In this study,we used the ECMWF ERA-Interim reanalysis datasets and NOAA/NCDC station datasets to construct a new coldness intensity(CI) index based on the amplitude of daily anomalously cold temperatures in winter,which was different from the sub-seasonal temperature variance.Next we analyzed the abnormal changes of atmospheric circulation,shortwave and longwave radiation and temperature advection,so as to reveal the change characteristics of winter cold events,as well as the causes of recent increasing winter cold events in the mid-latitudes of Eurasia during the period of 1998-2012.The results showed the following:1) Cold winters and events were frequently found in the mid-latitudes of Eurasia over the past 16 years,especially in northwestern Europe,Siberia and East Asia.The linear trend of winter coldness intensity was consistently clearly enhanced in these areas,but the sub-seasonal variance of winter temperature did not exhibit a clear intensified linear trend.The consistency of coldness intensity and cold events showed that the coldness intensity may indicate the recent intensification of cold events.2) Since 1998,an intensification and northwest expansion of the Siberian High associated with enhancing northerly wind and weakening westerly wind in the mid-latitudes of Eurasia was observed,which led to negative winter temperature anomalies and winter extreme cold events increase over the mid-latitudes.In addition,recent frequent and persistent cold surges facilitated the significant decreasing of winter temperature over the mid-latitudes of Eurasia,coupled with continuously strengthening of winter coldness intensity.3) We further decomposited the temperature advection,and observed that the temperature advection was mainly dominated by cold advection in the mid-latitudes of Eurasia during the period of 1998-2012,and this feature had been particularly significant since 2005.Cold zonal advection mainly dominated in Europe and East Asia,while meridional temperature advection mainly cooled Siberia,and both zonal and meridional advections were critical components.Aside from the meridional wind and temperature gradient components cooling effects,the zonal wind and temperature gradient components also played a particularly significant role in cold anomalies in the mid-latitudes of Eurasia.The meridional temperature gradient was one aspect that affected the temperature drop in the mid-latitudes of Eurasia,and its value was smaller than the other contributions.Abnormal zonal and meridional temperature gradients and zonal wind drove the cooling effect over Europe,among which the zonal wind value was the strongest.The changes of zonal and meridional winds played a key role cooling Siberia,while the abnormal zonal temperature gradient mainly cooled down East Asia,which may have been related to the temperature differences enhanced between sea and land there.In general,the dominant temperature advection components varied among different regions.Compared to the cooling effects of temperature advections throughout the entire Eurasian continent,shortwave and longwave radiations only cooled the local areas where autumn and winter snow cover increased.