The time series of the earth’s rotation rate, eastern equatorial Pacific sea surface temperature (Tss), sea level pressure (Psl) and atmospheric angular momentum (Maa) during 1976 -1989 are used to study the relation...The time series of the earth’s rotation rate, eastern equatorial Pacific sea surface temperature (Tss), sea level pressure (Psl) and atmospheric angular momentum (Maa) during 1976 -1989 are used to study the relation between atmosphere-earth angular momentum exchange and ENSO cycle. The result shows that (i) there are synergetic relationships among the variations of solid earth’s rotation, eastern equatorial Pacific T,, Psl, different latitude zonal Maa and global Maa; (ii) local atmosphere-ocean interaction over low-latitude area can form ENSO-like cycle through Hadley circulation; (iii) the solid earth and global atmosphere-ocean interaction can form some aperiodic behavior and asynchronous oscillations by mountain torque and earth spin anomalous friction torque acting on each component of solid earth-ocean-atmosphere system; and (iv) actual ENSO cycle is a phenomenon reflecting in Pacific basin through interaction among solid earth, global ocean and the atmosphere.展开更多
The atmospheric angular momentum (AAM) functions in terms of contribution to polar wobble and length of day change, are calculated from the output data of GSM9603 global circulation model (GCM) of Japan Meteorological...The atmospheric angular momentum (AAM) functions in terms of contribution to polar wobble and length of day change, are calculated from the output data of GSM9603 global circulation model (GCM) of Japan Meteorological Agency (JMA), from the reanalysis data of the National Centers for the Environmental Prediction (NCEP)/National Center for Atmospheric Research (NCAR), and from the operational objective analysis data of JMA, respectively. The comparison shows that during the period from 1985 to 1995, the values of the pressure terms in the equatorial components of AAM functions calculated from three data sets agree with each other better along 90°E longitude than along Greenwich meridian direction. The axial component of relative AAM function estimated from GSM 9603 agrees well with those from the other two data sets in terms of seasonal variations with the moderate amplitudes, but not so well with the composite axial component of relative AAM functions estimated from 23 GCM models anticipating in the first phase of AMIP. In addition, its interannual variation from 1979 to 1996 shows the main characteristics of ENSO evolution, just as does the axial component of relative AAM function estimated from NCEP reanalysis data except for the period of anomalous ENSO from 1991 to 1993.展开更多
Earth＇s variable rotation is mainly produced by the variability of the AAM（atmospheric angular momentum）. In particular, the axial AAM component X_3, which undergoes especially strong variations,induces changes in ...Earth＇s variable rotation is mainly produced by the variability of the AAM（atmospheric angular momentum）. In particular, the axial AAM component X_3, which undergoes especially strong variations,induces changes in the Earth＇s rotation rate. In this study we analysed maps of regional input into the effective axial AAM from 1948 through 2011 from NCEP/NCAR reanalysis. Global zonal circulation patterns related to the LOD（length of day） were described. We applied MSSA（Multichannel Singular Spectrum Analysis） jointly to the mass and motion components of AAM, which allowed us to extract annual, semiannual, 4-mo nth, quasi-biennial, 5-year, and low-frequency oscillations. PCs（Principal components） strongly related to ENSO（El Nino southern oscillation） were released. They can be used to study ENSO-induced changes in pressure and wind fields and their coupling to LOD. The PCs describing the trends have captured slow atmospheric circulation changes possibly related to climate variability.展开更多
基金Project supported by the Postdoctoral Program Foundation of China and the National Science Foundation of China.
文摘The time series of the earth’s rotation rate, eastern equatorial Pacific sea surface temperature (Tss), sea level pressure (Psl) and atmospheric angular momentum (Maa) during 1976 -1989 are used to study the relation between atmosphere-earth angular momentum exchange and ENSO cycle. The result shows that (i) there are synergetic relationships among the variations of solid earth’s rotation, eastern equatorial Pacific T,, Psl, different latitude zonal Maa and global Maa; (ii) local atmosphere-ocean interaction over low-latitude area can form ENSO-like cycle through Hadley circulation; (iii) the solid earth and global atmosphere-ocean interaction can form some aperiodic behavior and asynchronous oscillations by mountain torque and earth spin anomalous friction torque acting on each component of solid earth-ocean-atmosphere system; and (iv) actual ENSO cycle is a phenomenon reflecting in Pacific basin through interaction among solid earth, global ocean and the atmosphere.
基金the National Natural Science Foundation of China under Grant Nos. 49904002 and 40074004, the National Climbing Project of China
文摘The atmospheric angular momentum (AAM) functions in terms of contribution to polar wobble and length of day change, are calculated from the output data of GSM9603 global circulation model (GCM) of Japan Meteorological Agency (JMA), from the reanalysis data of the National Centers for the Environmental Prediction (NCEP)/National Center for Atmospheric Research (NCAR), and from the operational objective analysis data of JMA, respectively. The comparison shows that during the period from 1985 to 1995, the values of the pressure terms in the equatorial components of AAM functions calculated from three data sets agree with each other better along 90°E longitude than along Greenwich meridian direction. The axial component of relative AAM function estimated from GSM 9603 agrees well with those from the other two data sets in terms of seasonal variations with the moderate amplitudes, but not so well with the composite axial component of relative AAM functions estimated from 23 GCM models anticipating in the first phase of AMIP. In addition, its interannual variation from 1979 to 1996 shows the main characteristics of ENSO evolution, just as does the axial component of relative AAM function estimated from NCEP reanalysis data except for the period of anomalous ENSO from 1991 to 1993.
基金supported by Russian Foundation for Basic Research grants No. 17-05-00989, No. 16-05-00753,NRU HSE and visiting grants positions at Paris observatory and Wuhan university for the first authorpartially supported by grants by NSF/IGFA Belmont Forum Project (Grant No. ICER-1342644)the Chinese Academy of Sciences/SAFEA International Partnership Program for Creative Research Teams(Grant No. KZZD-EW-TZ-05)
文摘Earth＇s variable rotation is mainly produced by the variability of the AAM（atmospheric angular momentum）. In particular, the axial AAM component X_3, which undergoes especially strong variations,induces changes in the Earth＇s rotation rate. In this study we analysed maps of regional input into the effective axial AAM from 1948 through 2011 from NCEP/NCAR reanalysis. Global zonal circulation patterns related to the LOD（length of day） were described. We applied MSSA（Multichannel Singular Spectrum Analysis） jointly to the mass and motion components of AAM, which allowed us to extract annual, semiannual, 4-mo nth, quasi-biennial, 5-year, and low-frequency oscillations. PCs（Principal components） strongly related to ENSO（El Nino southern oscillation） were released. They can be used to study ENSO-induced changes in pressure and wind fields and their coupling to LOD. The PCs describing the trends have captured slow atmospheric circulation changes possibly related to climate variability.
