1 COMPARISOM OF TWO ALGORITHMS ON HAB DETECTECION

ABSTRACT: Dinoflagellate and diatom blooms often occur in spring and summer in ECS（East China Sea）, which we usually called red tides or HAB (harmful algal bloom). Some of the red tides can make the water toxic and anoxic and then lead to aquaculture loss. So it’s of great importance if HAB, especially those of large scales, can be continuous monitored and forecast by remote sensing methods. Both Shang et al. and Mao et al. came up with a novel red tides detection algorithm in 2014 which were put forward based on field data they collected in China. We made comparison between two algorithms by applying them to the MODIS satellite data which match with red tides issues collected from China Oceanic Information network. The result indicates that both of two algorithms can work well in ECS, but sometimes they can also be misleading. By the way, they identify the dinoflagellate bloom which broke out in Xiapu (ECS, at the end of May, 2015) correctly based on field sampling and Rrs data we collected. We also applied them in other China seas, but it turns out they did not show the same accuracy as they did in ECS. To expand their application scope we tried some ways to apply them to SeaWiFS, but unfortunately the result is not good because of their unique bands, which means we cannot simply substitute the data into the formulae. In short, more jobs need to be done to improve the accuracy of the two algorithms and keep trying to apply them to other satellite data resources. 1