Seasonal variability of the Black Sea Chlorophyll-a concentration

Journal of Marine Systems, 56The article of record as published may be located at http://dx.doi.org/10.1016/j.jmarsys.2005.01.001The optimal spectral decomposition (OSD) method is used to reconstruct seasonal variability of the Black Sea horizontally averaged chlorophyll-a concentration from data collected during the NATO SfP-971818 Black Sea Project in 1980–1995. During the reconstruction, quality control is conducted to reduce errors caused by measurement accuracy, sampling strategy, and irregular data distribution in space and time. A bi-modal structure with winter/spring (February–March) and fall (September–October) blooms is uniquely detected and accurately documented. The chlorophyll-a enriched zone rises to 15 m depth in winter and June, and deepens to 40 m in April and 35 m in August. The June rise of the chlorophyll-a enriched zone is accompanying by near continuous reduction of upper layer maximum chlorophyll-a concentration

Rotation method for reconstructing process and field from imperfect data

International Journal of Bifurcation and Chaos, 14Reconstruction of a process and fields from noisy data is to solve a set of linear algebraic equations. Three factors affect the accuracy of reconstruction: (a) a large condition number of the coefficient matrix, (b) high noise-to-signal ratio in the sorce term, and (c) no a priori knowledge of noise statistics. To improve reconstruction accuracy, the set of linear algebraic equations is transformed into a net set with minimum condition number and noise-to-signal ratio using the rotation matrix. The procedure does not require any knowledge of low-order statistics of noises. Several examples including highly distorted Lorenz attractor illustrate the benefit of using this procedure

Probabilistic stability of an atmospheric model to various amplitude perturbations

Journal of the Atmospheric Sciences, American Meteorological Society, 5