Several active fire signals are recorded by OSEI with the NOAA AVHRR Sensor on 2 May 1999 in Mexico and Central America .
Fig.1. and Fig.2. NOAA image of smoke form areas of
vegetation fires in Mexico and Central America on 2 May 1999
(Source: NOAA http://www.osei.noaa.gov/)
In Figure 1 smoke (light brown haze on the image) drifts over the Gulf of Mexico and the Caribbean Sea from areas of fire burning in eastern Mexico and Guatemala. The second satallite image (Figure 2) shows heat signatures and smoke from areas of fire burning in Mexico and Central America. Some of the hot spots in the Sierra Madre mountains of southern Mexico may be due to solar heating of the surface sensed by AVHRR channel 3. Hot spots in the Bay of Campeche are likely due to offshore oil platforms. They are visible throughout the year.
Fig.3. NOAA image of vegetation fires in Mexico and
Central America on 3 May 1999
(Source: NOAA http://www.osei.noaa.gov/)
In Figure 3 provides an image of smoke from fires in Mexico and Central America over the Gulf of Mexico. Other smoke similar effects on the left below side of the satallite image is due to sun glare.
Most of the fires in Central America must be seen in the context of intensive land development. Fire is used as a tool in forest conversion. This is done by small farmers as well as large agro-industrial companies. The careless use of fire often allow the "prescribed" burnings to escape and become forest fires in the adjacent forests. Almost all fires inCentral America are human-caused, natural fires play a minor role in the tropical rain forest of Central America.
Under normal weather conditions the primary forest in the humid tropics does not catch fire. The hydrological cycle in the closed forests produces a very humid microclimate where unfavourable conditions for forest fire exist. But in forests where selective logging already took place the former closed canopy is disturbed. This allows more light to penetrate through the canopy and thereby changing the energy balance within the forest - the forest becomes more susceptible to drought and consequently to fire.
For detailed reports on fire use and wildfires in Mexico refer to the IFFN Country Notes.
For a detailed report on the remote sensing of vegetation fires in Nicaragua refer to the
report "The Use of Low
Spatial Resolution Remote Sensing for Fire Monitoring in Nicaragua: a survey of three
successive burnings seasons".