Summer showers, in contrast to the protracted and dull autumn ones, are more often associated in our minds with the cheerful patter of drops on the window glass, washed with greenery and streams of water on the asphalt. Anyone who did not have the opportunity to splash through puddles during the warm rain as a child and step with his bare heels on the bubbles jumping up here and there has definitely missed out on something in his life... Why, by the way, do they appear? Let's find out. And at the same time we’ll find out what signs say about bubbles in puddles.
Cause of bubbles
Look for this funny a natural phenomenon during drizzling rain it is useless - in order for the water under your feet to bubble, several variables must come together at once.
First, the droplet size. When one of them falls into a puddle, forming a small funnel for a split second, water splashes up from the resulting hole. Its edges collapse, capturing a small particle of air, and a bubble runs along the surface of the puddle. It is clear that the larger and heavier the drop, the harder it will hit the surface of the water - which means more bubbles will appear.
It takes a real downpour to make bubbles
Secondly, the wind. Or rather, its absence. While the drops fly vertically down from the cloud, the force of impact on the water increases, and the bubbles become large and strong. But as soon as the wind deflects the flight of a small projectile, the drops begin to scatter across the surface of the puddle and dissolve in it, unable to raise the “wave” of the required height.
And finally, atmospheric pressure. When it is raised, falling drops momentarily bounce off the puddle before dissolving into it, creating splashes instead of bubbles.
What do they mean?
Surprisingly folk signs They just can’t agree on what the bubbles in the puddles mean. Some argue that this is a direct promise that the rain will soon end: they say, now it will all pour out and the sun will come out. Others, on the contrary, are convinced that bubbling puddles promise prolonged bad weather. Who is right?
Heavy rain usually doesn't last long
And those and others. On the one hand, large drops usually fall from cumulus clouds, which themselves are not very large. This is how summer thunderstorms usually happen - they swooped in, made noise, whipped up bubbles in the puddles and died down.
On the other hand, following cumulus clouds nimbostratus often extends. And here you can’t count on a quick end to the bad weather: once it starts, a quiet and light rain can drizzle all day.
Most often, signs advise paying attention to the size of the bubbles. The larger and stronger they are, the longer the bad weather will last.
Signs about bubbles in puddles are changeable and rarely provide accurate predictions. But is it worth being upset about this? As is known, “nature has no bad weather" And when it rains, it’s so nice to sit by the window with a cup of hot tea and even meditate a little, looking at the bubbles bursting in the puddles.
Most of the water from a rainfall ends up in the river runoff in the short period after rainfall. Water from small streams combines with others in the drainage basin and increases river flow.
Thus, during and after a rainstorm, many times more water may occur within the next few hours than after a few days (when the precipitation has stopped).
Large amounts of annual river flow can occur within a few days. For example, in 2001, 10 days of high average daily river flow accounted for 36 percent of the total river flow for the year.
If you've ever wondered how many liters of water fall during a rainstorm, you might want to do the math. Let's try to help you do this using a calculator.
To do this, you need to measure the amount of precipitation in millimeters and multiply by the area of precipitation and get approximate quantity fallen water.
During rainfall, the water level in streams rises. This water feeds groundwater and, accordingly, affects the flow rate of the Abyssinian well.
Data has been rounded
The river flow at 10:00 was 154 times greater than at midnight. Almost 150 thousand liters of water per second flowed during the peak period.
In natural watershed areas, more precipitation seeps into the ground, but impervious surfaces prevent this from happening. In urban areas, most precipitation falls on impervious areas such as paved roads and areas, parking lots and large buildings.
Water falling on impervious surfaces flows into storm drains where it flows into streams. Thus, a lot of runoff enters water streams within the first minutes after a rainstorm.
The high water level after a rainfall quickly subsides.
Within a few hours after the end of the rainfall, the river flow returns to its base level.
IN natural conditions, precipitation seeped into aquifers will gradually come to the surface and feed water flows.
The rate of increase in river flow during a rainstorm is much greater than the return to base conditions.
The characteristics of precipitation, and therefore river flow, can be different for different rainfall events.
Reasons for the decline in baseline water flow
In the absence of precipitation, water flows into stream beds from aquifers. As the number of impervious surfaces in a watershed increases, the amount of water that infiltrates the ground during rainfall decreases. Thus, the aquifer receives less water for supply to the water stream.
Folk signs and beliefs often help people predict the weather. Such predictions have been developed and tested over centuries and therefore can be trusted. One of these predictions is the sign of bubbles in puddles during... This belief belongs to the category of weather beliefs, and can be useful both to gardeners and summer residents, and to those who like to spend time in nature and want to know in advance how long the bad weather will last.
Folk signs about bubbles in puddles
Many people debate whether the formation of bubbles in puddles indicates long rain, or on the contrary, this means that the bad weather will end soon. According to, the rain with bubbles will be prolonged, and in extreme cases it may even last more than one day.
Our ancestors knew that the formation of such a phenomenon as a bubble promised only prolonged bad weather and they were absolutely right, because its formation requires a certain atmospheric pressure, which happens when rain clouds do not even think of dissolving. This means that precipitation will continue to fall for a long time. Atmospheric pressure, which regulates the movement of warm and cold air fronts and explains how long severe weather will last. If two extended and slow-moving fronts collide, you can’t expect sun and warmth soon.
So the sign about bubbles in puddles also has scientific basis and not even one. Except atmospheric pressure, for a bubble to form, the raindrop must be large enough. Only in this case will it be able to break through the surface tension of water. Large drops, as a rule, occur during showers and thunderstorms, and this in itself indicates that the bad weather may drag on. Although there are exceptions to this rule, for example, in southern regions Bad weather often begins suddenly and ends quickly.
“Warming” of water in a river during rain is an apparent phenomenon. If you arm yourself with a thermometer and measure the water temperature before and during rain, you will not be able to detect a significant difference.
Warming illusion
The water in the river during rain seems warmer not because it actually becomes warmer, but in comparison with the air temperature. Rain is always accompanied by cold weather. This happens for several reasons.
Very often, cold weather comes with rain. Rain may be accompanied by wind. Objectively, the wind does not reduce the air temperature, but it affects the perception of it by a person, carrying away a layer of air heated by the human body.
Raindrops occur at quite high altitude, where the air temperature is significantly lower than that of the Earth’s surface, so the temperature of rainwater is also low. Upon reaching the ground, raindrops do not have time to heat up to such an extent that their temperature is comparable to the air temperature, so they cool the air.
The action of any of these factors is sufficient to cool the air to such an extent that, in comparison with it, river water appears warmer.
Why does water keep its temperature?
When it rains, the air cools, but not the water. This is due to the high heat capacity of water. Heat capacity is a physical quantity that expresses the ratio of the heat received by a body and the change in its temperature. According to this feature, water in nature is not a “record holder”, but one of the “champions” among various substances. It is second only to ammonia and hydrogen in terms of heat capacity.
Such a high heat capacity, which scientists even call anomalous, is explained by the special structure of water. It consists of triatomic H2O molecules, but only a small part of such molecules in liquid water is in a free state. Most of them are combined into associates - crystal-like structures of several molecules. When water is heated, hydrogen bonds in associates are broken. This process requires large quantity energy, so it’s not easy to heat water, but it will also give off heat just as slowly.
Maintaining the temperature of water in rivers during rain is just one of the manifestations of the high heat capacity of water. It is this property that allows water to protect the Earth from catastrophic temperature changes that could destroy all living things.