Galuh Dilla Nirmala

Polar stratospheric clouds  ( PSCs ), also known as  nacreous clouds  ( from  nacre , or mother of pearl , due to its iridescence), are clouds  in the winter polar st ratosphere  at altitudes of 15,000–25,000 m (49,000–82,000 ft). They are u sually spotted only near the poles, nacreous clouds form very high  in the atmosphere (twice as high as commercial airplanes fly), where the air is particularly cold and dry. However, they  are best observed during civil twilight , when the Sun is between 1 and 6 degrees below the horizon, as well as in winter  and in more northerly latitudes.   The colorful shine actually comes from the setting sun being lower  in the sky than the clouds, so they reflect sunbeams back toward Earth. Unfortunately, while they're beautiful, nacreous clouds also destroy ozone , the compound that protects us from the sun's most dangerous rays.  They are implicated in the formation of ozone holes.  The effects on ozone depletion  arise because they

To: Oxford Scholarship Selection Committee I am writing this letter on behalf of Karin Astrid Wibowo, a student of SMAN 3 bandung who is applying for Oxford Scholarship program. I had the pleasure of teaching Karin in her 11th grade. From the very first day, she impressed me with her passionate self and how hardly she works when it comes to achieving her purpose. She always does her work wholeheartedly that it makes sense how the results are always exceptional. With many activities she joins outside school, she still manages herself to focus on her main goal and finds time to study. This makes her not only a talented person, but also a clever one. Other than that, she doesn't get distracted and quit easily. When she finds herself in a difficult situation, she pushes herself harder and believes that she could get through any obstacles that get in her way, which is true. Karin is also a creative person. She always finds a way to solve the problems she has to face. Her creativity