Improving the Prediction of Winter Precipitation and Temperature over the Continental United States: Role of the ENSO State in Developing Multimodel Combinations

2010 ◽  
Vol 138 (6) ◽  
pp. 2447-2468 ◽  
Author(s):  
Naresh Devineni ◽  
A. Sankarasubramanian
2010 ◽  
Vol 138 (6) ◽  
pp. 2447-2468 ◽  
Author(s):  
Naresh Devineni ◽  
A. Sankarasubramanian

Abstract Recent research into seasonal climate prediction has focused on combining multiple atmospheric general circulation models (GCMs) to develop multimodel ensembles. A new approach to combining multiple GCMs is proposed by analyzing the skill levels of candidate models contingent on the relevant predictor(s) state. To demonstrate this approach, historical simulations of winter (December–February, DJF) precipitation and temperature from seven GCMs were combined by evaluating their skill—represented by mean square error (MSE)—over similar predictor (DJF Niño-3.4) conditions. The MSE estimates are converted into weights for each GCM for developing multimodel tercile probabilities. A total of six multimodel schemes are considered that include combinations based on pooling of ensembles as well as on the long-term skill of the models. To ensure the improved skill exhibited by the multimodel scheme is statistically significant, rigorous hypothesis tests were performed comparing the skill of multimodels with each individual model’s skill. The multimodel combination contingent on Niño-3.4 shows improved skill particularly for regions whose winter precipitation and temperature exhibit significant correlation with Niño-3.4. Analyses of these weights also show that the proposed multimodel combination methodology assigns higher weights for GCMs and lesser weights for climatology during El Niño and La Niña conditions. On the other hand, because of the limited skill of GCMs during neutral Niño-3.4 conditions, the methodology assigns higher weights for climatology resulting in improved skill from the multimodel combinations. Thus, analyzing GCMs’ skill contingent on the relevant predictor state provides an alternate approach for multimodel combinations such that years with limited skill could be replaced with climatology.


2008 ◽  
Vol 20 (3) ◽  
pp. 97-105 ◽  
Author(s):  
Smita C. Banerjee ◽  
Kathryn Greene ◽  
Marina Krcmar ◽  
Zhanna Bagdasarov ◽  
Dovile Ruginyte

This study demonstrates the significance of individual difference factors, particularly gender and sensation seeking, in predicting media choice (examined through hypothetical descriptions of films that participants anticipated they would view). This study used a 2 (Positive mood/negative mood) × 2 (High arousal/low arousal) within-subject design with 544 undergraduate students recruited from a large northeastern university in the United States. Results showed that happy films and high arousal films were preferred over sad films and low-arousal films, respectively. In terms of gender differences, female viewers reported a greater preference than male viewers for happy-mood films. Also, male viewers reported a greater preference for high-arousal films compared to female viewers, and female viewers reported a greater preference for low-arousal films compared to male viewers. Finally, high sensation seekers reported a preference for high-arousal films. Implications for research design and importance of exploring media characteristics are discussed.


2020 ◽  
Vol 32 (3) ◽  
pp. 138-144
Author(s):  
Brian A. Jacobs

In federal criminal cases, federal law requires that judges consider the sentences other courts have imposed in factually similar matters. Courts and parties, however, face significant challenges in finding applicable sentencing precedents because judges do not typically issue written sentencing opinions, and transcripts of sentencings are not readily available in advanced searchable databases. At the same time, particularly since the Supreme Court’s 2005 decision in United States v. Booker, sentencing precedent has come to play a significant role in federal sentencing proceedings. By way of example, this article discusses recent cases involving defendants with gambling addictions, and recent cases involving college admissions or testing fraud. The article explores the ways the parties in those cases have used sentencing precedent in their advocacy, as well as the ways the courts involved have used sentencing precedent to justify their decisions. Given the important role of sentencing precedent in federal criminal cases, the article finally looks at ways in which the body of sentencing law could be made more readily available to parties and courts alike.


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