32 votes
Accepted

Why is the sea salinity high in the Mediterannean and Red Sea and low in Indonesia and Malaysia?

It has nothing (or very, very little) to do with desalinization plants. It has to do with the balance between Evaporation minus Precipitation (E-P), rivers, and advection. The link to E-P is the main ...
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  • 14.7k
8 votes
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FLUXNET15 - how to convert latent heat flux to actual evapotranspiration?

Yes. Evapotranspiration ($ET$) can be calculated from latent heat ($LE$) by dividing by latent heat of vaporization ($\lambda$) $$ ET = \frac{LE}{\lambda} $$ This assumes density of water equal to ...
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  • 96
8 votes

Why do anticyclones bring clear skies in summertime?

Why anticyclones are also called areas of high pressure Let's call anticyclones areas of high pressure. Areas of high pressure (anticyclones), pull air towards the earth's surface. The increase in ...
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  • 772
7 votes

Where does water vapor go/what does the sun do?

Simplistically, fog consists of water droplets. The sun provides energy, which heats the droplets and evaporates them, and also raises the air temperature. The water is still there, it's just in the ...
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  • 1,698
6 votes
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At what latitudes does the precipitation water for Europe evaporate?

A challenge is going to be "which moisture is from where". Because the atmosphere doesn't ever completely empty of moisture, for any given precipitation, which water molecules were from ...
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6 votes
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ERA5 mean evaporation rates data - Why is that negative?

Just leaving this for future readers. I finally found in some ECMWF documentation (referring to a different variable) that: "The ECMWF Integrated Forecasting System convention is that downward fluxes ...
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  • 1,258
6 votes
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How to find/calculate the yearly evaporation of a given area?

What you are asking is one of the most difficult issues in hydrology. The evaporation from open water is a function of air temperature, water temperature, humidity, wind speed and fetch, water depth, ...
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5 votes

Does negative reference evapotranspiration make sense using FAO Penman-Monteith equation?

We are calculating $ET_0$ on a 10 minute basis and ran into the same problem on http://lapalma.HDmeteo.com. I can confirm this problem with the FAO formula. We are clipping negative hourly values to ...
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  • 51
5 votes
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Does negative reference evapotranspiration make sense using FAO Penman-Monteith equation?

Short answer, especially if it is about 1% of the time series and these values are just slightly negative, this likely indicates that the ET needs to be recalibrated slightly, and for practical ...
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  • 751
5 votes
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How to interpret the negative (actual) evapotranspiration values?

Negative values for the ET, both potential and actual, usually refer to condensation. See also "ERA5 mean evaporation rates data - Why is that negative?" Regarding the ability of the ...
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  • 1,258
4 votes
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Does evaporated hand sanitizer pollute the environment?

Assuming you are talking about ethanol: it is a common chemical substance, generated naturally from e.g. rotting fruits. So any pollution from hand sanitizers should be negligible. What happens to the ...
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  • 156
4 votes

Sun's Effect on Water Vapor in the Air

You need to define what you mean by 'adding more sun'. I'm asuming you mean 'increase the solar constant'. The amount of water vapour in the air is, as a first order approximation, related to ...
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4 votes

In general, does the presence of vegetation increase/decrease gross water loss (evapotranspiration) compared to barren land (evaporation only)?

I think it is best to introduce some definitions. Often in such studies, two types of evapotranspiration (or evaporation, but I will stick to evapotranspiration during this answer for convenience) are ...
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  • 126
4 votes

In general, does the presence of vegetation increase/decrease gross water loss (evapotranspiration) compared to barren land (evaporation only)?

In addition to what has been (correctly) written in the other answers, I would like to add a couple of figures that could help to understand the dynamics involved: The first figure is borrowed from ...
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  • 1,258
4 votes

Where does water vapor go/what does the sun do?

The occurrence and disappearance of fog is due to the dew point, which is: the temperature at which the air can no longer "hold" all of the water vapor which is mixed with it, and some of ...
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  • 21.8k
3 votes

How to find/calculate the yearly evaporation of a given area?

Depending on the location, evaporation data is collected by some meteorological organisations. Class A pans or Symon's pans are used to collect daily evaporation data for selected sites. In Australia,...
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  • 21.8k
3 votes

Data of terrestrial evapotranspiration over large areas?

Millimeters per year measurements have an area component built into them, they're actually in cubic millimeters per square millimeter. So one millimeter of rainfall is enough to cover the given area ...
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  • 4,225
3 votes

When sea water evaporates does it carry small amounts of salt into the atmosphere?

Listen to your father ! Yes droplets of spray are carried on the wind several miles . There are any number of corrosion tables listing atmospheric corrosion more severe on sea coasts. Much of the ...
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3 votes

In general, does the presence of vegetation increase/decrease gross water loss (evapotranspiration) compared to barren land (evaporation only)?

In general, evapotranspiration from vegetated areas is greater than the bare soil evaporation. You are correct that vegetation will increase the boundary layer and thus reduce evaporation at the ...
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  • 4,319
3 votes

A simple formulation to calculate the sequence and rate of salt precipitation in a brine?

Here is a link to a hydrochemical consultant, Dr. C.A.J. Appelo, and the public-domain software FREEQC. It can be downloaded from here This link leads to an example of salt precipitation rates when ...
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3 votes

Cooling effect by evaporation

Someone (Casey?) can probably provide a fuller answer, but the basic idea is that ice molecules are kind of locked into place by the molecular structure of the ice crystal, and can't vibrate very much....
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3 votes

At what latitudes does the precipitation water for Europe evaporate?

I recently became aware of this dataset and paper, which I think is the sort of thing you're looking for: Tuinenburg et al (2020): Global evaporation to precipitation flows obtained with Lagrangian ...
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  • 3,303
2 votes

Recharge calculation for an aquifer

This methodology won't work. Haude's method only gives a rough estimate of evaporation. Consider the hydrologic cycle: Rainfall = evaporation (or evapotranspiration) + runoff + surface detention + ...
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2 votes

Possibility to influence oceanic evaporation to protect Sahel/Sahara

Changing ocean evaporation would impact weather & climate globally. While that may benefit some regions, it would be detrimental to other regions - robbing Peter to pay Paul. One of the risks ...
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  • 21.8k
2 votes
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Deep sea pumps that work on wind power, can they control the weather?

In theory your idea is not bad,But it needs to be placed as far from land as possible this is to avoid the soil on land from being contaminated by saltwater. So spraying saltwater into the air is not ...
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  • 1,830
2 votes

Can the formation of gypsum evaporites (sand roses) be simulated in the lab?

Yes, it has. Cody & Cody (1998), Journal of Sedimentary Research. http://archives.datapages.com/data/sepm/journals/v55-58/data/058/058002/0247.htm Abstract: Gypsum crystals were grown in ...
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  • 22.2k
1 vote
Accepted

Which ocean evaporates the most water per surface area?

When push comes to shove, the highest evaporation rate per unut area corresponds to the highest average temperature. As this pair of illustrations from NASA shows, that would be the Indian Ocean. ...
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  • 2,561
1 vote

can wet winters require more home heating than colder winters, in same place?

This probably has less to do with the rain and more to do with the wind. The wind helps move the colder air that is outside into your house more easily because there is more force being exerted on ...
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  • 416
1 vote

Estimation on how cold will my pond get - intent is to know if certain fish can survive in it

Your fish will be fine even in the coldest months of the year,And they will not stop eating if the temparature gets lower but their digestion of the food do slow down at the low temparatures. In the ...
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  • 1,830
1 vote

Estimation on how cold will my pond get - intent is to know if certain fish can survive in it

I doubt a pond temperature will stay above 60 in central FL winter.Without circulation there will be large temperature gradients caused by stratification, especially on warm days. Surface plants ...
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