The beginning “phase” of this project has been to historically reconstruct the extreme climate trends and to project those trends into the future. This information is proving to be highly valuable and intriguing and will hopefully provide some insight to how our daily lives are being affected by climate events.
At the heart of this project, we want to use this data to assess how aquatic ecosystems have been affected by climate variability and change. So how do we get from the air into the water?
I am presently working on answering that question. One approach example is simply asking this question: “Is the air temperature and water temperature correlated?” If the answer is yes, this suggests that the two are related.
Figure 1 demonstrates the intuitive answer to this question. Indeed, the water temperature at Taskinas Creek, VA is significantly positively correlated to the air temperature at this CBNERR site. This implies that changes to the air temperature (whether it gets warmer or cooler) are “felt” in the shallow water ecosystems of Chesapeake Bay. In other words, here is a direct link to show that changes to the temperature-based extreme climate indices have the potential to affect the critters living in Chesapeake Bay.
The next question we need to ask ourselves: “Is there a lag between temperature changes in the air and that change in the water?” For example, if we get a really hot day, will that affect the water? Or do we need a week of hot weather before the Bay changes?
Warning, my next image is very raw and my interpretation of this plot is still a work in progress!
To answer this question, I used a cross-correlation function (Figure 2). The resulting maximum lag was at 0 days with a regression of +0.91. Thus, the air and water temperatures equilibrate pretty quickly!
Intuitively, we know that the water temperature should lag behind the air temperature. (Changes in air temperature should be what mostly affects the water temperature). So I will have to tackle a better analysis to pinpoint what that lag (if any) could be!
While I still have much more to do to build this case, here is a first proof that changes to climate mean changes to the aquatic environment!