• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of oceanography >Estimating photosynthetically available radiation at the ocean surface from ADEOS-II global imager data
【24h】

Estimating photosynthetically available radiation at the ocean surface from ADEOS-II global imager data

机译：根据ADEOS-II全球成像仪数据估算海洋表面的光合有效辐射

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

A simple, yet efficient and fairly accurate algorithm is presented to estimate photosynthetically available radiation (PAR) at the ocean surface from Global Imager (GLI) data. The algorithm utilizes plane-parallel radiation-transfer theory and separates the effects of the clear atmosphere and clouds, i.e., the planetary atmosphere is modeled as a clear atmosphere positioned above a cloud layer. PAR is computed as the difference between the incident 400–700 nm solar flux at the top of the atmosphere (known) and the solar flux reflected back to space by the atmosphere and surface (derived from GLI radiance), taking atmospheric absorption into account. Knowledge of pixel composition is not required, eliminating the need for cloud screening and arbitrary assumptions about sub-pixel cloudiness. For each GLI pixel, clear or cloudy, a daily PAR estimate is obtained. Diurnal changes in cloudiness are taken into account statistically, using a regional diurnal albedo climatology based on 5 years of Earth Radiation Budget Satellite (ERBS) data. The algorithm results are verified against other satellite estimates of PAR, the National Centers for Environmental Prediction (NCEP) reanalysis product, and in-situ measurements from fixed buoys. Agreement is generally good between GLI and Sea-viewing Wide Field-of-view Sensor (SeaWiFS) estimates, with root-mean-squared (rms) differences of 7.9 (22%), 4.6 (13%), and 2.7 (8%) Einstein/m2/day on daily, weekly, and monthly time scales, and a bias of only 0.8–0.9 (about 2%) Einstein/m2/day. The rms differences between GLI and Visible and Infrared Spin Scan Radiometer (VISSR) estimates and between GLI and NCEP estimates are smaller and larger, respectively, on monthly time scales, i.e., 3.0 (7%) and 5.0 (14%) Einstein/m2/day, and biases are 1.1 (2%) and ?0.2 (?1%) Einstein/m2/day. The comparison with buoy data also shows good agreement, with rms inaccuracies of 10.2 (23%), 6.3 (14%), and 4.5 (10%) Einstein/m2/day on daily, weekly, and monthly time scales, and slightly higher GLI values by about 1.0 (2%) Einstein/m2/day. The good statistical performance makes the algorithm suitable for large-scale studies of aquatic photosynthesis.
机译：提出了一种简单但有效且相当准确的算法，用于根据Global Imager（GLI）数据估算海洋表面的光合有效辐射（PAR）。该算法利用平面平行辐射传输理论并分离了透明大气和云的影响，即，将行星大气建模为位于云层上方的透明大气。 PAR计算为大气顶部（已知）的入射400-700 nm太阳通量与大气和表面反射回太空的太阳通量之差（由GLI辐射得出），并考虑了大气吸收。不需要像素组成方面的知识，从而无需进行云筛查和有关子像素浑浊的任意假设。对于每个GLI像素（晴天或阴天），都会获得每日PAR估算值。使用基于5年地球辐射预算卫星（ERBS）数据的区域昼间反照率气候学，可以对云量的昼夜变化进行统计学处理。该算法的结果与PAR的其他卫星估计值，美国国家环境预测中心（NCEP）重新分析产品以及固定浮标的现场测量结果进行了验证。 GLI与海景宽视场传感器（SeaWiFS）估算值之间通常具有良好的一致性，均方根（rms）差异分别为7.9（22％），4.6（13％）和2.7（8％） ）在每天，每周和每月的时间尺度上的爱因斯坦/平方米/天，偏差仅为0.8-0.9（约2％）爱因斯坦/平方米/天。 GLI与可见光和红外自旋扫描辐射仪（VISSR）估计值之间的均方根差以及GLI与NCEP估计值之间的均方根差在月度时间尺度上分别越来越小，即爱因斯坦/ m2为3.0（7％）和5.0（14％） /天，偏差为1.1（2％）和？0.2（？1％）爱因斯坦/平方米/天。与浮标数据的比较也显示出很好的一致性，在每天，每周和每月的时间尺度上，均方根误差均值分别为10.2（23％），6.3（14％）和4.5（10％）爱因斯坦/平方米/天，并且稍高GLI值大约为爱因斯坦/平方米/天1.0（2％）。良好的统计性能使该算法适合于水生光合作用的大规模研究。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号