Space weather in Japan

In Japan, Communications Research Laboratory engages in operational space environment information services as National Forecasting Center and Regional Warning Center of ISES. Data from local observations and data collected via internet from domestic and foreign institutes are used for the daily operational forecast. Fundamental research on space weather issues has been carried out at several institutes and universities, including STE Laboratory and NASDA. In this presentation, an overview of current space weather forecast operations and a system for information outreach in Japan will be presented. Current and future observation programs from ground-base and space will be also briefly reviewed.     

Results of cosmic radiation dose field measurements aboard the “Salyut-6” orbital station

During the 3rd main expedition on board the “Salyut-6” orbital station in 1979 the integral characteristics of cosmic radiation were measured in various positions inside the manned modules (experiment “Integral”). Measurements were performed with thermoluminescent dosimeters, photographic films and solid state plastic detectors supplied for the experiment by specialists of the USSR, Bulgaria, Hungary, GDR and Romania. The dose gradient inside the manned modules of the station amounted to 70 % for long intervals of time. During the experimental period the dose rate inside the station was 15 to 30 mrad per day. The mean flux of particles with z 6 and LET 200 keV/μm was found to be 0.22 cm⁻² day⁻¹.     

Optical search for gamma-ray bursts

The preliminary results from optical search for light pulses associated with gamma ray bursts by means of the Czechoslovak Fireball Network plate collection at the Ondřejov observatory are given. Optical monitoring represents more than 7700 hours, but no real optical counterpart was found. Problems associated with the optical search for gamma ray bursts are discussed.     

Energy requirement of magnetic reconnection during magnetospheric substorms

Methods are discussed to estimate energy transfer from the solar wind to the magnetosphere during substorm growth phases. Observational and modeling constraints are then used to assess quantitatively the total amount of energy stored in the magnetotail. The major avenues of energy dissipation are examined and the energy that is released in the form of plasma sheet heating, ionospheric Joule heating, plasmoids, and energetic particle production during substorms is assessed. Energy sources are evaluated to drive substorm evolution in a particularly well-observed case: stored tail-lobe energy is sufficient to drive observed substorm dissipation processes (by large margins). On the other hand, energy in the closed field lines of the plasma sheet is insufficient to supply the substorm energy. Hence, magnetic reconnection is required on energy grounds during well-observed substorm cases.     

Microwave imaging observation of an electron stream in a solar flare

We report a Nobeyama Radioheliograph (NoRH) microwave observation of a propagating feature of non thermal emission in a solar flare. The flare had a very extended source well resolved by NoRH. In the rising phase of the microwave burst, a non-thermal gyrosynchrotron source was observed by the high-rate (10 images per second) observations to propagate from one end of the loop to the other with a speed of 9 × 10⁴ km s⁻¹. We interpret this non-thermal propagating source is emitted from streaming electrons.     

Heavy ion observations by MARIE in cruise phase and Mars orbit

The charged particle spectrum for nuclei from protons to neon, (charge Z=10) was observed during the cruise phase and orbit around Mars by the MARIE charged particle spectrometer on the Odyssey spacecraft. The cruise data were taken between April 23, 2001 and mid-August 2001. The Mars orbit data were taken March 5, 2002 through May 2002 and are scheduled to continue until August 2004. Charge peaks are clearly separated for charges up to Z=10. Especially prominent are the carbon and oxygen peaks, with boron and nitrogen also clearly visible. Although heavy ions are much less abundant than protons in the cosmic ray environment, it is important to determine their abundances because their ionization energy losses (proportional to Z²) are far more dangerous to humans and to instruments. Thus the higher charged nuclei make a significant contribution to dose and dose equivalent received in space. Results of the charged particle spectrum measurements will be reported.     

On the sudden disappearances of solar filamentsand their relationship with coronal mass ejections

Sudden disappearances of prominences/filaments were identified from the Prairie View Solar Observatory H imagesand Meudon Observatory spectroheliograms for the period January 1, 2000 to March 31, 2000. Three classes of disappearances were considered for the purpose of this study: eruptive, quasi-eruptive and vanishing filaments. The H events were compared with CME data from LASCO C2 and C3 coronographs aboard SOHO. Our study shows that the eruptive events are strongly associated with CMEs while the other types are not.     

导航星座整网自主定轨的动力学短弧段伪逆平差法

针对传统静态自由网平差进行自主定轨存在的秩亏问题,提出一种卫星动力学短弧段定轨和自由网伪逆平差理论相结合的自主定轨算法。该算法以导航星座星间链路(ISL)双向测距为基础,利用伪逆平差法,解决整网位置解算起算数据不足带来的秩亏问题;同时,利用轨道动力学建立不同历元之间状态转移关系,解决单历元平差无法对速度分量进行有效估计的问题。仿真结果表明,自主运行90天,平均用户测距精度（URE）小于1 m（2σ）,优于导航星座自主运行指标要求,验证了本文算法的有效性。     

The Emergence of Life

The Rosetta observations have greatly advanced our knowledge of the cometary nucleus and its immediate environment. However, constraints on the mission (both planned and unplanned), the only partially successful Philae lander, and other instrumental issues have inevitably resulted in open questions. Surprising results from the many successful Rosetta observations have also opened new questions, unimagined when Rosetta was first planned. We discuss these and introduce several mission concepts that might address these issues. It is apparent that a sample return mission as originally conceived in the 1980s during the genesis of Rosetta would provide many answers but it is arguable whether it is technically feasible even with today’s technology and knowledge. Less ambitious mission concepts are described to address the suggested main outstanding scientific goals.

     

The GOES-16 Spacecraft Science Magnetometer

Space Science Reviews - The Modular Multispectral Imaging Array (MMIA) is a suite of optical sensors mounted on an external platform of the European Space Agency’s Columbus Module on the...