Subjects: Geosciences >> Space Physics submitted time 2016-05-13
Abstract： According to the databases of AP-8 and CRRESPRO proton radiation belt models, comparison between both models on the magnetic equator is carried out and reasons for their differences are presented. The model of proton radiation belt for the peak radiation region is developed by using the analytic function, which includes the submodel for relationship between the L value corresponding to the peak value of omni-directional proton differential flux (L_c) and the proton energy, and the submodel for relationship between the peak value of omni-directional proton differential flux J_(max) and the proton energy. Finally, the observation of energetic proton on the magnetic equator from RBSP A satellite's REPT telescope is used to compare with the results from AP-8 model,CRRESPRO model and the central radiation model. It is found that the values of omni-directional proton differential flux for 78.9, 102.6 and 208 MeV channels from RBSP A satellite are obviously larger than those from the three models, but the values of L_c from RBSP A satellite are very close to those from AP-8 model and the central radiation model, and RBSP satellite also observes the hidden secondary proton radiation belt presented by CRRESPRO Quiet model.
Peer Review Status:
Awaiting Review
Subjects: Geosciences >> Space Physics submitted time 2016-05-13
Abstract： After lots of experiments by using 19~27MeV differential energetic proton data based on the observation of SAMPEX from July of 1992 to June of 2004, it is found that the change of F_(10.7) and altitude have a great influence on the distribution of differential energetic proton flux in South Atlantic Anomaly. During the geomagnetic quiet time at 54025km altitude, the energetic proton flux in South Atlantic Anomaly decreased with the increasing of F_(10.7), and the variation trend was flat when F10.7 ≥ 115 sfu. It is found that there was obviously an anti-correlation between the absolute value of SYM-H and the differential energetic proton flux in South Atlantic Anomaly for storms with SYM-H ? -50, and also there was a lasting effect on differential energetic proton flux in South Atlantic Anomaly. In addition, the proton flux could be significantly reduced in South Atlantic Anomaly during the main phase, while the proton flux showed a substantial resuming trend in the recovery phase of geomagnetic storms.
Peer Review Status:Awaiting Review
Subjects: Geosciences >> Space Physics submitted time 2016-05-13
Abstract： FY-3A satellite can measure the radiation dose data from different directions during the missions from 2008 to 2012. In this paper, we describe total radiation dose from two directions, and dose rate variation with energetic particle flux. The result shows that different sections of the spacecraft receive different amounts of radiation dose, which is always consistent with space distribution of energetic particles. Absorbed dose rate changed greatly from several rad (Si).d~(-1) during quite time to even more than tenfold during disturbances. The increased high energy electrons in polar regions during disturbances are responsible for significant increase of radiation dose. At last, FY-3A radiation dose during the operational period of the mission is compared with the results calculated by SPENVIS. It is obvious that observation data is more realistic to reflect the real space radiation environment.
Peer Review Status:Awaiting Review
Subjects: Geosciences >> Space Physics submitted time 2016-05-03
Abstract： The radio occultation (RO) technique using signals from the global navigation satellite system, is widely used to observe the atmosphere for applications such as numerical weather prediction (NWP) and global climate monitoring. Since 1995, there have been turborogue sounder on board global positioning system/meteorology, black jack sounder on board challenging minisatellite payload and gravity recovery and climate experiment, IGOR sounder on board constellation observing system for meteorology, ionosphere and climate, GRAS on board meteorological operational, which have been recieving a large number of RO data, but their observed signals come only from global positioning system (GPS). These RO data have been wildly used in NWP and climate monitoring, however they cannot meet the requirements for high accuracy and real time atmosphere observation, in this case compatible RO sounder to obtain more RO observations is significant. Global navigation satellite system occultation sounder (GNOS) on board the fengyun3 C (FY3 C) satellite, which is the first Bei Dou system (BDS)/GPS compatible RO sounder in the world, was launched on 23 September 2013. Up to now, lots of RO observations have been obtained. In this study, the components of GNOS are introduced; one-day GNOS RO events and their global distribution are analyzed; compared with the GPS RO observations, the accuracy and consistency of BDS real-time positioning results and BDS RO products are analyzed. The preliminary results show that the BDS can enhance the number of RO events by 33.3%; the average deviation and standard deviation of BDS real time positioning results are 6 m and 7 m, respectively; the BDS/GPS difference standard deviation of refrectivity, temperature, humidity, pressure and ionospheric electron density are lower than 2%, 2 K, 1.5 g/kg, 2%, and 15.6%, respectively. The BDS observations/products are consistent with those of GPS, therefore BDS RO products can bring benefit to numerical wheather prediction and global chlimate change analysis.
Peer Review Status:Awaiting Review
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