消融的格陵蘭 Greenland Is Melting Away
ON THE GREENLAND ICE SHEET — The midnight sun still gleamed at 1 a.m. across the brilliant expanse of the Greenland ice sheet. Brandon Overstreet, a doctoral candidate in hydrology at the University of Wyoming, picked his way across the frozen landscape, clipped his climbing harness to an anchor in the ice and crept toward the edge of a river that rushed downstream toward an enormous sinkhole.
格陵蘭冰蓋——凌晨1點，子夜太陽仍在照射着廣闊的格陵蘭冰蓋。懷俄明大學(University of Wyoming)水文學博士研究生布蘭登·奧弗斯特里特(Brandon Overstreet)在這片冰面上小心翼翼，將他的安全帶繫到冰層中的一個錨上，朝着一條向下流入巨大深坑的河流的邊緣徐徐前進。
If he fell in, “the death rate is 100 percent,” said Overstreet's friend and fellow researcher, Lincoln Pitcher.
奧弗斯特里特的朋友、同爲研究員的林肯·皮徹(Lincoln Pitcher)說，如果他掉進去了，“百分之百會死。”
But Overstreet's task, to collect critical data from the river, is essential to understanding one of the most consequential impacts of global warming. The scientific data he and a team of six other researchers collect here could yield groundbreaking information on the rate at which the melting of Greenland ice sheet, one of the biggest and fastest-melting chunks of ice on Earth, will drive up sea levels in the coming decades. The full melting of Greenland's ice sheet could increase sea levels by about 20 feet.
奧弗斯特里特的任務是從水中收集重要數據，這對了解全球變暖最重要的影響來說是必不可少的。他和其他六名研究員組成的團隊在這裏收集的科學數據，可能會提供有關格陵蘭冰蓋融化速度的突破性信息。該冰蓋是世界上最大且融化速度最快的冰塊之一，會在未來幾十年擡高海平面。格陵蘭冰蓋全部融化會將海平面擡高20英尺。
This summer in Greenland, the scientists set up camp on the ice, where they hoped to capture the first comprehensive measurements of the rate of melting. Their research could yield valuable information to help scientists figure out how rapidly sea levels will rise in the 21st century, and thus how people in coastal areas from New York to Bangladesh could plan for the change.
今年夏季，科學家們在格陵蘭冰蓋上搭起帳篷，他們希望在這裏獲取首批有關融化速度的全面測量數據。他們的研究可能會提供具有價值的信息，幫助科學家們瞭解海平面在21世紀的擡升速度，以及從紐約到孟加拉國等沿海地帶的居民該如何應對這種變化。
For years, scientists have studied the impact of the planet's warming on the Greenland and Antarctic ice sheets. But while researchers have satellite images to track the icebergs that break off, and have created models to simulate the thawing, they have little on-the-ground information and so have trouble predicting precisely how fast sea levels will rise.
科學家們多年來一直研究全球變暖對格陵蘭和南極冰蓋的影響。但當研究人員通過衛星圖像追蹤破裂冰山的情況，創建模型來模擬這種融化時，他們獲得的實地信息很少，因此難以精確預測海平面的擡升速度。
But the research is under increasing fire by some Republican leaders in Congress, who deny or question the scientific consensus that human activities contribute to climate change.
但這項研究遭到國會中一些共和黨領袖日益強烈的抨擊，他們否認或質疑一個科學共識，即人類活動在一定程度上導致氣候變化。
Getting Ready
做好準備
In July, Smith's team arrived in Kangerlussuaq, Greenland, a dusty outpost of 512 people on the island's southwest coast, which serves as a base for researchers to prepare for fieldwork on the ice sheet.
史密斯的團隊於今年7月抵達格陵蘭島康克魯斯瓦格，這是位於西南沿海的一個灰塵漫天的偏遠地帶，只有512名居民，充當研究人員冰蓋實地考察工作的準備基地。
The scientists were excited but anxious as they prepared to travel inland by helicopter to do the fieldwork at the heart of their research: For 72 hours, every hour on the hour, they would stand watch by a supraglacial watershed, taking measurements — velocity, volume, temperature and depth — from the icy bank of the rushing river.
科學家們準備乘坐直升機前往內陸，深入研究的核心地帶開展實地考察：接下來72個小時，他們每時每刻都要在一個冰面分水線邊值班，站在結冰的河岸上，測量這條湍急河流的流速、流量、溫度及深度。
“No one has ever collected a data set like this,” Asa Rennermalm, a professor of geography at the Rutgers University Climate Institute who was running the project with Smith, told the team over a lunch of musk ox burgers at the Kangerlussuaq airport cafeteria.
“從來沒有人這樣收集數據，”羅格斯大學氣候研究所(Rutgers University Climate Institute)的地理學教授阿薩·倫納馬爾姆(Asa Rennermalm)在康克魯斯瓦格機場餐廳一邊吃午餐——麝牛漢堡，一邊這樣對團隊說。倫納馬爾姆與史密斯是項目負責人。
Taking each measurement was so difficult and dangerous that it would require two scientists at a time, she said. They would have to plan a sleep schedule to ensure that a group was always awake to do the job. Everyone knew the team would be working just upriver from the moulin — the sinkhole that would sweep anyone who fell into it deep into the ice sheet.
她表示，獲取每個測量數據的過程都很艱難、危險，需要兩名科學家同時作業。他們需要制定一個作息時間表，以確保一直有人做這項工作。大家都知道，該團隊將在冰川鍋穴上游工作——人掉入這個沉洞後就會被捲入水中，墜入冰蓋底層。
As the researchers began to set up camp, Overstreet, the University of Wyoming doctoral student, headed toward the river, silent as it sliced through the ice. More than any other member of the team, the success of the mission rested on his shoulders.
在研究人員開始搭建帳篷的同時，懷俄明大學水文學博士研究生奧弗斯特里特向着這條靜靜地穿過冰層的河流前行。他的工作對這個團隊的成敗格外關鍵。
Overstreet, 31, who grew up kayaking and rafting in Oregon, had designed the rope-and-pulley system — modeled on swift-water boat rescue systems — that would be crucial to gleaning data from the treacherous waters. He had spent months refining and practicing his system on rivers in Wyoming.
31歲的奧弗斯特里特在俄勒岡州長大，從小玩皮划艇和木筏。他仿照激流皮划艇救援系統設計了繩索滑輪系統，這對從危險水域中收集數據的工作至關重要。他曾花了數月時間在懷俄明州的河流中對該系統進行改進、操練。
On the Ice
冰上的工作
The team soon got to work. A helicopter pilot flew two of Overstreet's colleagues, Pitcher and Matthew Cooper, across the 60-foot river. On the opposite bank they drilled into the ice, attached an anchor and harnessed themselves to it for safety. They attached a nylon line to the anchor, with the rest of the line coiled in a heavy bag.
團隊很快就投入工作。一名直升機飛行員帶着奧弗斯特里特的兩名同事皮徹和馬修·庫珀(Matthew Cooper)飛越60英尺寬的河流。在河對岸，他們在冰層上鑽洞，將錨放置在冰層中，並將安全帶繫到錨上，以保證安全。他們將一根尼龍繩繫到錨上，剩下的繩子盤繞在一個沉重的袋子中。
Now came the crucial part: The men took turns hurling the bag across the river, but it repeatedly fell into the water. After an anxious half-hour, Cooper finally got the rope across. Overstreet caught it and began setting up the rope-and-pulley system he had been testing for so long.
接下來就是關鍵部分：他們輪流將袋子扔到河對岸，但袋子多次掉進水中。折騰了半小時後，庫珀最終將繩子扔到對岸。奧弗斯特里特拿到了繩子，開始建立他測試了很久的繩索滑輪系統。
On the edge of camp, Johnny Ryan, a doctoral candidate in geography at Aberystwyth University in Wales, launched an airplane-shaped drone from a slingshot-like device, then guided it over a nearly 75-square-mile area. Then the drone went silent. “It stopped talking to me, and now it's crashed in the wilderness,” Ryan said.
在營地的邊緣，威爾士阿伯里斯特維斯大學(Aberystwyth University)地理學博士研究生約翰尼·瑞安(Johnny Ryan)用一個類似彈弓的裝置把飛機形狀的無人機發射出去，然後操控它在一塊將近75平方英里的區域上空飛行。接着無人機的聲音消失了。“它跟我斷絕聯繫了，現在已經墜毀在曠野裏，”瑞安說。
Ryan, who wore a hot-pink knit cap and purple sunglasses that set off his red beard, launched his backup drone. Feeling stressed, he monitored its flight nervously as the hours rolled by, drinking tea to keep warm.
瑞安戴着亮粉針織帽和紫色太陽鏡，跟他的紅鬍子很搭配。他啓動了一架後備的無人機。而後的幾個小時裏，他一邊喝茶取暖，一邊緊張地監控無人機的飛行。
At the riverbank, Overstreet and Pitcher started the data collection by clipping a device that looked like a boogie board to the line running across the river. Every hour they sent it back and forth to measure the water's depth, velocity and temperature.
在河岸邊，奧弗斯特里特和皮徹開始收集數據，將看起來像是滑板的裝置繫到跨越河流的繩子上。他們每小時都會來回推送該裝置，以測量水深、水流速度和水溫。
But as the day stretched into night, the device's battery, sapped by the cold, began to die. By now the sun had dropped lower, filling the sky with a spectacular orange glow. The scientists were worried — the death of the battery would mean the death of their mission.
但隨着夜幕的降臨，在嚴寒的侵蝕下，裝置的電池開始耗盡。現在太陽已經慢慢落下，壯觀的橙色光亮照亮整個天空。科學家們擔心——電池的耗盡意味着任務的終結。
An idea occurred to Overstreet. He found a roll of heat-reflecting silver sheeting at the camp and wrapped it around the boogie board battery. During the next run across the river, it stayed alive.
奧弗斯特里特想到了一個主意。他在營地裏找到了一卷銀色的熱反射薄膜，裹到電池上。下一次穿越河流時，裝置還能運轉。
But the battery continued to wane, so Pitcher took gel hand warmers from his gloves and tucked them into the battery's silver jacket. Success. The battery stayed warm and functional.
但電量在繼續減少，皮徹拿出了手套中的膠體暖手包，將它們塞進電池的銀色外殼。成功。電池得以保持溫度，繼續起作用。
For three days and three nights, the scientists continued to measure the river, as up to 430,000 gallons of water a minute poured off the ice and into the moulin. On the final morning, the team, tired but elated, gathered by the river as the boogie board made its final trip. By then, Ryan's backup drone had safely completed its mapping mission. Overstreet broke open a celebratory bag of dried mangoes — a lavish treat for the ice campers.
科學家們連續三天三夜對河水進行測量，每分鐘多達43萬加侖的水從冰層中涌出，流入冰川鍋穴。在最後一天的清晨，滑板裝置最後一次進行測量時，這個疲憊但又興奮的團隊聚集在河邊。此時瑞安的後備無人機也平安完成測繪任務。奧弗斯特里特打開了一包芒果乾，以示慶祝——這對於冰上露營者來說是一種奢侈。
