极端高温袭击美国，打破多地高温记录，今夏为何高温天气频发？ 第1页

引自大气科学家 Cliff Mass 的博客文章：

Throughout the region, all-time temperature records have been broken, if not smashed. Just to name a few:

The visible satellite imagery this morning showed that marine clouds not only covered the coast but pushed inland around the Olympics.

The cooling west of the Cascades will be a two-step affair. Last night's intrusion of cool, marine air was quite shallow. The figure below shows temperature (red lines are temperature in C, wind barbs in black) above SeaTac Airport during the past day. No cooling above 5000 ft. But lots of cooling and a switch to southerly flow below 2500 ft.

What happens in this situation is that where there is sun at the surface, the air starts to mix, with the mixing getting deeper over time. Eventually, we mix down the warm air above and temperatures surge. You will notice that today---- sometime after 10 AM temperatures will warm rapidly into the upper 80s. Sorry.

But the good news is that the marine air will push in again tonight as the thermal trough decidedly moves into eastern Washington...resulting in an additional temperature step down on Wednesday. The ensemble forecasts for Seattle show this clearly (see below). Good sleeping weather ahead!

大意是极端高温是异常条件正确组合的结果。也就是说，内陆异常高压和海岸附近的低压形成了从东到西的强大气流，有助于将凉爽的海洋空气推离海岸。此外，当暖空气流过喀斯喀特山脉时，它会在沿着山脉西坡下降时变得更加温暖。下周3就凉快了！

加拿大更厉害 49.5°；自上周五以来，由于灾难性的热浪带来了创纪录的气温，加拿大不列颠哥伦比亚省已有 230 多人死亡。

死亡事件发生之际，加拿大连续第三天创造了新的历史高温记录，在温哥华以东约 155 英里（250 公里）的不列颠哥伦比亚省利顿达到 121 华氏度（49.5 摄氏度）。

加拿大环境部已向不列颠哥伦比亚省、阿尔伯塔省、萨斯喀彻温省、育空地区和西北地区的部分地区发出警告。

环境部在警告中说：“这场历史性的热浪漫长而危险，将持续整整一周。”

这比正常温度高 15 到 20 摄氏度。

温哥华警察局表示已重新部署了数十名警察，并要求公众没事尽量少打 911。史蒂夫中士说，自 6 月 25 日热浪开始以来，警方已经对超过 69起猝死事件做出了处理。温哥华从未经历过热浪，人们因此而死亡。并动员义务人员给低收入人群发水，发食物。