This site summarizes my work to date on geoengineering a solution to a possible catastrophic disruption of Earth’s climate. The work began with an idea, that momentum in the Pacific Equatorial Undercurrent  (EUC) could be harnessed to influence Earth's natural thermostat. The EUC is as strong as the Florida Current where the Gulf Stream begins. It's core is 60 kilometers wide and it  runs straight east along the equator guided by Coriolis force. But it runs about 100 meters below the surface, which is to say 100 meters below where El Niño and La Niña dictate Earth’s largest year to year temperature changes. The speed of the EUC core exceeds 1 meter per second, and the high shear layer below it forms steep internal waves which will break if slightly amplified. The idea is to amplify these waves with an array of  controllable wave-makers, so they break and mix cold nutrient rich water to the surface. This may induce a mild La Nina mode, as occurred in 2008. The 2009 geoengineering proposal posted below describes the mechanics of such a wave-maker. A 20 kilometer width is sufficient to span the present concentration of equatorial upwelling.

La Niña is Earth’s natural interannual cold and dry phase.  Mark Cane of Lamont-Doherty Earth Observatory shows that Earth’s glacial phase is similarly drier in the tropics.  Though transient, water vapor is Earth’s most powerful greenhouse gas, and tropical oceans are its biggest source. Can La Niña also be the natural mechanism of global cooling that triggered past ice ages?  Here I believe the path of least risk is the one that follows nature. If the answer to the above question is yes, then geoengineered cooling by La Niña is that path.

The 2009 paper posted below explores this question. Analysis of one hour resolution sub-surface temperatures in the equatorial Pacific led to what may prove to be an extraordinary observation.  A rare circumstance of peak tide events in July 2000 (three eclipses in one month) is coincident with an equally rare (1) increase in internal tide resonance, (2) thermocline depression, and (3) westerly wind burst in the eastern equatorial Pacific. Tides can influence wind direction 

through sea surface temperature, but not vice-versa, and westerly wind bursts are a known El Niño trigger. This demonstrates a way in which tidal cycles may influence El Niño - La Niña cycles. Two papers by C. David Keeling (The Keeling Curve) and Timothy Whorf of Scripps Institution of Oceanography (1997 & 2000) proposed that millennial timescale climate changes were the result of an 1,800 year tidal cycle. Maybe they were right, but the action was only in the equatorial Pacific.

The July 2000 tidal event was not isolated in time, but is the center of a 5 month season of stronger tides at narrowed perigee-syzygy intervals. It is part of a fundamental 586 year cycle whose recent maxima were the Little Ice Age and drought of 1150 CE. This cycle is the result of the sun’s effect on the length of the synodic month (new moon to new moon), so its seasonality follows precession (21,000 year cycle) and it scales with eccentricity (100,000 year cycle).

The 2009 paper posted below presents a hypothesis that variations in internal tide resonance in the equatorial wave guide induce variations in the frequency of an equatorially symmetric La Niña (ESLN) mode in all of the above timescales. Maximum cooling is at March aphelion, and low obliquity angles (42,000 year cycle) focus tidal energy on the equator and also contribute to that cooling. A wave-maker tuned to the prevailing equatorial buoyancy frequency is an alternative external forcing that may yield the same result. The climactic consequences of La Niña are known.

Another significant benefit of this proposal is accelerated natural carbon sequestration. The North Equatorial Countercurrent merges with the EUC during ESLN, mixing EUC water into the sun-lit surface. The EUC is rich in primary production limiting nutrients. The 1998 ESLN example given (2009, Fig. 8e page 15) resulted in “the largest known natural year-to-year perturbation of the global carbon cycle” (Turk et al. 2001). Glacial ESLN is consistent with high observed equatorial sedimentation at glacial maxima, indicating a potentially significant role in atmospheric CO₂ drawdown at that time.