[Grad-postdoc-assn] Fwd: ATOC Colloquium: Friday, September 15 @ 11am MT – Ulla Heede, Michelle Maclennan, Kara Hartig – SEEC S228 and Zoom

Tue Sep 12 16:54:35 MDT 2023

FYI

---------- Forwarded message ---------
From: Andrew Winters <andrew.c.winters at colorado.edu>
Date: Mon, Sep 11, 2023 at 8:23 AM
Subject: ATOC Colloquium: Friday, September 15 @ 11am MT – Ulla Heede,
Michelle Maclennan, Kara Hartig – SEEC S228 and Zoom
To: atoc-faculty at colorado.edu <atoc-faculty at colorado.edu>, ATOC Graduate
Students <atoc-students at colorado.edu>, atoc-majors at colorado.edu <
atoc-majors at colorado.edu>, atoc-minors at colorado.edu <
atoc-minors at colorado.edu>, atoc-researchers at colorado.edu <
atoc-researchers at colorado.edu>, atoc-colloquium at colorado.edu <
atoc-colloquium at colorado.edu>
Cc: Hartig, Kara <kara_hartig at g.harvard.edu>

Hi everyone,

The next ATOC Colloquium will be held in a hybrid format on *Friday,
September 15 from 11a–12p MT over Zoom and in SEEC S228. *This week's
colloquium will feature a trio of talks from *Dr. Ulla Heede (ATOC/CIRES),
Michelle Maclennan (ATOC), and Kara Hartig (Harvard). *The zoom login
information and abstracts for each talk are provided below. Please join us
for conversation beginning at 10:45am MT, and stay afterwards for a lunch
catered by Illegal Pete's.
We look forward to seeing you on Friday!

-The ATOC Colloquium Committee

_________________________________________________

*Tropical Pacific Warming Patterns Influence Future Hydroclimate Extremes
in the Americas *
Ulla Heede (ATOC/CIRES)

The tropical Pacific has an uncertain future. The issue of how the tropical
Pacific will respond to global warming is vigorously debated, yet,
unfortunately, we still have no clear answer whether the eastern Pacific
will experience enhanced warming in the 21st century as global climate
models predict, or whether current trends will continue or perhaps plateau.
In this talk, I present a study in which my co-authors and I address this
issue head on by designing a novel set of A-GCM experiments where
everything is held constant except the pattern of warming in the tropical
Pacific. This way, we can isolate the effects of the eastern Pacific
warming on the terrestrial hydroclimate. We find that the eastern Pacific
warming has a very pronounced effect in several regions across the Americas
manifesting as both modulation of long-term trends, and changes in
ENSO-related extreme events. These findings have wide reached implications
for adaptation and climate risk assessment.

*Fieldwork on Thwaites Eastern Ice Shelf, Antarctica *
Michelle Maclennan (ATOC)

West Antarctica’s Thwaites Glacier is approximately the size of the state
of Florida and currently contributes 4% of all global sea-level rise. In
recent decades, the flow of ice from Thwaites Glacier into the ocean has
accelerated, and it could contribute several centimeters of sea level rise
by the end of the century. Thwaites Eastern Ice Shelf, the floating ice at
the terminus of Thwaites Glacier, is the fastest-changing part of the
glacier. Warm circumpolar deep water has melted the ice shelf from below
and large rifts are causing the ice shelf to crack apart from the side, and
as a result it is expected that Thwaites Eastern Ice Shelf will collapse in
the next 1-4 years. In December 2022, a team of 7 researchers traveled down
to Thwaites Eastern Ice Shelf to download oceanographic data on basal melt,
perform glaciological measurements of the ice shelf thickness and rifts,
and collect water samples and snow density profiles at the surface. This
was the third and final field season on the ice shelf, and the last major
opportunity to study this unique and rapidly changing region before its
imminent collapse. Here, we present a summary of the fieldwork conducted
and early results on the current conditions of Thwaites Eastern Ice Shelf,
along with pictures and stories from the field.

*How Warmer Climates Prevent Continental Interiors from Dropping Below
Freezing *
Kara Hartig (Harvard)

In spite of the mean warming trend over the last few decades and its
amplification in the Arctic, some studies have found no robust decline or
even a slight increase in wintertime cold air outbreaks over North America.
But fossil evidence from warmer paleoclimate periods indicates that the
interior of North America never dropped below freezing even in the depths
of winter, which implies that the maintenance of cold air outbreaks is
unlikely to continue indefinitely with future warming. To identify key
mechanisms affecting cold air outbreaks and understand how and why they
will change in a warmer climate, we examine the development of North
American cold air outbreaks in both a pre-industrial and a roughly 8xCO2
scenario with the Community Earth System Model, CESM2. Using a combination
of model climatology and air parcel trajectory analysis, we demonstrate how
the loss of the surface temperature inversion, increased heat and moisture
fluxes over the Arctic Ocean, and subsequent changes to diabatic heating
terms prevent North American temperatures from ever dropping below freezing
in the warmer climate.
__________________________________________________

*Zoom login Information:*

*Topic: ATOC Colloquium*
*Time: Sep 15, 2023 11:00 AM Mountain Time (US and Canada)*

*https://cuboulder.zoom.us/j/98582201579
<https://cuboulder.zoom.us/j/98582201579>*
*Meeting ID: 985 8220 1579*
*Passcode: ATOC*

One tap mobile
+17193594580,,98582201579# US
+12532158782,,98582201579# US (Tacoma)

Dial by your location
• +1 719 359 4580 US
• +1 253 215 8782 US (Tacoma)
• +1 346 248 7799 US (Houston)
• +1 669 444 9171 US
• +1 669 900 6833 US (San Jose)
• +1 253 205 0468 US
• +1 564 217 2000 US
• +1 646 558 8656 US (New York)
• +1 646 931 3860 US
• +1 689 278 1000 US
• +1 301 715 8592 US (Washington DC)
• +1 305 224 1968 US
• +1 309 205 3325 US
• +1 312 626 6799 US (Chicago)
• +1 360 209 5623 US
• +1 386 347 5053 US
• +1 507 473 4847 US

Join by SIP
• 98582201579 at zoomcrc.com

Join by H.323
• 162.255.37.11 (US West)
• 162.255.36.11 (US East)
• 115.114.131.7 (India Mumbai)
• 115.114.115.7 (India Hyderabad)
• 213.19.144.110 (Amsterdam Netherlands)
• 213.244.140.110 (Germany)
• 103.122.166.55 (Australia Sydney)
• 103.122.167.55 (Australia Melbourne)
• 149.137.40.110 (Singapore)
• 64.211.144.160 (Brazil)
• 149.137.68.253 (Mexico)
• 69.174.57.160 (Canada Toronto)
• 65.39.152.160 (Canada Vancouver)
• 207.226.132.110 (Japan Tokyo)
• 149.137.24.110 (Japan Osaka)

Meeting ID: 985 8220 1579
Passcode: 166543
_______________________________________________________

*Andrew C. Winters*
Assistant Professor
Department of Atmospheric and Oceanic Sciences (ATOC)
University of Colorado Boulder
311 UCB, Boulder, CO 80309-0311
Phone: 303-735-5775
https://acwinters.weebly.com
<https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Facwinters.weebly.com%2F&data=05%7C01%7Catoc-colloquium%40colorado.edu%7C3460e64a3e094f6621c408dbb2d251a8%7C3ded8b1b070d462982e4c0b019f46057%7C1%7C0%7C638300389796364835%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=xUu%2BwS2CNu8GdTsamY%2BOTFJOKJ52gmFzjakyKwwV%2BZA%3D&reserved=0>
||
@acwinters_wx || he/him/his

*CU Boulder acknowledges that it is located on the traditional territories
and ancestral homelands of the Cheyenne, Arapaho, Ute and many other Native
American nations. Their forced removal from these territories has caused
devastating and lasting impacts. Full CU Boulder land acknowledgment
<https://www.colorado.edu/about/land-acknowledgement> *

-- 
You received this message because you are subscribed to the Google Groups
"atoc-colloquium" group.
To unsubscribe from this group and stop receiving emails from it, send an
email to atoc-colloquium+unsubscribe at colorado.edu.

-- 
Scott Briggs (he/him/his)
Administrator

Advanced Study Program
Education, Engagement and Early-Career Development
National Center For Atmospheric Research
*phone: 303.497.1607*
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mailman.ucar.edu/pipermail/grad-postdoc-assn/attachments/20230912/e5708d07/attachment-0001.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: atoc_colloq_flyer_20230915.pdf
Type: application/pdf
Size: 349812 bytes
Desc: not available
URL: <https://mailman.ucar.edu/pipermail/grad-postdoc-assn/attachments/20230912/e5708d07/attachment-0001.pdf>