The Formation of Stable Components in the Atmosphere due to Energy Production

This paper is devoted to the possibility of taking into account the pressures of human activity on the atmosphere. It was presented at the International Workshop Envrisk '88 "Energy and Environment: the European Perspective on Risk" organized by the Italian Commission for Nuclear and Alternative Energy Sources, May 1988

Population Level Models of Forest Dynamics

This paper outlines several general aspects of modeling forest dynamics. First we describe forest dynamics at the population level, based upon the results of certain dynamical equations. Second we consider above-ground plant species such as grasses and mosses, which are most important for boreal forests since they provide the boundary conditions for tree generations. Modeling creativity in this field is very limited, compared with tree systems, and is in reality more an art than science in view of its specific nature. Several examples in this direction are shown

Energetically Active Climate-Forming Regions as Revealed from Data on Surface Evaporation from Land and Ocean

As is well known, a considerable part of the USSR belongs to marginal climatic regions that are permafrost, tundra, desert and mountains. Bioproductivity potential in the USSR is at least two times less than, for example, in the USA. A substantial part of the agricultural activity is held on marginal agricultural regions (dry, cold and high altitude). The total agricultural production in the country fluctuates from year to year as a result of climate impact. For example, the difference of total crop production in the extremely unfavorable year 1975, when severe drought damaged vast territories of the country, and the favorable year of 1976, was approximately 40%. Besides agriculture many other branches of the national economy -- transport, sport. construction, energy demand and production -- also largely depend on climatic conditions. It is now evident that technology development cannot completely remove the dependence of society on climate. It is excepted that significant climate changes may occur in various parts of the USSR. Therefore, Soviet policy makers consider climate impact analysis as a very important component in establishing, particularly long-term, state plans. A special feature of the Soviet planning system is that plans for short-term periods (5 years) and long-term (up to 20 years) are now made. Such a period. as considered by climatologists, is the period when substantial climatic changes may occur in the Northern Hemisphere. Hence, the establishment of a climate monitoring system based on a mechanism which truly corresponds to reality is very important from many points of view

Regional Strategies for Atmospheric Protection Using Simulation Models

This paper summarizes the results of research on ecological-economic modeling carried out in the Natural Environment and Climate Monitoring Laboratory (GOSKOMGIDROMET) in the period 1979-1987, embodied as a multi-goal, automated system (MARS). The system is designed to assist in developing air quality management strategies for urban and mesoscale regions. Management decisions on controlling atmospheric pollution are made in practice at several administrative levels, i.e., that of a republic, an economic region, a territorial-production complex, a separate state and so on. Such a territorial scale corresponds to the concept of a mesoscale region. One can consider a city as an elementary territorial administrative unit. At the present time, management goals for air quality are not simple. In addition, it is impossible to formulate a model capable of estimating realistically the state of the near-earth layer of the atmosphere. In cities and mesoscale regions, some hundred or even thousand sources of pollutants are situated and the emissions contain various harmful components. To decrease the pollution of the near-earth layers of atmosphere, some concrete measures (usually from 5 to 15) can be taken at each of the sources. Thus the task of identifying and analyzing the effectiveness of various atmosphere protection strategies is important. The MARS program package solves this complicated task for stationary sources. A mesoscale region and a city are represented in MARS by a regular grid of 0.5 km to 10 km (usually 1 km for a city and 10 km for a region). MARS is able to analyze the effectiveness of various control measures. The application of MARS requires a relatively small data bank comprising two parts: (a) information on natural climatic features of the territory and parameters of emission sources; (b) information on technology to reduce emission sources. The first part of the data bank is well worked out and does not cause any difficulties. The second part of the data bank requires a design study of possible technological measures for reducing effluents at the sources. For this it is also necessary to generalize analogues for use in other cities/regions. Proposed models, algorithms, and program packages are used in the USSR as a basis for strategies of atmosphere protection in cities and regions

Some Questions Relating to the Age Dynamics of Boreal Forests

This manuscript is a result of discussions prior to and during the workshops "Impacts of Change In Climate and Atmospheric Chemistry on Northern Forest Ecosystems and Their Boundaries" (August 1987) and "Global Vegetation Change" (April 1988) and is an initial step in the development of a synthesis between realistic (e.g. biological-detail-rich) computer oriented models of forest and more mathematically, tractable, but simpler forest models. The work is focused on the boreal forests of the world (an important carbon reservoir and an important reserve of softwood timber). The boreal forests are also potentially strong impact systems under current scenarios of CO2-induced climate warming. One purpose of building a model is to get an understanding of what may happen to the climate if, for example, all of the boreal belt were to disappear, or if its functional efficiency were to double. Could such a disappearance occur simultaneously with changes in the tropical forests? How would this change the exchange between atmosphere and the earth surface? The authors try to describe a forest (or vegetation as a whole) as a boundary layer between fast atmospheric processes and slow processes in soil and underground water systems, and consider the geometry of canopies and roots as a function of extremes corresponding to a stable equilibrium of soil and underground water systems. The authors hope to consider these and similar problems during their continuing cooperation

On Spatial Modelling of Long-Term Forest Fire Dynamics

The dynamics of forest fires over large territories is of great practical interest. Previous theoretical works are concerned mainly with point source fire models, and the transition from point source to area models -- large scale -- even simple models, is a shift forward. Certainly, the term "simple" has relative meaning in that it is relative to the level of achievement in an applied domain. However, it is very interesting that, to the authors, even such a simplified model appears not very trivial. As regards the stable state of the forest and the dependence of fire probability on the age of the forest, this conclusion can only be checked with models, as the time required for natural observations is much too long. In the model described in this paper, we do not claim to have created a quantitative model with which we could give a prognosis of the dynamics of specific forest regions. However, we can say that we have reached the following conclusions: 1. The absence of contemporary boreal forest of stable (in the absence of constant in time age-structure of forest) state, instead of that -- the stable fire regime, which is characterized by the large amount of fire year with little fired territory during the year, and irregular fires of great intensity. An explanation in the frame of a model -- effects like "synchronization" of forest formed processing (it must be an accumulation of a large amount of combustible material over a large area). In our model this regime has settled after 2000 years (steps) and long-term support (>10000). 2. The probability of burning a forest increases monotonically with increase in forest age. For a more accurate quantitative description of fire dynamics in forests, we must of course take into account the different primary and secondary succession lines, their ecological characteristics, climate fluctuations and so on

Impacts of Changes in Climate and Atmospheric Chemistry on Northern Forest Ecosystems and their Boundaries: Research Directions

In response to numerous suggestions with the research community that boreal forests should be targeted for analyses of potential ecosystem response to impending major changes in climate and atmospheric composition, a task-force meeting for research-planning purposes was held at the International Institute for Applied Systems Analysis in August 1987. Participants discussed objectives for an international collaborative research program on this subject, what the current state of knowledge is, what the relevant research questions are, and what research approaches should be developed to address these questions. This report summarizes the workshop discussions, and presents synopses of working-group discussions on the following types of investigations: (a) historical responses of boreal-forest stands to changing climate and atmosphere using correlational data analyses; (b) response of boreal ecosystems to warm and enhanced-CO2 environments using physical field experiments; (c) response of boreal ecosystems to raised or lowered levels of soil moisture using physical field experiments; (d) long-term behavior of boreal-forest stands in the face of changing atmosphere and climate using measurements from permanent plots; (e) development of comprehensive databases on ecological characteristics of boreal forests and silvical characteristics of boreal-forest tree species based on literature reviews and data syntheses; (f) response and sensitivity of boreal-forest stands and landscapes to changing atmospheric and climatic conditions using simulation models; and (g) response of regional boreal forests to changing climate and atmosphere in the context of forest management using simulation models and policy exercises. The research themes outlined above cover a wide range of spatial and temporal scales. As well, they cover a wide range of organization, from the organism through populations and communities to ecosystems (indeed, ecosystems including socio-economic subsystems). It is concluded that the various studies can benefit immensely from careful coordination that helps each study anchor its process mechanisms in lower hierarchical levels, and find its significance at higher levels. The coordination would also prevent wasteful duplication of effort in different countries where boreal forests exist, and would assist groups of researchers to benefit from (a) regular contact for exchange of data and information that would not normally be available through regular channels of dissemination, and (b) collaborative research arrangements for expensive, long-term, broad-scale projects that otherwise would probably not be possible

A Statistical Model of Background Air Pollution Frequency Distributions

The authors of this paper describe an approach for identifying statistically stable central tendencies in the frequency distributions of time series of observations of background atmospheric pollutants. The data were collected as daily mean values of concentrations of sulfur dioxide and suspended particulate matter at five monitoring stations -- three in the USSR, one in Norway, and one in Sweden. In their approach, the authors use well-developed statistical techniques and the usual method of constructing multimodal distributions. The problem is subdivided into two parts: first, a decomposition of the observations in order to obtain a description of each season separately and second, an investigation of this description in order to derive statistically stable characteristics of the entire data set. The main hypothesis of the investigation is that dispersion processes interact in such a way that in the zone of influence of one process (near its mode) the "tails" of the other process are not observed. This permits illumination of interrelations between the physics and the chemistry of the atmosphere. During the last 15-20 years, a wide range of monitoring programs has been initiated at national and international levels including, for example, the European Monitoring and Evaluation Program (EMEP) under the auspices of the ECE, and the Background Air Pollution Monitoring Network (BAPMoN) under the auspices of the WMO. The flow of data from the system of monitoring stations has led to national and international projects for the development of extensive environmental data bases such as NOAANET (NDAA), GRID/GEMS/UNEP/NASA, etc. The degree of information obtained should be sufficient for the goals of the analysis but often there is an overabundance of such data. The methods discussed in this paper therefore help in air pollution assessments, particularly with respect to distinguishing the baseline components, and their trends over decades