Snowflake chemistry can provide clues to ozone

The structure of ice flakes of ice also fascinated chemists as Travis Knepp Purdue University, Ph.D. candidate in analytical chemistry, studying the foundations of the structure of the bow to get a clearer picture of the dynamics of the ground level, or tropospheric reduction ozone in the Arctic. Until now, no one knew that the quasi-liquid layer has an important role in determining the shape of snow crystals. Our research clearly shows that this is the case.

While the impact of emissions from human activities continues to grow, we must be able to understand the impact of ozone global average, said Shepson. Understanding the ice and the snow is gone.

‘We do not know the long-term safety and efficacy of these procedures performed at an early age,’ he said.

Temperature, relative humidity, and the mole fraction of acid were measured for the first time at the time of crystal growth. Snow crystals morphological changes of the transition temperature were recorded according to the molar fraction of acid, and construed in accordance with the concentration of acid calculated quasi-liquid crystal layer, which is believed to have a greater thickness depending on the mole fraction acid, which affects the morphology of crystal consistent with the hypothesis of Kuroda and Lacmann. Gaps in understanding of the quasi-liquid layer and its role in determining the morphology of snow crystals are briefly discussed.

Gas phase acetic acid and its qualitative effects on the morphology of snow crystals and quasi-liquid layer

Ground-level ozone is very important. It gives the ability to clean the atmosphere. However, it is also toxic to humans and vegetation at high concentrations, such as those found in smog, Shepson said.

There is more to the snowflake its ability to please students and bottling.

Many people have heard of the ozone layer in the north and south poles. This happens in the stratosphere, about 15 miles, said Knepp. What people do not know is that we see as ozone levels increased significantly at ground level.

A lot of chemistry occurs on the surfaces of ice, Knepp said: With a better understanding of the physical structure of snow crystals -. How it develops and why it takes some form – we can have a better idea of ​​the chemistry that occurs on this surface.

Complex chemical reactions take place regularly on the surface of the snow. These reactions, involving the thin layer of water on the surface of snow crystals, causing the release of certain chemicals that deplete the ozone at ground level.

Snow crystals transition to other forms, sometimes back and forth, as the change in temperature and humidity.

The need to understand the complex chemical reactions and their implications for the reduction of the ozone layer led researchers to continue their studies in the snow.

For example, the sides of a crystal of a growing range of 27-32 degrees Fahrenheit thermal expansion more quickly up or down, causing to assume a plate structure. Between 14 and 27 degrees Fahrenheit, the crystals resemble large solid prisms or needles.

His work on the shape of snowflakes and how the temperature and humidity influence is held in a special laboratory chamber does not exceed a small refrigerator. Knepp can grow crystals of snow all year round on a string in this room. Room temperature ranges from 100 to 110 degrees Fahrenheit to minus 50 degrees Fahrenheit.

This thin layer of semi-liquid water on the top and sides of a snowflake. Its presence causes the crystals take different forms such as changing temperature and humidity.

For how long these reactions is partially limited by the surface of snow crystals , Knepp said.

The snow crystals with multiple branches have a larger surface area than non-branched snow crystals, the reaction speeds up.