What is the unit used to measure the thickness of the ozone layer? Scientists measure the amount of ozone gas in a column of air. To measure this, they use Dobson units (DU). Dobson was one of the first scientists to research ozone. One Dobâ¦son unit indicates 0.01 millimeter thickness of ozone gas in a column.
By common definition, a year is the length of time the earth takes to revolve around the sun in its orbit. The total number of days in a year is approximated to be about 365.24 days. However, this length varies based on the mode calculation used. The year calendar used is in sync with the four seasons experienced.
A solar year is the time that it takes the earth to complete one  cycle around the sun. The year is the time taken by earth to  complete a cycle around the sun which takes aâ¦bout 365.25 days.   So, a calendar year is 365 days and 1 quarter. Every Leap Year  (once in 4 years) there is an extra day in February.    A year technically is the time taken for a planet to make one orbit  of the sun. At that rate, an Earth year is shorter than a Mars  year, which is 687 days at a 24 hour day.