Why does the salinity of the Mediterranean Sea near Mallorca affect the rate of evaporation compared to the Atlantic?

The salinity of the Mediterranean Sea near Mallorca plays a significant role in influencing the rate of evaporation compared to the adjacent Atlantic Ocean. Salinity refers to the concentration of dissolved salts in water, and higher salinity means there are more salt particles dissolved in the seawater. The Mediterranean, including the area around Mallorca, tends to have a higher salinity than the Atlantic because it is a nearly enclosed sea with limited exchange of water and higher rates of evaporation than precipitation. This elevated salt content changes the physical properties of the seawater, specifically the vapor pressure, which affects how quickly water molecules escape into the air.

Because salt ions interfere with water molecules’ ability to evaporate, seawater with higher salinity generally has a lower vapor pressure, meaning fewer water molecules have enough energy to transition into a gaseous state. However, in the Mediterranean near Mallorca, despite this lower vapor pressure of the saline water, the overall rate of evaporation can still be relatively high. This is due to the region’s warm climate, strong sunlight, and dry air—all of which enhance evaporation by providing the energy needed to break molecular bonds and by allowing the air to absorb more moisture. Thus, the saline Mediterranean waters experience a delicate balance where salinity slightly restrains evaporation, but environmental conditions amplify it.

In contrast, the Atlantic Ocean near Mallorca has lower salinity, as it benefits from larger volumes of open water and more frequent freshwater inputs from rain and rivers. The higher vapor pressure of the less salty Atlantic seawater makes it easier for evaporation to occur under similar temperature and humidity conditions. However, because the Atlantic is colder and has higher humidity near the surface, the overall evaporation rate may often be slower than in the Mediterranean despite its lower salinity. This shows how salinity is just one of several interacting factors, including temperature and atmospheric moisture, that collectively determine evaporation rates around Mallorca.

In summary, the greater salinity of the Mediterranean Sea near Mallorca reduces the vapor pressure of seawater and can slightly inhibit the rate of evaporation compared to the Atlantic. Nonetheless, the Mediterranean’s warmer, drier weather conditions usually lead to stronger evaporation despite this effect. The Atlantic’s lower salinity and cooler, moister environment produce different evaporation dynamics, making the interaction between salinity and evaporation a nuanced aspect of the region’s marine climate.