ASP Seminar - Methane, Hydroxyl, and the Self-cleaning Capacity of the Atmosphere

Solar ultraviolet (UV) radiation energizes atmospheric photo-chemistry by generating highly reactive molecular fragments, the hydroxyl radicals (OH). These OH radicals are effective cleaning agents of the atmosphere as they oxidize many reduced compounds emitted by the biosphere and its humans.  The greenhouse gas methane (CH4) is one of these compounds, and its atmospheric mixing ratio has tripled in the last 200 years, having been nearly constant for the previous ½ million.

ASP Seminar - Climate Predictions and Projections in the Coming Decades: Uncertainty due to Natural Variability

Future climate change at local and regional scales will result from a combination of human and natural factors. In this talk I show that unpredictable, internally generated climate fluctuations make a substantial contribution to climate trends projected for the next 50 years over North America and Europe. Results are based on large ensembles of climate change integrations with the Community Earth System Model (CESM). I also will show that the large-scale atmospheric circulation is responsible for much of the diversity in climate change projections across the individual ensemble members.

ASP Seminar - The Madden-Julian Oscillation: Theory, Modeling, and Impacts

This talk will review our current understanding of the Madden-Julian oscillation (MJO). The MJO is the dominant mode of intraseasonal wind and precipitation variability in the tropical atmosphere. An up-to-date observational characterization of the MJO will be presented, including discussion of results from the recent CINDY/DYNAMO field program. New theoretical developments on MJO dynamics will then be discussed, including a discussion of how theoretical advances have helped us improve the representation of the MJO in global models.

ASP Seminar - Visualization of the weather-climate connection

Abstract:Data visualization is an appealing and fun craft. If done well, it can support realism in scientific reasoning, for example by layering the texture of weather and useful indicators of uncertainty (such as an ensemble of different data products) onto the smooth abstractions of climate statistics. These days, large time-aggregated archives of many reanalysis and satellite-observational datasets are available via OpenDAP.

ASP Thompson Lecture - Tropical Land Use in an Urban World

Abstract:In 2007, more than half of all the people in the world lived in cities and towns.  By 2030 that statistic is likely to rise to 80 percent.  In an urbanizing world, tropical landscapes will face many demands to produce food and energy crops, protect watersheds and airsheds, and conserve wildlands.  The management of these landscapes affects the ability to mitigate and adapt to climate change.  The presentation will discuss both the opportunities and challenges for tropical land use in an urban world, emphasizing the need to match the scale of analysis with the scale at which decisio

ASP Thompson Lecture - Remote Sensing of Land Use Processes: Beyond Patterns of Land Cover

Abstract:There have been major advances in remote sensing of land cover in the last several decades.  With new sensors and the availability of longer time series, possibilities for using remote sensing not just to monitor land cover but to understand the processes driving land use change, including the impacts of climate and management, are becoming more feasible. The presentation will discuss several approaches using different types of remote sensing data to assess land use processes in tropical landscapes.

ASP Seminar - Global distribution and trends of tropospheric ozone: An observation-based review

A comprehensive understanding of global surface ozone trends has eluded the scientific community due to limited long-term in situ observations and relatively few ozone monitors in regionally representative rural or oceanic regions.   Furthermore, satellite records of lower tropospheric ozone mixing ratios are presently too short to yield robust results.  However, in recent years several studies have provided updates to ozone trends at long-established sites, or reported trends at many newer sites that now have lengthy records sufficient for trend analysis.  To pull all these new findings to

ASP Seminar - Organized Convection in Global Context

Satellite observations show that precipitating convective cloud systems in Earth's atmosphere tend to organize into spatially coherent structures embedded in fields of cumulus notably, but not only, in the Tropics.  At a fundamental level this property is analogous to coherent structures in turbulent fluids. Although organization can occur in traditional climate models with 100s-km computational meshes, its morphology is usually not realistic. The reason for this misbehavior is two-pronged.

The Evolution of Nonhydrostatic Meteorological Modeling: From Cloud to Global Scales

Nonhydrostatic processes in the atmosphere are characterized by features in which the horizontal and vertical length scales are comparable. Because the fully compressible equations of motion admit acoustic modes as well as gravity-wave and rotational modes, much early modeling emphasis focused on developing efficient numerical techniques to accommodate these fast moving sound waves, which are typically not of meteorological interest.

ASP Seminar - Phil Rasch (PNNL)

The Advanced Study Program 2013-14 Seminar Series continues with a seminar presented by Dr. Phil Rasch of Pacific Northwest National Laboratory

Title: Problems and prospects for improved representation of aerosol impacts in climate models.


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