Identification of Intraseasonal Modes of Variability Using Rotated Principal Components

Richman, Michael B.; Mercer, Andrew E.

doi:10.5772/35364

Cited by 5 publications

(3 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Additionally, the method's utility in producing physically meaningful patterns in numerous gridded geospatial studies (e.g. Richman, 1986;Barnston and Livezey, 1987;Richman and Mercer, 2012;Dyer and Mercer, 2013; others) make it an ideal approach for the current work. In this study, two RPCAs were completed, one for the groundwater level data and one for the precipitation data (i.e.…”

Section: Methodsmentioning

confidence: 99%

Identification of recharge zones in the Lower Mississippi River alluvial aquifer using high-resolution precipitation estimates

Dyer

Mercer

Rigby

et al. 2015

Journal of Hydrology

Self Cite

View full text Add to dashboard Cite

Section: Methodsmentioning

confidence: 99%

Identification of recharge zones in the Lower Mississippi River alluvial aquifer using high-resolution precipitation estimates

Dyer

Mercer

Rigby

et al. 2015

Journal of Hydrology

Self Cite

View full text Add to dashboard Cite

“…Previous studies (Barnston and Livezey, 1987, Richman and Mercer, 2012, Mercer and Richman, 2012, others) have shown the benefits of using PCA to identify dominant spatial patterns within the mid‐tropospheric geopotential height fields. These analyses have led to the eventual development of teleconnection indices (specifically the NAO, PNA, and AO index) shown to be important for assessing the phasing of geopotential height fields over the U.S..…”

Section: Discussionmentioning

confidence: 99%

“…The NNRP Gaussian map projection on which Z was computed provides temperatures on converging gridpoints with poleward latitudes, which resulted in spurious elevated similarity results in K for northern gridpoints in the study domain (Figure 2(a)). The Fibonacci grid (Swinbank and Purser, 2007) has been used in previous work (Mercer and Richman, 2012; Richman and Mercer, 2012) to alleviate this issue, as Fibonacci grids yield equally spaced gridpoints over a given hemispheric domain, regardless of latitude. Barnes objective analysis (Barnes, 1964) was needed to transform the NNRP grid to a Fibonacci grid of 1,292 points (Figure 2(b)), meaning the new Z had a dimensionality of 1,292 gridpoints x 70 years.…”

Section: Methodsmentioning

confidence: 99%

Dominant United States Cold‐Season near surface temperature anomaly patterns derived from kernel methods

Mercer

2020

Intl Journal of Climatology

View full text Add to dashboard Cite

Cold season (December – February) 2‐m temperatures have a far‐reaching impact on critical infrastructure; medium or long‐term predictability would thus be an invaluable asset. However, a better understanding of the most prevalent underlying temperature patterns is needed before improvements in predictability are possible. Previous studies have shown that cluster analysis preprocessed with principal component analysis (PCA) can help identify the most prevalent spatial patterns within different atmospheric datasets. Additionally, nonlinear variability can be identified when coupling cluster analysis with PCA preprocessing based on the kernel matrix from support vector machines (known as KPCA). In this study, these methods were employed to create an updated 2‐m cold season temperature climatology.Temperatures were quantified using NCEP/NCAR global reanalysis data spanning 1948–2017. Kernel and rotated PCA combined with k‐means cluster analysis was tested against cluster analysis with no PCA preprocessing to identify the fields that best characterize the underlying climatological structures within the 2‐m temperature data. Four patterns emerged from the analysis. Two patterns were primarily constrained to years early in the study period that had a strong relationship with phasing in the North Atlantic Oscillation and the Arctic Oscillation. A third pattern revealed the anomalous warming along the West Coast that has been increasingly observed in recent years, while a fourth showed a broad anomalous warm region centered on the Midwest that expanded across most of the eastern two‐thirds of the nation. These final two patterns were weakly related to phasing within the Pacific North American teleconnection and phasing of the El Niño Southern Oscillation. Most years in the final two clusters occurred post 1990, demonstrating suggesting these anomalous warming patterns are becoming more prevalent in recent decades. These patterns can be used in future work to inform medium‐ and long‐term forecasting applications.

show abstract

Predictability of US tornado outbreak seasons using ENSO and northern hemisphere geopotential height variability

Sparrow

Mercer

2016

Geoscience Frontiers

View full text Add to dashboard Cite

Identification of Intraseasonal Modes of Variability Using Rotated Principal Components

Cited by 5 publications

References 17 publications

Identification of recharge zones in the Lower Mississippi River alluvial aquifer using high-resolution precipitation estimates

Identification of recharge zones in the Lower Mississippi River alluvial aquifer using high-resolution precipitation estimates

Dominant United States Cold‐Season near surface temperature anomaly patterns derived from kernel methods

Predictability of US tornado outbreak seasons using ENSO and northern hemisphere geopotential height variability

Contact Info

Product

Resources

About