동경만입구에서 대도에 이르는 해역에서의 해수의 광학적 성질을 조사하기 위하여, 1985년 6월에 6개 관측점에서 투명도, 수색, 태양고도, 태양광의 8가지 파장 (378, 422, 481, 513, 570, 621, 653, 677 nm)에 대한 해수의 표면조도 및 수심별 수중조도 등을 조사한 결과를 요약하면 다음과 같다. 1. 본 조사 해역의 투명도는 $12.9m;(7.2~18m)$ 였고, 수색은 $6.8;(5~10)$였다. 2. 해수의 평균소산계수는 $0.166;(0.061~0.644)$였고, 파장별로는 481nm가 0.097, 513nm가 0.099, 422nm가 0.105, 378nm가 0.121, 570nm가 0.138, 621 및 677nm가 0.253, 653nm가 0.258순으로 크게 나타났으며 파장에 따른 차이가 뚜렷했다. 3. 해수의 소산계수 K와 투명도 D와의 관계는 $K=2.87/D;(1.06/D~5.48/D)$였다. 4. 태양고도는 $70.79^{circ}(57.44^{circ}~78.42^{circ})$로 나타났다. 5. 태양광선의 표면광에 대한 평균해중투과율은 수심 1m층에서 $77.93\%$, 5m층에서 $35.46\%$, 10m층에서 $18.71\%$, 20m층에서 $7.00\%$로 나타났다. 6. 투명도층에서의 태양광의 해중투과율은 표면광의 $13.2\%(0.42~34.78\%)$였고, 파장별로는 677nm가 $0.78\%$, 653nm가 $0.94\%$, 621nm가 $1.30\%$, 570nm가 $10.50\%$, 378nm가 $17.98\%$, 422nm가 $22.69\%$, 513m가 $23.78\%$, 481nm가 $26.14\%$ 순으로 많게 나타났으며 파장에 따른 차이가 많았다.
Optical properties of sea water were studied in the Sagami Bay, Japan, based on the data obtained from six oceanographic stations in June, 1985. The observation of surface irradiance and underwater irradiance of sea water for eight kind of wavelengths (378, 422, 481, 513, 570, 621, 653, 677 nm) of sun light was conducted using the underwater irradiameter $(Isigawa;#;SR-8)$. The mean attenuation coefficient of the sea water was appeared to be 0.166 $(0.061~0.644)$ and the attenuation coefficient of the sea water for wavelength appeared such as 0.121 for 378 nm, 0.105 for 422 nm, 0.097 for 481 nm, 0.099 for 513 nm, 0.138 for 570 nm, 0.253 for 621 nm, 0.258 for 653 nm, 0.253 for 677 nm. The transparency was 12.9 m $(7.2~18m)$, water color was $(5~10m)$ in the study area and the sun altitude was $70.79^{circ};(57.44^{circ}~78.42^{circ}C)$ The relationship between attenuation coefficient (K) ana transparency (D) was $K=2.87/D(1.06/D~5.48/D)$. The rates of light penetration for eight kind of wavelenths (378, 422, 481, 513, 570, 621, 653, 677 nm) were computed with reference to the surface light intensity respectively, The mean rate of light penetration in proportion to depths were $77.93\%;(52.52~94.06\%)$ in 1 m layer, $35.46\%;(4.00~73.64\%)$ in 5m layer, $18.71\%;(0.24~54.23\%)$ in 10m layer and $7.00\%;(0.007~27.58\%)$in 20m layer. The rate of light penetration at the transparency layer with reference to the surface light intensity was shown as $13.02\%;(0.42~34.78\%)$.
