scholarly journals Spatiotemporal Snowfall Variability in the Lake Michigan Region: How is Warming Affecting Wintertime Snowfall?

2016 ◽  
Vol 55 (8) ◽  
pp. 1813-1830 ◽  
Author(s):  
Craig A. Clark ◽  
Travis J. Elless ◽  
Anthony W. Lyza ◽  
Bharath Ganesh-Babu ◽  
Dana M. Koning ◽  
...  
Keyword(s):  
Principal Component Analysis ◽  
Serial Correlation ◽  
Lake Michigan ◽  
Principal Component ◽  
Temporal Behavior ◽  
Temperature Peak ◽  
Spatiotemporal Structure ◽  
Teleconnection Patterns ◽  
Lake Effect ◽  
Trend Reversal

AbstractThis study has investigated the spatiotemporal structure and changes in Lake Michigan snowfall for the period 1950–2013. With data quality caveats acknowledged, a larger envelope of stations was included than in previous studies to explore the data using time series analysis, principal component analysis, and geographic information systems. Results indicate warming in recent decades, a near-dearth of serial correlation, midwinter dependence on teleconnection patterns, strong sensitivity of snowfall to temperature, peak snowfall variability and dependence on temperature within the lake-effect belt, an increasing fraction of seasonal snowfall occurring from December to February, and temporal behavior consistent with the previously reported trend reversal in snowfall.

scholarly journals Synoptic Climatology of Lake-Effect Snow Events off the Western Great Lakes

Climate ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 43
Author(s):  
Jake Wiley ◽  
Andrew Mercer
Keyword(s):  
Great Lakes ◽  
Large Scale ◽  
Lake Michigan ◽  
Lake Superior ◽  
Principal Component ◽  
Forecast Model ◽  
Synoptic Climatology ◽  
Synoptic Scale ◽  
Ongoing Research ◽  
Lake Effect

As the mesoscale dynamics of lake-effect snow (LES) are becoming better understood, recent and ongoing research is beginning to focus on the large-scale environments conducive to LES. Synoptic-scale composites are constructed for Lake Michigan and Lake Superior LES events by employing an LES case repository for these regions within the U.S. North American Regional Reanalysis (NARR) data for each LES event were used to construct synoptic maps of dominant LES patterns for each lake. These maps were formulated using a previously implemented composite technique that blends principal component analysis with a k-means cluster analysis. A sample case from each resulting cluster was also selected and simulated using the Advanced Weather Research and Forecast model to obtain an example mesoscale depiction of the LES environment. The study revealed four synoptic setups for Lake Michigan and three for Lake Superior whose primary differences were discrepancies in a surface pressure dipole structure previously linked with Great Lakes LES. These subtle synoptic-scale differences suggested that while overall LES impacts were driven more by the mesoscale conditions for these lakes, synoptic-scale conditions still provided important insight into the character of LES forcing mechanisms, primarily the steering flow and air–lake thermodynamics.

Trend Reversal in Lake Michigan Contribution to Snowfall

2012 ◽  
Vol 51 (11) ◽  
pp. 2038-2046 ◽  
Author(s):  
Luke Bard ◽  
David A. R. Kristovich
Keyword(s):  
Great Lakes ◽  
Traffic Accident ◽  
Lake Michigan ◽  
Negative Consequences ◽  
Lake Effect ◽  
Long Term Trends ◽  
Autumn And Winter ◽  
Climate Studies ◽  
Trend Reversal

AbstractOne of the most notable ways the Laurentian Great Lakes impact the region’s climate is by augmenting snowfall in downwind locations during autumn and winter months. Among many negative consequences, this surplus of snow can cause substantial property damage to homes and can escalate the number of traffic accident–related injuries and fatalities. The consensus among several previous studies is that lake-effect snowfall increased during the twentieth century in various locations in the Great Lakes region. The goal of this study is to better understand variability and long-term trends in Lake Michigan’s lake-contribution snowfall (LCS). LCS accounts for both lake-effect and lake-enhanced events. In addition, this study updates findings from previous investigations using snowfall observations found by a recent study to be appropriate for climate studies. It is demonstrated that considerable variability exists in 5-yr periods of LCS east and south of Lake Michigan from 1920 to 2005. A general increase in LCS from the early 1920s to the 1950–80 period at locations typically downwind of the lake was found. Thereafter, LCS decreased through the early 2000s, indicating a distinct trend reversal that is not reported by earlier studies. The reasons for this reversal are unclear. The reversal is consistent with observed increasing minimum temperatures during winter months after the 1970s, however.

Scanning x-ray fluorescence microscopy and principal component analysis

1992 ◽  
Vol 50 (2) ◽  
pp. 1752-1753
Author(s):  
Brian Cross
Keyword(s):  
Principal Component Analysis ◽  
Fluorescence Microscopy ◽  
Spatial Resolution ◽  
High Speed ◽  
Image Acquisition ◽  
Principal Component ◽  
Fluorescence Microscope ◽  
Acquisition Rate ◽  
X Ray ◽  
Speed Up

A relatively new entry, in the field of microscopy, is the Scanning X-Ray Fluorescence Microscope (SXRFM). Using this type of instrument (e.g. Kevex Omicron X-ray Microprobe), one can obtain multiple elemental x-ray images, from the analysis of materials which show heterogeneity. The SXRFM obtains images by collimating an x-ray beam (e.g. 100 μm diameter), and then scanning the sample with a high-speed x-y stage. To speed up the image acquisition, data is acquired "on-the-fly" by slew-scanning the stage along the x-axis, like a TV or SEM scan. To reduce the overhead from "fly-back," the images can be acquired by bi-directional scanning of the x-axis. This results in very little overhead with the re-positioning of the sample stage. The image acquisition rate is dominated by the x-ray acquisition rate. Therefore, the total x-ray image acquisition rate, using the SXRFM, is very comparable to an SEM. Although the x-ray spatial resolution of the SXRFM is worse than an SEM (say 100 vs. 2 μm), there are several other advantages.

A German version of the Intermittent Claudication Questionnaire (ICQ): cultural adaptation and validation

VASA ◽  
2012 ◽  
Vol 41 (5) ◽  
pp. 333-342 ◽  
Author(s):  
Kirchberger ◽  
Finger ◽  
Müller-Bühl
Keyword(s):  
Principal Component Analysis ◽  
Intermittent Claudication ◽  
Completion Time ◽  
Short Form ◽  
Principal Component ◽  
Component Analysis ◽  
German Version ◽  
Average Completion Time ◽  
Sf 36 ◽  
Related Quality

Background: The Intermittent Claudication Questionnaire (ICQ) is a short questionnaire for the assessment of health-related quality of life (HRQOL) in patients with intermittent claudication (IC). The objective of this study was to translate the ICQ into German and to investigate the psychometric properties of the German ICQ version in patients with IC. Patients and methods: The original English version was translated using a forward-backward method. The resulting German version was reviewed by the author of the original version and an experienced clinician. Finally, it was tested for clarity with 5 German patients with IC. A sample of 81 patients were administered the German ICQ. The sample consisted of 58.0 % male patients with a median age of 71 years and a median IC duration of 36 months. Test of feasibility included completeness of questionnaires, completion time, and ratings of clarity, length and relevance. Reliability was assessed through a retest in 13 patients at 14 days, and analysis of Cronbach’s alpha for internal consistency. Construct validity was investigated using principal component analysis. Concurrent validity was assessed by correlating the ICQ scores with the Short Form 36 Health Survey (SF-36) as well as clinical measures. Results: The ICQ was completely filled in by 73 subjects (90.1 %) with an average completion time of 6.3 minutes. Cronbach’s alpha coefficient reached 0.75. Intra-class correlation for test-retest reliability was r = 0.88. Principal component analysis resulted in a 3 factor solution. The first factor explained 51.5 of the total variation and all items had loadings of at least 0.65 on it. The ICQ was significantly associated with the SF-36 and treadmill-walking distances whereas no association was found for resting ABPI. Conclusions: The German version of the ICQ demonstrated good feasibility, satisfactory reliability and good validity. Responsiveness should be investigated in further validation studies.

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