![]() ![]() Cover the inside of the box lid with foil for a reflector.Tape all seams: bottom, sides, and around the inside top of the box.Put pieces of insulation around all the walls of the inside of the box.Put a piece of insulation inside the box on the bottom.Foil backed foam insulation board, approx.File storage box, or other box approx. ![]() Box ovens can be easily made from inexpensive or recycled materials, and are suitable for classroom construction and cooking. Commercially made box ovens can reach 400o on a clear sunny day. They use reflectors to concentrate more sunlight into the box, glazing to allow sunlight into the box and then trap the heat, and insulation to retain as much heat as possible. As the name suggests, they have an interior chamber (“box”), although it does not have to be square shaped. Solar (as well as other) indices can be divided into physical and synthetic according to the way they are obtained/calculated.Box cookers (also known as box ovens) can cook the same foods you would cook in a standard oven or a slow cooker. The indices of solar activity that are often used for long-term studies are reviewed below. In addition to the solar indices, indirect proxy data is often used to quantify solar activity via its presumably known effect on the magnetosphere or heliosphere. ![]() Most of the indices are highly correlated to each other due to the dominant 11-year cycle, but may differ in fine details and/or long-term trends. A variety of indices quantifying solar activity have been proposed in order to represent different observables and caused effects. For instance, solar-surface magnetic variability, eruption phenomena, coronal activity, radiation of the sun as a star or even interplanetary transients and geomagnetic disturbances can be related to the concept of solar activity. Whereas the concept of solar activity is quite a common term nowadays, it is neither straightforwardly interpreted nor unambiguously defined. ![]() 5), the existence of solar/stellar activity is clear. 2013) does not agree with solar data (Aulanier et al. Although a direct projection of the energy and occurrence frequency of superflares on sun-like stars (e.g.,Shibata et al. The presence of magnetic activity, including stellar flares, is considered as a common typical feature of sun-like stars (Maehara et al. Such nonstationary and nonequilibrium (often eruptive) processes can be broadly regarded as solar activity. The sun is known to be far from a static state, the so-called “quiet” sun described by simple stellar-evolution theories, but instead goes through various nonstationary active processes. Finally, conclusions are summarized in Sect. The long-term averaged flux of solar energetic particles is discussed in Sect. Section 4 gives an overview of what is known about past solar activity. The proxy method of solar-activity reconstruction is described in some detail in Sect. A description of the concept of solar activity and a discussion of observational methods and indices are presented in Sect. This paper gives an overview of the present status of our knowledge of long-term solar activity, covering the period of Holocene (the last 11 millennia). This allows one to study the temporal evolution of solar magnetic activity, and thus of the solar dynamo, on much longer timescales than are available from direct measurements. Over long timescales, quantitative information about past solar activity can only be obtained using a method based upon indirect proxies, such as the cosmogenic isotopes \(^\)Be in terrestrial archives. The concept of solar activity is discussed along with an overview of the special indices used to quantify different aspects of variable solar activity, with special emphasis upon sunspot number. Presented here is a review of present knowledge of the long-term behavior of solar activity on a multi-millennial timescale, as reconstructed using the indirect proxy method. ![]()
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