Translate

## Parameters Reported by the AQI/VSI System

Carbon Monoxide (CO)

Sulfur Dioxide (SO2)

Nitric Oxide (NO)
There is no national ambient air quality standard for nitric oxide. Nevertheless, it plays an important role in air pollution chemistry. For example, NO can react with hydrocarbons in the presence of sunlight to form a host of secondary air pollutants, including ozone.

Nitrogen Dioxide (NO2)

Ozone (O3)

Scalar Wind Speed
Wind is air in motion relative to the surface of the earth. The wind has both an orientation (direction) and a magnitude (speed). That is, it is a vector that is described by the speed and direction of the wind. These quantities are commonly referred to as "scalars" because they can be described by a single numerical value at a point in space. Thus, the scalar wind speed and scalar wind direction are averages of scalar quantities over a given time period.

Scalar Wind Direction
Wind is air in motion relative to the surface of the earth. The wind has both an orientation (direction) and a magnitude (speed). That is, it is a vector that is described by the speed and direction of the wind. These quantities are commonly referred to as "scalars" because they can be described by a single numerical value at a point in space. Thus, the scalar wind speed and scalar wind direction are averages of scalar quantities over a given time period.

Vector Wind Speed
vector wind speed and direction The vector wind direction and vector speed are the result of vector addition. For example, if the wind is blowing from the south at 5 mph for 30 minutes and then from the north at 5 mph for the next 30 minutes, the vector speed is zero and the vector direction is undefined. Another way of thinking of it is this: imagine that a balloon floating at 30 feet above the ground moves with the wind for 60 minutes. As it meanders around it eventually arrives at a point (after 60 minutes) which is at a compass heading of lets say 90 degrees from the start point and 10 miles from its start point. The vector or resultant wind speed would be 10 mph and the vector or resultant wind direction would be from 270 degrees.

Vector Wind Direction
The vector wind direction and vector speed are the result of vector addition. For example, if the wind is blowing from the south at 5 mph for 30 minutes and then from the north at 5 mph for the next 30 minutes, the vector speed is zero and the vector direction is undefined. Another way of thinking of it is this: imagine that a balloon floating at 30 feet above the ground moves with the wind for 60 minutes. As it meanders around it eventually arrives at a point (after 60 minutes) which is at a compass heading of lets say 90 degrees from the start point and 10 miles from its start point. The vector or resultant wind speed would be 10 mph and the vector or resultant wind direction would be from 270 degrees.

Temperature
A measure of the warmth or coldness of an object or substance with reference to a standard value.

Relative Humidity (RH) The ratio of the actual vapor pressure of the air to the saturation vapor pressure. That is, it is the amount of water vapor in the air as compared to the amount of water vapor it would take to saturate the air. Relative humidity is usually expressed as a percentage.

Visibility