Stephanie Rushley summarizes her interdisciplinary fellowship research “Examination of intraseasonal coral luminescence peaks during the Mid-Holocene”

In this project, Dr. Daehyun Kim (Dept. Atmospheric Sciences) and I partnered with Dr. Julian Sachs (Dept. Oceanography) to examine a hypothesis presented by Lough et al. (2014).  The authors examined streamflow and rainfall in the current and mid-Holocene climates using coral luminescence and found that there was an increase in the number of peaks in coral luminescence, hence heavy rain events, per year during the mid-Holocene, indicating an increase in intraseasonal variability of precipitation.  In the modern climate, more than one annual peak of luminescence is rare.  Lough et al. (2014) hypothesized that the increase in intraseasonal peaks in the mid-Holocene were driven by a stronger Madden-Julian Oscillation (MJO), which is the dominant source of intraseasonal precipitation variability in the tropics.

This fellowship project opened many doors to me that I would have never experienced.  Through Dr. Sachs I was introduced to Dr. Janice Lough, from the Australian Institute of Marine Science, who not only shared her monthly coral data from the modern period and mid-Holocene period from three different sites in the Great Barrier Reef, but also took the time to help me understand how to correctly use the data by answering numerous questions.  For example, Dr. Lough highlighted some possible errors that can cause unrealistic trends in the coral data that are caused by decay in skeletal density.  Dr. Lough has been extremely helpful and I am very grateful to have gotten connected with her during the course of this project.  Working with experts in very different areas I found a way to connect my work with the MJO to streamflow and coral proxy which I had never worked with before and find interesting results.

One of the most interesting results we found was related to the seasonal cycle of the coral luminescence.

Read the full report