For and about the people of NCAR and UCAR
Wednesday, May 16, 2012
For the purposes of measuring magnetic fields in sunspot umbrae, this near-IR spectrum line is better than other conventionally used lines by almost a factor of 10. Factors include wavelength, Lande g=3, temperature insensitivity, and freedom from blends. Observational results with S. Solanki, M. Penn, and L. Svalgaard are discussed; unexplained questions arise.
The ASP Thompson Lecture Series for 2012 begins with a visit from,
Stephanie Pfirman, Professor of Environmental Science at Barnard College - Columbia University.
Pfirman's general interest lecture abstract:
Warming of the Arctic and decreasing sea ice extent is stimulating increased interests in both development of resources and conservation of habitats, raising questions about how to manage remaining ice resources. Warming is also causing changes in sea-ice formation and melt regions. Analyzing satellite-derived sea ice formation and melt from the perspective of national Exclusive Economic Zones, shows that these changes are having an influence on ice dynamics. Sea ice is moving faster, and there is greater interchange of ice between the marginal seas. These changes increase the chance for any accidental releases into ice to impact the coastal habitat of other nations. Future resource management strategies would therefore have to include basin-scale monitoring, forecasting and planning.
The ASP Thompson Lecture Series for 2012 begins with a visit from,
Stephanie Pfirman, Professor of Environmental Science at Barnard College - Columbia University.
Pfirman's science lecture abstract:
Warming Climate models project that much of the Arctic Ocean could be ice-free in summer within a few decades. That is bad news for animals like polar bears and ringed seals, which need year-round ice to survive. But some 200,000 square miles may persist through the end of this century, along the northern coasts of the Canadian Arctic Archipelago and Greenland. With year-round, or nearly year-round, ice in this region, it may become a naturally formed refuge for ice-associated species. While some ice in this region forms locally, some is also transported to the area by winds and ocean currents. Both the central Arctic and Siberian shelf seas are likely to be part of the future refuge’s “ice shed.” This means that managing the last sea ice area requires both national and international strategies.
Resilient-Sustainable Cities at the National Center for Atmospheric Research (NCAR) cordially invites you to a presentation by the esteemed sociologist and human geographer Karen O'Brien on ethical transformation in response to climate change. Please join us at the NCAR Foothills Lab in Boulder on Friday, May 18th at 1:30pm. Details below.
The talk will address the following issues
• Importance of metaperspectives (the bigger picture, the longer story)
• Integration of perspectives, disciplines, and “ways of knowing” transdisciplinarity
• What is transformation and why is it important that it is deliberative, ethical and equitable?
• How do we approach change, and how can we change our approaches to change?
• Why do worldviews, beliefs and values matter?
• What are the leverage points for large-scale, systemic change?
• What is our role as scientists?
Bio: Karen O’Brien is a Professor in the Department of Sociology and Human Geography at the University of Oslo, Norway. Her research has focused on climate change impacts, vulnerability and adaptation and the implications for human security, as well as on the relationships between globalization and environmental change. Her current research looks at the relationship between personal, cultural, organizational and systems transformation, including how transdisciplinary and integral approaches to global change research can contribute to a better understanding of how societies both create and respond to change. She has participated in the IPCC Fourth and Fifth Assessment Reports, as well as the Special Report on Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX). She has written and edited a number of books, including Environmental Change and Globalization: Double Exposures (Oxford, 2008), Adapting to Climate Change: Thresholds, Values, Governance (Cambridge, 2009) and Climate Change, Ethics, and Human Security (Cambridge, 2010).
Ncar Community Art Program proudly invites you to join us at an art reception for photograher Chris Brown and Judith Trager's Fiber art. Reception will be held in the Mesa lab cafe May 18, 2012 from 5:00pm to 9:00pm.
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.
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.
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.
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