CIRA Seminars

Filter By Seminar Year (2007 thru 2018)

2015 CIRA Seminars

Friday, April 17, 2015 - 11:15 @ ATS room 101
Presenter: Jim Fleming, Professor, Science, Technology, and Society, Colby College

Atmospheric researchers have long attempted to untie the Gordian Knot of meteorology — that intractable and intertwined tangle of observational imprecision, theoretical uncertainties, and non-linear influences — that, if unravelled, would provide perfect prevision of the weather for ten days, of seasonal conditions for next year, and of climatic conditions for a decade, a century, a millennium, or longer.

Friday, April 17, 2015 - 03:00 @ ATS room 101

Outstanding student paper ceremony and 100th anniversary celebration of Herbert Riehl’s birth will begin at 2:30 p.m. in the Weather Lab.

Friday, April 10, 2015 - 11:15 @ ATS room 101
Presenter: Chuck Kutscher , Principal Engineer/Group Manager, Thermal Systems Group, National Renewable Energy Laboratory

Climate change is increasingly being recognized as a growing environmental crisis that must be addressed. Studies have shown that the costs of addressing this problem are much less than the costs of dealing with the consequences. Because the major driver is the emission of greenhouse gases associated with the burning of fossil fuels, the most direct way to address the problem is to rapidly decrease the use of these fuels. This can be done via the adoption of a combination of energy efficiency and carbon-free energy technologies.

Friday, April 3, 2015 - 11:15 @ ATS room 101
Presenter: Maria Cristina Facchini, Research Director, Institute of Atmospheric Sciences and Climate, National Research Council, Bologna

The Po Valley is a hot spot for air pollution both for the emission sources due to the intense industrial, agricultural and trading activities and the orography of the Valley, surrounded on three sides by high mountain ranges, that favors the accumulation of particulate and gaseous pollutants in the lower levels of the atmosphere.

Friday, March 27, 2015 - 11:15 @ ATS room 101
Presenter: Elizabeth A. Stone, Assistant Professor, Department of Chemistry, University of Iowa

In summer 2012, a landfill liner comprising an estimated 1.3 million shredded tires burned in Iowa City, Iowa. During the fire, continuous monitoring and laboratory measurements were used to characterize the gaseous and particulate emissions. In the tire fire plume, we observed significant enrichments in ambient concentrations of CO, CO2, SO2, particle number (PN), fine particulate (PM2.5) mass, elemental carbon (EC), polycyclic aromatic hydrocarbons (PAH), azaarenes (PAH with nitrogen heteroatoms) and aromatic volatile organic compounds (VOC).

Friday, March 13, 2015 - 10:45 @ ATS room 101
Presenter: Russ Schumacher, CSU ATS Professor

In the central and eastern U.S., as well as other continental locations at midlatitudes around the world, warm-season heavy precipitation is most frequent at night.

Friday, March 6, 2015 - 11:15 @ ATS room 101
Presenter: Zach Lebo, NOAA

A growing interest in the potential effects of aerosol perturbations on deep convective clouds has resulted in numerous publications over the past decade. These studies have primarily focused on aerosol-induced changes in updraft strength, precipitation amount, precipitation patterns, and lightning frequency. In this talk, I will highlight the primary mechanisms for aerosol effects on deep convective clouds that have been proposed in the literature.

Friday, February 27, 2015 - 11:15 @ ATS room 101
Presenter: David J. Raymond, Visiting ATS from Physics Department and Geophysical Research Center, New Mexico Tech

In this talk I will review the history of thought regarding the formation of tropical cyclones. The conditions required for their formation as presented by William Gray, John McBride, and Raymond Zehr are first discussed, followed by a review of early work by Jule Charney and others. The results of observational programs in the east and west Pacific and theoretical studies in the 1990s are reviewed, including the seminal work of Marja Bister and Kerry Emanuel. These works form the background for the most recent observational and theoretical results, which will be discussed in detail.

Friday, February 20, 2015 - 03:00 @ ATS room 101
Presenter: Christopher Davis, Visiting ATS from NCAR

The upscale aggregation of convection is used to understand the emergence of rotating, coherent midtropospheric structures and the subsequent process of tropical cyclone formation. The CM1 model is integrated on an f-plane with uniform SST and prescribed uniform background flow. Moist cyclonic vortices form, merge, and eventually result in a single dominant vortex that subsequently forms a tropical cyclone. Consistent with previous studies, the approach to saturation within the midtropospheric vortex accelerates the genesis process.

Thursday, February 19, 2015 - 03:30 @ ATS room 101
Presenter: John Walker, USEPA Office of Research and Development

Friday, February 13, 2015 - 11:15 @ ATS room 101
Presenter: Bill Gail, Visiting ATS from Global Weather Corporation

Climate change represents an enormous challenge for today’s generations. Yet we are thinking too small if we conclude its primary lessons concern greenhouse gases or even energy sustainability. The deeper lesson is about the critical milestone humanity has achieved with the scale of its reach. We can now readily change Earth in its entirety, something civilization has never been able to do previously. Our newfound global-scale reach will fundamentally alter both nature and society, mostly in ways we can barely anticipate.

Thursday, February 12, 2015 - 02:00 @ ATS room 101
Presenter: Graeme Stephens, JPL

Before the so-called ‘climate warming hiatus’, the answer to this question seemed certain. But our inability to explain observed changes in surface temperature over the past two decades, and associated sea level rise, ocean heat uptake, and the changes to the planetary energy balance in a physically consistent and connected way has caste doubt on our understanding behind this basic question. In this talk, recent and convincing evidence for where the heat is really going into Earth will be presented, and new insights on understanding the planetary energy balance will be described.

Friday, February 6, 2015 - 11:15 @ ATS room 101
Presenter: Barbara Ervens, NOAA

Aerosol particles in the atmosphere adversely affect climate, air quality and health. They interact with incoming radiation by absorbing/scattering light and by acting as condensation nuclei for cloud droplets. Organic material comprises a significant fraction of such atmospheric particulate matter. A large portion of this material is produced by physical and chemical processes in the atmosphere and is referred to as ‘secondary organic aerosol’ (SOA).

Thursday, February 5, 2015 - 10:30 @ CIRA Director's Conference Room
Presenter: Jason Dunion, NOAA/AOML/Hurricane Research Division

New GOES infrared satellite imagery has been developed to continuously monitor changes in the cloud top convective and cirrus canopy structure of tropical cyclones. This satellite imagery has also revealed a curious diurnal pulsing pattern that may represent an unrealized, yet fundamental process of mature tropical cyclones. These diurnal pulses appear as IR "cold rings" in the satellite imagery.

Friday, January 30, 2015 - 11:15 @ ATS room 101
Presenter: Profs. Collett, Denning, Kummerow, Ravishankara, Rutledge, Schubert, Thompson and van den Heever, ATS

What: 5–10 min intros by individual faculty members

Who: Profs. Collett, Denning, Kummerow, Ravishankara, Rutledge, Schubert, Thompson, van den Heever

Why: provide overview of research areas & groups in the department

Why2: gather for cookies & snacks before and pizza after (in Weather Lab)

Friday, January 23, 2015 - 08:15 @ ATS room 101
Presenter: Angie Pendergrass, Visiting ATS from NCAR

2014 CIRA Seminars

Friday, December 12, 2014 - 11:15 @ ATS room 101
Presenter: Juliana Dias, NOAA

Convectively coupled equatorial waves (CCEWs) represent the leading modes of synoptic scale organized convection in the tropical troposphere and they are known to affect weather in both the tropics and midlatitudes. Despite their prominence in the observations, CCEWs are poorly represented in current general circulation models used to predict weather and climate. Because of their implied level of deterministic predictability, it is important to understand the key physical mechanisms underlying their variability in order to improve their model representation.

Friday, December 5, 2014 - 11:15 @ ATS room 101
Presenter: Aaron Donohoe, Visiting ATS from the University of Washington

In response to increasing concentrations of atmospheric CO2, high-end general circulation models (GCMs) simulate an accumulation of energy at the top-of-the-atmosphere not through a reduction in out-going longwave radiation (OLR) as one might expect from green-house gas forcing but through an enhancement of net absorbed solar radiation (ASR). A simple linear radiative feedback framework is used to explain this counter-intuitive behavior.

Friday, November 21, 2014 - 11:15 @ ATS room 101
Presenter: Pinhas Alpert, Visiting ATS from Tel Aviv University, Israel

The propagation of electromagnetic radiation in the lower atmosphere, at centimeter wavelengths, is impaired by atmospheric conditions. Absorption and scattering of the radiation, at frequencies of tens of GHz, are directly related to the atmospheric phenomena, primarily precipitation, oxygen, mist, fog and water vapor.
As was recently shown, wireless communication networks supply high resolution precipitation measurements at ground level while often being situated in flood prone areas, covering large parts of these hazardous regions.
Thursday, November 6, 2014 - 02:00 @ ACRC Classroom
Presenter: Karri Muinonen, Visiting ATS from the University of Helsinki

We consider scattering of light by complex atmospheric particles with carbonaceous, silicate, and icy compositions. First, we pay attention to modeling the particle shapes with the so-called Gaussian-random-sphere and Gaussian-random-ellipsoid geometries, where the undulations on the basic regular shape are described by multivariate Gaussian statistics. Scattering by such particles is studied using next-to-exact (e.g., the discrete-dipole approximation) and approximate methods (e.g., the ray-optics approximation).

Friday, October 17, 2014 - 11:15 @ ATS room 101
Presenter: Amit Tandon, Visiting ATS from the University of Massachusetts - Dartmouth

Increased resolution in modeling and in observations in the ocean have revealed rich dynamics at O(km) lateral scales in the ocean associated with O(1) Rossby and Richardson numbers. These sub-mesoscale oceanic processes are very different from the quasi-geostrophic dynamics at the large scale and the isotropic mixing at the small scales. They are important in the upper ocean frontal regions and make important contribution to vertical fluxes of buoyancy and tracers in the ocean.

Tuesday, September 30, 2014 - 10:00 @ CIRA Director's Conference Room
Presenter: Daniel Nietfeld, NOAA/NWS WFO Omaha Nebraska

High impact meteorological and hydrological events, such as severe thunderstorms and flash floods, typically consist of phenomenon that occur on temporal and spatial scales that fall into the meso α, meso β, or meso γ range.   The associated atmospheric processes involve ageostrophic motions and are often nonhydrostatic, so Numerical Weather Prediction (NWP) models generally show poor predictive skill simulating the phenomenon, specifically the details.  Therefore, predicting the beginning, ending, areal distribution, and magnitude of high impact events remains a significant forecast challe

Monday, September 29, 2014 - 11:15 @ ATS room 101
Presenter: Dr. Shane Murphy, Visiting ATS from the University of Wyoming Dept. of Atmospheric Science

     The leakage rate from new oil and gas development in the U.S. is currently a matter of intense debate because the leakage rate affects how beneficial, from a climate perspective, switching from coal to natural gas is. Black carbon, for which biomass burning is the largest global source, is thought to be one of the most important anthropogenic emissions for heating the climate, perhaps second only to carbon dioxide.
      This talk will delve into recent research on both of these topics.
Thursday, September 4, 2014 - 11:00 @ CIRA Director’s Conference Room
Presenter: Ken Sperow, CIRA Senior Solutions Architect

Imagine a laboratory accessible 24 hours a day from all over the world where scientists can collaborate, innovate and easily transition their innovations. This is the idea behind the National Oceanic and Atmospheric Administration’s (NOAA) Virtual Laboratory (VLab).
Thursday, August 21, 2014 - 11:00 @ CIRA Director’s Conference Room
Presenter: Dan Vietor, CIRA Senior Research Meteorologist, Aviation Weather Center, Kansas City

New FAA (NextGen) and NWS (Weather Ready Nation) strategic priorities have resulted in an evolution of the Aviation Weather Center's mission that promotes the use of web services aimed at delivering operational Interactive decision support services.  This requires several steps for the AWC which include an easy-to-maintain data back-end leveraging ADDS (Aviation Digital Data Service), formatting the data for efficient and reliable delivery to the browser, better support for domestic and especially internat