Comparison of Simulated Cloud Cover with Satellite Observations over the Western United States

1995 ◽  
Vol 8 (2) ◽  
pp. 296-314 ◽  
Author(s):  
Melanie A. Wetzel ◽  
Gary T. Bates
2013 ◽  
Vol 13 (5) ◽  
pp. 14195-14220 ◽  
Author(s):  
H. Lei ◽  
J. X. L. Wang

Abstract. In order to better understand the characteristics of dust storm processes over the western United States, available dust storm events reported by media or recorded by NASA earth observatory are classified into four types based on the prevailing weather systems. Then these four types of dust storm events related to cold fronts, downbursts, tropical disturbances, and cyclogenesis and their selected typical representative events are examined to explore their identifiable characteristics based on in-situ and remote sensing measurements. We find that the key feature of cold front-induced dust storms is their rapid process with strong dust emissions. Events caused by rapid downbursts have the highest rates of emissions. Dust storms due to tropical disturbances show stronger air concentrations of dust and last longer than those caused by cold fronts and downbursts. Finally, dust storms caused by cyclogenesis last the longest. The analysis of particulate matter records also shows that the relative ratio of PM10 (size less than 10 μm) values on dust storm-days to non-dust storm-days is a better indicator of event identification compared to previous established indicators. Moreover, aerosol optical depth (AOD) measurements from both in-situ and satellite datasets allow us to capture dust storm processes. We show that MODIS AOD retrieved from the deep blue data better identify dust storm-affected areas and the spatial extension of event intensity. Our analyses also show that the variability in mass concentrations during dust storm processes captured only by in-situ observations is consistent with the variability in AOD from stationary or satellite observations. The study finally indicates that the combination of in-situ and satellite observations is a better method to fill gaps in dust storm recordings.


Author(s):  
Jennifer J. Smith

Coherence of place often exists alongside irregularities in time in cycles, and chapter three turns to cycles linked by temporal markers. Ray Bradbury’s The Martian Chronicles (1950) follows a linear chronology and describes the exploration, conquest, and repopulation of Mars by humans. Conversely, Louise Erdrich’s Love Medicine (1984) jumps back and forth across time to narrate the lives of interconnected families in the western United States. Bradbury’s cycle invokes a confluence of historical forces—time as value-laden, work as a calling, and travel as necessitating standardized time—and contextualizes them in relation to anxieties about the space race. Erdrich’s cycle invokes broader, oppositional conceptions of time—as recursive and arbitrary and as causal and meaningful—to depict time as implicated in an entire system of measurement that made possible the destruction and exploitation of the Chippewa people. Both volumes understand the United States to be preoccupied with imperialist impulses. Even as they critique such projects, they also point to the tenacity with which individuals encounter these systems, and they do so by creating “interstitial temporalities,” which allow them to navigate time at the crossroads of language and culture.


NWSA Journal ◽  
2004 ◽  
Vol 16 (2) ◽  
pp. 180-189
Author(s):  
Karen L. Salley ◽  
Barbara Scott Winkler ◽  
Megan Celeen ◽  
Heidi Meck

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