The Black Sea sits at the boundary between Europe and Asia and connects to the Mediterranean Sea via a chain of waterways. Its surface often appears dark, but each spring and summer it transforms into a striking expanse of swirling turquoise. The OCI (Ocean Color Instrument) on NASA’s PACE (Plankton, Aerosol, Cloud, ocean Ecosystem) satellite captured this image (above) of the colorful waters on June 22, 2026.
黑海位于欧洲和亚洲之间的边界，通过一系列水道与地中海相连。它的表面通常呈黑色，但每年春天和夏天，它都会变成一片引人注目的旋转绿松石色。美国宇航局 PACE（浮游生物、气溶胶、云、海洋生态系统）卫星上的 OCI（海洋颜色仪器）于 2026 年 6 月 22 日拍摄到了这张彩色水域的图像（上图）。
The turquoise color is likely caused by coccolithophores , a type of phytoplankton covered with calcium carbonate plates that can give surface waters a milky-blue appearance. These types of phytoplankton tend to dominate in late spring and early summer. Other times of the year, diatoms —a type of microscopic algae with silica shells—can become more prevalent, and they tend to darken the water rather than brighten it.
绿松石色很可能是由颗石藻造成的，颗石藻是一种覆盖着碳酸钙板的浮游植物，可以使地表水呈现出乳蓝色的外观。这些类型的浮游植物往往在春末和初夏占主导地位。一年中的其他时间，硅藻（一种具有二氧化硅外壳的微型藻类）会变得更加普遍，它们往往会使水变暗而不是变亮。
The Bosphorus, the narrow strait running through Istanbul that connects the Black Sea with the Sea of Marmara, also turned turquoise. An astronaut aboard the International Space Station photographed the strait on May 27, 2026 (below), about a month before the PACE image, capturing blooming phytoplankton as it traced currents on both sides of the waterway. (Note that north is oriented toward the bottom of the frame.)
博斯普鲁斯海峡是一条穿过伊斯坦布尔、连接黑海和马尔马拉海的狭窄海峡，也变成了绿松石色。国际空间站上的一名宇航员于 2026 年 5 月 27 日（下图）拍摄了该海峡，大约在 PACE 图像发布前一个月，在追踪水道两侧的水流时捕捉到了繁盛的浮游植物。 （请注意，北方向朝向框架的底部。）
Though coccolithophores are microscopic, they become so abundant during a bloom that they become visible from space. This makes remote sensing a useful tool for researchers studying bloom dynamics in regions where direct sampling is limited. Beyond their visibility, these blooms also contribute to the ocean’s carbon cycle . When they die, some of the carbon they’ve taken up sinks to the seafloor, where it can remain stored for long periods of time.
尽管颗石藻是微小的，但它们在开花期间变得如此丰富，以至于从太空中都可以看到它们。这使得遥感成为研究人员在直接采样有限的地区研究水华动态的有用工具。除了可见度之外，这些水华还有助于海洋的碳循环。当它们死亡时，它们吸收的一些碳会沉入海底，在那里可以长期储存。
NASA Earth Observatory image by Michala Garrison, using PACE data from NASA EOSDIS LANCE and GIBS/Worldview and the NASA Ocean Biology Distributed Active Archive Center OB.DAAC . Astronaut photograph ISS074-E-619520 was acquired on May 27, 2026, with a Nikon Z9 digital camera using a focal length of 50 millimeters. It is provided by the ISS Crew Earth Observations Facility and the Earth Science and Remote Sensing Unit at NASA Johnson Space Center. The image was taken by a member of the Expedition 74 crew . The image has been cropped and enhanced to improve contrast, and lens artifacts have been removed. The International Space Station Program supports the laboratory as part of the ISS National Lab to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth . Story by Kathryn Hansen.
NASA 地球观测站图像，由 Michala Garrison 拍摄，使用来自 NASA EOSDIS LANCE 和 GIBS/Worldview 以及 NASA 海洋生物学分布式主动档案中心 OB.DAAC 的 PACE 数据。宇航员照片 ISS074-E-619520 于 2026 年 5 月 27 日使用尼康 Z9 数码相机拍摄，焦距为 50 毫米。它由国际空间站机组人员地球观测设施和美国宇航局约翰逊航天中心的地球科学与遥感部门提供。这张照片是由 Expedition 74 号船员拍摄的。图像经过裁剪和增强以提高对比度，并且镜头伪影已被消除。国际空间站计划支持该实验室作为国际空间站国家实验室的一部分，帮助宇航员拍摄对科学家和公众最有价值的地球照片，并将这些图像在互联网上免费提供。宇航员拍摄的其他图像可以在 NASA/JSC 地球宇航员摄影网关查看。凯瑟琳·汉森的故事。