Solar activity

Living things, plants and ices are able to keep the results of environment impact, an information of that kind is recorded, for examples, by trees in a view of year layers (or Greenland ices). This recorded knowledge keeps a various facts about climate changes mechanisms, about solar activity, soil conditions and, in particular, the level of this very region contamination. 

The ionosphere is subject to sudden changes resulting from solar activity, particularly from solar emptions or flares that are accompanied by intense x-ray emission. The absorption of the x-rays increases the electron density in the D and E layers, so that absorption of radio waves intended for E-layer reflection increases. In this manner, solar flares dismpt long-range, ionospheric bounce communications. 

The comet s tail The tail only develops when the comet is inside the orbit of Mars and can reach a length of between 107 km and one AU. It is not always straight but is often curved. This happens when the comet is subject to strong solar winds, i.e., during periods of greater solar activity. Two types of tail can be distinguished ... 

The atmospheric 14C/C ratio during the last 50,000 y was sufficiently constant to make radiocarbon a remarkably reliable dating tool. Evidence for fluctuations of the 14C/C ratio could be found by high precision measurements on samples of known age. These fluctuations can be attributed to variations of processes in the solar system (solar activity) and on earth (fluctuations of C02 distribution among the atmospheric, oceanic, and biospheric reservoirs). Both fluctuations of solar activity and of the atmospheric C02 content may have contributed to past climatic changes. 

PRECIPITATION, SOLAR ACTIVITY, ATMOSPHERIC TURBIDITY (VULCANIC DUST)AND OPACITY(C02 content)... 

A logical explanation for the global nature of these correlations is that they are all related to variations of the sun, which cause variations in the temperature of the sea surface, thus causing variations in the isotopic composition of water vapor which distills off the sea and is stored as wood in trees and also forms the annual layers of the ice cap. The variations of the sun are furthermore related to the flux of solar neutrons in the earth s atmosphere and so cause small variations in the carbon-14 content of the bristle cones. During times of a quiet sun the average carbon-14 production is about 25 percent larger than when solar activity is high [43]. 

Increased production of oxides of nitrogen through solar proton events associated with the 11-year cycle in solar activity would be expected to be most important in the upper stratosphere, above the region where the majority of the ozone depletion was observed in addition, lower, rather than higher, concentrations of gas-phase oxides of nitrogen appear to be associated with the ozone depletion (e.g., see Noxon, 1978 McKenzie and Johnston, 1984 Thomas et al., 1988 Keys and Gardiner, 1991 and Solomon and Keys, 1992). Hence both of these explanations are not consistent with atmospheric observations. 

Zerefos, C. S., K. Tourpali, B. R. Bojkov, D. S. Balis, B. Rognerund, and I. S. A. Isaksen, Solar Activity-Total Column Ozone Relationships Observations and Model Studies with Heterogeneous Chemistry, J. Geophys. Res., 102, 1561-1569 (1997). 

The thermosphere is the thin outer layer of our atmosphere extending from the mesopause near 80 km. altitude out to the exosphere, some several thousand kin. altitude, where the mean free path is sufficiently long to allow escape of atomic hydrogen and helium and atmospheric capture of coronal gas constituents. In the lower thermosphere, heated by solar ultraviolet and x-radiation, the temperature increases rapidly with altitude, with temperatures above 400 km. varying between about 700° and 2100°K., depending on solar activity. 

The temperature of the upper atmosphere, and hence its density, varies with the intensity of solar ultraviolet radiation and this, in turn, varies with the sunspot cycle and with solar activity in general. The solar radionoise flux is a convenient index of solar activity, since it can be monitored at the earth s surface. The minimum nighttime temperature of the upper atmosphere above 300 kilometers has been expressed in terms of the 27-day average of the solar radio-noise flux at 8-ccntimctcr wavelength. This varies from about 600 K near the minimum of the sunspot cycle to about 1400 K near the maximum of file cycle. The maximum daytime temperature is about one-third larger than tile nighttime minimum. 

Variability may be defined as reflecting fluctuations in the atmosphere, of natural origin, with both temporal and spatial scales examples are diurnal, seasonal, solar activity-related variations impulsive events such as volcano eruptions and solar proton events fluctuations linked to some peculiar meteorological conditions, for example, intense cyclonic activities and jet streams. Variability by itself is a whole program to be conducted ideally on a four-dimensional basis (latitude, longitude, altitude, and time) by space vehicles, for example, satellites or from the space shuttle. This area of research is certainly the most urgent one to be de-... 

Variations in the biochemistry and physiology of fish from one year to another must be accepted as real. Such a cycle would be linked to long-term changes in the climate resulting from solar activity (Chizhevsky, 1976). The trouble is that observations are insufficiently representative to yield clear patterns. As with diurnal variation, much of the published work relates to terrestrial organisms rather than fish, and much of the study has centred on fluctuations in the abundance of species which tend to develop outbreaks - sudden marked increases in numbers. However, fish such as salmon, cod, herring, sardines and other species have also been shown to exhibit long-term fluctuations in their numbers. Klyashtorin (1996) has found a close correlation between the velocity of rotation of the earth, which affects the intensity of circulation of the water in the oceans, and the abundance of stocks of many species of fish. 

The change in extra-atmospheric solar radiation is a climate-forming factor that should be considered. The contribution of such a change to RF since 1750 might be as much as 20% compared with the contribution of C02. This is mainly explained by enhanced extra-atmospheric insolation in the second half of the 20th century (consideration of the 11-year cycle of insolation is vital here). However, the mechanisms that underly the impact of solar activity on climate are still far from being understood. Nonetheless, IPCC (2007) contains some conclusions and estimates. 

The rate of production depends on solar activity and ranges from 0.4 to 0.8 kg (4 to 8 MCi) per annum (National Council on Radiation Protection and Measurement, 1979). Most of the tritium is formed in the stratosphere, and remains there for some months, giving an inventory of 0.24 kg (2.3 MCi) (UNSCEAR, 1977). 

In Table 7.2, we summarize major He fluxes in the atmosphere. The He budget seems to be in balance, at least within a factor of two, although there is certainly room for modification of some of the terms or introduction of new ones. However, there is no reason to require the He budget to be in balance. On the 106 year scale of the mean residence time, variations in fluxes will be smoothed out, and the present epoch may not be typical. The geological and cosmic ray sources are probably fairly steady on this time scale, but the thermal loss is very sensitive to solar activity, the nonthermal loss is sensitive to the geomagnetic field, and precipitation is sensitive to both. At an extreme, the fluxes may be highly irregular Sheldon and Kern (1972),... 

Suess. H.E. (1968) Climatic changes, solar activity and the cosmic ray production rate of radiocarbon. Meteorol. Monogr. 8, 146-150. 

They thought the Sun had to be perfect and that spots would be an insult to God. Incidentally, there is evidence that solar activity can affect our weather and climate. For example, from 1645 to 1715, there was a period (called the Maunder minimum) when there were hardly any sunspots, and Earth s weather was unusually cold. ... 

Figure 6.12 Dramatic high-resolution image looking across the edge of the Sun. Shown here are arcs of hot gas suspended in powerful looping magnetic fields that rise above a solar active region. The image was made in the extreme ultraviolet light.

Essentially all of the energy for life originates in the form of electromagnetic radiation from the sun. In radiometric units the radiant flux density of solar irradiation (irradiance) perpendicularly incident on the earth s atmosphere—the solar constant — is about 1366 W m-2. The solar constant varies by up to 3.4% from the average due to the earth s elliptical orbit. The value given is for the mean distance between the earth and the sun (the earth is closest to the sun on January 3, at 1.471 x 10s km, and furthest away on July 4, at 1.521 x 108 km). There are additional variations in solar irradiation based on changes in solar activity, such as occur for sun spots, which lead to the 11-year solar cycle (Pap and Frolich, 1999). In Chapter 6 (Section 6.5) we will consider the solar constant in terms of the annual photosynthetic yield and in Chapter 7 (Section 7.1) in terms of the energy balance of a leaf. 

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