2  Data

2.1 Data Sources

2.1.1 EPA Water Quality Buoy placed in the Lower Charles River

Every 15 minutes, this self-contained solar powered buoy takes measurements for temperature, dissolved oxygen, pH, specific conductance, turbidity, chlorophyll, and phycocyanin. The sensors on the buoy are located 1 meter below the water’s surface. The data are transmitted in real-time using telemetry for remote access. The data from this buoy is used to assess water quality conditions and to help track cyanobacteria (blue-green algae) blooms.

Charles River Water Quality Buoy

Buoy Location

2.1.2 Visual Crossing Historical Weather Data API

Visual Crossing is a provider of weather data and enterprise analysis tools to data scientists, business analysts, professionals, and academics. Founded in 2003, this weather data API leads the industry by providing the lowest-cost access to all types of historical weather data, weather forecasts, climate summaries, and historical weather forecasts.

2.2 Missing Data Analysis

1. Fecal bacteria data is not measured by the Charles River Buoy (e.g. enterococci samples).
2. Buoy data is only reported between May and October. There is no data for November through April.