Nanjing experienced an unseasonable 25 degrees or so on Saturday. Yesterday, the temperature was half that. The overnight shift can be much more dramatic too; it’s been known for the temperature to go up or down as much as 20 degrees. Begging the question why?
It boils down to large temperature fluctuations related to cold-air activity and solar radiation.
它归结为与冷空气活动和太阳辐射有关的巨大温度波动。
And our particular location on the world’s surface. Last month, The Paper reported on the issue, speaking with Wang Ji, Director of the Beijing Climate Centre.
以及我们在世界表面的特殊位置。上个月，澎湃新闻采访了北京气候中心主任王吉。
“China is located between the largest continent in the world, Eurasia; and the largest ocean in the world, the Pacific. The huge differences in thermal properties between land and sea make for the region being the most monsoon-like climatic area in the world”, said Wang.
“中国位于世界上最大的大陆欧亚大陆和世界上最大的海洋太平洋之间。陆地和海洋热性质的巨大差异使该地区成为世界上最季风气候的地区。”王说。
And when it comes down to our locale in particular, on the one hand, Nanjing is far enough away from the coast not to benefit from the sea’s natural warming and cooling effects. On the other, we remain sufficiently close that the big ol’ Pacific Ocean still exerts an enormous influence over our weather.
尤其是就我们所处的地理位置而言，一方面，南京距离海岸足够远，无法受益于海洋自然变暖和冷却的影响。另一方面，我们仍然足够接近，以至于太平洋仍然对我们的天气产生巨大的影响。
As to why the temperature fluctuations are concentrated around this time of year, that’s down to the passing of the autumnal equinox and climate change.
至于为什么气温波动集中在一年中的这个时候，这与秋分的过去和气候变化有关。
Every year, solar radiation received at higher latitudes decreases significantly as the end of October comes. The air cools and sinks, forming a large-scale mass of cold air. As the specific heat capacity for land is limited and the temperature drops extremely rapidly, cold air will gather at high latitudes in Siberia and Mongolia.
每年，随着十月底的到来，高纬度地区接收到的太阳辐射会显着减少。空气冷却下沉，形成大面积的冷空气团。由于陆地比热容有限，气温下降极快，冷空气将在西伯利亚和蒙古等高纬度地区聚集。
Then it comes our way.
然后它就来了。
As for climate change, with artic sea ice largely melted, the temperature difference between cold air in the polar region and warm air in the tropics has decreased. This has led to a weakening of the impact of polar eddies on the global climate. At the same time, under the influence of the atmospheric circulation system, cold air in the polar vortex will move south more easily and frequently.
气候变化方面，随着北冰洋海冰大量融化，极地冷空气与热带暖空气的温差缩小。这导致极地涡流对全球气候的影响减弱。同时，在大气环流系统的影响下，极涡中的冷空气将更容易、更频繁地南移。
While temperature fluctuations experienced by southern parts of China are generally not as fast and intense as those in the north in the past, this year’s situation is indeed somewhat special.
虽然我国南方地区的气温波动总体上没有北方那么快和剧烈，但今年的情况确实有些特殊。
