(开场白) 夏天去过旧金山，尤其是黄昏到过金门大桥的人，应该见识过旧金山的海雾。学过海洋气象的我，偶尔也会润色几篇关于青岛海雾的文章。但是，下面这篇文章让我第一次知道海雾对人类生存的重要性。

The Elusive Future of San Francisco’s Fog

难以捉摸的旧金山雾的未来

John Branch, a Times reporter based in the Bay Area, and photographer Nina Riggio spent months chasing fog in and around San Francisco. Scott Reinhard, a Times graphics editor, worked with researchers to visualize decades of fog data.

Sept. 14, 2022

 （原文发表在NYT） 

第1部分：https://blog.sciencenet.cn/home.php?mod=space&uid=306792&do=blog&id=1355804

（在第1部分下面，有链接看第2部分…）

The late San Francisco newspaper columnist Herb Caen had a lifelong love affair with the city’s fog.

已故的旧金山报刊专栏作家 卡昂(Herb Caen), 终生喜爱旧金山海雾。

“The miraculous thing about the annual summer miracle is that the miracle continues,” he wrote in 1993. “The countryside sizzles, the Midwest fries when it isn’t drowning, the Right Coast is in its ‘it ain’t the heat, it’s the humidity’ miseries, but in San Francisco we are cool, if not, at times, downright cold.”

Caen considered foghorns the music of the gods.

他在 1993 年写道：“一年一度的夏季奇迹的神奇之处在于，奇迹还在继续。” “乡村被晒得咝咝作响。中西部地区如果没有被淹，就会干旱。“右海岸”正处于那个‘不是炎热、而是闷热’的痛苦。但在旧金山，我们很酷（潇洒），如果不是有时感觉很冷的话。”

卡昂（Caen）认为雾角（或雾号，foghorns）是众神的音乐。

“The fog is on schedule, morning and night, billowing through the Golden Gate despite the indignant protests of the horns under the great bridge,” he added.

他补充说：“尽管大桥下的雾角发出愤怒的抗议（警告），海雾总是如期而至，早、晚都会涌过金门大桥。”

Far below the bridge’s deck, on a perch accessible by a tiny elevator, operating engineer Randy Rosenkild examined one of the five foghorns. They are shaped like trumpets. Two larger ones, 48 inches long, face in opposite directions near the base of the south tower. Three slightly smaller ones are tucked below the roadway near midspan.

远在桥面下方，一个小电梯可以到达的栖木上，操作工程师兰迪·罗森基尔德（Randy Rosenkild）检查了五个雾角中的一个。它们的形状像喇叭。两个较大的，长 48 英寸，在南塔底部附近朝着相反的方向。三个稍微小一点的被塞在靠近中跨的公路下方。

The larger ones have a specific signal: two seconds on, 18 seconds off, over and over. The others burp something quite different: one second on, two seconds off, one second on, 36 seconds off, repeat.

The idea is that mariners blinded by fog can guide themselves between the distinct sounds.

较大的雾角有一个特定的信号：呼唤两秒，停18 秒；一遍又一遍。较小的雾角有完全不同的发声：呼唤一秒，停两秒关，呼唤一秒，停36秒；重复。

这样，被海雾搞得眼花缭乱的水手们，可以在两种不同的雾角呼唤之间，确定自己的航向。

Their bellows can be heard more than two miles out to sea, and sometimes in nearby places like Sausalito and Berkeley. There is a chorus of other warnings, too, in the soup of fog. Large ships squawk foghorns of their own. Buoys in the water bleat.

雾角的呼唤声在两英里外的大海里都能听到；有时在索萨利托（Sausalito）和伯克利（Berkeley）等附近的地方也能听到。在浓雾中，还有其他警告声的伴唱。大型船只会发出自己的雾角呼唤声。水中的浮标，也发出咩咩声。

Residents sometimes phone the bridge and ask why the foghorns are on at all. It’s not foggy at their house, they say.

居民有时会打电话给桥上的工作人员，询问为什么雾角一直在响。他们说，他们家那里没有雾。

Mr. Rosenkild’s job is to make sure the huge horns do their important work. Fall — reliably sunny, rarely foggy — is his favorite time to clamber to their hidden homes under the bridge. Summer is his least.

“If you’ve never walked into thick fog, it will literally take your breath away with the chill factor,” Mr. Rosenkild said. “It’s so cold.”

罗森基尔德（Rosenkild）先生的工作是确保巨大的喇叭不出问题。秋天——阳光充足，很少有雾——是他最喜欢的季节；他需要爬到桥下雾角的隐蔽处去检修。他最不喜欢夏天。

“如果你以前从来没有走进过浓雾，那寒冷的感觉会让你大吃一惊，”罗森基尔德（Rosenkild）先生说。 “非常非常冷。”

There is little precision or pageantry to the use of the bridge’s foghorns. When the electrician on duty notes that it is too foggy to see across the mile-wide channel of the Golden Gate, the foghorns are turned on with a click of a computer mouse.

使用桥梁的雾角几乎没有什么精确性或壮观性。当值班的电工注意到金门一英里宽的通道中雾太大而无法看到时，只需单击计算机鼠标即可“吹响”雾角。

Inside a room on the south end of the bridge, Del West, an electrical superintendent, decided it was time. He warned workers all over the bridge by walkie-talkie, warned them again, then once more.

在桥南端的一个房间里，电气主管德尔·韦斯特（Del West）认为是时候了。他用对讲机警告桥上的所有工人，一遍又一遍。

The bellow of a foghorn can be deafening, or even more dangerous, to people nearby. “It can interrupt your heartbeat,” Mr. Rosenkild said. It didn’t sound like a joke.

Mr. West clicked an icon on the computer screen that read “fog horns.” A moment later, bass tones bellowed from the belly of the bridge.

雾角的轰鸣声对附近的人来说可能震耳欲聋、甚至更加危险。 “它会打断你的心跳，”罗森基尔德（Rosenkild）先生说。这听起来不像是个玩笑。

韦斯特（West）先生点击了电脑屏幕上的一个图标，上面写着“雾角”。片刻后，低音从大桥的腹部传来。

He logged the time into a book with a green canvas cover that read, “Records.” Electricians leave notes from their shifts there, including the use of fog horns.

Fog researchers might want to see those records, but Mr. West said that most of the log books have been lost to time. No one thought of the importance of tracking fog through history.

他将时间记录在一本绿色帆布封面的记事本中，上面写着“记录”。电工在那里留下他们轮班的笔记，包括使用雾角。

研究雾的科学家可能希望看到这些记录，但韦斯特（West）先生说，大部分日志都已经丢失了。以前没有人想到追踪雾的历史的重要性。

Out on the bridge, about 40 full-time painters continued their endless work. Under the thump-thump-thump of passing cars overhead, Mr. Dzierman and his crew sandblasted, primed and painted. Last year they spread 2,590 gallons of International Orange paint around the bridge.

在桥上，大约 40 名全职油漆工继续着他们没完没了的工作。在头顶过往车辆的砰砰砰砰声中，齐尔曼（ Dzierman）先生和他手下的工作人员进行磨砂、涂底漆和喷漆。去年，他们在大桥周围涂抹了 2,590 加仑国际橙色（International Orange）涂料。

They do their work where the structure needs it most. And more often than not, it is the west side, because of the effect of the fog from the ocean — the wind, the salt, the moisture.

他们在大桥结构最重要的地方工作。由于海雾的影响——风、盐、湿气的影响，通常是在西侧。

“The west side gets pounded,” Mr. Dzierman said. “Pounded.”

But he’d rather have fog than no fog.

“I’d miss it,” Mr. Dzierman said. “It’s part of the bridge, right? It’s part of San Francisco. It’s part of the Golden Gate.”

The fog bank lurked on the horizon, a ghostly tease.

“西区受到重创，”齐尔曼（Dzierman）先生说。 “一次次重创。”

但他宁愿有雾也不愿没有雾。

“我会想念它的，” 齐尔曼（Dzierman）先生说。 “它是桥的一部分，对吧？它是旧金山的一部分。它是金门大桥的一部分。”

雾堤在远处的地平线等待着，像幽灵般地挑逗金门大桥。

Additional credits

参与者

Produced by Claire O’Neill and Jesse Pesta.

Photo editing by Matt McCann.

3D fog illustration produced by Nicholas Bartzokas, Evan Grothjan, Miles Peyton and Scott Reinhard.

Data assistance by Josh Katz and Christine Zhang.

Design and development assistance by Michael Beswetherick and Jon Huang.

Audio produced by Adrienne Hurst.

由克莱尔·奥尼尔和杰西·佩斯塔制作。

照片由马特·麦肯编辑。

由 Nicholas Bartzokas 、Evan Grothjan 、Miles Peyton 和 Scott Reinhard 制作的 3D 雾插图。

Josh Katz 和 Christine Zhang 提供数据协助。

Michael Beswetherick和 Jon Huang 提供设计和开发协助。

由 Adrienne Hurst 制作的音频。

Sources and methodology

资料来源和计算方法

【译者注：我没有太细究。有问题的话，我们一起讨论。】

In the lead fog animation, we created wind direction and speed by using ERA5 climate reanalysis data from July 21–22, 2022, produced by the European Centre for Medium-Range Weather Forecasts, to drive a Houdini computational fluid dynamics simulation. The simulation collided with a surface model created from Bay Area elevation data produced by the United States Geological Survey. We limited fog height to 100 meters, roughly corresponding to summer fog patterns in San Francisco observed in satellite imagery. We then used noise patterns to style the fog with turbulence at higher resolutions than satellite imagery could provide.

在前导的雾动画中，我们使用欧洲中期天气预报中心 2022 年 7 月 21 日至 22 日的ERA5 气候再分析数据，建立风向和风速，以驱动 Houdini 计算流体动力学模拟。该模拟与根据美国地质调查局生成的湾区地形数据创建的表面模型相结合。我们将雾的高度限制在 100 米，大致对应于卫星图像中观察到的旧金山夏季雾分布。然后，我们使用比卫星图像提供的分辨率更高的湍流和噪声分布来“神化”雾。

The graphics depicting fog’s journey up the California coast and fog overlaid with the historic redwood habitat use satellite records of low coastal clouds collected from May to September over 25 years, from 1996 to 2020. In the animated map of fog’s journey up the coast from month to month, the transparency of the fog corresponds to the percent of time fog was observed at each location during an average day in each month over the 25-year period, adjusted for seasonality. In the map of coastal fog overlaid with the historic redwood habitat prior to commercial logging, the transparency corresponds to the percent of time fog was observed at each location during an average day over the 25-year period, averaging the data for all months. The fog and coastal low cloudiness data was provided by Rachel Clemesha, a project scientist at Scripps Institution of Oceanography at the University of California, San Diego. The averaging and seasonal adjustment calculations use the methodology described in Clemesha et al., Geophysical Research Letters (2016).

描绘雾在加州海岸的移动以及雾与历史悠久的红木栖息地重叠的图形，我们使用了1996～ 2020 年 25 年的 5 月～ 9 月收集的低海岸云的卫星记录。以月为单位。雾的透明度对应于在 25 年期间每个月的平均一天内每个点观察到雾的时间百分比，并根据季节性进行调整。【译者注：我晕！】在商业伐木之前与历史红杉栖息地重叠的沿海雾地图中，透明度对应于 25 年期间平均每天在每个位置观察到雾的时间百分比，对所有月份的数据进行平均。雾和沿海低云量数据由加州大学圣地亚哥分校斯克里普斯海洋研究所的专题科学家Rachel Clemesha提供。平均和季节性调整计算使用Clemesha等人，Geophysical Research Letters (2016)中描述的方法。

The graphics explaining the formation of fog incorporated various sources. Footage of fog and other cloud movement was captured on July 21, 2022, by the Geostationary Operational Environmental Satellite (GOES-17), operated by the National Oceanic and Atmospheric Administration. Animation of the wind in the North Pacific Ocean uses ERA5 climate reanalysis data from July 21–27, 2022, produced by the European Centre for Medium-Range Weather Forecasts. Footage of sea surface temperature overlaid with wind data uses the OI SST V2 High Resolution Dataset from July 21–27, 2022, produced by NOAA. Land temperature uses High-Resolution Rapid Refresh data from July 21–22, 2022, produced by NOAA. Average fog in July and August from 1996–2020 was provided by Rachel Clemesha.

解释雾形成的图形包含了各种来源。 2022 年 7 月 21 日，由美国国家海洋和大气管理局运行的地球静止运行环境卫星 (GOES-17) 捕获了雾和其他云运动的画面。北太平洋风的动画使用欧洲中期天气预报中心制作的 2022 年 7 月 21 日至 27 日的 ERA5 气候再分析数据。与风数据叠加的海面温度镜头使用由 NOAA 制作的 2022 年 7 月21 日至 27 日的 OI SST V2 高分辨率数据集。陆地温度使用 NOAA 制作的 2022 年7 月 21 日至 22 日的高分辨率快速刷新数据。 1996 ～2020 年的 7 月和 8 月的平均雾由 Rachel Clemesha提供。

The map of fog throughout the world shows average monthly data from 2007–2017 from the ISCCP-H series cloud data from NOAA/NCEI, where fog occurrence was above 50 percent. The animation of wind in this graphic is from May 1 to Sept. 30, 2021, using ERA5 climate reanalysis data produced by ECMRWF.

全球雾图显示了来自 NOAA/NCEI 的 ISCCP-H 系列云数据的 2007 ～ 2017 年的月平均数据，只要雾的发生率超过 50%。此图中的风动画是 2021 年 5 月 1 日至 9 月30 日，使用 ECMRWF 生成的 ERA5 气候再分析数据。

（续完）

感谢读者的鼓励。