關(guān)于潮汐你需要知道什么

關(guān)于潮汐你需要知道什么

When we talk about tides, most of us think it's when the ocean is higher or lower on the beach. But there's so much more to know.

當(dāng)我們談?wù)摮毕臅r(shí)候，我們大多數(shù)人認(rèn)為是當(dāng)海洋在海灘上高或低的時(shí)候。但還有很多東西需要了解。

Photo: Spencer Dybdahl Riffle/MNN Flickr Group

For starters, high tide is actually the crest of a really long wave. The highest tides in the world are found at the Bay of Fundy in Nova Scotia, where they have a range of 44.6 feet, but it's the same process happening everywhere.

首先，漲潮實(shí)際上是一個非常長的波浪的頂峰。世界上最高的潮汐出現(xiàn)在新斯科舍省的芬迪灣，其范圍為44.6英尺，但世界各地都在經(jīng)歷著同樣的過程。

NOAA explains it best:

NOAA對此做了最好的解釋:

"Tides are very long-period waves that move through the oceans in response to the forces exerted by the moon and sun. Tides originate in the oceans and progress toward the coastlines where they appear as the regular rise and fall of the sea surface. When the highest part, or crest, of the wave reaches a particular location, high tide occurs; low tide corresponds to the lowest part of the wave, or its trough. The difference in height between the high tide and the low tide is called the tidal range."

“潮汐是一種非常長的周期波，它在月球和太陽的作用下穿過海洋。潮汐起源于海洋，并向海岸線推進(jìn)，在海岸線上，潮汐表現(xiàn)為海面有規(guī)律的漲落。當(dāng)波浪的最高部分或波峰到達(dá)某一特定位置時(shí)，就會出現(xiàn)漲潮;退潮對應(yīng)于波浪的最低部分，或波谷。漲潮和退潮之間的高度差稱為潮差。”

The moon's gravitational pull causes the tides, but the sun's gravitational pull also plays a role. The sun's gravitational force is only about 46% of the moon's, which means its pull on Earth's oceans is smaller and so too is its effect on the tides. When the moon, the sun and Earth are aligned, the pull of the sun adds to the pull of the moon and causes extreme tides — or, extra long waves.

月球的引力引起潮汐，但太陽的引力也起作用。太陽的引力只有月球的46%，這意味著它對地球海洋的引力更小，對潮汐的影響也更小。當(dāng)月亮、太陽和地球排成一線時(shí)，太陽的引力加上月亮的引力，就會引起極端的潮汐，或者說是超長的波浪。

This relationship also comes into play when we talk about king tides, a topic that comes up when a storm is on the horizon. King tides are simply an unscientific term used to describe really high tides. When the moon is closest to Earth — a state called perigee — and this coincides with a full or a new moon, this pushes the tidal range slightly higher.

當(dāng)我們談?wù)摮毕鯐r(shí)，這種關(guān)系也會發(fā)揮作用，當(dāng)暴風(fēng)雨即將來臨時(shí)，這個話題就會出現(xiàn)。國王潮汐只是一個不科學(xué)的術(shù)語，用來描述真正的高潮。當(dāng)月球離地球最近的時(shí)候——一個叫做近地點(diǎn)的狀態(tài)——與滿月或新月同時(shí)出現(xiàn)，這就把潮汐范圍推高了一點(diǎn)。

And when you throw a tropical storm or hurricane into the mix, things really get interesting because a storm system actually pushes more water ahead of it before it even makes landfall. Case in point, as Hurricane Dorian gets closer to the Florida coast, the tides become a bigger factor in how much damage is possible.

當(dāng)你把熱帶風(fēng)暴或颶風(fēng)混合在一起的時(shí)候，事情就變得有趣了，因?yàn)轱L(fēng)暴系統(tǒng)實(shí)際上在登陸之前就把更多的水推到了前面。舉個例子，當(dāng)颶風(fēng)多里安(Dorian)逼近佛羅里達(dá)州海岸時(shí)，潮汐成為可能造成多大破壞的一個更大因素。

"The fact that this storm is hitting during some of the highest tides of the year is very concerning," CNN meteorologist Brandon Miller said. "The King Tides adding a couple of feet to the water height is almost like the storm being a category higher on scale."

美國有線電視新聞網(wǎng)氣象學(xué)家布蘭登·米勒說:“事實(shí)上，這場風(fēng)暴是在今年一些最高的潮汐期間襲擊的，這是非常令人擔(dān)憂的。”“主潮使水位上升了幾英尺，這幾乎就像暴風(fēng)雨在規(guī)模上是一個更高的類別。”