# Tag Info

## Hot answers tagged evaporation

8

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 the number of air particles near the earth's surface causes a higher pressure for things on the earth, hence the name. Impact of high pressure areas on ...

6

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, water salinity, degree of thermal stratification, and boundary effects (as you correctly point out). It is certainly not a trivial calculation! As a first ...

5

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 form of (transparent) water vapor, rather than light-scattering droplets. PS: Maybe a similar example would help make things clear. Say you've just washed ...

5

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 0. This occurs during nighttime when there is no wind and the wind term does not compensate for the radiation term. It is true that during the night, with high ...

5

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 purposes you can set the ET on those days to 0 mm/d. The ET calculations typically calculate potential ET, meaning that if there is no water available no ET will ...

4

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 alcohol in the atmosphere is an interesting sequence of reactions. I took the info below from an article (see link below). In the air, ethanol is oxidized ...

4

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 temperature - every degree of temperature rise gives us 7% more water vapour. So if 'adding more sun' increases the temperature then it automatically increases water ...

4

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 are positive. Therefore, negative values indicate evaporation and positive values indicate condensation". This applies also to other variables. Thanks to Daniel ...

4

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 defined: actual and potential evapotranspiration: Source: presentation called Water resources and their management in Pakistan by Jannat Iftikhar As you have ...

3

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 the water vapor must condense into liquid water. The dew point is always lower than (or equal to) the air temperature. If the air temperature cools to the dew ...

3

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, such data is gridded to produce images like this one, from the Australian Bureau of Meteorology.

3

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 that rainfall is for to an average depth of one millimeter. For example if the area is a 100 square kilometer catchment then 1mm of rainfall is 100,000,000 cubic ...

3

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 testing was / is being done at Kure Beach ( N or S ) Carolina.

3

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. Increase the energy, and the molecules vibrate more until the molecular attraction is disrupted to become water, when they vibrate a lot. Increase the energy ...

3

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 this interesting paper (Ellison et al. 2017) So, as you correctly guessed, bare lands are "hotter" than forested areas. But when you say "barren land faced ...

3

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 ground surface but interception of precipitation will also mean that some of the precipitation will evaporate before it reaches the ground. There are effects of ...

3

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 evaporating sea water. The formulation used is detailed in a second manual

2

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 + soil moisture storage + infiltration +/- interbasin transfer. It sounds like you don't have nearly enough data to estimate the aquifer recharge.

2

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 would be the effect on rainfall intensity, rainfall duration and the amount of rain falling in any location. It could have disastrous consequences for landslide ...

2

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 usefull for creating rain over land,But it can be used to cool the ocean and the planet. Salt water spraying into the air can possibly help creating ...

2

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 experimental conditions analogous to saline terrestrial environments within bentonite clay gels by diffusion control at three different temperatures, four ...

1

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 your exterior walls and therefore cooler air can work its way through any small cracks. Sorta similar to the wind chill being colder on windier days. The lessened ...

1

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 coldest part ot the year the temparature at the bottom of a one and a half metres deep pond will stay at or close to the average temparature in your area,and ...

1

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 probably lower the maximum temperatures. For such a large pond ,the relative humidity and wind will make a temperature difference ( evaporation is a major heat loss)....

1

Magnesium sulfate is considerably more soluble than calcium sulfate. What happens during evaporation will depend on the original ion concentrations but, for example with sea water, evaporation will cause gypsum to precipitate first. This will decrease the sulfate concentration until it is gone before magnesium sulfate will precipitate. The remaining calcium ...

1

Solubilities (taken from Wikipedia): MgSO4: 35.1 g/100 mL (20 °C) Na2SO4: 13.9 g/100 mL (20 °C) It does seem that the solubilities should be an order of magnitude higher than is quoted in the paper you are reading. Several ideas: The paper is wrong. You did not understand the paper correctly. The solubilities mentioned above are of the pure compound in ...

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