Reconstructing past marine variability using the longest-lived animals on Earth

Category: Time:
Wednesday, February 6, 2019 - 12:00 to 13:00
Room: Speaker:
Dave Reynolds
David Frank

Variability in the North Atlantic Ocean plays a significant role in moderating atmospheric climate variability over large portions of the Northern Hemisphere. However, there remain large uncertainties in our understanding of how the North Atlantic Ocean has varied in the past and the role of external forcings and internal mechanisms in driving this variability. These uncertainties largely stem from the short temporal and spatially heterogeneous nature of direct observations, that are typically constrained to the past 50 years. In this talk I will discuss the recent advances in the field of sclerochronology (the marine counterpart to dendrochronology) that have facilitated the generation of millennial length annually resolved and absolutely dated records of past North Atlantic Ocean variability. The absolutely dated nature of these records, based on crossdating, facilitates the analysis of spatial networks of sclerochronologies to reconstruct broad scale variability in the North Atlantic, such as tropical and subpolar gyre sea surface temperatures and North Atlantic Current Salinity. The integration of these data with dendrochronologies is now providing unique insights into the coupling of the North Pacific, North Atlantic and atmosphere circulation patterns over the last 500 years.