Phillipsdale Landing
Sondes were swapped for routine maintenance on the morning of February 23rd. Depth data had been lost by the sondes on February 15th but was restored with the deployment of new sondes at the swap. Data in this week’s summary should be interpreted with caution due to the lack of depth data to confirm sonde positioning for most of the week.
Weather conditions this week included light to moderate rain or snow every day, totaling 0.62 inches as recorded at TF Green. The largest rain event was on February 23rd with 0.32 inches. Blackstone River flows showed a slight increase after this rain event but remained below the 18-year median flow rates. Surface salinity this week averaged 12.6 ppt and ranged from 4.1 ppt to 22.9 ppt. At the bottom, salinity averaged 21.0 ppt and ranged from 8.7 ppt to 27.5 ppt. Temperatures at the surface averaged 5.6°C, ranging 2.9°C – 8.0°C. At the bottom, temperatures averaged 5.8°C and ranged 4.1°C – 6.7°C.
Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold of 2.9 mg/L throughout the week. Surface DO averaged 10.8 mg/L and ranged 9.2 – 12.4 mg/L. Bottom DO concentrations averaged 10.0 mg/L and ranged from 8.9 mg/L to 11.6 mg/L. Chlorophyll readings generally remained low, averaging 1.5 ug/L at the surface and 4.2 ug/L at the bottom. The maximum chlorophyll reading this week was 35.5 ug/L at the bottom on February 23rd. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location.
Bullock Reach
Bullock Reach sondes will be deployed later this spring for the 2023 monitoring season.