Impacts of climate change on shelf sea stratification

Temperature stratification over the NW European shelf seas is showing evidence of beginning slightly earlier in the year, on average. There is some suggestion of strengthening of stratification beyond the normal inter-annual variability. Trends in stratification in regions influenced by fresh water inputs are also not apparent against the background of natural variability. Predictions for the end of this century suggest that thermal stratification will begin typically 1 week earlier than at present, and end 5 – 10 days later. The strength of the stratification over the whole NW European shelf seas is projected to increase in response to changes in the seasonal heating cycle. Changes to coastal stratification caused by inputs of fresh water cannot yet be predicted.