3-Dimensional Classification and Visualization of Clouds Simulated by Cloud-Resolving Atmospheric General Circulation Model

Cloud-resolving atmospheric general circulation models using large scale supercomputers reproduce realistic behavior of atmospheric field on a global scale. To understand the simulation result for scientists, visualizing individual clouds and their physical characteristics is necessary. In this study, we propose a new feature extraction and classification method of simulated clouds based on their 3-dimensional shape and physical properties. The results of applying the proposed method show the clouds' distribution of a tropical cyclone during its generation, development and disappearance process, and the relation between cloud-forms and precipitation

Impact of physical parameterizations on idealized tropical cyclones in the Community Atmosphere Model

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95185/1/grl27803.pd

Wind and Wave Extremes over the World Oceans from Very Large Ensembles

Global return values of marine wind speed and significant wave height are estimated from very large aggregates of archived ensemble forecasts at +240-h lead time. Long lead time ensures that the forecasts represent independent draws from the model climate. Compared with ERA-Interim, a reanalysis, the ensemble yields higher return estimates for both wind speed and significant wave height. Confidence intervals are much tighter due to the large size of the dataset. The period (9 yrs) is short enough to be considered stationary even with climate change. Furthermore, the ensemble is large enough for non-parametric 100-yr return estimates to be made from order statistics. These direct return estimates compare well with extreme value estimates outside areas with tropical cyclones. Like any method employing modeled fields, it is sensitive to tail biases in the numerical model, but we find that the biases are moderate outside areas with tropical cyclones.Comment: 28 pages, 16 figure

Tracking Scheme Dependence of Simulated Tropical Cyclone Response to Idealized Climate Simulations

Future tropical cyclone activity is a topic of great scientific and societal interest. In the absence of a climate theory of tropical cyclogenesis, general circulation models are the primary tool available for investigating the issue. However, the identification of tropical cyclones in model data at moderate resolution is complex, and numerous schemes have been developed for their detection. The influence of different tracking schemes on detected tropical cyclone activity and responses in the Hurricane Working Group experiments is examined herein. These are idealized atmospheric general circulation model experiments aimed at determining and distinguishing the effects of increased sea surface temperature and other increased CO2 effects on tropical cyclone activity. Two tracking schemes are applied to these data and the tracks provided by each modeling group are analyzed. The results herein indicate moderate agreement between the different tracking methods, with some models and experiments showing better agreement across schemes than others. When comparing responses between experiments, it is found that much of the disagreement between schemes is due to differences in duration, wind speed, and formation-latitude thresholds. After homogenization in these thresholds, agreement between different tracking methods is improved. However, much disagreement remains, accountable for by more fundamental differences between the tracking schemes. The results indicate that sensitivity testing and selection of objective thresholds are the key factors in obtaining meaningful, reproducible results when tracking tropical cyclones in climate model data at these resolutions, but that more fundamental differences between tracking methods can also have a significant impact on the responses in activity detected

Irradiation Enhances Proto-Oncogene c-erbB-2 Expression in Human Adenocarcinoma Cells

We investigated the effect of irradiation on the surface antigen expression of proto-oncogene c-erbB-2 on human adenocarcinoma cell lines. Cultured human colonic adenocarcinoma cell BM314 and gastric adenocarcinoma cells MKN45 were irradiated to investigate the expression of the Erb B-2 protein. Interferon-gamma (IFN-γ) was also used to treat these cancer cells. The expression of ErbB-2 showed remarkable increases on the surface of the membrane. Such upregulation was shown to be dose dependent, namely, higher radiation doses were associated with increased antigen expression. However, IFN-γ administ-ration did not show an increased expression of proto-oncogene c-erbB-2. These findings may explain partially the increased immunogenity of tumor cells following irradiation. The effect of irradiation is distinct from that of IFN-γ administration, suggesting that a different mechanism of action is present

Environmental control of tropical cyclones in CMIP5: A ventilation perspective

The ventilation index serves as a theoretically based metric to assess possible changes in the statistics of tropical cyclones to combined changes in vertical wind shear, midlevel entropy deficit, and potential intensity in climate models. Model output from eight Coupled Model Intercomparison Project 5 models is used to calculate the ventilation index. The ventilation index and its relationship to tropical cyclone activity between two 20 year periods are compared: the historical experiment from 1981 to 2000 and the RCP8.5 experiment from 2081 to 2100. The general tendency is for an increase in the seasonal ventilation index in the majority of the tropical cyclone basins, with exception of the North Indian basin. All the models project an increase in the midlevel entropy deficit in the tropics, although the effects of this increase on the ventilation index itself are tempered by a compensating increase in the potential intensity and a decrease in the vertical wind shear in most tropical cyclone basins. The nonlinear combination of the terms in the ventilation index results in large regional and intermodel variability. Basin changes in the ventilation index are well correlated with changes in the frequency of tropical cyclone formation and rapid intensification in the climate models. However, there is large uncertainty in the projections of the ventilation index and the corresponding effects on changes in the statistics of tropical cyclone activity