<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=Windows-1252">
<style type="text/css" style="display:none;"> P {margin-top:0;margin-bottom:0;} </style>
</head>
<body dir="ltr">
<blockquote style="margin-left: 0px;" class="elementToProof">
<div style="text-align: left; text-indent: 0px; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
Dear PCC community, </div>
<div style="margin: 0px; padding-bottom: 20px; min-width: 0px;" class="elementToProof">
<div style="margin: 8px 0px 0px;" class="elementToProof" id="m_8806915133225539242x_:18r">
<div class="elementToProof" id="m_8806915133225539242x_:18s">
<div style="direction: ltr; text-align: left; text-indent: 0px; line-height: 1.5; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
We are excited to continue the monthly Program on Climate Change Colloquium series. Please join us on Thursday November 20 at 3:30pm in Johnson Hall Room 075 for a presentation by Prof. Eric Steig on "Water isotopes are magical: fundamental things isotope records
from ice cores tell us about climate variability and ice sheet change across timescales from decades to millennia". This event will be held jointly with the ESS Departmental Colloquium.</div>
</div>
</div>
</div>
<div style="text-align: left; text-indent: 0px; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
<b>Speaker: Eric Steig (Ben Rabinowitz Professor in the Department of Earth and Space Sciences)</b></div>
<div style="text-align: left; text-indent: 0px; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
<b>Title: Water isotopes are magical: fundamental things isotope records from ice cores tell us about climate variability and ice sheet change across timescales from decades to millennia.</b></div>
<div style="text-align: left; text-indent: 0px; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
<b>Time and Location: Th Nov 20 at 3:30 in Johnson Hall (JHN) 075</b></div>
<div style="text-align: left; text-indent: 0px; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
<br>
</div>
<div style="text-align: left; text-indent: 0px; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
Abstract: The discovery that oxygen and hydrogen isotopes in snowfall provide a window into the past through ice cores is more than six decades old. Yet the “old” technology of water isotopes continues to be a cornerstone of our understanding of both past
and current climate in the polar regions. Recent advances include measurement methods that improve both resolution and precision; a revolution in dating of ice cores, allowing us to compare them with one another with high confidence; and the development of
ways to use water-isotope data to constrain and validate climate model simulations.</div>
<div style="text-align: left; text-indent: 0px; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
<br>
</div>
<div style="text-align: left; text-indent: 0px; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
Three examples – on very different timescales – illustrate the continued magic of ice-core isotope records.</div>
<div style="text-align: left; text-indent: 0px; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
<br>
</div>
<div style="text-align: left; text-indent: 0px; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
First, we have long wanted to know how big the Antarctic and Greenland ice sheets may have been during the last glacial maximum, how much they thinned during the Holocene, and how small they were during previous interglacial periods, when sea level was much
higher than present. We now know the answer to all these questions pretty well, because only certain ice-sheet configurations are compatible with the isotope data.</div>
</blockquote>
<div style="text-align: left; text-indent: 0px; line-height: 18px; margin: 0.5em 0px; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
Second, ice-core isotope records provide essentially the only observations of climate in Antarctica prior to the late 1950s, and they show that the variability of West Antarctic climate (in particular) is greater than one might suppose from direct meteorological
measurements. These observations, combined with modern numerical climate models, show how the complex interplay between winds, sea ice, ocean currents, and the geometry of the melting ice itself, all influence the efficiency with which warm water reaches and
melts the ice. As a result, we are close to being able to answer the attribution question: we know the Antarctic ice sheet is melting, but is it our fault?</div>
<div style="text-align: left; text-indent: 0px; line-height: 18px; margin: 0.5em 0px 0px; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
Third, I’ll touch on recent work showing how isotope records from ice cores have something new to teach us about the basic radiative physics of the polar atmosphere.</div>
<div style="text-align: left; text-indent: 0px; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
<br>
</div>
<div style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
The PCC Colloquium will rotate to other topics and units in the winter quarter. </div>
<div style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
<br>
</div>
<div id="Signature">
<div style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<br>
</div>
<div style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Program on Climate Change</div>
<div style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
University of Washington</div>
<div style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Ocean Sciences Building, Room 335A</div>
<div style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Phone: 206-543-6521</div>
<div style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
PCC Private Linkedin Group : <a title="https://www.linkedin.com/groups/14629330/" class="OWAAutoLink" id="OWAa5a5379c-0e17-503c-1504-f86cbaa5b6a7" href="https://www.linkedin.com/groups/14629330/">
UW Program on Climate Change Connector</a></div>
</div>
</body>
</html>