GEOGRAPHY
The values obtained reveal that the Brunt-Vaisala frequency is subject to a moderate change with height over the entire observation period, and once the height is fixed shows only weak seasonal changes. At the height interval 800–1800 m, the maximal values of N are observed between December and January, whereas from April to September smaller values of N represent a flat plateau. These variations generally decrease with increasing height. They are still recognizable in the interval 2500–3500 m, and fully diminish at 7000–8000 m.
The long-term series of fluctuation of monthly and annual Northern Hemisphere atmospheric circulation in non-tropical latitudes from 1899 to 2008 according to Dzerdzeevskii classification have been discussed. The differences in atmospheric circulation between circulation epochs have been identified. The circulation and climatic characteristics of extreme decades of circulation epochs in the Northern Hemisphere and its six sectors—Atlantic, European, Siberian, Far East, Pacific, and American—have been given. The recent, the 1981–2007 period, is characterized by the increase in frequency (number of cases) and duration (number of days) of the southern meridional circulation group.
ENVIRONMENT
This paper aims at a methodological evaluation of the discrete and analytical mathematical models hitherto available for quantitative assessments of spatial ecological complex systems.
These models are derived from cellular automata and nonlinear dynamics. They describe complex features and processes in landscapes, such as spatial ecological nonlinear interactions, unpredictability and chaos, self-organization and pattern formation.
Beginning with a distinction between two basic types of spatial ecological complexity (structural, functional), and after reviewing the quantitative methods so far available to assess it, the areas where the major challenges (and hence, difficulties) for future research arise are identified. These are: a) to develop measures of structural spatial-ecological complexity, b) to find Lyapunov functions for dynamical systems describing spatial interactions on the landscape (and related attractors), and c) to combine discrete time and continuous spatial data and models.
SUSTAINABILITY
NEWS AND REVIEWS
THE REPORT ON THE SPECIAL CONGRESS OF THE RUSSIAN GEOGRAPHICAL SOCIETY
THE NATIONAL ATLAS OF RUSSIA
ISSN 2542-1565 (Online)