During each deployment, the data collected by the TSRB are affected by variations in the sensor orientation, atmospheric conditions (particularly cloud cover and solar elevation), and the oceanic constituents.  The data presented here have not been corrected for any of these effects.  The high-frequency variations in the data collected are likely caused by variations in the sensor orientation caused by wave action (see the figure below for an example).  Longer-term fluctuations in the magnitude of irradiance and radiance are likely caused by variations in cloud cover (see the irradiance figure for Nov 13 1997 for an example).  Changes in solar elevation would cause a general change in the magnitude of the irradiances and radiances.  This effect is not obvious in the limited temporal (1-hour) data sets presented here.  Variations in the oceanic constituents are expected to result in gradual changes in upwelling radiances.  Note that the presence of bubbles (from breaking waves and the boat wake) and short-term submergences of the instrument may cause further anomalies in the data.

The figure below illustrates the temporal variations in measured downwelling irradiances, upwelling radiances, and the calculated reflectances (radiance/irradiance), for the 490 nm TSRB sensors over a short time period on Oct 28.  The reflectance data (upper graph) shows a relatively strong peak near the time 23.608.  This peak corresponds to a decrease in irradiance (which may have resulted from submergence of the instrument), and an increase in radiance (which may have resulted from the presence of bubbles).  Other reflectance peaks in this data set were caused solely by decreases in irradiance.  Hence, care should be taken when interpreting and using these data.

It should also be noted that it took approximately 3 minutes for the thermistor on the TSRB to record the appropriate sea surface temperature.  This cooling-down period can be seen in the sea surface temperature data from all of the deployments (see the bottom of the irradiance figures).

Webpage by Jasmine S. Bartlett, Oregon State University.