Imprint of the Atlantic Multidecadal Oscillation on Tree-Ring Widths in Northeastern Asia since 1568

We present a new tree-ring reconstruction of the Atlantic Multidecadal Oscillation (AMO) spanning 1568–2007 CE from northeast Asia. Comparison of the instrumental AMO index, an existing tree-ring based AMO reconstruction, and this new record show strongly similar annual to multidecadal patterns of variation over the last 440 years. Warm phases of the AMO are related to increases in growth of Scots pine trees and moisture availability in northeast China and central eastern Siberia. Multi-tape method (MTM) and cross-wavelet analyses indicate that robust multidecadal (∼64–128 years) variability is present throughout the new proxy record. Our results have important implications concerning the influence of North Atlantic sea surface temperatures on East Asian climate, and provide support for the possibility of an AMO signature on global multidecadal climate variability

Analysis of the Accuracy of Beidou Combined Orbit Determination Enhanced by LEO and ISL

In order to improve the precision of BeiDou orbit determination under the conditions of regional ground monitoring station and make good use of increasingly rich on-board data and upcoming ISL technology, a method of BeiDou precision orbit determination is proposed which combines the use of ground monitoring stations data, low earth orbit satellite(LEOs) data and Inter-Satellite Link(ISL) data. The effects of assisting data of LEOs and ISL on the precision orbit determination of navigation satellite are discussed. Simulation analysis is carried out mainly from the number of LEOs, orbit slot configuration and ISL. The results show that the orbit precision of BeiDou will greatly improve about 73% with a small number of LEOs, while improvement of clock bias is not remarkable; the uniform orbit slot configuration of the same number of LEOs has a modest effect on the accuracy of combined orbit determination; compared with LEOs, the increase of ISL will significantly improve the accuracy of orbit determination with a higher efficiency

The Preliminary Result and Analysis for BD Orbit Determination with Inter-satellite Link Data

The experimental satellite of BD navigation system has assembled inter-satellite link (ISL) payloads and has obtained the real ISL observation data. The paper presents the preprocessing method of ISL and the POD method and result for Ka only observation and the combination Ka observation with L-band. It's showed that:the radial orbit error is less than 0.5 m with Ka only observation; the radial orbit error is less than 0.3 m with the observation by combining the Ka ISL with L-band data which has improved the orbit accuracy remarkably in contrast to L-band only data; the accuracy of calibrating device delay is better than 0.1 m

Cross correlation between the tree-ring record from northeast Asia and Gray et al. (2004) AMO reconstruction.

<p>Blue horizontal line represents a 95% significance level tested by Pearson correlation analysis.</p

Site information and general statistics of six Scots pine tree-ring chronologies in northeast Asia.

<p>Notes: MS-Mean sensitivity; SD-Standard deviation; AC1-Autocorrelation order 1; MC-Mean correlation; SNR-Signal-to-noise ratio; EPS-Expressed population signal; VFE-Variance in first eigenvector.</p

Multi-taper method spectrums for this proxy series from 1564–2007 (A) and the tree-ring AMO reconstruction from Atlantic rim [<b>20</b>] (B).

<p>Significance was tested at three levels (99%, 95% and 90%) against a red-noise background. Digital values are the significant periods at 99% confidence level.</p

Correlation coefficients of monthly AMO index and six tree-ring chronologies (1856–2007).

<p>Notes: Bolded values for significance at the 95% confidence level as tested by Pearson correlation.</p

Comparison of PDSI for the warm and cold AMO phases at six nearby sampling sites.

<p>Comparison of PDSI for the warm and cold AMO phases at six nearby sampling sites.</p