PROJECT: Green Crop Lifting – an Alternative Producing Healthy Seed Potatoes in the System of Organic Farming

The standards of organic farming require the use of organically grown seeds in organic potato farming. Presumably the use of conventionally grown seeds under exceptional circumstances will end in 2003. Only organically grown seeds can be used thereafter. Therefore, it is important to check alternatives for organic potato seed production, which will reduce the cultivation risk, guarantee a high quality of seed potatoes (virus-free and healthy seed), and increase the fraction of marketable potatoes. On 7 farms in Northern Germany (4 sites in the coastal region (Schleswig-Holstein) and 3 sites in the inland region (Lower Saxony)) the green crop lifting (GCL) at two different dates was checked against the traditional process (haulm cutting) and a control plot (natural senescence) with regard to the effect of presprouting in the years 1999 to 2001. The focus of the investigation was the amount of viral load (tested with ELISA) and detection of other diseases (valuation) on / in the harvested potatoes. Yield reduction and tuber damage was recorded. Flying activity of aphids was monitored by yellow water traps.In the coastal region a very low pressure of aphids was observed over the three years. In contrast there was a higher pressure of aphids in the inland region, but only 1999 brought an early and outstanding pressure. In peak times (middle of July 1999) the number of aphids was more than 12 times higher compared to the coastal region. Only in 2000 an early aphid pressure was recorded in the middle of May. If there was a high pressure of aphids the early green crop lifting (in the middle of July) was an effective way reducing the virus diseases.Caused by the early date of GCL the total tuber yield reduction averaged out at 18,8 % over the three years compared to the control. Related to the marketable seed potatoes (28-50 mm) the yield reduction amounted 14.1 % only

Is the Sun Lighter than the Earth? Isotopic CO in the Photosphere, Viewed through the Lens of 3D Spectrum Synthesis

We consider the formation of solar infrared (2-6 micron) rovibrational bands of carbon monoxide (CO) in CO5BOLD 3D convection models, with the aim to refine abundances of the heavy isotopes of carbon (13C) and oxygen (18O,17O), to compare with direct capture measurements of solar wind light ions by the Genesis Discovery Mission. We find that previous, mainly 1D, analyses were systematically biased toward lower isotopic ratios (e.g., R23= 12C/13C), suggesting an isotopically "heavy" Sun contrary to accepted fractionation processes thought to have operated in the primitive solar nebula. The new 3D ratios for 13C and 18O are: R23= 91.4 +/- 1.3 (Rsun= 89.2); and R68= 511 +/- 10 (Rsun= 499), where the uncertainties are 1 sigma and "optimistic." We also obtained R67= 2738 +/- 118 (Rsun= 2632), but we caution that the observed 12C17O features are extremely weak. The new solar ratios for the oxygen isotopes fall between the terrestrial values and those reported by Genesis (R68= 530, R6= 2798), although including both within 2 sigma error flags, and go in the direction favoring recent theories for the oxygen isotope composition of Ca-Al inclusions (CAI) in primitive meteorites. While not a major focus of this work, we derive an oxygen abundance of 603 +/- 9 ppm (relative to hydrogen; 8.78 on the logarithmic H= 12 scale). That the Sun likely is lighter than the Earth, isotopically speaking, removes the necessity to invoke exotic fractionation processes during the early construction of the inner solar system

Vortices, shocks, and heating in the solar photosphere: effect of a magnetic field

Aims: We study the differences between non-magnetic and magnetic regions in the flow and thermal structure of the upper solar photosphere. Methods: Radiative MHD simulations representing a quiet region and a plage region, respectively, which extend into the layers around the temperature minimum, are analyzed. Results: The flow structure in the upper photospheric layers of the two simulations is considerably different: the non-magnetic simulation is dominated by a pattern of moving shock fronts while the magnetic simulation shows vertically extended vortices associated with magnetic flux concentrations. Both kinds of structures induce substantial local heating. The resulting average temperature profiles are characterized by a steep rise above the temperature minimum due to shock heating in the non-magnetic case and by a flat photospheric temperature gradient mainly caused by Ohmic dissipation in the magnetic run. Conclusions: Shocks in the quiet Sun and vortices in the strongly magnetized regions represent the dominant flow structures in the layers around the temperature minimum. They are closely connected with dissipation processes providing localized heating.Comment: Accepted for publicaton in A&

Морфологическая стратификация облаков электрическим полем атмосферы в периоды активного и спокойного солнца

Актуальность. В последнее десятилетие наблюдается стремительный рост регионального и глобального изменения климата в связи с хозяйственной деятельностью человека, которая в своих масштабах стала соизмерима с природными процессами. В качестве индикатора техногенной нагрузки может выступать электрическое поле атмосферы, так как техноэкономическая среда городов приводит к глобальным отклонениям и модификации естественных физических полей. Поэтому необходимость изучения влияния электрического поля атмосферы на распределение метеорологических параметров не вызывает сомнения, так как позволяет на качественном уровне проявить «тонкую» структуру стратификации атмосферы электрическим полем и ее изменение за счет антропогенного воздействия. Цель исследования: рассмотреть морфологическую стратификацию облачных образований электрическим полем атмосферы в период активного и спокойного солнца. Данный подход позволяет на качественном уровне прояснить механизм изменения процессов конденсации водяного пара (на примере облаков) сменой солнечной активности, как уменьшение количества возбужденных молекул за счет разной ионизации атмосферы, а также построить физическую теорию антропогенной нагрузки от промышленных предприятий на атмосферу и климат. Объект исследования: электрическое поле атмосферы, облака. Методика исследования построена на детальном статистическом анализе по данным самолетного зондирования в период международного геофизического года и международного геофизического сотрудничества 1958-1964 гг. Результаты исследования. Получены оценки радиационных сечений для молекул стандартной атмосферы и конденсированной фазы (облачные аэрозоли) в геометрическом приближении, которые показывают, что при характерном радиусе капель r-10[-3]см ионизация от конденсированной фазы соизмерима с фононовой ионизацией атмосферы. Приведена корреляционная зависимость средней водности облака и вертикального электрического поля. Анализ результатов показал, что среднегодовое распределение водности имеет высокую корреляцию со среднегодовым вертикальным распределением напряженности электрического поля для данного региона. Методами детального статистического анализа найдена взаимосвязь высоты образования облаков с электрическим полем атмосферы. Показано, что частота повторяемости нижней границы облаков совпадает с локальными точками равновесия плотности объемного заряда для этой же широты.Relevance of the research. In recent decade, regional and global climate has changed significantly due to human activities, which became comparable with natural processes. The electric field of atmosphere can serve as an indicator of anthropogenic impact, as the technical and economic environment of cities results in global deviations and modification of natural physical fields. Therefore, there is no doubt in the necessity to study the influence of the atmospheric electric field on distribution of meteorological parameters, since it allows us to reveal qualitatively the «thin» atmospheric stratification structure of the electric field and its change owing to anthropogenic impact. The aim of the research is to consider the morphological stratification of cloud formations by the atmospheric electric field in the period of the active and quiet sun. This approach allows us to clarify qualitatively the mechanism of change in water vapor condensation (on the example of clouds) by the solar activity change as the decrease in the number of excited molecules owing to different ionization of the atmosphere, as well as to build a physical theory of anthropogenic load from industrial plants on the atmosphere and climate. Research subject: the electric field of the atmosphere, clouds. Research technique: detailed statistical analysis of the data on an aircraft sounding during the International Geophysical Year and the International Geophysical Cooperation in 1958-1964. Results. The author has obtained the estimations of radiation cross-sections for the molecules of the standard atmosphere and the condensed phase (cloud aerosols) in geometric approximation. They show that when the characteristic radius is equal to r-10[-3] cm the ionization of the condensed phase is commensurate with the background ionization. The paper introduces the correlative relationship between average water content of clouds and vertical electric field. The analysis of the results demonstrates that the average annual distribution of water content is strongly correlated with the average vertical distribution of the electric field in this region. Using the methods of the detailed statistical analysis the author revealed the relationship between the height of cloud formation and the electric field of the atmosphere. It is shown that the repetition frequency of a cloud lower boundary demonstrates the high coincidence with local sites of neutrality of a bulk charge density for the same latitude