Neutral air temperatures at 90 km altitude over Svalbard (78°N, 16°E) for the period 2002 to 2019 inclusive have been estimated from observations by the Nippon/Norway Svalbard Meteor Radar (NSMR). The data are presented per se and we shall not attempt to identify contributions from extra-terrestrial or anthropogenic driving. On the other hand, comparison with the corresponding period of solar UV flux notably fails to exhibit similarities. Moreover, there is indeed evidence of systematic temporal changes, possibly with a breakpoint around 2012. Selecting winter and summer months and years before and after 2012 and fitting trend-lines, we see strong evidence for cooling during summer. An apparent winter cooling prior to 2012 lacks statistical significance. A suggestion of reversal to winter warming after 2012 is also very uncertain. The summer cooling is found to be 9.9 ± 2.9 K decade⁻¹ between 2002 and 2012, and 4.3 ± 1.2 K decade⁻¹ between 2002 and 2019. Importantly, there is a suggestion (although lacking statistical significance) that summer cooling alleviated after 2012, and even reversed in winter.

Nippon / Norway Svalbard Meteor Radar（NSMR）的观测值估计了2002年至2019年期间斯瓦尔巴群岛（78°N，16°E）上90 km高度的中性气温。数据本身是呈现的并且我们将不会试图确定来自地面或人为驾驶的贡献。另一方面，与太阳紫外线通量的相应时期的比较明显没有表现出相似性。此外，确实存在系统时间变化的迹象，可能在2012年左右出现断点。选择2012年前后的冬季和夏季月份以及年份，并拟合趋势线，我们看到了夏季降温的有力证据。2012年之前的明显冬季降温缺乏统计意义。关于2012年后冬季变暖的逆转建议也非常不确定。发现2002年至2012年之间的夏季降温为9.9±2.9 K十年^-1和4.3±1.2 K十年^-1 在2002年至2019年之间。重要的是，有一个建议（尽管缺乏统计意义）表明，2012年以后夏季降温有所缓解，冬季甚至有所逆转。