1. Divide brightness temperature residual into two sections, C2H4 frequencies

(red section, Figure 2b), and non-C2H4 frequencies (green section, Figure 2b).

1. Calculate the mean brightness temperature (K) for each segment.

2. Scan is categorized based on the mean of the C2H4 segment with respect to the

mean of the scan as a whole

3. Initial cutoff for detection is an ethylene feature one standard deviation outside

the mean of the scan as a whole

• Tropospheric Emission Spectrometer (TES)

• Fourier transform spectrometer in the thermal IR range aboard NASA’s

Aura Satellite

• Ethylene (C2H4)

• Common sources include fire plumes and the petrochemical industry

[Sawada et al., 1986]

• Reacts with O3 and OH to produce CO, CO2 and H2O [Alvarado et al.,

2010]

• First detected in a singular TES scan by Alvarado et al., [2011]

• Studied Data

• TES observations taken in support of the Arctic Research of the

Composition of the Troposphere from Aircraft and Satellites (ARCTAS)

campaign which observe fire plumes

• Primary Questions

• Is C2H4 visible in multiple TES scans?

• Is C2H4 spatially correlated with TES CO observations?

Satellite observations of ethylene (C2H4)Wayana Dolan1,2, Vivienne Payne1, Susan Kulawik3, Kevin Bowman1

wdolan@oxy.edu, vivienne.h.payne@jpl.nasa.gov1Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 2 Occidental College, Eagle Rock, CA 3Bay Area Environmental Research

Institute Moffett Field, Moffett Field, CA

Figure 1. TES special observations taken in support of the ARCTAS campaign.

Black dots indicate all TES scans during June and July 2008. Bold black dots

indicate orbit tracks in which Alvarado et al. [2010] had identified one or more

fire plumes within that track. Red dots correspond to scans with elevated CO.

1. Introduction and Background

Figure 2. (a.) TES observed

brightness temperature spectrum

with ethylene. (b.) Observed

spectrum minus a modeled

spectrum without ethylene. (c.)

Modeled brightness temperature

spectrum with ethylene minus

modeled brightness temperature

spectrum without ethylene.

2. Detection Methods

c.

a. b.

Figure 3. (a.) Thermal contrast for run 7849. (b.)

Thermal contrast for run 7849 plotted against the C2H4

signal due to thermal contrast. The resulting best-fit line

(Equation 1) is used to measure the inflation of the

ethylene signal due to thermal contrast. (c.) Signal for

the modeled ethylene signature due to thermal contrast

alone

Figure 4. Vertical Sensitivity. Red lines show a C2H4 profile

and jacobian for a background example case. Blue lines show

a C2H4 profile and jacobian for an example fire plume case

where we assume that the vertical variation of the C2H4

follows the vertical variation of the TES retrieved CO for the

strong CO plume in run 7656. This shows that TES is sensitive

to C2H4 in the mid-troposphere, but the exact details of the

vertical sensitivity depend on the vertical distribution of C2H4,

which is unknown.

Equation 1

𝑆𝑖𝑔𝑛𝑎𝑙 𝐾 𝑏𝑎𝑠𝑒𝑑 𝑜𝑛 𝑡ℎ𝑒𝑟𝑚𝑎𝑙 𝑐𝑜𝑛𝑡𝑟𝑎𝑠𝑡 𝑇𝐶 = 0.0252 ∗ 𝑇𝐶 + 0.0913

Equation 2

𝑆𝑐𝑎𝑙𝑒 𝐹𝑎𝑐𝑡𝑜𝑟 (𝑆𝐹) =𝑂𝑏𝑠𝑒𝑟𝑣𝑒𝑑 𝑆𝑖𝑔𝑛𝑎𝑙 𝑆𝑖𝑧𝑒 (𝐾)

𝑆𝑖𝑔𝑛𝑎𝑙 𝑆𝑖𝑧𝑒 𝑏𝑎𝑠𝑒𝑑 𝑜𝑛 𝑡ℎ𝑒𝑟𝑚𝑎𝑙 𝑐𝑜𝑛𝑡𝑟𝑎𝑠𝑡 (𝐾)

Equation 3

𝐴𝑚𝑜𝑢𝑛𝑡 𝑜𝑓 𝑒𝑡ℎ𝑦𝑙𝑒𝑛𝑒 𝑖𝑛 𝑠𝑐𝑎𝑛 𝑎𝑡 500 ℎ𝑃𝑎 𝑝𝑝𝑏𝑣 = 0.15 𝑝𝑝𝑏𝑣 ∗ 𝑆𝐹

3. Quantification

4. Errors and Uncertainties

Figure 5: Optical depth contributions from different trace

gases in the 940-960 cm-1 spectral range. Note similarly

located C2H4 and CO2 features

Figure 6. CO and C2H4 plotted against latitude for TES runs 7658 and 7808. The dashed line

represents the CO concentration used here to define a CO plume. Both sets of graphs show a

correlation between fresh CO plumes and C2H4

5. Key Findings

Figure 7. Black dots indicate all TES scans during June and July 2008. Bold

black dots indicate orbit tracks in which Alvarado et al., [2010] had identified

one or more fire plumes. Green dots indicate all scans with an ethylene signal

above the 0.2ppbv detection limit. Blue dots indicate scans with high ethylene

signals, above 0.5ppbv.

Noise Equivalent Spectral Radiance (NESR)

0.2 K = ~0.2 ppbv

Retrieval Uncertainties

Surface Temperature

1 K = ~0.07-0.08 ppbv shift in C2H4 signal

Atmospheric Temperature

0.5 K at all levels = ~0.02 ppbv shift in C2H4 signal

Total Column Water Vapor

5% total column = ~0.02 ppbv shift in C2H4 signal

Uncertainties are dominated by NESR

• Spatial correlation between C2H4 and CO in fresh fire plumes

• Potential for C2H4 to be developed into a TES standard product

• C2H4 from non-fire sources is visible in TES data

6. AcknowledgmentsThe research was carried out at the Jet Propulsion Laboratory, California Institute of

Technology, under a contract with the National Aeronautics and Space Administration.

In addition, thank you to the Caltech WAVE program for providing the opportunity to

work at the Jet Propulsion Laboratory.

Key References

A23A-0268

©2015 Government sponsorship acknowledged

b.

a.

c.

Alvarado, M., K. Cady-Pereira, Y. Xiao, D. Millet, and V. h. Payne (2011), Emission Ratios for Ammonia and Formic Acid and Observations of Peroxy Acetyl Nitrate (PAN) and Ethylene in Biomass Burning Smoke as Seen by the

Tropospheric Emission Spectrometer (TES), Atmosphere, 2(4), 633-654, doi:10.3390/atmos2040633.

Alvarado, M. J., J. A. Logan, J. Mao, E. Apel, D. Riemer, D. Blake, R. C. Cohen, K.-E. Min , A. E. Perring, E. C. Browne, P. J. Wooldridge, G. S. Diskin, G. W. Sachse, H. Fuelberg, W. R. Sessions, D. L. Harrigan, G. Huey, J. Liao, A.

Case-Hanks, J. L. Jimenez, M. J. Cubison, S. A. Vay, A. J. Weinheimer, D. J. Knapp, D. D. Montzka, F. M. Flocke, I. B. Pollack, P. O. Wennberg, A. Kurten, J. Crounse, J. M. St. Clair, A. Wisthaler, T. Mikoviny, R. M. Yantosca, C. C.

Carouge, and P. Le Sager (2010), Nitrogen oxides and PAN in plumes from boreal fires during ARCTAS-B and their impact on ozone: an integrated analysis of aircraft and satellite observations, Atmos. Chem. Phys., 10, 9739-9760.

Sawada, S., and T. Totsuka (1986), Natural and anthropogenic sources and fate of atmospheric ethylene, Atmospheric Environment (1967), 20(5), 821-832, doi:10.1016/0004-6981(86)90266-0.

Seifert, R., N. Delling, H. Hermann Richnow, S. Kempe, J. Hefter, and W. Michaelis (1999), Ethylene and methane in the upper water column of the subtropical Atlantic, Biogeochemistry, 44(1), 73-91, doi:10.1007/bf00992999.