You recently posted an article about a paper, entitled: ‘Oceanic Influences on Recent Continental Warming’, suggesting that it is warming of the oceans that has driven warming of the land since the 1970s.
You commented, “But it does not tell us what has warmed the oceans!”
Do you realize that is has been postulated that long-term variations in solar/lunar tides control inter-decadal ocean surface temperatures by influencing the rate of up-whelming of cold deep-water?
Climate scientists have long known that it takes about three terra-watts of power to maintain the up-welling of water in the great oceans. Two terra-watts of this power is provided by surface winds. The winds continually blow surface water off the top of cool deep water, allowing the cooler ocean water to rise to the surface.
The problem has always been finding the extra terra-watt of power that is necessary to maintain the up-welling. One possible source for this extra power is tidal friction.
Two-thirds of all the energy dissipated by the tides in the oceans is dissipated by friction between the ocean water sloshing up onto and flowing back-off the shallow continental shelves e.g. the Canning Basin of N-W Australia and the Bearing Sea of Alaska. The remaining one-third of the energy that is dissipated by the solar/lunar tides is dissipated by currents of deep ocean water smashing up against deep ocean ridges, like the mid-Atlantic ridge, and the flanks of the Hawaiian Island chain. Remarkably, this latter process dissipates about 1 terra-watt of energy, just the right amount of energy to maintain the up-welling process.
The following two papers support a link between changes in ocean temperature and subsequent changes in atmospheric temperature and provide a possible source that could be responsible for ocean heating and cooling.
Ian Wilson, Toowoomba, Australia
1. Tropical Pacific decadal variability and global warming
by Amy J. Bratcher and Benjamin S. Giese, 2002, Geophysical Research Letters, Vol 29, N0 19.
Abstract: An analysis of ocean surface temperature records show that low frequency changes of tropical Pacific temperature lead global surface air temperature changes by about 4 years. Anomalies of tropical Pacific surface temperature are in turn preceded by subsurface temperature anomalies in the southern tropical Pacific by approximately 7 years. The results suggest that much of the decade to decade variations in global air temperature may be attributed to tropical Pacific decadal variability. The results also suggest that
subsurface temperature anomalies in the southern tropical Pacific can be used as a predictor for decadal variations of global surface air temperature. Since the southern tropical Pacific temperature shows a distinct cooling over the last 8 years, the possibility exists that the warming trend in global surface air temperature observed since the late 1970’s may soon weaken.
2. Solar Forcing of Changes in Atmospheric Circulation, Earth’s Rotation and Climate
by Adriano Mazzarella, 2008, The Open Atmospheric Science Journal, Vol 2
Abstract: Cross analysis of available historical series of solar wind turbulence, atmospheric circulation, Earth’s rotation and sea surface temperature, when smoothed from the secular trend and periods shorter than 23 years, allowed a cascade climatological model to be set up that integrates the Sun-atmosphere-Earth system as a simple unit and ties solar corpuscular output to sea surface temperature through atmospheric circulation and the Earth’s rotation. An increase in solar corpuscular activity causes a deceleration of zonal atmospheric circulation which, like a torque, causes a deceleration of the Earth’s rotation that, in turn, causes a decrease in sea surface temperature. Application of this holistic model allows us to predict a gradual decline in global warming starting from the current decade.
Photograph of the waves taken at Alexandra Bay, Noosa National Park, in November 2008 by Jennifer Marohasy.