PALEOCLIMATE PROXIES & EL NIÑO SOUTHERN OSCILLATION Megan F. Gambs UW Oceanography UWHS Atmospheric Sciences 211 May 2013 Workshop

\ P ALEOCLIMATE P ROXY = – any “biological, physical, or chemical measurement made in: sediments, fossil shells, ice cores, trapped air, speleothems, corals, and other archives – that serve as surrogates for climate parameters…” W HAT IS A C LIMATE P ROXY ? Thomas Cronin; USGS

\ E XAMPLES OF P ALEOCLIMATE P ROXIES jpg El NiÑO Southern OSCILLATION

\ Coral Skeletons are made of CaCO3. – We can analyze two ratios: Oxygen isotopes (16-O to 18-O) – Tells us about water temperature Ratio of Magnesium to Calcium (Mg/Ca) – Tells us about salinity » This gives information about precipitation W HAT C AN C ORALS T ELL U S ? Thomas Cronin; USGS

\ El Niño vs. Normal E L N IÑO S OUTHERN O SCILLATION (ENSO)

\ La Niña vs. Normal E L N IÑO S OUTHERN O SCILLATION (ENSO)

\ El Niño vs. La Niña E L N IÑO S OUTHERN O SCILLATION (ENSO)

\ El Niño vs. La Niña E L N IÑO S OUTHERN O SCILLATION (ENSO)

\ El Niño vs. La Niña E L N IÑO S OUTHERN O SCILLATION (ENSO)

\ How do corals help with our understanding of ENSO? Corals & ENSO: Introduction Prof. Sandy Tudhope; University of Edinburgh, School of Geosciences

\ “coring” a living Porites coral Photo credits: USGS (above ), A. Tudhope (right)

\ C ORALS & ENSO: S TUDY A REA IN P APUA N EW G UINEA

\ Use δ 18 O records extracted from corals, as published in Science (Tudhope et al. 2001) Employ Excel to create plots of properties through time, from the corals Goal: illustrate the relationship between δ 18 O recorded in corals and modern El Nino events – Use this relationship to reconstruct El Nino events in the “paleo record” C ORALS & ENSO: T HE A CTIVITY

\ (1) Modern Corals – Compare the living coral data to modern SST measurements (2) Ancient Corals – Now, that you’ve proved that del18O records track ENSO events (variations in precipitation and temperature), study ENSO back in time. C ORALS & ENSO: T HE A CTIVITY

\ PALEO: C ORALS & ENSO *

\ ENSO & C ORALS : A NCIENT C ORALS FROM H UON P ENINSULA, P APUA N EW G UINEA Photo credit: Prof. Sandy Tudhope Raised Coral Reef Terraces

\ (1) Modern Corals – Compare the living coral data to modern SST measurements (2) Ancient Corals – Now, that you’ve proved that del18O records track ENSO events (variations in precipitation and temperature), study ENSO back in time. C ORALS & ENSO: T HE A CTIVITY

\ M ODERN : C ORALS & ENSO pe2001/tudhope.html *

\ This presentation can be found at the following website: ntity&title=NASA/UWHS%20Climate%20Science ntity&title=NASA/UWHS%20Climate%20Science Or, *Timeseries presented, here, are sourced from and are based on published work by Tudhope et al Alexander W. Tudhope, Colin P. Chilcott, Malcolm T. McCulloch, Edward R. Cook, John Chappell, Robert M. Ellam, David W. Lea, Janice M. Lough, and Graham B. Shimmield. Variability in the El Niño-Southern Oscillation Through a Glacial-Interglacial Cycle. Science, v.291(5508), pp , February 23, 2001