi, Josh Paul, Sam Henry, Aster Kammrath, Erin.](https://reader033.fdocuments.us/reader033/viewer/2022061603/56649ef25503460f94c04230/html5/thumbnails/29.jpg)
29Quantum Yield of HCHO Fluorescence
Mqdf
ff Pkkk
kΦ
*15f s102k
**16d s102.53k
Probability of a stimulated HCHO molecule to fluoresce
@ 100 torr, ≈ 4.5%
* Yeung & Moore. J. Chem. Phys. 58, 3988 (1973).
** Moortgat & Warneck. J. Chem. Phys. 70, 3639 (1979).
**114q sTorr101.7k
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Contemporary HCHO Techniques
Hantzsch Derivitization*– Ex situ, insufficient time resolution– LOD: 75 pptv/min (3σ)
Proton Transfer Reaction – Mass Spectrometry (PTR-MS)*– Insufficient selectivity, bulky instrument– LOD: 300 pptv/2 s (3σ)
Tunable Diode Laser Absorption Spectroscopy (TDLAS)†
– Slow sampling, cannot measure fluxes– LOD: 180 pptv/1 s (3σ)
* Wisthaler et al. SAPHIR, Atmos. Chem. Phys., 8, 2189 (2008).† Weibring et al. Opt Exp., 15, 13476 (2007).
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31