The bimodal magnetosphere and ring current, radiation belt, and tail transducers

It has generally been assumed that a geomagnetic storm is entirely driven by external forces—e.g., solar wind E_y = V_x × B_z, V_x, V²_x (where the components of the electric field, E, the magnetic field, B, and velocity, V, are given in GSE coordinates)—which would imply that particle injections in the ring current (RC) or outer radiation belts should be highly correlated. However the data from ISTP are showing that the magnetosphere can have at least two very different responses to the same solar wind (SW) conditions: a classic, enhanced RC with Dst response, or a 1000-fold increase in the outer radiation belt MeV electrons (ORBE). August 29, October 14 and 23, 1996 are examples of Dst storms, whereas April 15, 1996 and January 10, 1997 are examples of MeV storms. It is this second response that is so deadly to some geosynchronous spacecraft, whereas geomagnetic storms are categorized by the first response. Neither of these appear to be correlated to the SW conditions driving substorms. Why should the SW energy appear in the radiation belts or the ring current independently? We hypothesize that the RC couples to the electric power available (E_y), the ORBE couple to the mechanical power available (V_x), and the Tail couples to the magnetic energy (B_z) available in the SW. The transducer for RC may be subauroral parallel potentials, the transducer for ORBE may be the cusp, while the Tail substorm transducer is yet a third independent mechanism for extracting SW energy. Evidence for this theory comes from the novel POLAR satellite that traverses the cusp, the plasmasheet and the radiation belts.     

Is the Sun a Sun-Like Star?

Various observable properties of the Sun are compared with those of solar-type stars. It is concluded that the Sun, to a remarkable degree, is “solar-type”. As regards its particular mass and age, and probably its non-binarity, “anthropic” explanations may seem in place. The possible tendency for the Sun, as compared with similar stars, to be somewhat rich in iron relative to other elements needs further exploration. This is also true concerning its presently small micro-variability amplitude. This revised version was published online in June 2006 with corrections to the Cover Date.     

Transport of ions in presence of induced electric field and electrostatic turbulence: Source of ions injected into ring current

The transport of ions from the polar ionosphere to the inner magnetosphere during stormtime conditions has been computed using a Monte Carlo diffusion code. The effect of the electrostatic turbulence assumed to be present during the substorm expansion phase was simulated by a process that accelerated the ions stochastically perpendicular to the magnetic field with a diffusion coefficient proportional to the energization rate of the ions by the induced electric field. This diffusion process was continued as the ions were convected from the plasma sheet boundary layer to the double-spiral injection boundary. Inward of the injection boundary, the ions were convected adiabatically. By using as input an O⁺ flux of 2.8 × 10⁸ cm^?2 s^?1 (w > 10 eV) and an H⁺ flux of 5.5 × 10⁸ cm^?2 s^?1 (w > .63 eV), the computed distribution functions of the ions in the ring current were found to be in good agreement, over a wide range in L (4 to 8), with measurements made with the ISEE-1 satellite during a storm. This O⁺ flux and a large part of the H⁺ flux are consistent with the DE satellite measurements of the polar ionospheric outflow during disturbed times.     

Oxygen line mapping of SN 1006 with Suzaku

SN 1006 is one of the supernova remnants (SNRs) with relatively low-temperature electrons, considering the young age of just 1000 years. We carried out SN 1006 mapping observations with the X-ray Imaging Spectrometers (XIS) and the Hard X-ray Detector (HXD) onboard Suzaku, the fifth Japanese X-ray satellite. Thanks to the excellent spectral resolution of XIS in the soft X-ray band, H-like and He-like oxygen emission lines were clearly detected, and we could make a map of the line intensity, and as well as a flux and the photon index of nonthermal component. We found that these parameters have spatial dependences from region to region in the SNR; the north region is bright in nonthermal, while dim in thermal; the east region is bright in both nonthermal and thermal; the inner region shows dim nonthermal and bright thermal emission. The photon index is the smallest in the north region.     

Tidal associated temperature disturbances observed at the middle atmosphere (30–65 km) by a Rayleigh lidar at 23°S

A lidar has been operated in São José dos Campos, Brazil (23.2°S, 45.8°W) since 1972, mainly dedicated to the study of mesospheric sodium at the 589 nm resonant line. The molecular Rayleigh scattering can also be used provided we limit the height to ∼75 km where the sodium scattering begins. Nevertheless, the weak signal obtained only permits the determination of density and temperature profiles by accumulating a large number of shots giving only nocturnal average profiles. Temporal variations in density and temperature on the scale of hours can however, be obtained by performing a superposed epoch analysis for a given time interval and covering a period of several days. In this way we obtained hourly mean profiles grouped by months, seasons and overall, with data acquired from 1993 to 2004. The difference between the hourly temperatures and the nocturnal means shows for some months, with enough data coverage, downward propagating structures that apparently have tidal origin. The seasonal averages show a recurrent feature with high temperatures before and low temperatures after midnight above 50 km. Some similarity is found with the GSWM model, but the observed temperature amplitudes are twice of that for the model.     

The Flight 2000 avionics suite: paving the way to free flight

The FAA's Flight 2000 project is an innovative initiative to implement and validate selected operational improvements leading to Free Flight. It integrates new avionics, new ground systems, new procedures, avionics certification, and operational approval. Approximately 2000 aircraft operating in Alaska, Hawaii, and Oceanic airspace will be equipped with new capabilities enabling benefits such as improved situational awareness, increased flexibility, and efficiency gains. By developing and fielding these operational improvements, the actual benefits of new procedures and capabilities will be validated and risks associated with national implementation will be reduced     

Interpretation of data on laser sensing of aerosol atmosphere from space

A single-frequency lidar, using aerosol scattering as an informative component, is the simplest and reliable facility for remote sensing of the atmosphere. The information on vertical distribution of atmospheric aerosol which can be obtained using such a lidar is necessary for investigating the physics of atmospheric processes and forecast of optical state of the atmosphere. At the same time, the interpretation of data on single-frequency sounding is associated with some difficulties of fundamental character, mainly due to insufficient software of the experiment. Under such conditions the problems of optimal processing of lidar returns aiming at extracting the useful information on aerosol are of great importance, especially if one takes into account the hindering effects of atmospheric background and optical noises. This paper presents a statistical approach to this problem, and the possibilities of single-frequency sounding from space are analyzed.     

Using sunshine for elementary space science education: A model for IHY scientist–teacher partnerships

An elementary science education professional development partnership between Culver City Unified School District teachers and UCLA has been formed. The project was designed to assist teachers to comfortably present introductory space science concepts, to support them in their efforts, and to aid them in encouraging their students to develop inquiry skills related to space sciences. The project encourages teacher use of observational science techniques in their classrooms, the use of NASA solar mission images and enhanced use of astronomical observation to facilitate discovery learning. The integrated approach of the project has fostered collegial learning activities among the participating teachers and offered them opportunities for continued renewal and professional development of teacher competencies in astronomy and space science. The activities used in the classroom were developed by others, classroom tested, and specifically address National Science Education and California Science Content Standards. These activities have been sustained through on-going collaboration between the scientist and the teachers, a summer Research Experience for Teachers program, and on-going, grade-specific, district-sponsored workshops. Assessment of the value of the program is done by the school district and is used to continuously improve each workshop and program component. Culver City (California) Unified School District is a small urban school district located on the Westside of Los Angeles. This paper describes the program and the plans for incorporating IHY-themed science into the classroom.     

Development of an improved ground-based prototype of space plant-growing facility

Based on a formerly developed ground-based prototype of space plant-growing facility, the development of its improved prototype has been finished, so as to make its operating principle better adapt to the space microgravity environment. According to the developing experience of its first generation prototype and detailed demonstration and design of technique plan, its blueprint design and machining of related components, whole facility installment, debugging and trial operations were all done gradually. Its growing chamber contains a volume of about 0.5 m³ and a growing area of approximate 0.5 m²; the atmospheric environmental parameters in the growing chamber and water content in the growing media were controlled totally and effectively; lighting source is a combination of both red and blue light emitting diodes (LED). The following demonstrating results showed that the entire system design of the prototype is reasonable and its operating principle can nearly meet the requirements of space microgravity environment. Therefore, our plant-growing technique in space was advanced further, which laid an important foundation for next development of the space plant-growing facility and plant-cultivating experimental research in space microgravity condition.     

Hypothesis-test-based landcover change detection using multi-temporal satellite images – A comparative study

Remote sensing images and technologies have been widely applied to environmental monitoring, in particular landuse/landcover classification and change detection. However, the uncertainties involved in such applications have not been fully addressed. In this paper two hypothesis-test-based change detection methods, namely the bivariate joint distribution method and the conditional distribution method, are proposed to tackle the uncertainties in change detection by making decisions based on the desired level of significance. Both methods require a data set of class-dependent no-change pixels to form the basis for class-dependent hypothesis test. Using an exemplar study area in central Taiwan, performance of the proposed methods are shown to be significantly superior to two other commonly applied methods (the post-classification comparison and the image differencing methods) in terms of the overall change detection accuracies. The conditional distribution method takes into consideration the correlation between digital numbers of the pre- and post-images and the effect of the known pre-image digital number on the range of the post-image digital number, and therefore yields the highest change detection accuracy. It is also demonstrated that the class-dependent change detection is crucial for accurate landuse/landcover change detection.