- Publications

   - Patents

   - Global Warming Research: Methane
          and Arctic Geoengineering

  
1.  Thompson, J. D., “A Study of Radiative Properties and Composition of the Turbine Exhaust Products in the F-1 Engine,” Rocketdyne Report R-6743 Canoga Park, CA [1966] (benzene - Table I, pp 12)
2.  Hartsfield, C. R., “Reacting Shear Layer Mixing and Growth Rate Effects on the Afterburning Properties...,” Naval Post-Grad Sch., Monterey, CA [2008] (dissertation)
3.  Huebner, A., "High-pressure LOX/hydrocarbon Preburners and Gas Generators," NASA CR-161814 [1981(link)
4.  SpaceX EPA-Mandated Environmental Assessments which omit any valid assessment of well-known and legally-regulated rocket motor toxic effluents (retrieved from epa.gov dec 2010): Falc1; Falc1/9   
5.  UEMS Weather Forecasting


Research on Orbital Debris:         (video)




Unclassified/non-Restricted Publications:
  1. Pitch-based processing of carbon-carbon composites
  2. Mesophase Behavior in Carbon Fiber Bundles
  3. White, J.L., Sheaffer, P.M., Ng, C.B. and Buechler, M., 1984. 50. "Mesophase Formation Within Carbon Fiber Bundles," Carbon, 22(2), pp.208-209.
  4. Mesophase Behavior Fundamental to the Processing of Carbon-Carbon Composites
  5. Transverse Expansion of Individual Carbon and Graphite Filaments
  6. Formation of Triplet CO in Atomic Oxygen Flames of Acetylene and Carbon Suboxide
  7. UV to Near-IR CO Emissions from O+C2H2 and O+C3O2 Flames at Low Pressure and High Temperature
  8. Combustion of Nitrogen in Low-Pressure H2+O2 and H2+CO+O2 Flames
  9. New Laboratory-Based Satellite Impact Experiments for Breakup Fragmentation - Joint NASA/USAF/SMC
  10. Characterization of Hypervelocity Impact Debris from DebriSat
  11. DebriSat and DebrisLV   (DebrisLV was designed and built by P. M. Sheaffer)
  12. Rocket Impacts on the Earth's Atmosphere
  13. Experimental and Computer Modeling and Study of Carbon Combustion in Low Pressure Laminar H2+O2 Flames
  14. Carbon Oxidation in Low Pressure Laminar H2+O2 Flames II: The Lifted-Flame Testbed
  15. Static and Dynamic Light Scattering of Dilute Magnetorheological Emulsions, International Journal of Modern Physics B Vol. 10, No. 23n24, pp. 3057-3065 (1996)
  16. Sheaffer, et al., Multi-spectral Decluttering, ATAC Conf., National Inst. Std. and Technol., Gaithersburg MD, US [2016]
  17. Atmospheric and Space Impacts of SpaceX Rocket Engines (ITAR restricted session, AIAA, 2017)
  18. On-Orbit Contamination Impacts of SpaceX Rocket Engines (ITAR restricted session, AIAA, 2017)
  19. Parametric study of prompt methane release impacts on global mean temperature, Chapman Conference on Understanding Carbon Climate Feedbacks [2019] https://doi.org/10.1002/essoar.10503094.1
  20. Parametric Study of Prompt Methane Release Impacts II: Effect of a Dynamic Ocean on Model Results, Amer. Geophys. Union; Fall Meeting [2020] https://doi.org/10.1002/essoar.10504907.6
  21. Parametric Study of Prompt Methane Release Impacts III: AOGCM Results Which Respect Historical PIOMAS Measurements, Amer. Geophys. Union; Fall Meeting, GC35E-0744 [2021]
  22. Garbage-In Garbage-Out (GIGO): The Use and Abuse of Combustion Modeling and Recent Spacelaunch Environmental Impacts, Amer. Geophys. Union; Fall Meeting, A35Q-1876 [2021]



United States Patents:
        # 5,376,407 - Bendable Carbon-Carbon Composites
        # 4,986,943 - Stabilization of Pitch-Based Matrices
        # 4,932,264 - Microballoon-Tagged Materials (nondestructive test method)
        # 5,024,710 - Specular, Stable, and impervious Surfaces on Carbon-
                                Carbon Composites


My name is PattiMichelle and I am a USAF  Rocket Scientist (no, really).   My career has turned me into an interdisciplinary researcher.  My most recent research involves spectroscopic studies of simulated and real-world rocket plume exhausts with the stratosphere, hypersonic combustion chemistry, atmospheric dynamics and chemistry, and rocket engine design.  In the past I have also done research in the fields of metallography, ceramics, computer programming, carbon, ceramics, materials science, and nondestructive evaluation.  


Some things I've built and used for my research...

Tracking a Rocket Launch                       Measuring Orbital Motions
 
High Altitude Combustion Chamber
Stratospheric/Exospheric Combustion Chamber

Close Up of
                  Stratospheric/Exospheric Combustion Chamber

Impact at orbital velocity on DebrisLV



PUBLICATIONS








Parametric study of prompt methane release impacts on global mean temperature using GISS ModelE


There have been important criticisms of the Intergovernmental Panel on Climate Change (IPCC) recent reports for failing to communicate the dire nature of the current predicament facing civilization – so-called “scientific reticence” – as well as for assuming functional, planetary-effective scale biomass carbon capture and storage in its survivable scenarios [1-3].  In the light of major reports released in 2018 [4,5] which underscore the discrepancy between the current climate trajectory and requirements to maintain global civilization, the current predicament is often described as an “existential” crisis [6].  Part of the confusion appears to stem from the lack of discussion of specific scenarios, such as rapid arctic methane release [7,8], which are not discussed by the IPCC in proportion to their catastrophic potential.  This scenario is briefly examined using the Goddard Institute for Space Studies (GISS) ModelE v2 7.50.05 [9].  It is suggested that the results presented here represent a lower bound to climate disruption since in this set-up, neither the oceans nor arctic sea ice (a significant and ongoing runaway feedback [10]) are allowed to respond to the changes modeled; namely, a sudden release of stored methane gas.




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Discussion    
It was somewhat surprising when the post-transient data shown in the figure entitled “Global Land Surface Mean Annual Temperature Change” was averaged for the various scenarios and gave rise to the plot entitled “Global Land Surface Annual Data, Averaged 2031-2039.”   That is, a simple linear fit to the model results yielding,
with low variance, a mean temperature rise coefficient of 0.01 C per gigaton of added methane.  It is also remarked that this was the first and only analysis attempted, and was chosen “by eye” to be the region of approximate temperature stabilization following the transient introduction of uniformly dispersed methane into the earth’s atmosphere.  Simplified experiments such as this can have a useful clarity.

The clarity of the estimate of this coefficient is likely at least partially a result of the simplicity of the model input conditions.  The spatially uniform distribution of methane in the atmosphere is not highly-realistic and likely contributes to the simplicity and linearity of the result.  Both the Arctic/taiga snow/ice fields and the ocean surface temperatures in this model are prescribed (and therefore do not change in consecutive years); however, it may be unlikely that the ocean and arctic can respond at the same short time scales as the atmosphere given a large methane release.  A more complete analysis would likely incorporate a fully-coupled AOGCM; however, it is not clear that existing AOGCMs could reliably model the Arctic/taiga snow/ice responses to a sudden methane increase given the failure of the AR5 models to accurately predict well-observed changes in the Arctic snow/ice.

It should also be noted that in this experiment, the post-transient stabilization of the atmospheric methane burden implies that additional methane is released at a slower rate following the rapid transient release in order to maintain the atmospheric methane concentration since the model chemistry continuously degrades methane, for instance, into carbon dioxide and water.  Such additional releases are not an unphysical scenario for a general atmospheric circulation model as the Arctic oceans continue to warm following the phase change from ice-cover to open-ocean. 

The effect of decreasing Arctic insolation ~20% is also of interest given the recent rapid decrease in Arctic and taiga snow and ice and the importance of the polar regions to global weather patterns and circulations.  A slight Arctic mean land surface cooling was observable in the data when the annual mean data points were boxcar-averaged over at least 4 years, and was observable only in the Arctic.  

1.    Anderson, K., Nature, 24/31 DECEMBER| VOL 528 | 437 [2015];  Watson, M., Bristol U., Geoengineering, Roy. Soc. London, November 2014
2.    Anderson, K., and Peters, G., “The trouble with negative emissions,” Science, Vol. 354, Issue 6309, pp. 182-183  [2016]
3.    Muratori, et al., “Global economic consequences of deploying bioenergy with carbon capture and storage (BECCS),” Environ. Res. Lett. 11 [2016]
4.    Fourth National Climate Assessment, United States [2018]
5.    IPCC Special Report SR-15, Figure SPM3.b  [2018]
6.    Spratt, Dunlop; Schellnhuber, “What Lies Beneath,” Natnl. Ctr Climate Rest., Melbourne, Australia [2017]
7.    Stolaroff, et al., “Review of Methane Mitigation Technologies with Application toRapid Release of Methane from the Arctic,” Environ. Sci. Technol., 46, 6455−6469  [2012]
8.    Natalia Shakhova, et al., "Extensive Methane Venting to the Atmosphere from Sediments of the East Siberian Arctic Shelf," Science 327, 1246 [2010]
9.    Schmidt, G.A., et al., ”Configuration and assessment of the GISS ModelE2 contributions to the CMIP5 archive,” J. Adv. Model. Earth Syst., 6, no. 1, 141-184 [2014]
10.    Guiles, et al., “Circumpolar thinning of Arctic sea ice following the 2007 record ice extent minimum,” Geophys. Res. Lett., Vol 35, Issue 22 [2008]
11.    National Center for Atmospheric Research Staff (Eds). "The Climate Data Guide: SST data: HadiSST v1.1.“ https://climatedataguide.ucar.edu/climate-data/sst-data-hadisst-v11.




© 1999 - 2022 Patti M. Sheaffer, I.Sc.