Saturday, March 24, 2007

Phytoplankton Biomass the Ecofuel powering the Pacific climate.

Phytoplankton are the “fuel” powering the climatic oscillation of the Pacific weather system. The growth phase in antiphase to the weather pattern are drivers due to the well known mechanisms of attenuation /amplification of the sea surface water temperature differentials. IE Growth and phytoplankton bloom is a priori to SST amplification,and the population decline is a priori to SST attenuation, the pacific oscillation-La Nina –El Niño.

The energy transfer pathway is Solar-heat and momentum- flux-spectral wavelengths changes and photon flux growth-pigmentation (chlorophyll)change sst change enhanced metabolic growth..

The interpretation of the population and SST variance is somewhat a chicken-egg analogy, depending on which organization analysis is used however the premis is unchanged the changes to the spectral density of the phytoplankton oscillation change the SST the level of the thermocline and atmospheric temperature gradient over the Pacific.When the phase change occurs the population reduction of zoo and phytoplankton carry the carbon to the sea floor.

The information about atmospheric warming imparts particular significance to the task of determining the real-life dynamics of the biosphere. The actual contributions of the land and ocean biotas have not been accurately determined, although there is a great body of literature on the subject.

The extensive scientific discussion of global warming causes a natural wish to relate this process to possible changes in the amount and dynamics of terrestrial and oceanic vegetation. Does this process influence variations in the amount and diversity of plants? Does it influence the pattern of their seasonal and long-term variations? It would seem that continuous elevation of CO2 and increase in the mean global temperature must cause permanent long-term changes in the amounts of phytopigments in the biosphere. But is this really so? What should be the direction of these changes?

Thus, the initial task was to reveal long-term trends of phytopigment concentrations in the ocean. This task could be fulfilled based on daily satellite measurements conducted for many years.

However, analysis of variations in phytopigment concentrations under different biogeographic conditions showed that the initial statement of the problem of studying linear or nonlinear trends was not quite correct. It has been found that on a global scale, the variations are oscillatory and the trends revealed for separate time periods must be just parts of a long-period oscillatory process. Moreover, these oscillations at different latitudes and in different times (e.g. in the time of CZCS and SeaWiFS functioning, in different seasons, etc.) are often in antiphase.

El Niño and La Niña play with the populations of microscopic ocean plants called phytoplankton. That's what scientists have found using NASA satellite data and a computer model.

The computer model showed that during El Niño periods, warm waters from the Western Pacific Ocean spread out over much of the ocean basin as upwelling weakens in the Eastern Pacific Ocean. Upwelling brings cool, nutrient-rich water from the deep ocean up to the surface. When the upwelling is weakened, there are less phytoplankton, making food more scarce for zooplankton that eat the ocean plants.

During La Niña conditions as in 1998, the opposite effect occurs as the easterly trade winds pick up and upwelling intensifies bringing nutrients like iron to the surface waters, which increases phytoplankton growth. Sometimes, the growth can take place quickly, developing into what scientists call phytoplankton "blooms."
As phytoplankton flourish during La Niña years, a large amount of carbon is used to build their cells during photosynthesis. The plants get carbon from carbon dioxide in surface waters. In the atmosphere, carbon dioxide is an important greenhouse gas. When marine organisms die, they carry carbon in their cells to the deep ocean. Surprisingly, this study found that this transfer of carbon to the deep ocean increased by a factor of eight due to the large phytoplankton blooms that can occur during a La Niña. At the same time, the effects of El Niños can reduce phytoplankton numbers, and decrease the impacts of this "biological carbon pump."

Phytoplankton alter the absorption of solar radiation, affecting upper ocean temperature and circulation. These changes, in turn, influence the atmosphere through modification of the sea surface temperature (SST). To investigate the effects of the present-day phytoplankton concentration on the atmosphere, an atmospheric general circulation model was forced by SST changes due to phytoplankton. The modified SST was obtained from ocean general circulation model runs with space- and time-varying phytoplankton abundances from Coastal Zone Color Scanner data. The atmospheric simulations indicate that phytoplankton amplify the seasonal cycle of the lowest atmospheric layer temperature. This amplification has an average magnitude of 0.3 K but may reach over 1 K locally. The surface warming in the summer is marginally larger than the cooling in the winter, so that on average annually and globally, phytoplankton warm the lowest layer by about 0.05 K. Over the ocean the surface air temperature changes closely follow the SST changes. Significant, often amplified, temperature changes also occur over land. The climatic effect of phytoplankton extends throughout the troposphere, especially in middle latitudes where increased subsidence during summer traps heat. The amplification of the seasonal cycle of air temperature strengthens tropical convection in the summer hemisphere. In the eastern tropical Pacific Ocean a decreased SST strengthens the Walker circulation and weakens the Hadley circulation. These significant atmospheric changes indicate that the radiative effects of phytoplankton should not be overlooked in studies of climate change.

In fact the energy production is around 5 times the total world consumption of energy.

Physical and biological oceanographers led by FSU Professor William Dewar put the yearly amount of chemical power stored by phytoplankton in the form of new organic matter at roughly 63 terawatts, and that's a lot of juice: Just one terawatt equals a trillion watts. In 2001, humans collectively consumed a comparatively measly 13.5 terawatts.

What's more, their study found that the marine biosphere –– the chain of sea life anchored by phytoplankton –– invests around one percent (1 terawatt) of its chemical power fortune in mechanical energy, which is manifested in the swimming motions of hungry ocean swimmers ranging from whales and fish to shrimp and krill. Those swimming motions mix the water much as cream is stirred into coffee by swiping a spoon through it.

And the sum of all that phytoplankton-fueled stirring may equal climate control.

"By interpreting existing data in a different way, we have predicted theoretically that the amount of mixing caused by ocean swimmers is comparable to the deep ocean mixing caused by the wind blowing on the ocean surface and the effects of the tides," Dewar said.

In fact, he explained, biosphere mixing appears to provide about one third the power required to bring the deep, cold waters of the world ocean to the surface, which in turn completes the ocean's conveyor belt circulation critical to the global climate system.


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