cowley_ - Climate Engineering Conference 2014

Aidan Cowley (Presenting), Daragh Byrne, Sean Kelly
National Centre for Plasma Science & Technology (NCPST),
Dublin City University, Ireland.
Introduction & Motivation
Fluorinated & Chlorinated gases are the most potent and longest lasting type of
greenhouse gases emitted by human activities (CFC, HCFC)
Greenhouse Warming Potential (GWP) of significant
greenhouse gases normalized to a comparative unit of CO2
In general, fluorinated gases are removed from the atmosphere only when they
are destroyed by sunlight in the upper atmosphere via ionizing radiation.
Previous work by a variety of groups and authors has shown that these long-lived
greenhouse gases can be decomposed using plasma discharges in atmosphere.
Additionally, generation of ozone is a frequent by-product of many ionising
phenomena such as plasma discharges.
The large scale adoption of such technology on the ground is hampered by the
substantial energy requirements to strike and maintain such discharges for any
appreciable effective timescale.
Climate Engineering Conference 2014, Berlin.
SSP for Atmospheric Geoengineering & Pollution Control
• Poses the question: are there any potential, non-environmentally
damaging approaches to help reduce/mitigate the impact of these
high GWP gases?
• We believe the SSP concept (Space Solar Power) is ideally suited to
address this challenge:
- Represents a means of generating energy independently of any
terrestrial source (i.e. does not directly contribute to emissions
from within the troposphere (excluding fabrication & deployment
- Targetable: vantage point in orbit allows for direction of beam to
areas of greatest concentration, as determined by Earth
observation satellites and ground stations. Also removes health
issue of ionisation within the troposphere (and the associated
health risks involved therein).
Climate Engineering Conference 2014, Berlin.
What is Space Solar Power (SSP)?
SSP is candidate for future baseload utility power:
Continuous power generation (in GEO 24/7/365)
Non-depleting energy source (solar power)
Minimal environmental emissions in product cycle
Multi-TW capacity in final deployment stage
Interest in the US:
- ERDA/NASA studies in 1970-80s
- NASA, NSF, NRC, DoD, NSSO studies 1990/2000
- First commercial SSP incorporations in late 2000s
- First ‘real-life’ testing of SPS platform prototype
at NRL (P. Jaffe et al, 2013)
• International interest: advances in
RnD industry
- Japan (JAXA), Europe (ESA),
China (CNSA)
World oil
World proven oil
300 TW-years
1 km
Solar energy received in
1km band at GEO per year:
310 TW-years
Climate Engineering Conference 2014, Berlin.
SSP for Atmospheric Geoengineering & Pollution Control
1. Use the SSP approach as a means of energy
generation, ex-situ of our atmosphere
2. Use this power to induce plasma states at
targeted regions of the atmosphere using an
appropriate technology
3. These regions will breakdown long-lived
greenhouse gases via reaction chains, in turn
helping mitigate environmental damage
Illustration showing SSP powered laser array targeting
a region with a high concentration of atmospheric
pollution in order to reduce the
concentration via plasma decomposition
Two technologies are proposed which could conceivably allow for the formation
of targeted plasma discharges within the atmosphere:
- Plasma Filamentation: Using solid state lasing and the formation of plasma
- RF Ionisation: Utilizing conventional RF antennae to heat & ionize the
Climate Engineering Conference 2014, Berlin.
Plasma Filamentation
Utilize a competing linear/non-linear optical effect
Competing criteria of the focusing Kerr effect and
the defocusing effect of the plasma on the laser
beam results in the formation of a plasma filament
This approach allows for the propagation of over
distances much longer than the Rayleigh length
The filamentation effect as the beam propagates
through air results from a balance between Kerr-lens
focusing and defocusing caused by the ionized plasma [1]
The plasma discharge would generate ozone,
via photoionization, excitation and dissociation
of gaseous species within the targeted volume.
Terrestrial Tw Femtosecond
Filament Properties
Power Intensity
5 x 1013 W/cm
Ne (Electron Density)
1015 – 1016 cm3
Spectral Emission Range
230 – 1400 nm
[1] European Physical Journal – Applied Physics
Photograph of a terawatt femtosecond laser pulse
directed into the sky from the University of Jena.
The pulses form filaments of white light that can
extend more than 20 km into the atmosphere
Climate Engineering Conference 2014, Berlin.
Plasma Filamentation in Atmosphere
Concentrations of ozone were measured in the volume
surrounding the filament; both by experiments in the
atmosphere and in controlled lab conditions.
O3 concentrations were measured to be in the parts
per million range (ppm) and were typically found to be
between 100 and 1000 times higher then the
background atmospheric measurement.
This is a significant ozone generation mechanism,
attributed to the excitation interaction of the plasma
discharge and the atmospheric gases.
Largely immune to atmospheric turbulence, allowing
for precise targeting of the filament within an
atmospheric volume.
Time lapse CCD images from same experiment showing the
Additionally, self-guided filaments generated by
optical emission from the filament at ~20 km from the ground laser[1]
ultrashort laser pulses can assist water condensation,
even in undersaturated atmosphere conditions.
May allow for the formation of clouds (compared to
traditional seeding mechanisms), with a potential to
change the atmospheric albedo (an additional geo[1] J. Kasparian et al., “White-Light Filaments for
engineering approach)
Atmospheric Analysis”, Science 301, 61, 2003.
Climate Engineering Conference 2014, Berlin.
HF RF Induced Ionization
Using high power RF heating of the atmosphere to
generate diffuse plasma states at targeted
altitudes (Mesosphereic & Stratospheric)
RF heating of the atmosphere has already been
demonstrated by various authors since the late
1950s and is still under study by many terrestrial
RF heating facilities (i.e. Sura, SPEAR, HAARP, etc)
Ozone concentration modification using high
power RF was reported by Kulilov et al [1] at
heights of between 22 to 60 km at the the Sura
Ionospheric Heating Facility in Russia
The Phased Antenna Array at the
High Frequency Active Auroral Research Program,
Alaska, US.
[1] Yu. Yu. Kulilov et al, “Response of mesospheric ozone to the heating of the lower ionosphere
by high-power HF radio emission”,
Geomagnetism and Aeronomy, 2013, Volume 53, Issue 1, pg 96-103 a
Climate Engineering Conference 2014, Berlin.
Validating the Concept
Lab/Ground Based Validation
• Using conventional plasma tool diagnostics to
measure discharge byproducts, e.g. Ozone, etc
•Design or utilise existing low-pressure chambers to
simulate upper atmosphere conditions
•Currently limited understanding of interactions of
power beams with atmosphere
DCU atmospheric mass spectrometer
for plasma discharge diagnostics
• Ground-based facilities have potential to significantly
exceed cost-efficiency and amount of data collected
compared to orbital probes
• Ionosphere Research Facilities could provide extensive
capabilities to study atmospheric power beam
interactions for ‘minimum’ first upgrade
Could become first large-scale, concerted effort to
establish comprehensive scientific knowledge of
atmospheric power beam interactions
O3 density vs distance to differential pumping
Aperture (Mass spectrometer)
Climate Engineering Conference 2014, Berlin.
Experimental Studies of RF Beams in Atmosphere
• Ionospheric heating tests at HAARP (USA), Arecibo (Puerto Rico), etc. in
MHz range
• Two direct spacecraft-based investigations:
MINIX (1986)
- Microwave-Ionosphere Nonlinear Interaction Experiment (MINIX):
Matsumoto, Kaya, Nagatomo et al., (1986)
- Microwave Energy Transmission in Space (ISY-METS):
Matsumoto, Kaya, Akiba et al. (1992)
- separated transmitter-receiver spacecraft flown in ionosphere
- transmitter ~2.4 GHz; RF power ~ 900 W
- narrow microwave beams (smaller than scale of power beams)
- limited RF power: beams probing immediate surroundings of
- orbital motion: no continuous illumination of same atmospheric
Lack of extensive data for microwave beam interaction with atmosphere
[1] Towards Space Solar Power - Examining Atmospheric Interactions of Power
Beams with the HAARP Facility, Leitgab M., Cowley A., IEEE Aerospace 2014.
[2] Shinohara, Whitepaper: WPT for SPS; GaTech 2005
Climate Engineering Conference 2014, Berlin.
Bringing it all together…
Modification of Type I-SPS Microwave beaming
- 2.45 ghz transmission of power or other
nominal power transmission frequency for
primary use
- Supplementary directional HF RF antenna which
can be used as needed to target atmospheric
Modification of Type II-SPS Laser Beaming
- Solid-state fs Lasing System (array)
- Owing to the specialty of the required lasing
system, it might be optimum to deploy as a
separate satellite
Type II
Type I
Summary & Future Directions
• We propose a new approach to decomposing long lived greenhouse gases in an emission free approach using
the SSP concept
• Orbiting SSP satellites would be used to generate ionising phenomena (this talk detailed two potential
Open Challenges:
• Ionisation rate as a function of RF power and local power density – is the effect sufficiently pronouced to have
an impact at a local and (ultimately) global scale?
• Complexity of upper atmosphere interactions
• The propagating signal may be affected by its passage through the ionosphere (upper atmosphere) before
reaching a target volume of pollution. These effects depend significantly on frequency, but include signal
absorption, scintillation, Faraday rotation and bandwidth decoherence
Validation of Concept:
• Experimental measurement of atmospheric conditions at target heights via existing low-pressure gas chambers
and interactions with ionising phenomena
• Much could be learned from existing low-pressure & atmospheric plasma models (species density, cross
sections, lifetimes, etc)
Future Directions:
• Potential applications to bodies beyond our own planet, e.g. terraforming
• Could also used a as means of fundamental research into upper atmosphere, e.g.LIDAR, etc.
Climate Engineering Conference 2014, Berlin.
Thank you for your attention!
Aidan Cowley (Presenting)
National Centre for Plasma Science & Technology, Dublin City University, Ireland,
[email protected]
Daragh Byrne
National Centre for Plasma Science & Technology, Dublin City University, Ireland,
[email protected]
Sean Kelly
National Centre for Plasma Science & Technology, Dublin City University, Ireland,
Climate Engineering Conference 2014, Berlin.

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