| 摘要: |
| 利用2003—2008年在渤海所测的212组气溶胶数据, 研究了气溶胶光学厚度(AOT)、浑浊度系数(β)和?ngstr?m指数α的时空分布规律, 并初步探讨了气溶胶特征参数之间的关系。结果表明, 在时间分布方面, 渤海气溶胶光学厚度、浓度和粒径尺度在一天中的变化比较小, 中午AOT较大, 10 点左右AOT较小。从6月份到9月份, AOT、β 和α的范围和均值均呈下降趋势; 3月份AOT、β和α均明显小于六、8、9月份的对应值。离岸25 km之内的大部分地区, AOT 随离岸距离的增大而减小; 但25 km以外, 气溶胶变化没有规律。比较而言, 气溶胶AOT和β变化比较一致。浑浊度系数(浓度因子)β 比?ngstr?m指数(尺度因子)α对气溶胶光学厚度AOT的影响更明显, AOT 和β的关系可采用一阶线性回归方程表示。 |
| 关键词: 气溶胶光学厚度, 浑浊度系数, ?ngstr?m指数, 水汽 |
| DOI：10.11693/hyhz201202003003 |
| 分类号: |
| 基金项目:我国近海海洋综合调查与评价专项(908), 908-02-03-01号; 国家重点基础研究规划(973)项目, 973-2007CB411807 号 |
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| TEMPORAL AND SPATIAL DISTRIBUTIONS OF AEROSOLS OVER THE BOHAI SEA |
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MA Yu-Juan1,2, ZHAO Dong-Zhi2, LIU Yu-Guang1, YANG Jian-Hong2, GU Yan-Zhen1
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1.College of Physical and Environmental Oceanography, Ocean University of China;2.National Marine Environmental Monitoring Center
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| Abstract: |
| Aerosol optical thickness (AOT) data between 2003to 2008 obtained using a ship-based multiband sun photometer were taken to study the temporal and spatial distributions and the influencing factors of AOT, turbidity coeffi-cient (β) , and ?ngstr?m exponent (α)over the Bohai Sea. We obtained a total of 212 datasets from eight cruises and two fix-point measurements. There were 72 datasets in 2003, 21datasets in 2004, 98 datasets in 2005, and 21 datasets in 2008.
Intra-day variations of AOT, β,and α were inconspicuous. The mean values and ranges of AOT, β,and α decreased from June to September. The values of AOT, β,and α in June, August and September were larger than those in March due to smog, sandstorm, and ocean moisture. In most areas within 25 km offshore, AOT and βdecreased with increasing dis-tance from shore. However, the variation of α did not show a clear trend.
Over the Bohai Sea, the influence of βon AOT was more significant than α. The relationship between AOT and βwas described by AOT = 2.52×β + 0.07 when α is greater than 0.8, and he relationship became AOT = 1.20×β+ 0.16 when α is smaller than 0.8. We classified the aerosols into two types based on whether α was greater than 0.8. The influence of small changes in aerosol particle size on AOT may be ignored for certain types of aerosols. |
| Key words: Aerosol optical thickness, Turbidity coefficient, ?ngstr?m exponent, Moisture |
