IFYLE Total Suspended Matter (TSM) Data 2005

Procedure for measuring the concentration of total suspended material (TSM) on the buoy cruises on the Laurentian.

Triplicate water samples were collected at each station and depth (measured from the water surface) using a 5 L Niskin bottle. Three separate casts were made to collect the three samples. The water from each cast was poured into a temporary storage bottle (4L) for transfer to the ship’s laboratory.

In the laboratory measured aliquots of water were filtered through rinsed, pre-weighed Gelman A/E glass-fiber filters (47 mm diameter, 1 micron nominal pore size). Prior to filtering the sample containers were inverted several times to resuspend any deposited material. Filtering was done between 1 and 8 hours after collection.

The filters were dried at 40? C and then put in the weighing room for at least several hours prior to weighing. Weights were measured in grams using a Mettler AT250 balance, and recorded to 5 decimal places. Blank filters were used to correct for changes in atmospheric conditions between the two weighings. TSM was calculated by dividing the sample weight by the volume of water filtered. A value of -999 indicates that no TSM value could be computed. All measurements and calculations were recorded on a log sheet.

The August buoy cruise was done aboard the Lake Guardian. The only change in the sample procedure was that the water samples were collected simultaneously in three 8 L Niskin bottles on the Lake Guardian’s rosette water sampler.

Nathan Hawley
NOAA-GLERL, 2205 Commonwealth Blvd.
Ann Arbor, MI 48105-2945
(734)741-2273