Any thunderstorm which produces hail that reaches the ground is known as a hailstorm. Hail is in essence, frozen rain. It only falls from a specific type of cloud called a cumulonimbus cloud also known as a thunderstorm cloud. Hailstones usually measure between 5 mm (0.2 in) and 15 cm (6 in) in diameter and fall anywhere a thunderstorm can form. Hailstone's larger than 2 cm (0.80 in) are usually considered large enough to cause damage.

Hail is often confused with sleet. Sleet is rain containing some ice, usually seen with snow. Below is an image of sleet which has settled on the ground it's visibly different to hailstones on the ground due to sleet being more of a wet mulch.

Hail formation requires environments of strong, upward motion of air within the thunderstorm, these tiny raindrops are carried upward by updrafts freezing levels of the atmosphere and form hailstones.

These then sink back down in the cloud with added weight and are then carried back up by the updraft growing by colliding with liquid water drops and other smaller hailstones that freeze onto the hailstone's surface as if adding layers of layers of frosting to a cake but in a really lumpy random irregular way, then sinking and rising until the cloud can not contain it's weight any more.

I'd like this too.

Possibly a really British post so I apologise if it is, but I think a Rain Alarm would be great.

If we could get an hour/half hour notification that it's going to rain in our geographic location (wherever our cellphones location is or if we've got that turned off, our home location on Windy) the map already shows where the rain cloud is going to sweep so we know what areas are going to hit but if the forecast changes and no ones checked, it could be a nice feature.

Ultimately other apps for this exist I just thought it'd be cool to have in your push notification ideas.

Great idea!

Hair Ice was first observed by continental drift discoverer, Alfred Wegener in 1918. A rare type of ice formation, Hair Ice grows exclusively on dead wood and he theorised it was due to some sort of fungal growth. Almost 100 years later, science has the answers.

Wegner theorised it was due to a fungi but it wasn't until 2015 where German and Swiss scientists Hofmann, Mätzler and Preuß found the cause of hair ice, linking its formation to the presence of a specific fungus called Exidiopsis effusa.

Exidiopsis effusa is part of the Auriculariaceae family which contain 7 genera and over 100 species which usually live on dead, fallen or rotting woods.

In the study, Preuß examined samples of dead wood that had previously grown hair ice from the winters of 2012, 2013 and 2014 in forests near Brachbach in western Germany. Preuß placed these under a microscope and found 11 different species of fungi. When the Hair Ice was investigated microscopically Preuß found Exidiopsis effusa on every hair ice sample examined by her and she was able to disable the fungus with fungicide and prevent hair ice forming.

The presence of the Exidiopsis effusa led to a process called 'ice segregation'. Which is where water in the wood begins to freeze and it creates a barrier that traps liquid between the ice and the pores of the wood.

This created a suction force which pushes water out of the pores to the edge of the ice surface where it freezes and extends outwards. As this repeats it pushes a thin 'hair' of ice out of the wood which is around 0.01 mm in diameter, an inhibitor similar to antifreeze proteins present in the fungus allows the strands of ice to stabilise over several hours sometimes days.

The researchers also found that the root of the hair ice, called a crystallization nucleus, is likely composed of lignin and tannin. Lignin is found in vascular plants like mosses and conifers and help give wood its hardness and resistance to rotting. Tannin also occurs widely in vascular plants and protects plants from herbivores who dislike its bitter taste.

According to The Met Office, "The conditions required for the formation of hair ice are extremely specific, hence the relative scarcity of sightings. To form, moist rotting wood from a broadleaf tree is required with the presence of moist air and a temperature slightly below 0 °C. It is generally confined to latitudes between 45°N and 55°N."

"The same amount of ice is produced on wood with or without fungal activity, but without this activity, the ice forms a crustlike structure," Christian Mätzler.

It's worth noting if you go out looking for it in the right conditions that Hair Ice is very rare and it will grow mostly at night and melt in the morning sun. It grows only at the mouth of wood rays and never on the bark and their thickness is similar to the diameter of the wood ray channels. A piece of wood that produces hair ice once may continue to produce it over several years so if you do see some it's worth revisiting it the next year.

For those interested in some hardcore science Biogeoscience have the original publication by the scientists on: Evidence for biological shaping of hair ice

Zoe Wilderspin
*Amateur Mycologist With Questionable Morels. Follow me on Twitter or for more mycology follow me on Facebook

Climate change, it’s a fact. We’re seeing it more and more every year. From burning hot summers with excruciating long droughts to short sharp springs and non-existent autumns blurring into a wet winter. Everyone and everything living is affected, big and small and this includes our local mycology of the UK.

But who is noticing?

Well actually, it’s quite a few people and more than just a few mushrooms. Professional and amateur mycologists (Those are people who like fungi and study them) have noticed the decline for a while but recently shroomers and psychonaughts (These are people who take magic mushrooms for the hallucinogenic purposes) are also noticing the decline and talking about this on drugs forums such as Bluelight.

Fungi play a huge role in our ecosystems more than what most people usually think about, they’re responsible for decomposition, ecological recycling and creates nitrogen, this is the gas which makes up 78.09% of dry air.

Fungi decompose the hard-to-digest organic material into easier to-digest-forms that other organisms can use. Fungi also play a role in floods with water infiltration and soil water holding capacity.

“Climate impact is already apparent: fungal reproduction, geographic distributions, physiology and activity have changed markedly in the last few decades, through direct climate change effects on fungal growth and indirect effects on their habitats” – Peter G. Kennedy, Carrie Andrew (State of the World’s Fungi 2018 9. Climate change: Fungal responses and effects)

Fungi play a major component in the regulation of atmospheric carbon dioxide, they help store carbon dioxide in soils and according to Clemmensen, K. E., et al. (2013) “approximately 50–70% of carbon stored in boreal forest soils in Scandinavia was derived from dead roots and associated fungi.”

This vividly highlights the large role in which fungi play amongst our ecosystem and how fragile and delicate this balance is and how much carbon dioxide mycelium locks away in the soil.

Seasons play a huge role in fungi, and have a fruiting season depending on the species. Mushrooms are in essence like apples, the mycelium is the tree and the mushroom is the fruiting body.

The fruiting body contains millions of spores of which are transported by many ways from woodland animals to casual, not professional, foragers who will carry these fungi far and wide spreading their spores.

Naturally because of this damper seasons tend to be the best for fruiting bodies, and with British summers lasting longer and drought becoming more prevalent drought, as a rule, reduces the length of the reproductive season.

Andrew, C., et al. (2018) discovered that fungal reproductive timing (called phenology) has become extended because little as 0.2°C can shift the production of spore-bearing fungi by one day (especially for fungi that reproduce in autumn). The temperature also drives the rate of compositing patterns across Europe.

Some fungi are more adaptable to climate change than others. For example species of jelly fungi like the Crystal Brain Fungus (above), have cell walls that can contract down to become hard and resistant when dry but go back to a gelatinous structure when moisture is available.

These fungi are particularly resistant to droughts which is particularly useful in British climates which are becoming increasingly susceptible to summertime droughts.

Other fungi have thicker spore walls which can deal with environmental stresses better than fungi which produce thinner celled wall spores. Depending on the thickness, these could survive prolonged high temperatures, droughts and even fires.

Zoe Wilderspin
Amateur Mycologist With Questionable Morels. Follow me on Twitter.

@rick1francis @kad666

Large areas of the UK currently have weather warnings for flooding.. Flooding is a temporary overflow of water onto land that is normally dry.

1. Do not walk, swim, cycle or drive through flood waters

Turn around and go the other direction. It takes less than 15cm of moving water to sweep a vehicle away.

2. Turn off all gas, water and electricity

If you are at home or in the office and have time to do this.

3. Prepare a bag that includes medicines and insurance documents

If the flood is rising slowly put all these things in a bag and take them upstairs, if you have time you can also move other valuable keepsakes.

4. Move to higher ground or a higher floor

Do not climb into a closed attic or loft. You may become trapped by rising floodwater. Go on the roof only if necessary. Once there, signal for help by shouting, flashing a torch or phone light and screen or waving, not like this guy but I couldn't find someone waving a light...

5. If told to evacuate, do so immediately

Bring any medications and pets but do not go back in for things like photo albums or other keepsakes.

6. Never drive or walk around barricades

These are there for your own safety and even though it may look dry the land underneath may be very unstable.

7. Stay off of bridges over fast-moving water

This is because the ground becomes unstable around bridges and causes movement like what happened at Grinton, Yorkshire, where this bridge collapsed after parts of the region had up to 82.2mm of rain in 24 hours on Tuesday.

8. If your vehicle is trapped in rapidly moving water, then stay inside

If water is rising inside the vehicle, then seek refuge on the roof, by climbing out of the windows or doors if they can be opened.

9. Be aware of the risk of electrocution

Do not touch electrical equipment if it is wet or if you are standing in water. Underground or downed power lines can also electrically charge the water so be wary.

10. Do not take selfies during a flood

Focusing on your face rather than what is going on around you can be a dangerous thing, focus on the above and you'll have more time to upload to your social media after. The last thing you want is to slip and break something, or worse.

Stay safe out there!

Recent research has found that Ozone layer depletion does not cause global warming, however both of these environmental issues have a common cause: human activities that release pollutants into the atmosphere altering it.

For years people have thought that using spray deodorants and squirty cream were heating up the planet slowly but fear not, your armpits no longer have to smell and your hot chocolates can now be topped with as much delicious topping as you wish, because many products no longer use the suspect CFCs gasses.

Hot chocolate aside, Ozone makes up the higher band of the atmosphere and absorbs ultraviolet radiation. Ultraviolet radiation is a type of solar energy that's harmful to humans, animals and plants and it's this which is causing the issues for the majority of people down on Earth.

So What Is Causing The Issue In More Detail?

There is something a lot of people call the 'Ozone hole’ it's a large area of depleted ozone layer over Earth's polar regions which, which you can see below. People, plants, and animals living under the ozone holes area are harmed by the solar radiation reaching the Earth's surface which causes eye damage, skin cancer and more.

CFCs and halons, usually found in aerosols, cause chemical reactions that break down these ozone molecules, reducing ozone's ultraviolet radiation absorbing capacity. UV radiation plays a very small role in global warming because its quantity is not enough to cause the excess heat trapped in the atmosphere.

But What About The Weather?

Since the 1960s, there has been a trend of greenhouse gases increasing heat in the lower atmosphere, called the troposphere, a cooling is occurring in the upper atmosphere called the stratosphere.

This warming-cooling dynamic creates conditions that lead to more ozone loss. This is largely because heat from Earth's surface would normally convey through the troposphere and stratosphere and eventually escape to space is now being trapped and confined to the troposphere like a giant blanket.

Carbon dioxide and other heat-trapping gases rise into the atmosphere and spread around the globe, again like this blanket wrapping Earth. This blanket warms the surface of the Earth and protects it from the cold air above it.

However, now wrapped in a thicker blanket, Earth’s surface warms up and heats the blanket itself and traps more heat in the lower atmosphere. The blanket also unfortunately prevents heat from moving from the lower atmosphere to the stratosphere, cooling down the stratosphere as a result.

Heat-trapping gases contribute to creating the cooling conditions in the atmosphere that lead to further ozone depletion. Greenhouse gases absorb heat at relatively low altitudes and warm the surface, but they have the opposite effect in higher altitudes because they prevent heat from rising.

In a cooler stratosphere, ozone loss creates a cooling effect which results in further ozone depletion. UV radiation releases heat into the stratosphere when it reacts with ozone. With less ozone there is less heat released, amplifying the cooling in the lower stratosphere, and enhancing the formation of ozone-depleting polar stratospheric clouds, especially near the South Pole.

For those inclined below is a brilliant diagram by Research Gate.

These clouds are found at altitudes of 15,000–25,000 m. One main type of these clouds are made up mostly of supercooled droplets of water and nitric acid and is implicated in the formation of ozone holes.

The other main type consists only of frozen ice crystals and is not considered harmful. This type of PSC is also referred to as nacreous from nacre, or mother of pearl, due to its iridescence.