advancing the mitigation of Climate Change and Global Warming through Geoengineering education and research
Ocean Albedo Modification | Microbubbles
Ocean albedo modification using microbubbles is a solar radiation management geoengineering or climate engineering approach that increases the reflectivity or albedo of the surface of the ocean. Ocean albedo modification using microbubbles in the geoengineering scientific literature can also be found by searching for terms that include ocean albedo enhancement, bright water, hydrosols, micron-sized bubbles, oceanic bubbles, oceanic or sea foams, bubble clouds and ship wakes.
During windy conditions, breaking waves on the surface of the ocean form white caps. White caps are breaking waves that trap and suspend small bubbles of air in the wave water. Breaking waves on the world’s beaches also form white water due to the same process. The formation of these tiny bubbles of air or microbubbles in white caps and white water turns the color of the ocean white. Because white surfaces reflect light, microbubbles reflect sunlight into space.
The natural formation of microbubbles. Courtesy of the Argonne National Laboratory and Wai Hong, Ronald Chan, Shahab Mirjalili, Suhas Jain Suresh, Javier Urzay, Ali Mani and Parviz Moin at Stanford University’s Center for Turbulence Research.
In 2011, Harvard University Professor Russell MacGregor Seitz published this geoengineering approach which involves spraying or injecting microbubbles of air into the surface waters of the ocean to reflect sunlight into space. Reflecting sunlight into space before it is absorbed by the ocean is a way to cool the ocean and mitigate Climate Change and Global Warming.
The vast majority of the ocean is very deep and dark in color. Because it is dark in color, it tends to absorbs a lot of sunlight. When sunlight is absorbed into ocean waters, it is converted into heat or thermal energy which raises the temperature of the water. The property of the surface of the Earth to reflect or absorb solar radiation is known as albedo. Albedo ranges from 0 to 1 with 1 representing the reflection of all light. The ocean’s average albedo is about 0.05 to 0.10 (Seitz, 2011). This low albedo results in the absorption of approximately 93% of incident solar radiation (Seitz, 2011).
White caps and white water have a relatively high albedo of about 0.22 which is similar to the albedo of clouds (Moore et al., 2000). Seitz’s proposed solution, which replicates the characteristics of white caps and white water, is to increase the albedo of the ocean by creating suspensions of microbubbles in ocean surface waters. These suspensions of microbubbles or “hydrosols” are produced by “methods involving the expansion of air-saturated water through vortex nozzles or by the use of mechanical shakers or ultrasonic transducers (Seitz, 2011).”
Dr. Russell MacGregor Seitz producing microbubbles or “Bright Water” in a laboratory. Courtesy of Dr. Russell MacGregor Seitz. Please visit his YouTube channel https://www.youtube.com/channel/UCXpotupJanKti1t1Nuj3gZA.
Similar to naturally produced white caps and white water, suspensions of microbubbles would significantly increase the albedo of the ocean. When considering that the ocean covers 71% of the surface of the Earth, this climate engineering approach, if successful, could be instrumental in helping to counteract Global Warming.
- Moore, K.D., Voss, K.J. and Gordon, H.R., 2000. Spectral reflectance of whitecaps: Their contribution to water‐leaving radiance. Journal of Geophysical Research: Oceans, 105(C3), pp.6493-6499.
- Seitz, R., 2011. Bright water: hydrosols, water conservation and climate change. Climatic Change, 105(3-4), pp.365-381.