True polar wander(TPW),or planetary reorientation,is the rotation of solid Earth(crust and mantle)about the liquid outer core in order to stabilize Earth’s rotation due to mass redistribution.Although TPW is well-doc...True polar wander(TPW),or planetary reorientation,is the rotation of solid Earth(crust and mantle)about the liquid outer core in order to stabilize Earth’s rotation due to mass redistribution.Although TPW is well-documented on Earth presently with satellites and for multiple planets and moons in the Solar System,the prevalence of TPW in Earth history remains contentious.Despite a history of controversy,both the physical plausibility of TPW on Earth and an empirical basis for it are now undisputed.Lingering resistance to the old idea likely stems from the fact that,like plate tectonics,TPW may influence much of the Earth system,thus acknowledging its existence requires rethinking how many different datasets are interpreted.This review summarizes the development of TPW as a concept and provides a framework for future research that no longer regards TPW like a ghost process that may or may not exist,but as an integral part of the Earth system that can relate shallow and deep processes that are otherwise only mysteriously linked.Specifically,we focus on the temporal regularity of large TPW,and discuss its relationship with the supercontinent-megacontinent cycle based on previous studies.We suggest the assembly of megacontinents has a close linkage to large TPW.Meanwhile,supercontinent tenure and breakup have a close linkage to fast TPW.The effects of TPW on sea level changes,paleoclimate,biological diversity,and other facets of the Earth system are presented and require interdisciplinary tests in the future.展开更多
In this study,the characteristics of environmental factors associated with typhoon Kongrey were examined using radiosonde,wind-profiler,radar,and Automated Surface Observing System(ASOS)data in Uljin,which is located ...In this study,the characteristics of environmental factors associated with typhoon Kongrey were examined using radiosonde,wind-profiler,radar,and Automated Surface Observing System(ASOS)data in Uljin,which is located the eastern coast of Korea.The radiosonde data were obtained from intensive observation between 1500 LST 5 to 0000 LST 7 October 2018.Environmental factors such as Total Precipitable Water(TPW)and Strom Relative Environmental Helicity(SREH)were selected to examine their relations to typhoon-accompanied precipitation.The TPW peak with 60.54 mm appeared at 1200 LST 6 October,which is 6 h after the peak of typhoon precipitation.It was found that the TPW variation is largely associated with the effect of water vapor supply from the typhoon with nearest proximity to Uljin at 1500 LST 6 October.Mean SREH,which indicates mechanical instability,was 761 m2 s-2 during the period in which typhoon precipitation occurred.These environments would provide a good condition for the development of super-cell storms,causing heavy precipitation associated with typhoon.In addition,it was found that the correlation coefficient between SREH and typhoon rainfall is 0.8(p-value=0.02).展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.42102243,41888101,41890833)the China Postdoctoral Science Foundation(Grant No.2022T150642)the Project of Chinese Academy of Sciences(Grant No.IGGCAS-201905).
文摘True polar wander(TPW),or planetary reorientation,is the rotation of solid Earth(crust and mantle)about the liquid outer core in order to stabilize Earth’s rotation due to mass redistribution.Although TPW is well-documented on Earth presently with satellites and for multiple planets and moons in the Solar System,the prevalence of TPW in Earth history remains contentious.Despite a history of controversy,both the physical plausibility of TPW on Earth and an empirical basis for it are now undisputed.Lingering resistance to the old idea likely stems from the fact that,like plate tectonics,TPW may influence much of the Earth system,thus acknowledging its existence requires rethinking how many different datasets are interpreted.This review summarizes the development of TPW as a concept and provides a framework for future research that no longer regards TPW like a ghost process that may or may not exist,but as an integral part of the Earth system that can relate shallow and deep processes that are otherwise only mysteriously linked.Specifically,we focus on the temporal regularity of large TPW,and discuss its relationship with the supercontinent-megacontinent cycle based on previous studies.We suggest the assembly of megacontinents has a close linkage to large TPW.Meanwhile,supercontinent tenure and breakup have a close linkage to fast TPW.The effects of TPW on sea level changes,paleoclimate,biological diversity,and other facets of the Earth system are presented and require interdisciplinary tests in the future.
基金funded by the Korea Meteorological Administration Research and Development Program“Development and Application of Monitoring,Analysis and Prediction Technology for High Impact Weathers”under Grant(KMA2018-00123)
文摘In this study,the characteristics of environmental factors associated with typhoon Kongrey were examined using radiosonde,wind-profiler,radar,and Automated Surface Observing System(ASOS)data in Uljin,which is located the eastern coast of Korea.The radiosonde data were obtained from intensive observation between 1500 LST 5 to 0000 LST 7 October 2018.Environmental factors such as Total Precipitable Water(TPW)and Strom Relative Environmental Helicity(SREH)were selected to examine their relations to typhoon-accompanied precipitation.The TPW peak with 60.54 mm appeared at 1200 LST 6 October,which is 6 h after the peak of typhoon precipitation.It was found that the TPW variation is largely associated with the effect of water vapor supply from the typhoon with nearest proximity to Uljin at 1500 LST 6 October.Mean SREH,which indicates mechanical instability,was 761 m2 s-2 during the period in which typhoon precipitation occurred.These environments would provide a good condition for the development of super-cell storms,causing heavy precipitation associated with typhoon.In addition,it was found that the correlation coefficient between SREH and typhoon rainfall is 0.8(p-value=0.02).
