The average upper mantle P wave velocity structure and lateral heterogeneity in the northern part of China and Mongolia are investigated by waveform inversion of broadband body waveform data recorded by CDSN and digit...The average upper mantle P wave velocity structure and lateral heterogeneity in the northern part of China and Mongolia are investigated by waveform inversion of broadband body waveform data recorded by CDSN and digital stations around China. The average model has a low P wave velocity lid (about 7.8～8.0 km·s -1 ) with thickness about 60 km, and two discontinuities with velocity jumps of 0.29 km·s -1 and 0.55 km·s -1 at depth of 410 km and 665 km respectively. In the Jungger basin, the P wave velocity of uppermost mantle is about 7.7 km·s -1 . The lid thickness (90～100 km) and velocity gradient (average gradient is greater than 0.005 5/s) are large. At the depth of 140 km the P wave velocity reaches to 8.2 km·s -1 . Near in Baikal, the lid is about 30 km thick with average P wave velocity of 8.00～8.05 km·s -1 .展开更多
In this study, interannual variability of summer rainfall over the northern part of China （NPC） and associated circulation patterns were investigated by using long-term （1961-2013） observational and reanalysis dat...In this study, interannual variability of summer rainfall over the northern part of China （NPC） and associated circulation patterns were investigated by using long-term （1961-2013） observational and reanalysis data. Two important NPC rainfall modes were identified by empirical orthogoual function analysis： the first is characterized by an almost uniformly distributed rainfall anomaly over most parts of the NPC, while the second shows rainfall variability in Northeast China （NEC） and its out-of-phase relationship with that in North China （NC） and the northern part of Northwest China. The results also suggest that the NPC summer rainfall anomalies are also closely associated with those in some other parts of China. It is revealed that the circumglobal teleconnection pattern associated with the anomalous Indian summer monsoon （ISM） and the Polar/Eurasia （PEA） pattern work in concert to constitute the typical circulation pattern of the first rainfall mode. The cooperative engagement of the anomalous ISM circulation and the PEA pattern is fundamental in transporting water vapor to the NPC. The study emphasizes that the PEA pattern is essential for the water vapor transport to the NPC through the anomalous midlatitude westerly. In the second NPC rainfall mode, the typical circulation pattern is characterized by the anomalous surface Okhotsk high and the attendant lower tropospheric circulation anomaly over NEC. The circulation anomaly over NEC leads to a redistribution of water vapor fluxes over the NPC and constitutes an out-of-phase relationship between the rainfall anomalies over NEC and NC.展开更多
文摘The average upper mantle P wave velocity structure and lateral heterogeneity in the northern part of China and Mongolia are investigated by waveform inversion of broadband body waveform data recorded by CDSN and digital stations around China. The average model has a low P wave velocity lid (about 7.8～8.0 km·s -1 ) with thickness about 60 km, and two discontinuities with velocity jumps of 0.29 km·s -1 and 0.55 km·s -1 at depth of 410 km and 665 km respectively. In the Jungger basin, the P wave velocity of uppermost mantle is about 7.7 km·s -1 . The lid thickness (90～100 km) and velocity gradient (average gradient is greater than 0.005 5/s) are large. At the depth of 140 km the P wave velocity reaches to 8.2 km·s -1 . Near in Baikal, the lid is about 30 km thick with average P wave velocity of 8.00～8.05 km·s -1 .
基金Supported by the National Natural Science Foundation of China(41375064 and 41630424)National Science and Technology Support Program of China(2015BAC03B03)
文摘In this study, interannual variability of summer rainfall over the northern part of China （NPC） and associated circulation patterns were investigated by using long-term （1961-2013） observational and reanalysis data. Two important NPC rainfall modes were identified by empirical orthogoual function analysis： the first is characterized by an almost uniformly distributed rainfall anomaly over most parts of the NPC, while the second shows rainfall variability in Northeast China （NEC） and its out-of-phase relationship with that in North China （NC） and the northern part of Northwest China. The results also suggest that the NPC summer rainfall anomalies are also closely associated with those in some other parts of China. It is revealed that the circumglobal teleconnection pattern associated with the anomalous Indian summer monsoon （ISM） and the Polar/Eurasia （PEA） pattern work in concert to constitute the typical circulation pattern of the first rainfall mode. The cooperative engagement of the anomalous ISM circulation and the PEA pattern is fundamental in transporting water vapor to the NPC. The study emphasizes that the PEA pattern is essential for the water vapor transport to the NPC through the anomalous midlatitude westerly. In the second NPC rainfall mode, the typical circulation pattern is characterized by the anomalous surface Okhotsk high and the attendant lower tropospheric circulation anomaly over NEC. The circulation anomaly over NEC leads to a redistribution of water vapor fluxes over the NPC and constitutes an out-of-phase relationship between the rainfall anomalies over NEC and NC.
