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ABSTRACT Land use and land cover change (LUCC) is an important external forcing agent of climate change. The comparison of current (2000 A.D.) with historical (1850 A.D.) land cover maps suggests that most of the Eurasian continent has experienced robust and significant LUCC during the past century, especially evident transition from forests to croplands. Therefore, two experiments (control and sensitivity experiments with current and historical land cover maps, respectively) are conducted by using the Community Atmosphere Model Version 5.0 (CAM5.0) coupled with the Community Land Model Version 4.0 (CLM4.0) to investigate the potential effects of LUCC on temperature extremes over Eurasia. Results show significant increases (e.g., 0.2-0.7 °C) in extreme cold indices (e.g., TNn) over central and eastern China, India and mainland Southeast Asia in response to such robust LUCC. Broad and significant decreases (e.g., approximately −1 °C) in extreme warm indices (TXx) are mainly observed in Eastern Europe and western Siberia. Moreover, the effects of LUCC on high and low-percentile extreme indices of minimum temperature ( Tmin) are generally symmetrical, but those for maximum temperature ( Tmax) indices are asymmetrical, which are characterized by stronger influences on high-percentile indices rather than low ones. Further analyses suggest that LUCC-induced changes in temperature extremes are mostly influenced by shifts in the mean state of Tmin/ Tmax. Furthermore, the responses and sensitivities of Tmin/ Tmax to LUCC are remarkably distinct among regions. This result mainly occurs because of different LUCC-induced changes in surface energy components, which depend on the region-specific climatology of each energy component and the dominant plant functional types. [ABSTRACT FROM AUTHOR]

ABSTRACT This study investigated the potential connection of the October-December Arctic Oscillation ( AO-OND) with the following January East Asian temperature extremes and the possible mechanisms. It was found that the extreme cold (warm) events are less (more) frequent in January over East Asia following a positive phase of AO-OND, which might be attributed to the intrinsic persistence of AO-OND in stratosphere and the memory of Eurasian snow cover. It is revealed that the barotropic structure of AO-OND could extend to stratosphere. By the following January, wave activities propagate from stratosphere downwards to upper troposphere, then bent equatorwards to mid-latitudes. Consequently, the January circumpolar jet (polar vortex) gets strengthened (colder) because the equatorward-pointing (upwards) wave activities correspond to poleward meridional eddy momentum (eddy heat) flux. In such a way, the anomalous AO-OND persists into the following January. On the other hand, positive phase of AO-OND causes significant surface warming in most parts of Eurasia, leading to Eurasian snow melt. The October-December snow melt has intrinsic climatic memory and further weakens the January Siberian High through reducing surface albedo. Besides, the surface warming in North Europe because of reduced surface albedo caused by snow melt could stimulate a Rossby wave train propagating eastwards across Eurasia, which restrains the blocking events around Ural region. In such a context, the incidence of extreme warm (cold) events over East Asia is more (less) frequent. [ABSTRACT FROM AUTHOR]

Seasonal anomalies of surface air temperature were analyzed for the North Eurasian regions in mid-latitudes using long-term data from the end of the 19th century with an assessment of El Niño Southern Oscillation (ENSO) effects. In particular, temperature anomalies in the spring–summer months for the European (ER) and Asian (AR) Russian regions for different phase transitions of the ENSO phenomena were estimated using the Niño3, Niño3.4 and Niño4 indices. The largest frequency of the extremely high-temperature and drought conditions in spring–summer months in ER was detected for years starting in the El Niño phase with the transition to the La Niña phase at the end of the year. Such conditions were realized in ER in summer 2010 ("Russian heatwave"). The corresponding largest frequency of high temperature in AR was obtained for conditions with the continuation of the El Niño phase during the whole year. Such conditions in AR were noted, in particular, in the summer of 2015, with an extremely high temperature and extremely low precipitation in the Lake Baikal basin. [ABSTRACT FROM AUTHOR]

Gypsy moth Lymantria dispar (GM) is a polyphagous insect and one of the most significant pests in the forests of Eurasia and North America (U.S. and Canada). Accurate information on GM cold-hardiness is needed to improve methods for the prediction of population outbreaks, as well as for forecasting possible GM range displacements due to climate change. As a result of laboratory and field studies, we found that the lower lethal temperature (at which all eggs die) range from −29.0 °C to −29.9 °C for three studied populations of L. dispar asiatica , and no egg survived cooling to −29.9 °C. These limits agree, to within one degree, with the previously established cold-hardiness limits of the European subspecies L. dispar , which is also found in North America. This coincidence indicates that the lower lethal temperature of L. dispar is conservative. Thus, we found that the Siberian populations of GM inhabit an area where winter temperatures go beyond the limits of egg physiological tolerance, because temperatures often fall below −30 °C. Apparently, it is due to the flexibility of ovipositional behavior that L. dispar asiatica survives in Siberia: the lack of physiological tolerance of eggs is compensated by choosing warm biotopes for oviposition. One of the most important factors contributing to the survival of GM eggs in Siberia is the stability of the snow cover. • The lower lethal temperature for three populations L. dispar asiatica : –30 °C. • The values of lethal temperature are the same for Asian and European populations. • Siberian air temperature below the limit of physiological tolerance of L. dispar. • L. dispar egg survival depends on the choice of warm biotopes for oviposition. [ABSTRACT FROM AUTHOR]