The characteristics of small, cool fires undetected by the MODIS contextual algorithm are listed in Tables 1 and 2. The T22 brightness temperatures of these small, cool fires are lower than 310 K, a critical threshold for identifying potential fire pixels in the MODIS contextual algorithm. The thresholds ofΔT and R2 in the MODIS contextual algorithm are valid for small, cool fires undetected by the MODIS contextual algorithm. The fire characteristics of small, cool fires suggest that the threshold of T22 greater than 310 K is too high to detect small, cool fires in the southeast, and the corresponding adjustment in the improved algorithm is reasonable. The improved algorithm is less sensitive to negative effects caused by large view angles mainly due to decreasing the T22 threshold to 293 K.