If the salinity1 of ocean waters is analyzed2, it is found to vary only slightly from place to place. Nevertheless, some of these small changes are important. There are three basic processes that cause a change in oceanic salinity. One of these is the subtraction3 of water from the ocean by means of evaporation4--- conversion6 of liquid water to water vapor5. In this manner the salinity is increased, since the salts stay behind. If this is carried to the extreme, of course, white crystals of salt would be left behind.
The opposite of evaporation is precipitation, such as rain, by which water is added to the ocean. Here the ocean is being diluted8 so that the salinity is decreased. This may occur in areas of high rainfall or in coastal9 regions where rivers flow into the ocean. Thus salinity may be increased by the subtraction of water by evaporation, or decreased by the addition of fresh water by precipitation or runoff.
Normally, in tropical regions where the sun is very strong, the ocean salinity is somewhat higher than it is in other parts of the world where there is not as much evaporation. Similarly, in coastal regions where rivers dilute7 the sea, salinity is somewhat lower than in other oceanic areas.
A third process by which salinity may be altered is associated with the formation and melting of sea ice. When sea water is frozen, the dissolved materials are left behind. In this manner, sea water directly materials are left behind. In this manner, sea water directly beneath freshly formed sea ice has a higher salinity than it did before the ice appeared. Of course, when this ice melts, it will tend to decrease the salinity of the surrounding water.
In the Weddell Sea Antarctica, the densest10 water in the oceans is formed as a result of this freezing process, which increases the salinity of cold water. This heavy water sinks and is found in the deeper portions of the oceans of the world.
海水鹽度如果我們分析海水的鹽度，會發(fā)現(xiàn)地區(qū)間只有輕微的變化，然而有些小的變化是重要的。
導(dǎo)致海洋的鹽度變化的基本過程有三個，其中之一是通過蒸發(fā)的方式即把液態(tài)水轉(zhuǎn)化為水蒸氣來減少海洋中的水分。這樣由于鹽留了下來，所以鹽度增大。
當(dāng)然，如果這種方式走向極端，將會余下白色的鹽晶體。與蒸發(fā)相反的是降水，如降雨，由此水被加入海中，海水被稀釋，從而鹽度降低。
這種情形會發(fā)生在大量降雨的地區(qū)，或江河入海岸處。因此，鹽度通過蒸發(fā)減少水分而上升或通過降水或徑流增加淡水成分而下降。一般來說，在陽光很
強烈的熱帶地區(qū)，海水的鹽度略高于世界上其它沒有熱帶那樣多的蒸發(fā)的地區(qū)。同理，在江河稀釋海水的海岸地帶，海水鹽度略低于其它海區(qū)。
第三個可以變更鹽度的過程與海洋中冰的形成和融化有關(guān)。海水凍結(jié)時，溶于其中的物質(zhì)被留了下來。這樣，在新形成的海
水冰面的正下方的海水比在冰形成之前有更高的鹽度。當(dāng)然，當(dāng)冰融化的時候，會降低周圍水中的鹽度。
在南極洲邊緣的威德爾海中，結(jié)冰過程增加低溫海水的鹽度，從而形成了濃度的海水。這些大密度的海水下沉，可以在世界海洋的深水域發(fā)現(xiàn)。
1 salinity
n.鹽分；咸度；鹽濃度；咸性
參考例句：
In the sea water sampled the salinity is two parts per thousand.在取樣的海水中，鹽度為千分之二。
In many sedimentary basins the salinity of the formation water increases with depth or compaction.在許多沉積盆地中，地層水的含鹽量隨深度或壓實作用而增高。
2 analyzed
v.分析( analyze的過去式和過去分詞 )；分解；解釋；對…進行心理分析
參考例句：
The doctors analyzed the blood sample for anemia. 醫(yī)生們分析了貧血的血樣。 來自《簡明英漢詞典》
The young man did not analyze the process of his captivation and enrapturement, for love to him was a mystery and could not be analyzed. 這年輕人沒有分析自己蠱惑著迷的過程，因為對他來說，愛是個不可分析的迷。 來自《簡明英漢詞典》
3 subtraction
n.減法，減去
參考例句：
We do addition and subtraction in arithmetic.在算術(shù)里,我們作加減運算。
They made a subtraction of 50 dollars from my salary.他們從我的薪水里扣除了五十美元。
4 evaporation
n.蒸發(fā)，消失
參考例句：
Be careful not to lose too much liquid by evaporation.小心不要因蒸發(fā)失去太多水分。
Our bodies can sweat,thereby losing heat by evaporation.我們的身體能出汗，由此可以蒸發(fā)散熱。
5 vapor
n.蒸汽，霧氣
參考例句：
The cold wind condenses vapor into rain.冷風(fēng)使水蒸氣凝結(jié)成雨。
This new machine sometimes transpires a lot of hot vapor.這部機器有時排出大量的熱氣。
6 conversion
n.轉(zhuǎn)化，轉(zhuǎn)換，轉(zhuǎn)變
參考例句：
He underwent quite a conversion.他徹底變了。
Waste conversion is a part of the production process.廢物處理是生產(chǎn)過程的一個組成部分。
7 dilute
vt.稀釋，沖淡；adj.稀釋的，沖淡的
參考例句：
The water will dilute the wine.水能使酒變淡。
Zinc displaces the hydrogen of dilute acids.鋅置換了稀酸中的氫。
8 diluted
無力的，沖淡的
參考例句：
The paint can be diluted with water to make a lighter shade. 這顏料可用水稀釋以使色度淡一些。
This pesticide is diluted with water and applied directly to the fields. 這種殺蟲劑用水稀釋后直接施用在田里。
9 coastal
adj.海岸的，沿海的，沿岸的
參考例句：
The ocean waves are slowly eating away the coastal rocks.大海的波浪慢慢地侵蝕著岸邊的巖石。
This country will fortify the coastal areas.該國將加強沿海地區(qū)的防御。
10 densest
密集的( dense的級 )； 密度大的； 愚笨的； （信息量大得）難理解的
參考例句：
Past Botoi some of the densest jungle forests on Anopopei grew virtually into the water. 過了坊遠灣，島上的莽莽叢林便幾乎直長到水中。
Earth is the densest of all of these remaining planets. 地球是所剩下行星中最致密的星球。
The opposite of evaporation is precipitation, such as rain, by which water is added to the ocean. Here the ocean is being diluted8 so that the salinity is decreased. This may occur in areas of high rainfall or in coastal9 regions where rivers flow into the ocean. Thus salinity may be increased by the subtraction of water by evaporation, or decreased by the addition of fresh water by precipitation or runoff.
Normally, in tropical regions where the sun is very strong, the ocean salinity is somewhat higher than it is in other parts of the world where there is not as much evaporation. Similarly, in coastal regions where rivers dilute7 the sea, salinity is somewhat lower than in other oceanic areas.
A third process by which salinity may be altered is associated with the formation and melting of sea ice. When sea water is frozen, the dissolved materials are left behind. In this manner, sea water directly materials are left behind. In this manner, sea water directly beneath freshly formed sea ice has a higher salinity than it did before the ice appeared. Of course, when this ice melts, it will tend to decrease the salinity of the surrounding water.
In the Weddell Sea Antarctica, the densest10 water in the oceans is formed as a result of this freezing process, which increases the salinity of cold water. This heavy water sinks and is found in the deeper portions of the oceans of the world.
海水鹽度如果我們分析海水的鹽度，會發(fā)現(xiàn)地區(qū)間只有輕微的變化，然而有些小的變化是重要的。
導(dǎo)致海洋的鹽度變化的基本過程有三個，其中之一是通過蒸發(fā)的方式即把液態(tài)水轉(zhuǎn)化為水蒸氣來減少海洋中的水分。這樣由于鹽留了下來，所以鹽度增大。
當(dāng)然，如果這種方式走向極端，將會余下白色的鹽晶體。與蒸發(fā)相反的是降水，如降雨，由此水被加入海中，海水被稀釋，從而鹽度降低。
這種情形會發(fā)生在大量降雨的地區(qū)，或江河入海岸處。因此，鹽度通過蒸發(fā)減少水分而上升或通過降水或徑流增加淡水成分而下降。一般來說，在陽光很
強烈的熱帶地區(qū)，海水的鹽度略高于世界上其它沒有熱帶那樣多的蒸發(fā)的地區(qū)。同理，在江河稀釋海水的海岸地帶，海水鹽度略低于其它海區(qū)。
第三個可以變更鹽度的過程與海洋中冰的形成和融化有關(guān)。海水凍結(jié)時，溶于其中的物質(zhì)被留了下來。這樣，在新形成的海
水冰面的正下方的海水比在冰形成之前有更高的鹽度。當(dāng)然，當(dāng)冰融化的時候，會降低周圍水中的鹽度。
在南極洲邊緣的威德爾海中，結(jié)冰過程增加低溫海水的鹽度，從而形成了濃度的海水。這些大密度的海水下沉，可以在世界海洋的深水域發(fā)現(xiàn)。
1 salinity
n.鹽分；咸度；鹽濃度；咸性
參考例句：
In the sea water sampled the salinity is two parts per thousand.在取樣的海水中，鹽度為千分之二。
In many sedimentary basins the salinity of the formation water increases with depth or compaction.在許多沉積盆地中，地層水的含鹽量隨深度或壓實作用而增高。
2 analyzed
v.分析( analyze的過去式和過去分詞 )；分解；解釋；對…進行心理分析
參考例句：
The doctors analyzed the blood sample for anemia. 醫(yī)生們分析了貧血的血樣。 來自《簡明英漢詞典》
The young man did not analyze the process of his captivation and enrapturement, for love to him was a mystery and could not be analyzed. 這年輕人沒有分析自己蠱惑著迷的過程，因為對他來說，愛是個不可分析的迷。 來自《簡明英漢詞典》
3 subtraction
n.減法，減去
參考例句：
We do addition and subtraction in arithmetic.在算術(shù)里,我們作加減運算。
They made a subtraction of 50 dollars from my salary.他們從我的薪水里扣除了五十美元。
4 evaporation
n.蒸發(fā)，消失
參考例句：
Be careful not to lose too much liquid by evaporation.小心不要因蒸發(fā)失去太多水分。
Our bodies can sweat,thereby losing heat by evaporation.我們的身體能出汗，由此可以蒸發(fā)散熱。
5 vapor
n.蒸汽，霧氣
參考例句：
The cold wind condenses vapor into rain.冷風(fēng)使水蒸氣凝結(jié)成雨。
This new machine sometimes transpires a lot of hot vapor.這部機器有時排出大量的熱氣。
6 conversion
n.轉(zhuǎn)化，轉(zhuǎn)換，轉(zhuǎn)變
參考例句：
He underwent quite a conversion.他徹底變了。
Waste conversion is a part of the production process.廢物處理是生產(chǎn)過程的一個組成部分。
7 dilute
vt.稀釋，沖淡；adj.稀釋的，沖淡的
參考例句：
The water will dilute the wine.水能使酒變淡。
Zinc displaces the hydrogen of dilute acids.鋅置換了稀酸中的氫。
8 diluted
無力的，沖淡的
參考例句：
The paint can be diluted with water to make a lighter shade. 這顏料可用水稀釋以使色度淡一些。
This pesticide is diluted with water and applied directly to the fields. 這種殺蟲劑用水稀釋后直接施用在田里。
9 coastal
adj.海岸的，沿海的，沿岸的
參考例句：
The ocean waves are slowly eating away the coastal rocks.大海的波浪慢慢地侵蝕著岸邊的巖石。
This country will fortify the coastal areas.該國將加強沿海地區(qū)的防御。
10 densest
密集的( dense的級 )； 密度大的； 愚笨的； （信息量大得）難理解的
參考例句：
Past Botoi some of the densest jungle forests on Anopopei grew virtually into the water. 過了坊遠灣，島上的莽莽叢林便幾乎直長到水中。
Earth is the densest of all of these remaining planets. 地球是所剩下行星中最致密的星球。