Variability of Bio-Optical Properties at Sampling Stations and Implications for Remote Sensing: a Case Study in the North-East Gulf of Mexico

C. Hu, B. Nababan, D. C Biggs, Frank E Muller-Karger

Research output: Contribution to journalArticlepeer-review

Abstract

Variations of bio-optical properties at oceanographic sampling stations, although important for satellite data validation and algorithm development, have rarely been documented or studied. Using flow-through data and water samples collected from the flow-through system and Niskin bottles at ∼260 stations between summer 1998 and spring 1999 in the north-east Gulf of Mexico (27.5° to 30.4° N, 90° to 80° W), we study the variability of several properties, including chlorophyll-a concentration and Gelbstoff absorption, at the sampling stations. It is found that the standard deviations for both Gelbstoff and chlorophyll are less than 10% of the mean values for more than 90% of the stations, including the coastal stations where water is turbid or Case II. High variations are found in the frontal regions near river plumes. At several stations chlorophyll-a and Gelbstoff vary by nearly two-fold due to spatial and/or temporal variations of the properties near the plume waters. This suggests that for water samples collected from moderately coloured waters (chlorophyll-a >0.25 mg m-3) or coastal river plume waters, special care should be taken to validate the sample data by using multiple samples, a continuous flow-through system, or a concurrent satellite data product map. Otherwise large uncertainties are likely to occur when these data are used to validate satellite estimates.

Original languageAmerican English
JournalInternational Journal of Remote Sensing
Volume25
DOIs
StatePublished - Jan 1 2004

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