Simulation and Predictability of Seasonal and Interannual Variations

MEASUREMENTS OF CHANGES in atmospheric molecular oxygen using a new itechnique shows that the oxygen content of air varies seasonally in both the Northern and Southern Hemispheres, and is decreasing from year to year. The seasonal variations provide a new basis for estimating global rates of biological organic carbon production in the ocean, and the interannual decrease constrains estimates of the rate of anthropogenic CO2 uptake by the oceans.

One example of research into variations are the interannual and interdecadal zooplankton population changes that have been observed in parallel with temperature (SST) changes at Helgoland, in the North Sea, over a period of 32 years.

Temperature determines the phenological timing of populations for each species in a unique way as to be seen in multiannual regressions. Sign, inclination of the regressions of phenophases with temperature and determination coefficient vary from species to species. Besides the limited predictability of annual temperature dynamics the species specificity limits the predictability of future phenophase timing. However, the strong correlation of phenophase timing with preceding SST permits the prediction of the annual seasonality based on statistical models separately for each population.

The regressions determined in the correlation analyses are the first approach to the phenological prognoses which the the Senckenberg Research Institute calculates daily for 192 phenophases of zooplankton including ichthyoplankton on a daily basis and which it publishes since April 2004 on the home page of the institute at www.senckenberg.de/dzmb/plankton. The calculations are based on more than 30 years of weekly and more frequent sampling at Helgoland Roads (54°11'18" N 7°54' E), the only proper offshore island of the North Sea. Temperatures were provided by the Biologische Anstalt Helgoland and the German Weather Service. Beyond the historic data used, current temperature measurements for the operative daily calculations are obtained from the websites. They are corrected according to the historic deviations stemming from current temperature measurements for the position at Helgoland Roads, published on the internet and weather report measurements and are then used for the calculation of the minimum current error for phenophase prediction. The prognoses is exclusively restricted to temporal prognoses. Abundance predictions are not included.

SEE ALSO: Oceanic Changes; Oceanography.

BIBLIOGRAPHY. Helgoland Marine Research, The Warming Trend at Helgoland Roads, North Sea: Phytoplankton Response (Springer Berlin/Heidelberg, 2004); Research Institute Senckenberg, German Centre for Marine Biodiversity Research, www.senckenberg.de/dzmb/plankton.

Wulf Greve Independent Scholar

Renewable Energy 101

Renewable Energy 101

Renewable energy is energy that is generated from sunlight, rain, tides, geothermal heat and wind. These sources are naturally and constantly replenished, which is why they are deemed as renewable. The usage of renewable energy sources is very important when considering the sustainability of the existing energy usage of the world. While there is currently an abundance of non-renewable energy sources, such as nuclear fuels, these energy sources are depleting. In addition to being a non-renewable supply, the non-renewable energy sources release emissions into the air, which has an adverse effect on the environment.

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