Tuesday, May 22, 2012 - 3:30pm
Abrupt climate transitions, known as Dansgaard-Oeschger and Heinrich events, occurred frequently during the last glacial period, specifically from 80–11 thousand years before present, but were nearly absent during interglacial periods and the early stages of glacial periods, when major ice-sheets were still forming. Here we show, with a fully coupled state-of-the-art climate model, that closing the Bering Strait and preventing its throughflow between the Pacific and Arctic Oceans during the glacial period can lead to the emergence of stronger hysteresis behavior of the ocean conveyor belt circulation to create conditions that are conducive to triggering abrupt climate transitions. Hence, it is argued that even for greenhouse warming, abrupt climate transitions similar to those in the last glacial time are unlikely to occur in the future as the Bering Strait remains open. Earlier studies suggested that the Bering Strait may also have contributed to the formation of the Quaternary-style climate. Therefore, it seems that the Bering Strait may have played a central role in the glacial-interglacial climate stability.
Presenter(s): Aixue Hu, NCAR
Type of event: CGD Seminar/Symposium
Building: Mesa Lab
Room: Main Seminar Room
Posted by Gaylynn Potemkin (Email) at x1618
Lab/division hosting the event: CGD
Thursday, May 24, 2012 - 1:30pm
Day switched to Thursday, May 24!!
In this talk I will describe a new diagnostic technique that simultaneously utilizes two completely different types of observations - in-situ measurements of solar wind charge states, and high-resolution spectroscopy of the inner solar corona--to determine the temperature, density and velocity of the solar wind as a function of height in the inner corona, below the plasma freeze-in point. This technique relies on the ability to calculate the evolution of the ion charge composition as the solar wind escapes the Sun given wind temperature, density and velocity profiles as a function of distance. The resulting charge composition can be used to predict frozen-in charge states as well as spectral line intensities, to be compared with insitu and remote sensing observations.
This diagnostic technique is applied to SOHO/SUMER and Ulysses/SWICS observations of the fast solar wind, in order to test two different models of fast solar wind acceleration: a wave-driven model where the solar wind is expected to originate from the lower chromosphere and a reconnection-driven model where the wind originates in the inner solar corona. We also show that line intensity profiles may significantly depart from those obtained using the common ionization equilibrium assumption even at low altitudes.
Presenter(s): Enrico Landi
Type of event: University of Michigan Seminar/Symposium
Building: CG1
Room: 1210, South Auditorium
Posted by Wendy Hawkins (Email) at x1552
Lab/division hosting the event: HAO
Thursday, May 31, 2012 - 10:00am
In this presentation, we describe, motivate, and present preliminary results from the dense GNSS meteorological network (~20 stations) in the central Amazon Basin in Brazil; a network that has been developed for studies of deep convection/water vapor interactions and feedbacks. This meso-scale (~80km x 80km area) ground-based network of GNSS receivers and meteorological stations was constructed in and around Manaus, Amazonas, Brazil in April of 2011. The motivations for the network are several-fold: 1) gain insight into smaller-scale water vapor fluxes/convergence and convective activity, for example, the role of “cold pools” in the transition from shallow-to-deep convection and organization of convection at the mesoscale; 2) constrain (“close” with sondes/profilers) the atmospheric component of the hydrological cycle during deep precipitating convection during the GPM-CHUVA IOP Belem (June 2011); 3) create high spatial/temporal resolution (3D with slant path/tomography) water vapor fields for model initialization and/or providing constraints for testing physical parameterizations.
Presenter(s): David K. Adams
Type of event: Programa do Clima e Ambiente Universidade do Estado do Amazonas and Instituto Nacional de Pesquisa da Amazônia
Centro de Ciencias de la Atmósfera Universidad Nacional Autónoma de México
Seminar/Symposium
Building: FL2
Room: 1001
Posted by Rebecca Nowak (Email) at x2606
Lab/division hosting the event: COSMIC
Thursday, May 31, 2012 - 3:10pm
Late last year I somehow managed to haul myself out of bed before 7am on a
Saturday and attend a Code Retreat. We spent the day, except for a lunch break,
splitting into groups of 2 or 3 people and spend 30 minutes experimenting with
developing software. At the end of the 30 minutes you delete the progress so far
and start over with a new group.
The goal is that you should not be able to complete the program, but instead you
should concentrate on software development best practices such as testing,
documentation, pair-programming, and even refactoring came into play.
In this talk I will talk about my experiences at my first Code Retreat and how it has
impacted my software development since.
Presenter(s): Sean Reifschneider
Type of event: Other Seminar/Symposium
Building: CG1
Room: 1210 - South Auditorium
Posted by Scott Briggs (Email) at x1607
Tuesday, June 5, 2012 - 11:00am
An exposure/sensitivity/adaptation framework is used to allow all stakeholdersin an
industry or situation to contribute their expert knowledge to develop an
understanding of key areas of vulnerability to climate change impacts.The 'Climate
Change Risk Management Matrix' was used by stakeholders to identify climate
impacts and identify possible adaptation options.The adaptation options derived
from this process can guide businesses, researchers, and resource managers in their
response to climate change impacts and increase resilience of businesses,
industries and communities. Key outcomes of the process included:
• a shared understanding by all stakeholdersof how climate change will impact on
key elements, important to a business or industry and whether those impacts are
positive or negative in their effect;
• a shared understanding of potential adaptation options that can be explored by
stakeholders at all levels, from individual businesses, through to management
and research responses;
• improved communication between stakeholders around management and other
issuesmore generally; and
• a beginning of business level interventions to assist industry adaptation involving
government and industry.
Presenter(s): Neil Cliff
Type of event: Queensland Department of Agriculture Seminar/Symposium
Building: FL2
Room: 1001
Posted by Carol Makowski (Email) at x8450
Lab/division hosting the event: HAP
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