基于卫星加速度数据反演的热层大气密度与NRLMSISE-00模式结果的比较研究

Comparison Between the CHAMP/STAR Derived Thermospheric Density and the NRLMSISE-00 Model

利用CHAMP/STAR加速度数据反演的热层大气密度与NRLMSISE-00模式反演的热层大气密度进行比较,结果表明,热层大气密度在春秋季期间高于冬夏季,并且太阳活动高年比低年更加显著;日照面和阴影区大气密度的比值在低纬地区由太阳活动高年的4下降到太阳活动低年的2左右,中纬地区大约由3变化到1.5,高纬地区变化较小;NRLMSISE-00模式能够较好地模拟热层大气密度的变化趋势,但是磁暴期间模式精度较差.统计结果表明,模式整体比反演结果偏高,2002—2008年相对偏差分别为16.512%,20.004%,18.915%.18.245%,25.161%,33.261%和41.980%;NRLMSISE-00模式在高纬地区的相对偏差为27.337%,高于中低纬地区的24 047%;模式在中等太阳活动水平相对偏差较为稳定,基本在15%左右.

The derived thermospheric density from the CHAMP/STAR accelerometer observations has been compared with NRLMSISE-00 model, and the major results can be summarized as follows. The thermospheric density is lager in Equinoxes than Solstices, and this is much more notable in high solar level. The ratio between dayside and nightside thermospheric density in low-latitude during the high solar level is about 4 but reduces to 2 in low solar activity, and 3 to 1.5 in middlelatitude. NRLMSISE-00 model can capture the main character of the neutral density, but has lowerperformance during strong geomagnetic activities. This model overestimates density derived from satellite, and the relative errors are 16.512%, 20.004%, 18.915%, 18.245%, 25.161%, 33.261% and 41.980% from 2002 to 2008. The relative error in high latitude is 27.337%, but low-middle latitude is 24.047%. The model has a better performance under the conditions of middle solar activity level, and the relative error is about 15%.