Stratospheric Aerosol Injection by Coulombic Hoist

last update 06-25-2024; for later updates, see my blog Experimentalist’s Progress, Blogspot.

An exploration of possible modern uses of clear-weather atmospheric electricity.

The idea: On clear, calm days, release tiny, negatively charged sulfur particles near ground level (but no lower than 25 cm) and wait for them to rise into the stratosphere on the sky voltage. They should then oxidize to a sulfuric acid aerosol, which is a powerful climate cooling agent if present in the stratosphere. The stratosphere begins 8 km above the surface in the arctic and 16 km above the surface in the tropics (mode= 12 km). At the surface, the electric field of the sky voltage has an intensity of 100 to 200 volts/m, earth negative, with the maximum occurring at 18:00 UTC, no matter where you are. It is part of the global atmospheric electric circuit, which is powered by thunderstorms and other electrified clouds. Solid sulfur can be negatively charged by friction, a process called tribocharging. Tribocharging is already used in one type of powder coating technology. 

A network of photochemical reactions given here  https://doi.org/10.1073/pnas.1620870114 (scheme 1) suggests that elemental sulfur will change into sulfuric acid aerosols in the atmosphere. (The scheme is presented as applying to anoxic conditions, but in the text, it is presented as describing current knowledge of atmospheric sulfur chemistry.) A fly in the ointment is that an irreversible step is shown going from gaseous S8 to solid S8, and I want reversible, so I am still searching for a rigorous chemical precedent for the supposed transformation. DOI:10.1126/sciadv.abc3687 figures 5B and S4, shows that when suspended in an aqueous solution at pH 6, solid sulfur generates sulfate when irradiated at 280 nm (shortest-wavelength end of the UVB range). That precedent isn’t rigorous either but it is helpful in addressing the question of providing sulfur in solid elemental form.

If stratospheric temperatures are too low to permit useable oxidation rates, microwave heating using ground-based projectors could be tried.

To charge negatively, the teflon tube that is standard on a tribo gun will have to be replaced by a tube made with an electron donor, or else corona charging used instead of tribocharging. I calculate that to rise in the atmospheric electric field, a particle needs a charge to mass ratio ("specific charge") greater than 50 millicoulomb/kilogram, which may be another factor requiring corona charging.

The figure of 50 mC/kg was derived by dividing g, the gravitational acceleration at the Earth's surface (about 10 m/s²), by 200 V/m, and multiplying by 1000 to get the units used in studies of powder-coating physics (and the units analysis checks out).

Extrapolating from data in Meng et al., 2008, http://dx.doi.org/10.1088/0022-3727/41/19/195207 , 2.3-micron-diameter sulfur particles corona charged at 90 kV should fly. However, a ten-fold smaller sulfur particle will have a ten-fold greater specific charge, giving some margin to allow for discharging on the way up.

The diameter of the sulfur particle injected into the stratosphere is unrelated to the diameter of the eventual sulfuric acid droplets it produces upon oxidation in the stratosphere, because one reaction intermediate, sulfur dioxide, is gaseous.

At this time, my best guess as to how fast the particles would rise is 3 cm/s (because I believe I have seen it), which will take them up to the stratosphere in four to five days. 

Ideal release conditions are low barometric pressure (i.e., rising airmass) but no clouds. This need not be a contradiction in terms if the rising air is dry to begin with. For example, dry polar air warmed by contact with arid ground should rise without cloud formation.

However, thus far, my calculations have not addressed the fact that the sky electric field weakens with height. At an altitude of 12 km, it is only 5...

Better Project Pix

1) Another view of Sensor Gun:

The handle is made from an acrylic artist's palette.

2) My second white noise machine:

The board on the left is for signals and the board on the right is for power. It still needs an automatic gain control circuit.

3) Chord keyset

Shown is an end view of four identical modules, one to a finger. Each module has two paddles operated as an analyzing linkage. All eight paddles and their respective bearings are in a sandwich structure stacked on a common axle and held together by a pair of compression screws on the end.  The bearing shown can be simplified: all but the outermost ring of ball bearings and its retaining ring can be replaced with a thick washer. Another, larger washer is used to adjust the paddle spacing along the axle.

Can probably also be used as a one-handed MIDI controller if the thumb is used to cut in virtual black keys. Some chromatic concert harmonicas are set up this way. Suggested name: a MIDI-ola. If the depress finger movements play ABCD going from pinky to index, and the curl movements play EFGA, then each finger can play a perfect fifth by itself. Most cords contain a perfect fifth.