Why Mediteranian sea has the same dew point like tropical and humid subtropical regions, but weather is not tropical or humid subtropical?
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@vujacicm
Dew point is not the only one criterion to charachterize the CLIMATE of a region. Many other parameters must considered (especialy temperature).
e.g. In the map you provide, Sahara desert has the same d.p. with England and of course they don't have the same climate! -
@Gkikas-LGPZ Also surface temperature is in Mediteranian sea the same like in tropical in subtropical regions. Probably events on upper troposhphere are more important. Because if we focus only on surface, we can say: "Mediteranian sea is humid subtropical region."
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@vujacicm said in Why Mediteranian sea has the same dew point like tropical and humid subtropical regions, but weather is not tropical or humid subtropical?:
"Mediteranian sea is humid subtropical region."
Reason why there are tropical cyclones-like in Mediterranean Sea, the medicanes.
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@idefix37 But not in the summer.
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@vujacicm
At the end of summer, like for tropical cyclones in tropical areas, when sea temperature is at its maximum (September, October) -
@idefix37 But is still difference between Mediteranian sea and south-east USA.
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@vujacicm said in Why Mediteranian sea has the same dew point like tropical and humid subtropical regions, but weather is not tropical or humid subtropical?:
But is still difference between Mediteranian sea and south-east USA.
OF course, it is obvious !
And from your point of view, if "we can say: "Mediteranian sea is humid subtropical region", there is no difference between Mediterranean Sea and humid tropical regions !
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@idefix37 I think I realrned something. 2m dew point is from precipitation view important only for ants. When temperature reach dew point, ants would say: "Hey, it's rainy today." But for humans this is important for from apperent view. High dew point = high discomfort
For human probablly levels, lower then 850mb are not important. Fix me, if I am not right.
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For humans, levels below 850 hPa are important.
You should note that when drawing climate conclusions, you should avoid using maps on a meteorological scale. A map forecast for an xx-hour on an yy-day does not give you a climate average. -
@idefix37 On surface is always very high humidity like in tropical regions, that's why I wrote this post. Otherwise I would just ignore it.
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@vujacicm Situation after 1 week is the same.
High dew point on both surface, south-east USA and Mediteranian.
And high only on south-east USA, but not in Mediteranian on 850mb.
We are now more close to climate. Looks like that level 850mb is in south-east tropical and on Mediteranian (dry) subtropical. Maybe is really here the key.
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@vujacicm A big difference is the location within the larger global circulation belts. Hot air rises in the tropics, and that rising motion creates clouds and thunderstorms. The air spreads north and south from the equator and cools as it does so.
Cool air is denser than warm air and sinks to the ground. Around 30°N and 30°S, the air is sinking. You need to lift moisture to create clouds. Because the air over the Mediterranean is sinking, that high moisture content is trapped near the surface and does not form clouds.
This describes conditions generally and there are obviously times when there are storms along the Mediterranean, but this is why precipitation values there are far lower than in the tropics over the course of the year. This is also why the world's major warm deserts (Sahara, Gobi, Mojave) are located near 30° from the equator.
For a more detailed discussion, see this Wikipedia article: https://en.wikipedia.org/wiki/Hadley_cell
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@mark-ingalls This is what I also have in mind. Surface in Mediteranian can be the same like in south-east USA. But if can not lift, precipitation will not happend. In case of Sahara, there is low dewpoint in both, surface and 850mb.
But if you look Canarian current, there even sea surface has low dewpoint.
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@vujacicm The SE United States benefits from dense vegetation which adds additional moisture due to evapotranspiration. Italy does get pretty moist thunderstorms during the summer as moist air comes onshore, similar to Florida. In those regions it is both terrain and the boundary between onshore and offshore flow that generates the lift needed for storm development.
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@mark-ingalls The same is in Slovenia, where I live. Now we have heatwave with dew point 15+ and 30+ temperature. In Madrid at the same time is 10 degress dew point and 30+ degress and more easy to tolerate. North Adriatic is very humid place. And here even in the summer have a lot of thunderstorms. Last year we had high floods that destroy some villages in Slovenia in start of Avgust. On 850mb dew point is the same like in south Mediteranian, but because are is colder, can condensate even with low dew point. So North Adriatic climate is humid subtropical on sea level, on higher elevations is oceanic. On the other side is Egypt, who has desert climate, even if it's on Mediteranian sea. But rest has mediteranian climate.
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You're right, the Mediterranean Sea can have dew points similar to tropical and humid subtropical regions, but the overall climate is different. Here's why:
Dew Point vs. Climate:
Dew Point: Dew point is a measure of moisture content in the air. High dew point indicates more moisture, potentially leading to humid conditions.
Climate: Climate encompasses a region's long-term weather patterns, including temperature, precipitation, and wind. It's influenced by factors like latitude, ocean currents, and prevailing winds.
The Mediterranean Case:Warm Sea: The Mediterranean Sea acts as a giant heat reservoir, absorbing warmth during summer. This warmth translates to high dew points in the surrounding air, similar to tropical or humid subtropical regions.
Seasonal Shifts: However, the Mediterranean climate experiences distinct seasons. Unlike true tropical or humid subtropical regions with consistent warmth and high precipitation, the Mediterranean has:
Hot, Dry Summers: Prevailing winds shift, bringing dry air from landmasses, leading to hot and dry summers.
Cool, Wet Winters: Westerly winds from the Atlantic bring cooler temperatures and precipitation, creating a milder and wetter winter season. -
@Mia-Luna Even in the winter surface dew point is very high in Mediteranian sea. On higher elevation is different. In the summer, dew point is low, on winter become higher because Atlantic air reach Mediteranian sea. In humid subtropical regions opposite happens. In the winter dew point is higher on higher elevations then in the summer. This is what I see here.
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@vujacicm said in Why Mediteranian sea has the same dew point like tropical and humid subtropical regions, but weather is not tropical or humid subtropical?:
Even in the winter surface dew point is very high in Mediteranian sea. On higher elevation is different. In the summer, dew point is low, on winter become higher because Atlantic air reach Mediteranian sea. In humid subtropical regions opposite happens. In the winter dew point is higher on higher elevations then in the summer. This is what I see here.
You're right! The Mediterranean flips dew point trends compared to humid subtropical regions due to winter Atlantic air. Winter brings moist air, while summer brings hot, dry air.
