ARC Centre of Excellence for Climate Extremes, School of Earth Atmosphere and Environment, Monash University, Clayton, 3800, Victoria, Australia.
Nat Commun. 2020 Nov 10;11(1):5677. doi: 10.1038/s41467-020-19338-z.
A robust eastern Pacific surface temperature cooling trend was evident between ~1990-2013 that was considered as a pronounced contributor to the global surface warming slowdown. The majority of current climate models failed to reproduce this Pacific cooling trend, which is at least partly due to the underrepresentation of trans-basin teleconnections. Here, we investigate whether common Pacific mean sea surface temperature biases may further diminish the Atlantic-Pacific trans-basin induced Pacific cooling. Our results suggest that background Pacific SST biases act to weaken the trans-basin teleconnection by strengthening the Atlantic atmospheric stability and reducing Atlantic convection. These Pacific SST biases also act to substantially undermine the positive zonal wind-SST feedback. Furthermore, when combined, the Pacific and Atlantic SST biases led to Pacific cooling response that is almost non-existent (underestimated by 89%). Future efforts aim at reducing the model mean state biases may significantly help to improve the simulation skills of trans-basin teleconnections.
在 1990 年至 2013 年期间，东太平洋表面温度出现了明显的冷却趋势，被认为是导致全球表面变暖减缓的一个显著因素。大多数当前的气候模型未能再现这种太平洋冷却趋势，这至少部分是由于跨洋遥相关的代表性不足。在这里，我们研究了常见的太平洋海表温度偏差是否会进一步减弱大西洋-太平洋跨洋引起的太平洋冷却。我们的结果表明，背景太平洋 SST 偏差通过加强大西洋大气稳定性和减少大西洋对流，从而削弱跨洋遥相关。这些太平洋 SST 偏差还会大大破坏纬向风-SST 正反馈。此外，当太平洋和大西洋 SST 偏差结合在一起时，导致太平洋冷却的响应几乎不存在（低估了 89%）。未来减少模式平均状态偏差的努力可能会显著有助于提高跨洋遥相关的模拟技能。
