Curious why we have chosen to measure the environmental parameters you see in the Live Data Table?

See below for the description and importance of each environmental parameter we are measuring with the Jordan Pond Buoy and the Pond House Weather Station. 

Jordan Pond Buoy 

Temperature: Water Temperature (°C)

Water temperature can affect water chemistry and biology. For example, the amount of oxygen that water can hold is directly related to the temperature of the water. The higher the temperature, the less oxygen water can hold, which can be observed in both daily and seasonal shifts. Oxygen will naturally decline during the summer months as water temperatures rise. Temperature can also determine the kinds of plants and animals found in a lake or pond. Algae growth is influenced by water temperature: algae grows more quickly in warmer temperatures.

Sp Cond: Specific Conductance (μS/cm)

Conductivity: Conductivity (μS/cm)

Specific conductance is a measure of how well water can conduct an electrical current and reflects the content of charged (or ionic) materials in the water. When specific conductance increases it means the water is receiving more dissolved materials, often from storm runoff.  The Conductivity value (found in the following line of the Live Data chart) is the same measurement that has not been corrected for water temperature.

Salinity: Salinity (PPT)

The dissolved salt content of a lake is important because, along with temperature and pressure, it governs physical characteristics such as heat capacity and density. Salinity is expressing in parts per thousand, or ppt. Jordan pond has low salinity. The salinity of freshwater is typically less than 0.05 ppt.

pH:   (su: standard units)

pH mV:  pH (mV: millivolts)

The pH of a water body reflects how acidic or basic the water is, measured on a scale of 1 to 14, with 7 being neutral. Acid waters are below 7, and alkaline waters are above 7. A one unit change in pH represents a 10-fold change in acidity or alkalinity. Lake pH is determined by measuring the concentration of hydrogen ions in the lake. The pH of water determines the solubility and biological availability of nutrients (such as phosphorus, nitrogen, and carbon) for aquatic life. pH is affected by the bedrock of a lake and the balance between photosynthesis and respiration in the lake, as well as characteristics of the lake watershed and precipitation (rain and snow) chemistry.  The pH mV  value is the “raw” reading of the pH probe.

ODO Sat: Dissolved Oxygen (%)

ODO: Dissolved Oxygen (mg/L)

ODO stands for “Optical Dissolved Oxygen” because it is measured with an optical sensor. Dissolved oxygen is gaseous oxygen dissolved in the water. Oxygen enters aquatic systems by from the atmosphere, mixing of the lake water, and as a byproduct of photosynthesis of aquatic plants and algae within the lake. In general, dissolved oxygen levels above 5.0 mg/L are necessary to support aquatic animals, such as fish, that don’t breathe air. The saturation of oxygen in water is expressed in percent (%); the concentration is expressed in milligrams per liter (mg/L).

Chlorophyll RFU: Chlorophyl (RFU)

Chlorophyll: Chlorophyl (μg/L)

Chlorophyll is a green pigment found in plants and algae that allows the organism to use energy from light to grow. Chlorophyll’s presence in water is an indicator for the amount of algae in the lake.  “RFU” stands for "relative fluorescence unit" - a unit of measurement used in analysis which employs fluorescence detection. The RFU values are converted to chlorophyll concentrations, expressed in micrograms per liter (μg/L).

BGA-Phycocyanin RFU: Bluegreen Algae (RFU)

BGA-Phycocyanin: Bluegreen Algae (cell/mL)

Measurement of the pigment phycocyanin helps us to determine the amount of bluegreen algae in Jordan Pond.  Bluegreen algae are also known as cyanobacteria. Too much bluegreen algae in lakes can be detrimental for aquatic life because the algae consume oxygen necessary for aquatic plants and animals.

fDOM (RFU): Dissolved Organic Matter

fDOM (raw)

fDOM refers to organic matter in water that absorbs strongly in the ultraviolet (UV) spectrum. fDOM fluorescence corresponds to total organic carbon (TOC), which is an indicator of discharge water quality.

Temp00- Temp15: Water Temperature (°C) (0 m – 16 m)

Temperature sensors, mounted at one meter intervals from the lake’s surface to a depth of 16 meters, make it possible to determine the extent of stratification (temperature layering) of the lake.

PAR 1: Photosynthetically Active Radiation Sensor 1 (μmol/s/m2) (0.5 m deep) 

PAR 2: Photosynthetically Active Radiation Sensor 2 (μmol/s/m2) (3 m deep) 

Photosynthetic organisms are able to use light with a wavelength range of 400 – 700 nm (essentially the range of light visible to the human eye) as an energy source for metabolism. PAR sensors allow us to determine how deep light in this range penetrates into the water column and as a corollary, how deep photosynthesis can occur in the lake.


Jordan Pond Weather Station

PAR: Photosynthetically Active Radiation (μmol/s/m2)

A PAR sensor at the weather station allows us to compare levels of irradiance at the Jordan Pond House to levels measured by the PAR sensors on the buoy.

Wind Direction (degrees)

Wind direction is reported by the direction from which it originates.  0° means the wind is blowing from the North, 90° from the East, 180° from the south, and 270° from the West.

Max Wind Direction (degrees)

Maximum wind direction value (see above for info on reporting) from previous 15 minute sample interval.

Min Wind Speed (mph)

Minimum wind speed value from previous 15 minute sample interval expressed in miles per hour (mph).

Wind Speed: Average wind speed (m/sec)

Average wind speed value calculated from previous 15 minute sample interval expressed in meters per second (m/sec). Higher wind speeds promote mixing of the lake water and exchange between the water and air.

Max Wind Speed (mph)

Maximum wind speed value from previous 15 minute sample interval expressed in miles per hour (mph).

Air Temperature (°C)

Air temperature affects lake chemistry, biology, and physical condition. Some factors influenced or controlled by air temperature include the rate of algae growth and the timing and extent of lake turn over and ice cover.

Barometric Pressure (mmHg)

Higher barometric pressure is generally associated with clear weather, while dropping pressure can indicate impending storms.

Daily Rain (mm)

Higher and more intense rain events can cause higher stream flow in inlets, increased run-off from the watershed into the lake, and increased mixing of the lake water column.  Rainfall is expressed in millimeters (mm).