:max_bytes(150000):strip_icc()/GettyImages-96470791-0333f56236a84ba08755cb9440d2ddbf.jpg?w=780&resize=780,470&ssl=1 "What is fire air? Definition and monitoring")
Sometimes, an weather warning will arise on airy but otherwise on a pleasant day, on your mobile phone or TV. No, this is not a mistake; It is probably a notification for fire atmosphere – weather conditions that are suitable for firing and spread of fires.
Fire mood may occur in any season, but when dry air and dry fuels (fallen leaves and still trees) were common, in the end of summer and decreased. Although the fire air is globally experienced, Western United States poses a greater risk for forest fires such as Australia, Africa and Amazon.
Conditions that cause fire air
Fire needs three materials to burn: Heat, oxygen and dry fuel source. The following weather conditions conspiracy to supply them and therefore syllab the danger of fire.
High air temperatures
Very hot temperatures increase evaporation, which easily peels moisture from flammable materials, including pine needles, including kindness for herbs, shrubs, trees, dead leaves and forest fires. Sun heated fuels are also fired faster, because less heat energy is needed to bring them to the temperature of the ignition.
Low rainfall
Rainfall is faint to the point where the fuel surface can not ignite. In the lack of rain or snow or in extreme cases, drought makes the opposite; Fuel dries, so it allows them to burn easier.
Low soil moisture
Soil moisture (the amount of water contained in the soil) is a good indicator of “fuel moisture” or how full of plants that live water are. When the moisture of the soil is low, local vegetation is probably dry and water stressful, which is more likely to burning. The soil moisture in the southern large plains according to a study on the size of the forest fire, soil moisture plays such an inseparable role in fire activity that it predominates more than the contributions of hot temperatures and low rainfall.
Low relative moisture
When relative moisture (a measure of how much water vapor in the air) is low, it helps to dry the fuels and makes them more flammable.
Gusty Winds
John W Banagan / Getty Images
If a fire holds, the winds can worsen in various ways. First, they provide more oxygen fever, which causes it to burn faster. High winds also increase the evaporation by reducing fuel moisture and at the same time encouraging a fire by physically pushing a fire and moving the embers in front of the flaming façade.
If you are watching the air map, look for low moisture and powerful, powerful winds to move after a dry cold façade (a cold façade associated with dry air mass). The critical fever air is usually linked to high pressure at the upper levels of the atmosphere, because these air properties can function as “heat domes”, can bring open sky, temperatures above the average of the air, very dry air and the hot months of the year.
Fire Air Hours and Warnings
Since fire control is very much based on weather conditions, Noaa’s National Weather Service (NWS) works with terrain management organizations to monitor problematic weather conditions. When several fire weather occurs simultaneously and overlapping with dry fuels, the NWs will either give either a fire air hour or red flag warning.
Fire Weather Watch
In the near future, the red flag criteria can be met within the next 24 to 72 hours.
Watches give the ring and fire brigade time to prepare for a high risk of fire.
Red Flag Criteria
The red flag criteria are the threshold wind and moisture values that indicate the risk of increasing fire hazard. Criteria are determined by local NWS offices and vary from region to region depending on the type of local vegetation, topography, drought conditions and more. At least the criteria:
- Winds of 15 miles or larger per hour (measured at a height of 20 feet from the ground).
- Minimum relative humidity (usually occurs in the afternoon) less than 25%.
- A 10 -hour fuel moisture (a measure of how much water is held with grass and leaves that lasts 10 hours to respond to changes in wetness/dryness) 10 % or less.
Red Flag Warning
If the red flag warning is given, it means that the red flag criteria are already met or will be met in a short time, usually within the next 12 to 24 hours.
Wait quickly spread and to be controlled or pressed. Under the red flag warnings, burn bans will also be in force.
How does climate change affect the air of fever
If you seem to see more red flag warnings than in the past years, blame climate change. Global warming actually increases the length of the fire air or the number of days every year when atmospheric conditions mature for fire danger. A study Nature Communication Between 1979-2013, fire air seasons increased by an average of 19% in a quarter of the world’s vegetation areas. Zoom in Western US forests and you will see that the fire air seasons extend for eight days.
The same work also looked at the air seasons longer than normal. He found that they became more frequent as a result of climate change – 53% globally.
Research -focused on California shows that since the 1980s, the increases of the state in autumn temperature and the decrease in rainfall decreased by a 20% increase in fire air indices. If the last trends continued, California could have increased by 25% until 2100 on autumn fire days.
Have a fire of fire
Fire air days are about to reduce the risk of feeding forest fire. Some ways of being more careful and proactive on fire air days:
- Postpone activities such as welding, grid, burning of the garbage, fireworks shows and exterior torches, luminaires or fire pits.
- Clean your dead leaves, brush and old Christmas trees and throw them properly through your city brush collection services.
- Do not pass over dry grass or vegetation; The heat in your vehicle can lead to fire.
- Throw cigarette butts to the garbage boxes or ashes.
- Report to local Emergency Management officials about the activities that cause fire, smoke or fire.
- Visit NOAA STORM PROVIDANCE Center Fire air sessions page.
