CHL_water_quality_Saturday
Short description
Chlorophyll-a concentration is an indicator of algae abundance which fluctuates naturally over space and time, as a result of combined atmospheric and oceanic effects (e.g., marine currents and upwelling). In coastal areas, strongly influenced by river inputs and human activities, high Chl concentration can result from the discharge of urban sewage, industrial runoffs, and fertilizers from agriculture activities over watersheds. In particular, nutrient inputs of anthropogenic origin affect the natural amount of phytoplankton in marine and inland waters, representing a continuous threat to biodiversity and leading to undesirable modifications of phytoplankton concentration (i.e., eutrophication).Total Suspended Matter (TSM) i.e, the concentration of organic and inorganic materials suspended in the water, is another proxy for water quality as different contaminants, including nutrients, trace metals, semi-volatile organic compounds, and numerous pesticides, can aggregate to these solids and brought in suspension. This can alter the state of the aquatic ecosystem and the use of freshwater resources. For instance, excessive suspended material might condition primary productivity. TSM concentration can be very high near the coasts due to the resuspension of terrestrial or submarine particulate matter by tides, waves, and currents.Example of the impact of COVID-19 on Water Quality
A general, negative trend of Chl concentration anomaly is observed in the Venice Lagoon as well as offshore the whole Po River coastal zone during the Italian lockdown. In the Venice lagoon, this pattern of low Chlorophyll concentration can be most probably linked to the decrease of maritime traffic and tourism frequentationOffshore the lagoon, this striking negative trend is likely due to remarkably well-stratified thermohaline conditions, which maintained values of Chl concentration fairy low and hindered alongshore transport of riverine loads in the northern sector of the basin. These well-stratified conditions, clearly exemplified by the observed increase in Sea Surface Temperature (figure below) as measured by a multi-sensor product (including data from NOAA-18, MetOpA-B, Aqua, Terra, MSG1, NPP, Meteosat11, Sentinel 3A-B), resulted from the particular interplay between low and warm Po River runoff and low wind intensities.
The product contains one single band named "chl" expressed in anomaly %
North Adriatic - Chlorophyll-a concentration anomalies