Calculation of the extreme ultraviolet radiation of the earth’s plasmasphere

et al. 2013

JGR Space Physics

Self Cite

[1] The EUV imager on board the Chang'E-3 lunar lander will image the Earth's plasmasphere from a lunar perspective to focus on some of the open questions in plasmaspheric researches (i.e., global structures, erosion, and refilling of plasmasphere). In order to achieve the understanding of the plasmaspheric dynamics in relation to these EUV images in lunar perspective, the He + 30.4 nm emission intensities and global structures of the plasmasphere viewed from the moon are investigated using a dynamic global core plasma model embedded with TS07 magnetic field model and W05 electric field model. Two typical storms observed by the IMAGE EUV imager are systematically simulated from the perspectives of the moon. It is found from the simulations that the maximum emission intensity of the plasmasphere is~12.3 R which is greater than that detected from polar orbit, and the global shapes and temporal evolutions of large-scale plasmaspheric structures (plasmapause, shoulder, and plume) also have different patterns in moon-based simulated images. It is also shown that the plasmaspheric structures extracted from moon-based EUV images are in agreement with those from IMAGE EUV images. Systematic simulations demonstrate that specific latitudinal distribution of the plasmaspheric structures can only be imaged at specific positions in lunar orbit. It is expected that this investigation provides us with an overall understanding on moon-based EUV images and helps to identify the plasmaspheric structures and evolution patterns in future moon-based EUV imaging.

“…[] and He et al . []. Figures a–c are for the storm on 24 May 2000 and Figures d–f are for the storm on 26 June 2000.…”

Section: Imaging the Plasmasphere From The Moonmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Moon‐based EUV imaging of the Earth's Plasmasphere: Model simulations

Zhang

et al. 2013

JGR Space Physics

Self Cite

“…According to the characteristics of the density distribution of the plasmasphere, however, it can be greatly shrunk and the efficiency of the algorithm can be improved. Based on the DGCPM simulations [17] and satellite observations [3] , the maximum plasmaspheric density is less than 4000 cm −3 near the earth, and the minimum density is greater than 0.1 cm −3 in the trough region. So the overall plasmasphere density is between 0.1 and 4000.…”

Section: Real-coding and Search Spacementioning

confidence: 99%

Inversion of the Earth's Plasmaspheric Density Distribution from EUV Images with Genetic Algorithm

Zhang

Chinese J of Geophysics

et al. 2012

Self Cite

The principles for inversion of plasmaspheric He+ density from the extreme ultraviolet images of the Earth's plasmasphere with one‐dimensional genetic algorithm are introduced. The three‐dimensional problem is transformed into one‐dimensional case through flux tube approximation and dipole magnetic field approximation. With a weighted matrix, the extreme ultraviolet intensity integration equation is discretized into linear equation systems, then the one‐dimensional real‐coded genetic algorithm is used to inverse the equatorial plane plasmaspheric He+ density, and finally the three‐dimensional density is obtained by magnetic field line tracing. The density and intensity simulated by the dynamic global core plasma model are used as the primary input parameters, and the corresponding density distribution is determined through genetic iterations. The results show that the relative density error is less than 8% and the relative intensity error tends to be zero, which proves that our algorithm is effective and feasible. The result of this work will provide a basis for the inversion of the moon‐based EUV images in the Second Phase of Chinese Lunar Exploration Program.

“…Approximately 10-20 % of the plasmasphere's plasma particles are He + , which resonantly scatter EUV radiation at 30.4nm under the solar radiation (He et al 2010;Lemaire and Gringauz 1998;Li et al 2009). The extreme ultraviolet (EUV) detection can provide the He + distribution of the plasmasphere by detecting its emission at 30.4 nm.…”

Section: Introductionmentioning

confidence: 99%

“…Several years later, another EUV imager installed on the IMAGE satellite was launched by NASA, which provided the global images of the terrestrial plasmasphere with a spatial resolution of 0.1 R E every 10 min (Davis et al 2013;Keyser et al 2009;Sandel et al 2001). These images showed the temporal evaluation of the plasmaspheric dynamics and gave the electron density distribution (Fu et al 2010;He et al 2010;Sandel et al 2003). In the SELENE mission, the EUV sensor also observed the terrestrial plasmasphere from the perspective of the lunar orbit (Yoshika et al 2008(Yoshika et al , 2010.…”

Section: Introductionmentioning

confidence: 99%

Geocentric position preliminary detection from the extreme ultraviolet images of Chang’E-3

Ping

Wang

et al. 2015

Astrophys Space Sci

An Extreme ultraviolet (EUV) Camera was installed onboard the Chinese lunar surface landing mission, the Chang'E-3 lander, as a useful method to observe the Earth plasmasphere. This EUV optical payload obtained more than 600 moon-based Earth plasmasphere images since December 14, 2013. However, due to errors of unknown size and origin in the platform attitude control of the lander and in the EUV telescope pointing control during the mission operating periods, the geocentric coordinates in these EUV images are not fixed in the same position of CCD pixel. Before adequately calibrating, these positioning offsets will introduce extra errors into the analysis of the plasmaspheric structure. With only a little insufficient telemetry information, an effective calibrating method of circle-based differential algorithm is suggested and demonstrated, for automatically and precisely detecting the geocentric position in each EUV image of Chang'E-3 mission. In each EUV image, the tested method uses the outline of a circle as the basic unit to capture the contour for the bright region based on the spectral characteristic. Then, the center of the extracted circle is adopted as the geocentric position for the image. The preliminary analysis shows that this method can effectively detect the geocentric position being always consistent with the recognition result by the basic hand labor method. It is found that the radius of the circles varies from month to month from December, 2013 to May, 2014. The monthly averages of radius show relative notable positive correlation and negative correlation with the changes of both Zenith angle of the Earth at the landing area of Chang'E-3 lander, and B C. Zheng the Earth-moon distance, respectively. This method and results here will benefit the Chang'E-3 EUV study.