OSU Chlorophyll Anomaly V2, MODIS Aqua, West US, 2003-present

U.S. West Coast Moderate Resolution Imaging Spectroradiometer (MODIS) Aqua High Resolution Chlorophyll-a (CHLA) Anomaly Fields (July 2002 - March 2014). This suite of CHLA and Sea Surface Temperature (SST) climatology and anomaly data products are derived from daily, 0.0125 degree x 0.0125 degree, MODIS Aqua CHLA and SST fields that cover the California Current System (22N - 51N, 155W - 105W) for the 11-year period July 2002 through June 2013. These daily fields, obtained from the NOAA CoastWatch West Coast Regional Node website, were processed using a successive 3x3, 5x5 and 7x7 grid cell hybrid median filtering technique. This technique was found to effectively reduce noise in the daily fields while maintaining features and detail in important regions such as capes and headlands. The resulting median filtered daily fields were then linearly interpolated to a 0.025 x 0.025 degree grid and averaged to create 132 monthly mean fields. The seasonal cycles at each 0.025 degree x 0.025 degree grid cell were obtained by fitting each multiyear time series of monthly means to a nine-parameter regression model consisting of a constant plus four harmonics (frequencies of N/(1-year), N-1,4; Risien and Chelton 2008, Journal of Physical Oceanography (JPO)). Even with the median filtering and the temporal averaging of the daily fields, the highly inhomogeneous nature of the MODIS fields still resulted in regression coefficients that were excessively noisy. We therefore applied the same successive 3x3, 5x5 and 7x7 hybrid median filtering technique, described above, to the regression coefficients before finally spatially smoothing the coefficients using a loess smoother (Schlax et al. 2001, JTECH) with filter cutoff wavelengths of 0.25 degree latitude by 0.25 degree longitude. The seasonal cycles were then calculated from the filtered regression coefficients for each 0.025 degree x 0.025 degree grid cell using the mean and all four harmonics. It is important to note that THIS SUITE OF DATA PRODUCTS IS HIGHLY EXPERIMENTAL and is strictly intended for scientific evaluation by experienced marine scientists.
cdm_data_type=Grid
contact=Craig Risien ([e-mail])
Conventions=CF-1.10, COARDS, ACDD-1.3
Easternmost_Easting=255.0
geospatial_lat_max=51.0
geospatial_lat_min=22.0
geospatial_lat_resolution=0.0125
geospatial_lat_units=degrees_north
geospatial_lon_max=255.0
geospatial_lon_min=225.0
geospatial_lon_resolution=0.0125
geospatial_lon_units=degrees_east
geospatial_vertical_max=0.0
geospatial_vertical_min=0.0
geospatial_vertical_positive=up
geospatial_vertical_units=m
infoUrl=???
institution=Oregon State University - College of Earth, Ocean, and Atmospheric Sciences
Northernmost_Northing=51.0
references=Risien, C.M., and P.T. Strub. Satellite-Derived Climatologies: The California Current Large Marine Ecosystem. Cooperative Institute for Oceanographic Satellite Studies. Available online at http://cioss.coas.oregonstate.edu/CIOSS/Documents/Published_Reports/Risien_USWC-Sat-Climatology.pdf
rights=The data may be used and redistributed for free but is not intended for legal use, since it may contain inaccuracies. Neither the data Contributor, CoastWatch, NOAA, nor the United States Government, nor any of their employees or contractors, makes any warranty, express or implied, including warranties of merchantability and fitness for a particular purpose, or assumes any legal liability for the accuracy, completeness, or usefulness, of this information.
sourceUrl=(local files)
Southernmost_Northing=22.0
spatial_resolution=0.025 degree
standard_name_vocabulary=CF Standard Name Table v70
testOutOfDate=now-40days
time_coverage_end=2024-11-16T00:00:00Z
time_coverage_start=2003-01-16T00:00:00Z
Westernmost_Easting=225.0

美国西海岸高分辨率成像光谱仪（MODIS）Aqua高分辨率叶绿素a（CHLA）异常场（2002年7月-2014年3月）。本套CHLA和海面温度（SST）气候学及异常数据产品源自每日0.0125度x0.0125度分辨率的MODIS Aqua CHLA和SST场，覆盖加利福尼亚海流系统（22N-51N，155W-105W）11年（2002年7月至2013年6月）期间的加利福尼亚海流系统。这些每日场数据由NOAA CoastWatch西海岸区域节点网站提供，经过连续的3x3、5x5和7x7网格单元混合中值滤波技术处理。该技术被发现能有效降低每日场中的噪声，同时保持如海角和半岛等重要区域的特征和细节。随后，对中值滤波后的每日场进行线性插值至0.025x0.025度网格，并平均生成132个月平均场。通过将每个多年代月平均时间序列拟合到一个由常数加四个谐波（频率为N/(1年)，N-1,4；Risien和Chelton 2008，物理海洋学杂志（JPO））组成的九参数回归模型，获得了每个0.025度x0.025度网格单元的季节周期。即便对每日场进行了中值滤波和时间平均，MODIS场的极高异质性仍然导致了回归系数的噪声过大。因此，我们对回归系数也应用了上述相同的连续3x3、5x5和7x7混合中值滤波技术，最终使用具有0.25度纬度x0.25度经度截止波长的loess平滑器（Schlax等，2001，JTECH）进行空间平滑。然后，使用每个0.025度x0.025度网格单元的滤波回归系数及其所有四个谐波计算季节周期。重要的是要注意，本套数据产品极具实验性，且严格限于经验丰富的海洋科学家进行科学评估。