AIUB-RL02: an improved time-series of monthly gravity fields from GRACE data
AIUB-RL02: an improved time-series of monthly gravity fields from GRACE data
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DOI：
10.1093/gji/ggw081
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发表时间：
2016-05
影响因子：
2.8
通讯作者：
U. Meyer;A. Jäggi;Yoomin Jean;G. Beutler
中科院分区：
文献类型：
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作者：
U. Meyer;A. Jäggi;Yoomin Jean;G. Beutler
新发布的每月重力模型AIUB-RL02来自GRACE GPS和k波段距离速率数据，基于参考框架IGb08的再处理卫星轨道。该版本符合IERS2010约定。相对于其前身aiubs - rl01的改进包括使用再处理（RL02） GRACE观测，新的大气和海洋分层产品（RL05），升级的海潮模式（EOT11A），以及浅海潮汐（导纳）插值。AIUB-RL02的随机参数化采用了日加速度计尺度因子，在C20的161 d周期和其他低次、低阶重力场系数下，显著降低了杂散信号。此外，每月重力模式中的噪声与太阳活动之间的相关性在新版本中大大降低。研究了新AIUB-RL02月重力场的信号和噪声含量，并根据其非长期和非季节变率推导了校准误差。海洋上空的短周期时变信号（主要代表噪声）相对于AIUB-RL01减少了50%。与官方的GFZ-RL05a和CSR-RL05月度模式相比，AIUB-RL02的突出之处在于其在高程度上的低噪声，这一事实来自于对选定流域的季节变化和极地地区的大规模趋势的估计。2003年3月至2014年3月期间，每月的AIUB-RL02重力模型有两个版本，分别为60度和90阶的球谐分辨率，可在国际全球地球模型中心（ICGEM）或ftp://ftp.unibe.ch/aiub/GRAVITY/GRACE上获得
The new release AIUB-RL02 of monthly gravity models from GRACE GPS and K-Band range-rate data is based on reprocessed satellite orbits referring to the reference frame IGb08. The release is consistent with the IERS2010 conventions. Improvements with respect to its predecessor AIUB-RL01 include the use of reprocessed (RL02) GRACE observations, new atmosphere and ocean dealiasing products (RL05), an upgraded ocean tide model (EOT11A), and the interpolation of shallow ocean tides (admittances). The stochastic parametrization of AIUB-RL02 was adapted to include daily accelerometer scale factors, which drastically reduces spurious signal at the 161 day period in C20 and at other low degree and order gravity field coefficients. Moreover, the correlation between the noise in the monthly gravity models and solar activity is considerably reduced in the new release. The signal and the noise content of the new AIUB-RL02 monthly gravity fields are studied and calibrated errors are derived from their non-secular and non-seasonal variability. The short-period time-variable signal over the oceans, mostly representing noise, is reduced by 50% with respect to AIUB-RL01. Compared to the official GFZ-RL05a and CSR-RL05 monthly models, the AIUB-RL02 stands out by its low noise at high degrees, a fact emerging from the estimation of seasonal variations for selected river basins and of mass trends in polar regions. Two versions of the monthly AIUB-RL02 gravity models, with spherical harmonics resolution of degree and order 60 and 90, respectively, are available for the time period from March 2003 to March 2014 at the International Center for Global Earth Models (ICGEM) or from ftp://ftp.unibe.ch/aiub/GRAVITY/GRACE