Evolution of periodic orbits near the Lagrangian point L2

A study of the evolution of the periodic and the quasi-periodic orbits near the Lagrangian point L₂, which is located to the right of the smaller primary on the line joining the primaries and whose distance from the more massive primary is greater than the distance between the primaries, in the framework of restricted three-body problem for the Sun–Jupiter, Earth–Moon (relatively large mass ratio) and Saturn–Titan (relatively small mass ratio) systems is made. Two families of periodic orbits around the smaller primary are identified using the Poincaré surface of section method – family I (initially elliptical, gradually becomes egg-shaped with the increase in the Jacobi constant C and elongated towards the more massive primary) and family II (initially egg-shaped orbits elongated towards L₂ and gradually becomes elliptical with the increase in C). The family I in the Sun–Jupiter and Saturn–Titan systems contains two separatrix caused by third-order and fourth-order resonances, while the Earth–Moon system has only one separatrix which is caused by third-order resonances. Also in the Sun–Jupiter and the Saturn–Titan systems, family I merge with family II, around Jacobian constant 3.0393 and 3.0163, respectively, while in the Earth–Moon system, family II evolves separately from two different branches. The two branches merge at C = 3.184515. In the Earth–Moon system, the family II contains a separatrix due to third-order resonances which is absent in the other two systems.     

Study of satellite retrieved CO2 and CH4 concentration over India

This paper reports a study of spatial and temporal variations of columnar averaged concentration of CO₂ and CH₄ over India using SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) and Greenhouse gas Observing SATellite (GOSAT) data. Comparison of these data with the global view National Oceanic and Atmospheric Administration (NOAA) land data and also location specific flask data is made. The temporal variation in column averaged global CO₂ is similar to that over India and it is also similar to the NOAA surface flask data and global view. The variation in NOAA surface CH₄ is location dependent and its global view appears to vary seasonally in opposite phase with the column averaged CH₄ values from satellites, reflecting the limited comparability of surface and column averaged data. Over India the CO₂ maximum is in May and minimum in August/September while for CH₄ the maximum is in September and minimum in February/March. The seasonal variation of CH₄ over India is correlated with the eastern coastal rice cultivation.     

The effects of CO2 on growth and transpiration of radish (Raphanus sativus) in hypobaria

Plants grown on long-term space missions will likely be grown in low pressure environments (i.e., hypobaria). However, in hypobaria the transpiration rates of plants can increase and may result in wilting if the water is not readily replaced. It is possible to reduce transpiration by increasing the partial pressure of CO₂ (pCO₂), but the effects of pCO₂ at high levels (>120 Pa) on the growth and transpiration of plants in hypobaria are not known. Therefore, the effects of pCO₂ on the growth and transpiration of radish (Raphanus sativus var. Cherry Bomb II) in hypobaria were studied. The fresh weight (FW), leaf area, dry weight (DW), CO₂ assimilation rates (C_A), dark respiration rates (DR), and transpiration rates from 26 day-old radish plants that were grown for an additional seven days at different total pressures (33, 66 or 101 kPa) and pCO₂ (40 Pa, 100 Pa and 180 Pa) were measured. In general, the dry weight of plants increased with CO₂ enrichment and with lower total pressure. In limiting pCO₂ (40 Pa) conditions, the transpiration for plants grown at 33 kPa was approximately twice that of controls (101 kPa total pressure with 40 Pa pCO₂). Increasing the pCO₂ from 40 Pa to 180 Pa reduced the transpiration rates for plants grown in hypobaria and in standard atmospheric pressures. However, for plants grown in hypobaria and high pCO₂ (180 Pa) leaf damage was evident. Radish growth can be enhanced and transpiration reduced in hypobaria by enriching the gas phase with CO₂ although at high levels leaf damage may occur.     

Seasonal and diurnal behavior of NO2 column density in Antarctica as observed by Mark IV,Brewer Ozone Spectrophotometer Number 153

The Meteorology Department of India has been measuring vertical column density of NO₂ at Maitri (70.7°S, 11.7°E), Antarctica since July 1999 using a Mark IV, Brewer Ozone Spectrophotometer. Maitri is situated at the south of the Antarctic circle. An analysis of 6 years of data shows that NO₂ column has seasonal variation with a maximum value during summer. It is also found that during the period when sun does not set, the NO₂ column exhibits a diurnal variation, with a peak around noon and lower values in the morning and afternoon hours. Using a simple steady-state chemical reaction scheme, an attempt has been made to explain these features.     

SCIAMACHY limb measurements of NO2, BrO and OClO. Retrieval of vertical profiles: Algorithm,first results,sensitivity and comparison studies

The Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) measures scattered sun light also in limb viewing mode (i.e. tangential to Earth’s surface and its atmosphere), which allows determining vertical profiles of atmospheric trace gases. First results on the retrieval of NO₂, BrO and OClO profiles from the SCIAMACHY Limb measurements are presented and compared to independent satellite and balloon borne observations.     

Chlorella vulgaris culture as a regulator of CO2 in a bioregenerative life support system

It is the primary task for a bioregenerative life support system (BLSS) to maintain the stable concentrations of CO₂ and O₂. However, these concentrations could fluctuate based on various factors, such as the imbalance between respiration/assimilation quotients of the heterotrophic and autotrophic components. They can even be out of balance through catastrophic failure of higher plants in the emergency conditions. In this study, the feasibility of using unicellular Chlorella vulgaris of typically rapid growth as both “compensatory system” and “regulator” to control the balance of CO₂ and O₂ was analyzed in a closed ecosystem. For this purpose, a small closed ecosystem called integrative experimental system (IES) was established in our laboratory where we have been conducting multi-biological life support system experiments (MLSSE). The IES consists of a closed integrative cultivating system (CICS) and a plate photo-bioreactor. Four volunteers participated in the study for gas exchange by periodical breathing through a tube connected with the CICS. The plate photo-bioreactor was used to cultivate C. vulgaris. Results showed that the culture of C. vulgaris could be used in a situation of catastrophic failure of higher plant under the emergencies. And the productivity could recover itself to the original state in 3 to 5 days to protect the system till the higher plant was renewed. Besides, C. vulgaris could grow well and the productivity could be affected by the light intensity which could help to keep the balance of CO₂ and O₂ in the IES efficiently. Thus, C. vulgaris could be included in the design of a BLSS as a “compensatory system” in the emergency contingency and a “regulator” during the normal maintenance.     

Influence of the interaction between light intensity and CO2 concentration on productivity and quality of spinach (Spinacia oleracea L.) grown in fully controlled environment

The effects of the factorial combination of two light intensities (200 and 800 μmol m⁻² s⁻¹) and two CO₂ concentrations (360 and 800 ppm) were studied on the productivity and nutritional quality of spinach (Spinacia oleracea L.) grown under controlled environment. After 6 weeks within a growth chamber, spinach plants were sampled and analyzed for productivity and quality. There were no statistically significant interactions between the effects of light and CO₂ for all of the variables studied, except for the nitrate and oxalic acid content of the leaves. High light and high CO₂ independently one from the other, promoted spinach productivity, and the accumulation of ascorbic acid, while their interactive effect limited the accumulation of nitrate and oxalic acid in the spinach leaves. The results highlight the importance of considering the effects of the interaction among environmental variables on maximizing production and the nutritional quality of the food when cultivating and modeling the plant response in controlled environment systems such as for bioregenerative life support.