海水从古老的珊瑚礁上倾泻而下，杭莱，越南 Seawater cascades over an ancient coral reef, Hang Rai, Vietnam (© Thang Tat Nguyen/Getty Images)

潮汐探戈 A tidal tango

永希湾，越南

欢迎来到杭莱，这里既有古老的岩层，又有生机勃勃的珊瑚礁！这个洞穴也被称为獭洞，被努伊蔡国家公园包围着，是越南中南部海岸地区永希湾的一部分。该地区的天然珊瑚礁被岩层环绕，这些岩层堆叠在一起，形成了一组洞穴。“杭莱”或“獭洞”名称的由来之一，是人们偶尔会看到水獭在洞穴中栖息。另一种解释是由于该地区盛产莱树，这种树的油可以用于船只防水。无论是水下还是水上，这里都有令人惊叹的景观：深潜者可以观赏五颜六色的珊瑚，喜欢在海风中露营的游客可以欣赏美丽的日落。

Vinh Hy Bay, Vietnam

Welcome to Hang Rai, a blend of ancient rock formations and vibrant coral reefs. Also called Rai Cave, this cavern is part of the Vinh Hy Bay—enclosed by Nui Chua National Park—in the South Central Coast region of Vietnam. The area's natural coral reefs are surrounded by rock formations that are stacked upon each other to form a group of caves. One origin of the name 'Hang Rai' or 'Rai Cave' comes from otters (rai) that were occasionally seen seeking shelter in the caves. Another explanation is attributed to the abundance of rai trees in the area, whose oil was used to waterproof boats. The landscape is an awe-inspiring sight both under and above water: corals for deep divers and colorful sunsets for those who like camping in the sea breeze.

弗雷泽河谷的郁金香田，阿伯兹福德，不列颠哥伦比亚省，加拿大 (© LeonU/Getty Images)

春意盎然

不列颠哥伦比亚省，阿伯兹福德

伴随着不断绽放的花朵，春天正式开始倒计时。在今天的照片中，弗雷泽河谷的郁金香绽放出鲜艳的色彩，为四月的阿伯兹福德郁金香节做准备。流经城市北部边界的弗雷泽河滋养了阿伯兹福德肥沃的土壤。

阿伯兹福德最早的居民是斯托洛民族，距今约有4000—10000年历史。19世纪淘金热时期，欧洲移民来到这里。如今，这座城市已成为高科技企业和教育机构的中心。如果你来到阿伯兹福德，千万不要错过讲述早期拓荒者故事和文化变迁的遗产博物馆和公共艺术遗址。

巴西亚马逊上空巨大的砧状云 Large anvil clouds above the Amazon in Brazil (© NASA)

造雾 Making a fog-cast

世界气象日

“当云层像岩石和高塔一样出现时，地球就会因频繁的阵雨而焕然一新”，这句古老的气象谚语对于雷暴云（又名积雨云或砧状云）来说有几分道理。而照片中展示的正是砧状云。今天，在世界气象日，我们向大气层的这个奇迹致敬。为了纪念世界气象组织于1950年3月23日成立，世界气象日的首次纪念活动于1961年的3月23日举行。但这一天不仅仅是对历史的致敬，还是为了呼吁人们认识到气象学在我们生活中的重要作用。天气预报可能并不总是可靠的，但由于卫星和超级计算机等技术的进步，天气预报已经取得了长足的进步。由于这些进步，全球天气模型可以提供长达16天的预报，龙卷风预警的平均提前时间从1974年的-15分钟缩短到今天的15分钟左右。让我们为气象学已取得的进展和将要取得的进步欢呼吧!

World Meteorological Day

'When clouds appear like rocks and towers, the Earth's refreshed with frequent showers.' There's a whisper of truth to this old proverb for the storm clouds, also known as cumulonimbus or anvil clouds, which are pictured here. Today, on World Meteorological Day, we honor the marvel that is our atmosphere. This observance, first held in 1961, commemorates the establishment of the World Meteorological Organization and recognizes the vital role meteorology plays in our lives. Weather forecasts may not always appear reliable, but thanks to advances in technology like satellites and supercomputers, they have come a long way. Global weather models provide forecasts for up to 16 days and, the average lead time for tornado warnings is now around 15 minutes. Cheers for the progress made and much more to come!

蓝泉，蒂怀霍步道，新西兰 Blue Spring, Te Waihou Walkway, New Zealand (© Ian Beattie/Alamy Stock Photo)

我们在庆祝“水”？ 'Water' we celebrating?

世界水日

今天是世界水日，这是一个已有31年历史的传统节日，在全球范围内具有重要的影响力。世界水日的宗旨是唤起公众的节水意识，加强水资源保护。水是既可以解渴，又能灌溉庄稼。如果没有水，就会破坏社会的繁荣和稳定。世界经济论坛将水危机列为全球最大的风险之一，全球仍有22亿人无法获得干净的饮用水，联合国的这次纪念活动正是为了呼吁大家采取行动解决这一危机。从教育论坛里的科普宣传到各地组织的清理活动，每一个行动，或大或小，都是有用的。今年世界水日的主题是“以水促和平”，当我们在水问题上开展合作时，就会产生积极的连锁效应。所以，你准备好加入这股浪潮了吗？

World Water Day

It's World Water Day, a United Nations event that ripples across the globe, reminding us of the importance of this essential resource. Water quenches thirst and irrigates harvests, and its absence can derail prosperity and stability. The World Economic Forum lists the water crisis among the top global risks, with 2.2 billion people still lacking access to clean water. From educational forums to local cleanups, each action, big or small, contributes to the wave of change needed to address the crisis. This year's theme, 'Water for Peace,' invites us to reflect on water's power to foster unity. So, are you ready to dive into a current that flows deeper than New Zealand's Blue Spring at Te Waihou Walkway, pictured on our homepage? This clear spring is renowned for its purity, supplying about 70% of the country's bottled water. For those in regions without easy access to safe water, World Water Day is here to promote greater cooperation to help conserve this crucial resource, for everyone.

布恩迪国家公园，乌干达 Bwindi Impenetrable National Forest, Uganda (© Art Wolfe/DanitaDelimont.com)

森林多美好呀！ Woodn't it be nice

国际森林日

今天是国际森林日，让我们走出家门，扎根林地吧！森林是地球上重要的生态系统之一，为了提高人们对保护森林和欣赏森林景观的意识，就在11年前的今天，联合国设立了国际森林日。据悉，世界各地的林地占地球陆地面积的30%以上，林地中的树木种类繁多，令人难以置信，据估计，全球共有超6万种不同种类的树。森林在提供食物、水和药物等基础资源方面发挥着至关重要的作用。今天的图片展示的是乌干达的布恩迪国家公园，这里有160种树木和100种蕨类植物，以及世界上50%的山地大猩猩种群。森林中的树木之间还生长着茂密的竹林，导致人们在这片森林中寸步难行，因此布恩迪国家公园又名“难以穿越的森林”。

International Day of Forests

Today we're rooting for woodlands worldwide as we celebrate the International Day of Forests. Established by the UN 11 years ago, the day draws attention to the need to preserve these essential ecosystems, which supply food, water, medicines, and other resources. Covering over 30% of land on Earth, it is thought that woodlands around the world contain more than 60,000 tree species. Featured here is the Bwindi Impenetrable National Forest in Uganda, which is home to 160 species of trees and 100 species of ferns, as well as an extraordinary 50% of the world's mountain gorilla population. The forest has thickets of bamboo growing between the trees, making access on foot difficult, giving the Impenetrable Forest its name.

鸟瞰春日盛开的樱花，中国 Aerial view of cherry blossom in Spring, China (© outcast85/Getty images)

粉嫩的春日美景 Pink spring scenery

春分

春分时节，中国大部分地区已进入明媚的春天。此时，严寒已过，气温迅速回升。春分过后，人们开始陆续外出。在户外活动中，放风筝是一项重要的项目。古代还有春分戴花、饮酒的习俗。在这一天，无论男女老少都会在头发上戴花。

樱花原产北半球温带环喜马拉雅山地区，最初的这种樱花，就是山樱与野樱为代表的中华樱花。日本樱花大约在中国宋代时候开始引进栽培，当时也是野生的中华樱花。在当地一代代改良栽培下，进化为现在著名的日本樱花。武汉的清凉寨景区的中华樱花面积多达3200余亩，数量有11万余株，在武汉地乃至全国首屈一指。该地区的樱花分早中晚三期开放，早樱于每年3月10日前后、中樱3月25日前后，晚樱4月5日前后开放，花期均在15-20天左右。

盛开的扁桃树, 加利福尼亚州，美国 Almond trees in full bloom, California (© Jeffrey Lewis/Tandem Stills + Motion)

春日私语 Whispers of spring

盛开的扁桃树, 加利福尼亚州

在阳光普照的金州（加利福尼亚州的别称）果园中，扁桃仁享有崇高的地位，它以美味的果实诱惑着人们的味蕾，用漂亮的花朵装点着自然环境。而加利福尼亚州种植的扁桃仁占世界市场供应量的80%，占美国市场供应量的100%。据悉，扁桃仁中含有对心脏有益的单不饱和脂肪，还富含纤维、蛋白质以及大量的维生素和矿物质，是一种营养丰富的食物。二三月份，在加利福尼亚州的中央山谷中，这些扁桃树的种子会从娇嫩的花朵中孕育出来，然后在一种毛茸茸的、有着保护作用的外壳中生长，直至成熟。扁桃树属于蔷薇科，在花期会绽放出美丽的花朵，而这些芬芳的花朵会将果园涂染成白色和粉色色调。

大象岩，古城欧拉，沙特阿拉伯 Elephant Rock, Al-Ula, Saudi Arabia (© Lubo Ivanko/Shutterstock)

温柔的“沙丘巨人” Gentle giant of the dunes

大象岩，古城欧拉，沙特阿拉伯

经过数百万年的时间，大自然雕琢出了这片耀眼夺目的砂岩地貌，名为大象岩。该岩石高达117英尺，位于沙特阿拉伯古城欧拉附近，由于风水的侵蚀，它呈现出大象的形状，并成为了该地区的著名地标。日落时，夕阳洒在这片沙漠上，为红色的“猛犸象”及其周围金色的沙子镀上一层温暖的光辉。

古城欧拉距离大象岩约7英里，其历史可追溯到公元前6世纪，它见证了商人、朝圣者和商队穿越这片干旱的土地的历史。其周边地区的岩层和赫格拉纳巴泰古王国陵墓有着岩画和碑文，其中一些碑文的历史可以追溯到公元644年。

Elephant Rock, Al-Ula, Saudi Arabia

Over millions of years, the dazzling sandstone formation known as Elephant Rock was carved by nature. Thanks to the wind and water erosion, this 117-foot-high rock near the city of Al-Ula in Saudi Arabia took on the shape of an elephant and has become a prominent landmark in the region. As the sun sets, it casts a warm glow upon the red-hued mammoth and the golden sand of the surrounding desert.

About 7 miles from the Elephant Rock, the city of Al-Ula traces its roots back to ancient civilizations and has witnessed the passage of traders, pilgrims, and caravans crossing its arid landscapes. The surrounding area, including rock formations and Hegra's Nabataean tombs, boasts petroglyphs and inscriptions, some dating as far back as 644 CE.

圣菲尼安湾，凯里郡，爱尔兰 St. Finian's Bay, County Kerry, Ireland (© Atlantide Phototravel/Getty Images)

今天，让我们穿绿衣裳吧！ Let's wear green today!

圣菲尼安湾，凯里郡，爱尔兰

今天，全球数百万具有爱尔兰血统的人都在庆祝圣帕特里克节。圣帕特里克是爱尔兰国家的守护神，大约在公元432年，他将基督教引入到爱尔兰。公元461年3月17日，圣帕特里克逝世，这一天成为了爱尔兰纪念他的日子。

而在美国，圣帕特里克节也具有重要的文化意义，那里有超过3000万人声称自己拥有爱尔兰血统，尤其是在波士顿、纽约和芝加哥等城市。美国第一次庆祝圣帕特里克节的活动是在1737年波士顿举办的，组织者是思乡的爱尔兰士兵，其目的是纪念和传承他们的爱尔兰文化。现代的庆祝活动通常包括游行、传统爱尔兰音乐和舞蹈表演、穿绿色的服装，享用爱尔兰美食和饮料。转眼又到了圣帕特里克节，喜欢爱尔兰文化的你，是否已在夹克上别上了三叶草？

St. Patrick's Day

Today, we're looking out to sea from the green pastures of St Finian's Bay in County Kerry, Ireland, to celebrate St Patrick's Day. The country's patron saint introduced Christianity to Ireland around the year 432, and his passing on March 17, 461, became a day of commemoration in his homeland.

The holiday holds cultural significance in the United States, where there are over 30 million people who claim Irish ancestry, specifically in cities like Boston, New York, and Chicago. The first festivity in America took place in Boston in 1737, organized by homesick Irish soldiers to honor their heritage. The modern celebration typically includes parades, traditional Irish music, and dance performances, wearing green clothes, and indulging in Irish cuisine and beverages. Have you pinned a shamrock to your jacket yet?

安沙波利哥沙漠州立公园，美国加利福尼亚州 Anza-Borrego Desert State Park, California (© Stephen Matera/Tandem Stills + Motion)

一抹春色 Where is this colorful desert?

安沙波利哥沙漠州立公园，美国加利福尼亚州

也许距离春天伊始还有好些天，但是加州最大的州立公园——安沙波利哥沙漠州立公园的野花已经在这里向你问好了！每年春天，这片贫瘠的沙漠都会经历一次戏剧性的改变。向日葵、沙漠菊和蒲公英等花朵竞相绽放，形成色彩斑斓的奇观。对于那些想要寻求更多冒险体验的游客来说，从半岛山脉仙人掌丛生的丘陵到峡谷、荒地和天然棕榈绿洲，这个公园有很多可供选择的地方。此外，作为指定的国际黑暗天空公园，这里还是绝佳的观星地点。除了自然奇观之外，占地超过60万英亩的公园还拥有丰富的文化和历史遗产，如古老的象形文字或岩画。

Anza-Borrego Desert State Park, California

The first day of spring may be just days away, but the season's wildflowers at California's largest state park—Anza-Borrego Desert State Park—are already here to say hello! Every spring, this barren desert floor undergoes a dramatic makeover. Flowers like heliotrope, brittlebush, and desert dandelion burst into a riot of bloom, creating a spectacle of color. For those seeking a more adventurous experience, this park has a lot to offer—from the mountains of the Peninsular Ranges and cactus-studded hills to slot canyons, badlands, and natural palm oases. In addition, as a designated International Dark Sky Park, it is an exceptional spot for stargazing. Beyond its natural wonders, the park, spanning over 600,000 acres, is also home to a rich cultural and historical legacy, including ancient pictographs, or rock paintings, from the Native American tribes that once lived here.