At the top and bottom of the planet, the seasons arrive on a schedule all their own. Satellite data from a mission measuring infrared energy reveal just how differently—and how dramatically—surface temperatures swing across two full years at the poles.
在地球的顶部和底部，季节都有自己的时间表。来自测量红外能量任务的卫星数据揭示了两极地表温度在整整两年内的变化有多么不同和多么剧烈。
In this animation, surface temperatures across the Arctic and Antarctic pulse between cold (dark blue) and milder to warm (lighter blue to red). Data for the animation come from NASA’s PREFIRE (Polar Radiant Energy in the Far-InfraRed Experiment) satellites. The mission’s twin CubeSats began collecting science data in July 2024 and have now captured two complete seasonal cycles at each pole.
在此动画中，北极和南极的表面温度在寒冷（深蓝色）和温和到温暖（浅蓝色到红色）之间变化。动画的数据来自 NASA 的 PREFIRE（远红外实验中的极辐射能）卫星。该任务的双立方体卫星于 2024 年 7 月开始收集科学数据，现已在每个极点捕获了两个完整的季节周期。
Because the two poles sit in opposite hemispheres, their seasons occur at opposite times—and the swing between seasons differs, too. In the Arctic, cold, dark winters give way to summers warm enough to thaw vast stretches of tundra and sea ice. In Antarctica, Earth’s coldest continent, summer temperatures rarely climb above freezing before the bitter cold of winter returns.
由于两极位于相反的半球，因此它们的季节发生在相反的时间，而且季节之间的波动也不同。在北极，寒冷、黑暗的冬季被温暖的夏季所取代，足以融化大片苔原和海冰。在地球上最冷的大陆南极洲，在冬季严寒来临之前，夏季气温很少升至冰点以上。
Surface temperatures, and how they fluctuate, offer a window into Earth’s energy budget , the net flow of energy into and out of the Earth system. Sunlight absorbed by the surface is re-radiated as infrared heat, which bounces between Earth’s surface and atmosphere before escaping to space. The poles play an important role in this process. Atmospheric and ocean circulation carries excess heat absorbed in the tropics toward the poles, where it radiates away to space , helping regulate the planet’s temperature.
表面温度及其波动方式为了解地球的能量预算（即流入和流出地球系统的能量净流量）提供了一个窗口。地表吸收的阳光会以红外热的形式重新辐射，在逃逸到太空之前在地球表面和大气层之间反弹。两极在此过程中发挥着重要作用。大气和海洋环流将热带吸收的多余热量带到两极，在那里辐射到太空，帮助调节地球的温度。
“By measuring invisible heat radiating from Earth’s coldest places, PREFIRE is helping scientists understand why the poles are changing so rapidly, and what those changes might mean for the rest of the planet,” said Chad Greene, a glaciologist at NASA’s Jet Propulsion Laboratory.
美国宇航局喷气推进实验室的冰川学家查德·格林 (Chad Greene) 表示：“通过测量地球最冷地方辐射的不可见热量，PREFIRE 正在帮助科学家了解两极变化如此迅速的原因，以及这些变化对地球其他地区可能意味着什么。”
Scientists have long known that far-infrared radiation accounts for nearly 60 percent of the energy Earth loses to space, but that portion of the spectrum—invisible to human eyes—had never been comprehensively measured on a global scale. By directly tracking this invisible energy in near-real-time, the PREFIRE mission is helping scientists refine models and gain a better understanding of the Earth system.
科学家们早就知道，远红外辐射占地球损失到太空的能量的近 60%，但这部分光谱（人眼看不见）从未在全球范围内进行过全面测量。通过近乎实时地直接跟踪这种看不见的能量，PREFIRE 任务正在帮助科学家完善模型并更好地了解地球系统。
“Weather systems, river flows, shipping routes, and ice sheet stability are all influenced by energy movement in a part of the spectrum that only PREFIRE can see,” said Tristan L’Ecuyer, an atmospheric scientist at the University of Wisconsin-Madison and principal investigator of the PREFIRE mission. “Now that the invisible has been made visible, we can begin to improve weather and climate predictions that industries, our national defense, and Arctic communities rely on.”
威斯康星大学麦迪逊分校大气科学家、PREFIRE 任务首席研究员 Tristan L’Ecuyer 表示：“天气系统、河流流量、航运路线和冰盖稳定性都受到只有 PREFIRE 才能看到的部分光谱中能量运动的影响。” “既然看不见的东西已经变得可见，我们就可以开始改进工业、国防和北极社区所依赖的天气和气候预测。”
Maps courtesy of Chad Greene, NASA/JPL, using data from NASA’s PREFIRE mission. Story by Kathryn Hansen.
地图由 NASA/JPL 的 Chad Greene 提供，使用了 NASA PREFIRE 任务的数据。凯瑟琳·汉森的故事。