Space and time scales of optical variability in and about Mobile Bay as defined by a NOAA AVHRR visible sensor c660 algorithm

作者：La Violette PE; Arnone RA^*; Ladner S

来源：Continental Shelf Research, 1999, 19(3): 299-315.

DOI：10.1016/S0278-4343(98)00066-1

Optical values extracted from a NOAA AVHRR database were used to derive the spatial and temporal scales of optical variability of Mobile Bay and its nearby sounds. The study used the attenuation coefficient, c660, (derived from Channels 1 and 2 algorithm) to define the coastal surface turbidity for April 1995 through July 1996. The optical spatial variability of 201 images were investigated to establish 15-day, seasonal, and annual means. The 15-day graphs of the seasonal trends show that minimum turbidity variability occurred in summer and the maximum (by a ratio of about twice in Mobile Bay) in winter. The spring and fall transition periods were not as definite, appearing highly variable and brief. Interannual differences were noticeable between the 1995 and 1996 spring periods. Seasonal c660 composite images show a low-spring turbidity, a comparatively uniform summer season, a fall transition period followed by a highly turbid winter period. Residual images (derived by subtracting the annual mean from each seasonal composite) show that in spring, a much less turbid field was generally found throughout the area than shown by the annual mean. The summer residual showed mixed contributions in different regions of the area, whereas the fall composite most closely resembled the annual mean. The winter months show a much stranger positive residuals in almost all of the area (except in the western Mississippi Sound).

• 出版日期1999-3