Educational Model: Factors Determining Planetary Temperature

Part of the IUMC (Innovative Educational and Methodological Complex) “Ecology: Constructing the Biosphere,” developed in 2008 by D. A. Shabanov, A. G. Kozlenko, and M. A. Kravchenko by order of the NTFP (National Training Foundation) of the Russian Federation (more about this project is discussed in the article “Innovation and Reality”; reasons why this complex is not used are briefly described in the column “Textbooks: Straight into the Day After Tomorrow”). This model is posted here for educational use. The model makes it possible to assess the effects of three factors on planetary temperature. The theoretical material related to the model is in the section Greenhouse Effect and the supplement Venus, Earth, Mars of the manual “Ecology: Biology of Interactions.” The working area of the screen shows part of the Solar System, including the orbits of the terrestrial planets. At the same time, a hypothetical planet X is assumed, for which the following numerical parameters can be changed: – radiation flux value (solar constant, W/m²), which depends on distance to the star (at fixed stellar emission), – total albedo (the fraction of radiation reflected by the planet’s surface and atmosphere), – atmospheric greenhouse effect (expressed in relative units). The solar constant of a specific Solar System planet is determined by its distance from the star. Albedo depends on planet type, surface properties, and atmospheric composition and properties (for example, clouds substantially increase albedo). The greenhouse effect depends on atmospheric density and composition of greenhouse gases. Navigation in the model is performed using sliders in the working area. Mean annual temperature is shown there in two scales (Kelvin and Celsius). Instructions for working with the model are located at the very bottom of its window; if these instructions do not fit in the box, they can be scrolled up and down with the arrows on the right. Some tasks that can be solved while working with the model: 1. Compare hypothetical planet X with terrestrial planets. Assess the influence of the indicated factors on planetary temperature. 2. Compare the effects of changing the three parameters varied in the model. Select two different parameter sets in which planet X has different characteristics but the same surface temperature.