1. Assessment on Phytoplankton Quantity in Coastal Area by Using Remote Sensing Data RI Songgun Marine Environment Monitoring and Forecasting Division State Hydrometeorological Administration DPR Korea

2. Contents Background NDVI from Sea Water with phytoplankton Relationship between NDVI and phytoplankton chlorophyll-a concentration Relationship between NDVI and phytoplankton quantity Conclusion

3. Background Phytoplankton - primary index of ecosystem - basic factor to assess the marine primary production Water color is used to measure the concentration of phytoplankton chlorophyll-a Concentration value of phytoplankton chlorophyll-a on sea surface is very similar to the observation one in situ

4. Background NDVI(Normalized Difference Vegetation Index) NDVI is closely related to the growth of phytoplankton NDVI is used to survey the growth of vegetable by remote sensing and is very effective to find out vegetable existence and growth status, assess its quantity, define temporal and spatial distribute.

5. NDVI NDVI is calculated from image data in visible and nearly infrared bands.

6. NDVI from Sea Water with Phytoplankton The principle of surveying phytoplankton quantity by remote sensing is based on difference of reflection spectrum between sea water and chlorophyll-a. Plant has a unique reflection (or absorption) characteristics in channel 1(0.58~0.68 ㎛ ) and 2(0.725~1.1 ㎛ ) of NOAA/AVHRR unlike other objects, for example water, cloud, soil and so on.

7. NDVI from Sea Water with Phytoplankton NDVI – very large

8. NDVI from Sea Water with Phytoplankton Sea Water NDVI < 0 NDVI > 0

9. Relationship between NDVI and phytoplankton chlorophyll-a concentration Hypothesis Concentration of phytoplankton is equal in the area, about 1 ㎢, of a pixel of NOAA image data

10. Relationship between NDVI and phytoplankton chlorophyll-a concentration The experiments show that the relationship is an exponential one Y : estimated concentration value of chlorophyll-a, X: NDVI, A, B : coefficient.

11. Relationship between NDVI and phytoplankton chlorophyll-a concentration Seasonal and continuous variation of atmospheric stratification affects the estimated precision of equation On the same days the atmospheric stratification variation on other sea areas also affects the estimated precision of the equation Relative Error 20~40%

12. Relationship between NDVI and phytoplankton quantity The phytoplankton quantity has a linear relationship with the concentration of phytoplankton chlorophyll-a Relationship between NDVI and phytoplankton quantity is also an exponential relation

13. Relationship between NDVI and phytoplankton quantity Y : current quantity of phytoplankton, X : NDVI a, k, B : coefficient.

14. Relationship between NDVI and phytoplankton quantity Experiment in Water Area No. 2 from July 2001 to March 2003 Correlation R=0.87 Relative error = 30.02%

15. Conclusion Phytoplankton quantity by NDVI from remote sensing and evaluate its precision, about 70% We suggest one model for estimating phytoplankton quantity in the coastal area of Yellow Sea in the restrict condition that we can receive remote sensing data only from polar orbit satellite NOAA in the DPRK. We can approximately estimate phytoplankton quantity in the coastal water area of the Yellow Sea by NOAA

16. Conclusion From the last year, we have worked to assess on phytoplankton quantity in the coastal area of the Korean West Sea by remote sensing data of MODIS. Based on successful results of these research works, we would further correctly estimate the quantity of phytoplankton in the West Sea and contribute to implement the SAP. In the future we would assess phytoplankton quantity by better satellite remote sensing data with implementing the YSLME plan.