2008 CIRA Seminars
Climate change poses a frustrating challenge for communicators and advocates seeking to galvanize public action in response to the issue. To begin with, climate change is often communicated as a global scale issue, shrouded in the complexity and uncertainty inherent in modeling the future, and with impacts often perceived as geographically and temporally distant.
While the pollution of our atmosphere continues to receive increased attention, the microbiological quality of both indoor and outdoor air (generically termed "bioaerosols") has been largely ignored by the engineering community. Certainly, this is not consistent with the public health charter given to civil and environmental engineers regarding water quality.
This talk will discuss some observational aspects of the organization of equatorialrainfall systems. It is well-known that convective disturbances in the tropics occurover a very broad spectrum of scales, ranging from individual cumulus cells toplanetary scale features such as the Madden-Julian Oscillation (MJO). It is alsoobserved that the larger scale features are composed of smaller scale equatorialwaves, so that for example the "envelope" of the MJO is often comprised ofeastward propagating Kelvin, and westward inertio-gravity waves.
This talk is abstracted from an invited chapter on Weather and Climate Engineering of a book on aerosol impacts on climate that I have written. I will begin by focusing on what we have learned from cloud seeding research or what I call weather engineering. I then present an overview of the concepts for climate engineering to counter greenhouse warming. These include seeding in the stratosphere with sulfate-producing gases and aerosols, and carbonaceous aerosols.
We examine the relative roles of direct atmospheric radiative forcing (due to observed changes in well-mixed greenhouse gases, tropospheric and stratospheric ozone, sulfate and volcanic aerosols, and solar output) and observed sea surface temperature (SST) forcing of global atmospheric circulation trends during the second half of the 20th century using atmospheric general circulation modeling experiments.
From a large-scale perspective the West African monsoon (WAM) can be described in terms of the annual march of the ITCZ and its associated regional circulations. On the synoptic and mesoscale, the WAM is comprised of a complex collection of wave patterns, organized weather systems and deep convection (see Figure). These include synoptic systems such as African easterly waves (AEWs) and mesoscale convective systems (MCSs), the main rain-producers in the region.
Observations and models suggest substantial changes in the ocean carbon sink over the past two decades in the Southern Ocean (LeQuere et al., 2007), North Atlantic (Schuster and Watson, 2007), North Pacific (Takahashi et al., 2006) and equatorial Pacific (Feely et al. 2006). The changes appear to make significant contributions to the increasing retention of anthropogenic CO2 emission in the atmospheric reservoir (Canadell et al. 2007).
Stratospheric ozone has been the subject of intense research since the mid 1970s, when the prospect of ozone depletion by human activities was first raised. This talk will show how the spectacular Antarctic ozone hole was unexpected, introduced new chemistry to the science of understanding ozone, and was a key factor in national and international policy decisions. The massive ozone hole has more recently been shown to lead to changes in temperatures and hence the climate not only in the Antarctic stratosphere, but also in its troposphere.
Airborne particles pose serious health risks and have a controlling influence on the Earth's climate. This talk will begin with a general overview of atmospheric particles, highlighting typical concentrations and effects. The talk will then focus on the organic component of atmospheric particles. Organics contribute a significant fraction of fine particle mass across all regions of the atmosphere, but the sources of this material are poorly understood.
Changes in the atmospheric hydrologic cycle that accompany climate change are profound, yet many aspects of the process which control the humidity of the atmosphere remain uncertain. The isotopic composition of water vapor gives insight into the balance between moisture transport and exchange processes because isotopes reflect the history of moist exchanges. HDO measurements from the Tropospheric Emission Spectrometer on NASAs Aura spacecraft are used to evaluate the large-scale circulation of water in the tropics and subtropics.
Although it is well-established that the Laurentide Ice Sheet collapsed over Hudson Bay ca. 8500 14C yrs bp, the role of climate in this event remains ambiguous. We use a finite- element glaciological model to test the hypothesis that the ice sheet would have survived throughout the Holocene via mass-balance feedbacks if its marine-based core had not disintegrated mechanically. Experiments that incorporate a parameterization of the Weertman (1974) marine instability mechanism show a complete Laurentide deglaciation in good accord with geologic data.
Costal storms account for 71% ($7B) of U.S. disaster losses annually. In addition, over 50% of the U.S. population lives in coastal areas that account for less than 20% of the nation's land, and coastal development still is increasing. As a result, more homes, businesses and lives will be vulnerable to coastal storms and more accurate forecasts will be required to reduce the risks associated with hazardous weather.
Based on recent field studies the seminar will highlight insights into the surface/atmosphere exchange of Volatile and Semivolatile Organic Compounds (VOC, SVOC). Vegetation contributes the largest fraction of this reactive organic carbon released into the atmosphere. Tropical ecosystems are of particular interest because high isoprene emissions are thought to drastically change the oxidation capacity of the clean tropical atmosphere.
Data assimilation schemes are confronted with the presence of model errors arising from the imperfect description of atmospheric dynamics. These errors are usually modeled on the basis of simple assumptions such as bias, white noise, first order Markov process. In the present work, a formulation of the sequential extended Kalman filter is proposed, based on recent findings on the universal deterministic behavior of model errors in deep contrast with previous approaches (Nicolis, 2004). This new scheme is applied in the context of a spatially distributed system proposed by Lorenz (1996).
Four Americans and eight Norwegians spent 3 and a half months (2007-2008) traversing from the Antarctic Coast to the South Pole as part of an International Polar Year (IPY) field expedition. Our scientific measurements included 1) drilling 700 meters of ice cores to measure chemical and physical properties; 2) collecting 2500-km of radar data to map snow and ice accumulation between drill sites; 3) making detailed near-surface physical and chemical snow measurements; 4) installing two automatic weather stations; and 5) making deep-ice temperature measurements.
Provides an overview of the grassroots Weather and Society * Integrated Studies (WAS*IS) movement to change the weather enterprise by comprehensively & sustainably integrating social science into meteorological research and practice
Summarizes WAS * IS progress & provides examples of how social science is benefiting meteorological research & practice
Aerosols influence climate by altering the global energy balance via scattering and absorbing solar radiation (direct effects), and by their effect on the reflectance of clouds and occurrence of precipitation (indirect effects). As noted in the IPCC Fourth Assessment Report (2007), aerosol effects exhibit the greatest uncertainty in our understanding of all global radiative forcing components. Aerosols also influence biogeochemical cycles, lead to diminished visibility, and harm human health.
Ancillary data, describing the radiative transfer characteristics of the earth's surface and the atmosphere, are required to derive from satellite radiances information on cloud field characteristics. They are also needed to compute radiative fluxes within the atmosphere and at the surface.
2007 CIRA Seminars
Emissions of trace gases and aerosols from the terrestrial biosphere are significant. These emissions can impact air quality and climate, and it is therefore important to quantify the magnitude of the emissions, their spatial and temporal distributions, and environmental controls. This talk will discuss the development of emission estimates from fires and from undisturbed vegetation. An emissions model has been developed to provide modelers and managers quick emission estimates of trace gases and aerosols from fires in North and Central America.
9:30 Introduction (Chris MacDermaid)
9:35 Google Earth Overview and Data Locator (Jeff Smith)
9:55 GSD Satellite Data for Google Earth (Paul Hamer)
10:05 OGC Standards and FAA's NNEW Project (Chris MacDermaid)
10:15 Wrap-up and Discussion
Five Americans and two Canadians traveled from Fairbanks, Alaska to Hudson Bay (Baker Lake), Canada in March and April, 2007, following the Arctic Circle for much of the route. In keeping with IPY goals, in addition to the snow measurements we made during this 4200 km IPY traverse, we passed through dozens of historic locations, two arctic diamond mines, and 11 villages where we conducted outreach. As part of previous Artic research expeditions, we have found our mode of travel (snowmobiles) to smooth and facilitate researcher-villager interactions.
This talk presents a newly developed atmospheric model system, the YOnsei University Research model System (YOURS), which has a great flexibility with multi-platforms with either thread mode or message parallel modes. The dynamical core of the YOURS-Global Spectral Model (GSM) can be either spherical harmonics (SPH) or double Fourier spectral (DFS) (Cheong 2006). The system also has multiple options in each physics parameterization, with newly devised algorithms. The YOURS-GSM has been widely evaluated for seasonal simulations as well as weather prediction.
Unmanned Aircraft Systems (UAS) have the potential to expand the current observing network over remote or dangerous areas, such as the polar regions or inside tropical cyclones. Many different aircraft platforms and instrumentation combinations are under consideration to help fill existing observational gaps. In order to determine the >possible benefits of UAS observations on operational forecasting as >well as to find the optimal configuration of aircraft and observations, >an Observing System Simulation Experiment (OSSE) is under development.
This seminar will discuss the work of the National Park Service Night Sky Team (NST). The NST is a group of scientists, managers, and interpreters who work on the quantification, protection, and restoration of dark night skies throughout the national park system.
Active and passive microwave remote sensing systems have shown the ability to measure the soil moisture content in the near-surface layer under a variety of topographic and land cover conditions. The successful mapping of soil moisture from active microwave sensors with high spatial resolution (up to 25 m) would be an advantage to agricultural and hydrological application. However, passive microwave sensors provide low spatial resolution (40 to 50 km) has application in meteorological and weather prediction modeling.