The effect of surface heterogeneity on cloud absorption estimates

This study presents a systematic and quantitative analysis of the effect of inhomogeneous surface albedo on shortwave cloud absorption estimates. We used 3D radiative transfer modeling over a checkerboard surface albedo to calculate cloud absorption. We have found that accounting for surface heterogeneity enhances cloud absorption. However, the enhancement is not sufficient to explain the reported difference between measured and modeled cloud absorption

What Did We Think Could Be Learned About Earth From Lagrange Point Observations?

The scientific excitement surrounding the NASA Lagrange point mission Triana, now called DSCOVR, tended to be forgotten in the brouhaha over other aspects of the mission. Yet a small band of scientists in 1998 got very excited about the possibilities offered by the Lagrange-point perspective on our planet. As one of the original co-investigators on the Triana mission, I witnessed that scientific excitement firsthand. I will bring to life the early period, circa 1998 to 2000, and share the reasons that we thought the Lagrange-point perspective on Earth would be scientifically revolutionary

Emergent Processes

This century is going to be about biology. I don’t want to confuse architecture with biology. You can take analogies too far of course. But, as Gödel once said in his Theory of Incompleteness, sometimes to solve a problem in a particular discipline, you have to switch to completely different territory

Spectrally-invariant behavior of zenith radiance around cloud edges simulated by radiative transfer

In a previous paper, we discovered a surprising spectrally-invariant relationship in shortwave spectrometer observations taken by the Atmospheric Radiation Measurement (ARM) program. The relationship suggests that the shortwave spectrum near cloud edges can be determined by a linear combination of zenith radiance spectra of the cloudy and clear regions. Here, using radiative transfer simulations, we study the sensitivity of this relationship to the properties of aerosols and clouds, to the underlying surface type, and to the finite field-of-view (FOV) of the spectrometer. Overall, the relationship is mostly sensitive to cloud properties and has little sensitivity to other factors. At visible wavelengths, the relationship primarily depends on cloud optical depth regardless of cloud phase function, thermodynamic phase and drop size. At water-absorbing wavelengths, the slope of the relationship depends primarily on cloud optical depth; the intercept, by contrast, depends primarily on cloud absorbing and scattering properties, suggesting a new retrieval method for cloud drop effective radius. These results suggest that the spectrally-invariant relationship can be used to infer cloud properties near cloud edges even with insufficient or no knowledge about spectral surface albedo and aerosol properties

An Exploratory Analysis of Sexual Violence and Rape Myth Acceptance at a Small Liberal Arts University

Male perpetrated sexual violence is a highly prevalent, but underreported, crime on college campuses. Experts state that in order to effectively deal with the problem of sexual violence, it is important to determine the severity and nature of the problem. The purpose of this study was to provide data based evidence to define the actual problem of sexual violence on a specific college campus in order to raise awareness and provide baseline data for further examination of the issue of sexual violence. Risk factors for sexual violence were examined as well as demographic information for male and female students to determine the prevalence of sexual violence and the relationship of these known risk factors with incidents of sexual violence. Alcohol, Greek membership, athletic participation, and rape myth acceptance were analyzed to determine which factors contributed to the problem of sexual violence within this particular setting. Results indicate that sexual violence is a problem that warrants attention and further examination on this campus. Fifty seven female students reported experiencing 229 incidents of sexual violence, with being taken advantage of while too drunk as the most common tactic used against them. Twenty-nine males reported perpetrating 129 incidents of sexual violence. Female athletes were found to have a higher level of acceptance of rape myths than female students not participating in athletics. Fraternity members were found to have a lower level of acceptance of rape myths than male students not belonging to a Greek organization. Future research should be directed at repeat victims and perpetrators, as the numbers indicate a small number of men and women experienced a substantial portion of the sexually violent experiences. Implications for prevention and intervention were discussed to ensure that victims are being assisted and the student population, as well as the entire campus community, is educated on the realities of sexual violence

Best practice and future challenges. Telling ePortfolio Stories 2008: The road to ‘stickiness’, 5th June 2008, University of Wolverhampton

After three years of development in partnership with two other HEI's, employers and related organisations the University of Wolverhampton launched its Foundation Degree in Travel Operations Management in September 2008. The course was designed to be a pilot for a national programme and the institution is now leading the Curriculum Development element of the national product, in partnership with FDF. This workshop explores the journey so far and the trials and tribulations of developing a work based Foundation Degree in association with two other HEI’s, employers and related organisations. It is delivered on-line using Pebble Pad technology and supported by a face to face induction with ongoing email and telephone tutorials. The first cohort of 60 students is nearing the end of the first year of the programme, and the process has highlighted a number of difficulties including resources in planning and developing on line learning materials (both the materials themselves, the costs of technical expertise and ongoing Technology Supported Learning (TSL) training). In addition agreeing the programme regulations (including the size of modules); agreements in financial arrangements between employers and the HEI partners (each of which have different rates of pricing for FD); preparing industry personnel for their mentoring and coaching roles and changing personnel in supporting organisations contributed to the issues. Finally ensuring compliance with sector skills organisations who have not yet written their FD frameworks; industry partners frustration in timely decision making processes through the complicated list of personnel involved in agreeing decisions at different strategic levels of the university structures contribute to periods of frustration. By sharing these experiences and the current experience of being involved in the development of a wider partnership the authors hope to prevent future problems that may arise in innovative developments and to share the good practice that the programme has so far established, and which will from September 2008, be delivered using a broader national model

Study of Shortwave Spectra in Fully 3D Environment: Synergy Between Scanning Radars and Spectral Radiation Measurements

The main theme for our research is the understanding and closure of the surface spectral shortwave radiation problem in fully 3D cloud situations by combining the new ARM scanning radars, shortwave spectrometers, and microwave radiometers with the arsenal of radiative transfer tools developed by our group. In particular, we define first a large number of cloudy test cases spanning all 3D possibilities not just the customary uniform-overcast ones. Second, for each case, we define a "Best Estimate of Clouds That Affect Shortwave Radiation" using all relevant ARM instruments, notably the new scanning radars, and contribute this to the ARM Archive. Third, we test the ASR-signature radiative transfer model RRTMG_SW for those cases, focusing on the near-IR because of long-standing problems in this spectral region, and work with the developers to improve RRTMG_SW in order to increase its penetration into the modeling community

Earth Radiation Imbalance from a Constellation of 66 Iridium Satellites: Climate Science Aspects

The "global warming hiatus" since the 1998 El Nino, highlighted by Meehl et al., and the resulting "missing energy" problem highlighted by Trenberth et al., has opened the door to a more fundamental view of climate change than mere surface air temperature. That new view is based on two variables which are strongly correlated: the rate of change of ocean heat content d(OHC)/dt; and Earth Radiation Imbalance (ERI) at the top of the atmosphere, whose guesstimated range is 0.4 to 0.9 Watts per square meters (this imbalance being mainly due to increasing CO2). The Argo float array is making better and better measurements of OHC. But existing satellite systems cannot measure ERI to even one significant digit. So, climate model predictions of ERI are used in place of real measurements of it, and the satellite data are tuned to the climate model predictions. Some oceanographers say "just depend on Argo for understanding the global warming hiatus and the missing energy", but we don't think this is a good idea because d(OHC)/dt and ERI have different time scales and are never perfectly correlated. We think the ERB community needs to step up to measuring ERI correctly, just as oceanographers have deployed Argo to measure OHC correctly. This talk will overview a proposed constellation of 66 Earth radiation budget instruments, hosted on Iridium satellites, that will actually be able to measure ERI to at least one significant digit, thus enabling a crucial test of climate models. This constellation will also be able to provide ERI at two-hourly time scales and 500-km spatial scales without extrapolations from uncalibrated narrowband geostationary instruments, using the highly successful methods of GRACE to obtain spatial resolution. This high time resolution would make ERI a synoptic variable like temperature, and allow studies of ERI's response to fast-evolving phenomena like dust storms and hurricanes and even brief excursions of Total Solar Irradiance. Time permitting, we will also discuss the emerging view of clear vs. cloudy and its implications for the traditional ERB approach

Remote sensing of cloud properties using ground-based measurements of zenith radiance

We have conducted the first extensive field test of two new methods to retrieve optical properties for overhead clouds that range from patchy to overcast. The methods use measurements of zenith radiance at 673 and 870 nm wavelengths and require the presence of green vegetation in the surrounding area. The test was conducted at the Atmospheric Radiation Measurement Program Oklahoma site during September–November 2004. These methods work because at 673 nm (red) and 870 nm (near infrared (NIR)), clouds have nearly identical optical properties, while vegetated surfaces reflect quite differently. The first method, dubbed REDvsNIR, retrieves not only cloud optical depth τ but also radiative cloud fraction. Because of the 1-s time resolution of our radiance measurements, we are able for the first time to capture changes in cloud optical properties at the natural timescale of cloud evolution. We compared values of τ retrieved by REDvsNIR to those retrieved from downward shortwave fluxes and from microwave brightness temperatures. The flux method generally underestimates τ relative to the REDvsNIR method. Even for overcast but inhomogeneous clouds, differences between REDvsNIR and the flux method can be as large as 50%. In addition, REDvsNIR agreed to better than 15% with the microwave method for both overcast and broken clouds. The second method, dubbed COUPLED, retrieves τ by combining zenith radiances with fluxes. While extra information from fluxes was expected to improve retrievals, this is not always the case. In general, however, the COUPLED and REDvsNIR methods retrieve τ to within 15% of each other

Single scattering from nonspherical Chebyshev particles: A compendium of calculations

A large set of exact calculations of the scattering from a class of nonspherical particles known as Chebyshev particles' has been performed. Phase function and degree of polarization in random orientation, and parallel and perpendicular intensities in fixed orientations, are plotted for a variety of particles shapes and sizes. The intention is to furnish a data base against which both experimental data, and the predictions of approximate methods, can be tested. The calculations are performed with the widely-used Extended Boundary Condition Method. An extensive discussion of this method is given, including much material that is not easily available elsewhere (especially the analysis of its convergence properties). An extensive review is also given of all extant methods for nonspherical scattering calculations, as well as of the available pool of experimental data