News

Air quality: ¿What is a compass rose and a pollution rose?.

A Compass Rose is a graphical database that summarizes the Vectorial behavior of the wind in a place. It has three main components: direction, intensity and frequency.

The information of each Compass Rose shows the frequency of occurrence of the winds in 16 sectors of direction (E, ENE, NE, NNE, W, WNW, NW, NNW, ESE, SE, SSE, S, SSW, N, WSW , SW) and types of wind speed for a specific place and periods of time, the classification most used for wind is the BEAUFORT SCALE.

A Compass Rose is made just like a frequency table, one category is the address and its subcategories are the 16 directions, the other one category is the speed and the different types of wind considered by Beaufort as the subcategories.

A Pollution Rose is a graphic database, which indicates the direction of the emission sources that influence any station. It has three main components: speed, direction and concentration levels.

For this example, the Pollution Rose indicates that the main emission source is local (low speeds) and it comes mainly from the Southwest (SW).

The Polar Circumference is a graphical database, which represents in the wind direction the concentrations reached in function of the hours of the day.

In this way, it is possible to see at what times of the day the highest concentrations have occurred and in which wind direction have occurred most.

For this example, the Polar Circumference for the period of analysis, indicate that the highest concentrations come from the northeast (NE), east-northeast (ENE) and east (E) and occur after 07:00 hours.