Interannual And Interdecadal Variability Of The Major Modes Of The Summer Northern Atmosphere Circulation

The leading modes of summer200hPa geopotential height over the northernHemisphere have been discussed in this paper and found that the anomaly patterns ofatmospheric circulation in the northern hemisphere summer there are two significantmain modal, the sum of the variance contribution of48.8%, where the first variancecontribution of the main mode of35.6percent, the second main mode is13.2%. Firstmain mode is consistent with warming modes, the time-series performance for asignificant upward trend, spatial distribution mainly reflects the consistent positive, theintensity center is located in the mid-latitude East too-North America-the NorthAtlantic along the we call the Western Hemisphere, Central hemisphere mode. Furtherdiscussion on the interannual and interdecadal variations of the modal high decadalcomponent of the first principal mode of spatial and temporal distribution of the NorthernHemisphere summer circulation, the time series of up to0.76. The spatial distribution ofthe correlation coefficient reached0.68. This indicates that the interdecadal componentmodal right hemisphere mode of Northern Hemisphere ring main modes played a majorcontribution.The second principal mode spatial distribution of the Northern Hemisphere summercirculation is mainly manifested as-low-latitude seesaw type distribution class AnnularMode, the center of its large value is mainly distributed in the Western Hemisphere,Western Europe-East Asia-Western Pacific area. The big value of its variancecontribution in the mid-latitudes. Modal time series show significant decadal andinter-annual variation. On decadal time scales, time series in the mid-1960s to the1970swas positive, while the mid-1970s to the mid-1990s as a negative area, then enter thepositive period. Further discussion of this mode state interannual and interdecadalvariations of the high temporal correlation of the decadal component of the secondprincipal mode of spatial and temporal distribution of the northern hemisphere summer circulation of the second dominant mode, the time series of up to0.61. The spatialdistribution of the correlation coefficient reached0.55. This indicates that theinterdecadal component modal right hemisphere mode of Northern Hemisphere ring mainmodes played a major contribution.Interdecadal time scale also exists corresponding to the two main modes. The modalvariance of57.2%, mainly in low-latitude interaction, the variance in the WesternHemisphere low and middle latitudes and the regional distribution of large values, aconsiderable value. The vertical results in the troposphere performance significantlybarotropic structure in the troposphere above the regional variation of performance out ofthe troposphere contrary. The center of the strong value of the same first-line in theWestern Hemisphere. The further results show that the modal variation of the rise inglobal temperatures closely related to the modal time series with the global warming timeseries correlation coefficient of0.92, and global surface temperature regression resultsalso show that global warming characteristics. This indicates that the dominant mode ofthe decadal state that reflects the characteristics of global warming. State main’s theoccasion of the second dominant mode is mainly reflected the changes in characteristicsof middle and high latitudes, the vertical structure in the high-latitude regions in theentire atmosphere, performance changes up and down the opposite characteristics, whilethe performance of the upper and lower in the low-latitude region of structures. Thecenter of its strong value in high-latitude region0-60E and120-180E the100hPa Centerand the60-120E500-1000hPa center where the center of three strong values in theEastern Hemisphere region. Further studies showed that closely related to decadalchanges in decadal modes AO and Arctic sea ice.Two dominant modal scale interannual variability of the Northern Hemisphereatmospheric circulation showed22.4%of the contribution of the first mode of the totalvariance accounted for13.3percent of the second mode, the first mode of performance isconsistent with changes in the northern hemisphere mode, the maximum variancecontribution percentage distribution at low latitudes, middle and high latitudes of theWestern Hemisphere there is a strong variance big value, the decay phase of the mode islargely the El Nino; the second mode is manifested in the mid-latitudes and low latitudes anti-the spatial characteristics of the phase oscillations, proposed by previouspredecessors CGT is a modal, its biggest percentage of variance is mainly distributed inthe vicinity of the equator and mid-latitude40N, mode mainly associated with La Ninadevelopment process linked.In addition, the study also found that the second mode of CGT decadal Features ofTransformation, since the late1970s, several remote center of the CGT are significantlyweakening and northward offset in the Atlantic-Nordic area, study the reason, the CGTmay be affected by the tropical monsoon rainfall abnormal heating of the atmosphere, inparticular, play a major contribution of the Indian monsoon precipitation on the globalcharacteristics of the CGT, the monsoon rainfall in Africa, the Americas and the WesternPacific main strength of the center of the game to CGT changework; a major cause of theCGT interdecadal transition may be related to the transition related to the decadalENSO-monsoon relationship.