Decadal variations in the global atmospheric land temperatures

Interannual to decadal variations in Earth global temperature estimates have often been identified with El Nino Southern Oscillation (ENSO) events. However, we show that variability on time scales of 2-15 years in mean annual global land surface temperature anomalies T-avg are more closely correlated with variability in sea surface temperatures in the North Atlantic. In particular, the cross-correlation of annually averaged values of T-avg with annual values of the Atlantic Multidecadal Oscillation (AMO) index is much stronger than that of T-avg with ENSO. The pattern of fluctuations in T-avg from 1950 to 2010 reflects true climate variability and is not an artifact of station sampling. A world map of temperature correlations shows that the association with AMO is broadly distributed and unidirectional. The effect of El Nino on temperature is locally stronger, but can be of either sign, leading to less impact on the global average. We identify one strong narrow spectral peak in the AMO at period 9.10.4 years and p value of 1.7% (confidence level, 98.3%). Variations in the flow of the Atlantic meridional overturning circulation may be responsible for some of the 2-15 year variability observed in global land temperatures.Keywords: global warming, decadal variations, Earth surface temperature, climate change, AM

Whither the whale shark wanders: Tools and methods for modelling whale shark movement

The whale shark is the largest fish living in our oceans but little isknown about its ecology and natural history. Tagging studies allow us to learn more about whale shark movements and habitat use. This knowledge is essential for planning the management and conservation of whale sharks to ensure their continued coexistence with humans.This thesis is concerned with modelling the movements of whale sharks using stochastic models estimated from tracks obtained by tagging studies. In particular, it focusses on using stochastic differential equations being driven by potential functions. Approximations are presented that reduce the task of estimating the potential function to regression problems. I present a method for obtaining smooth potential functions and explicitly modelling measurement error.The primary scientific questions addressed by the thesis are: Where do whale sharks go, both in terms of geographical location and habitat? Do whale sharks interact with each other? Remote sensing data on sea surface temperature, chlorophyll concentration and sea surface currents are readily available. These time varying covariates are incorporated into the potential function model allowing investigation of their influence on the whale shark's movements

Age of initiation and Internet gaming disorder : The role of self-esteem

The link between early initiation and problematic use has been observed for substance use disorders; however, this link has not been as clearly established for Internet gaming disorder (IGD). Available studies indicate that individuals who initiate Internet use at younger ages exhibit an increased risk for general Internet addiction. Prior research also suggests unique cognitive processes in online gaming, such that an individual's overall sense of self-worth can become contingent upon self-esteem derived from the gaming environment. The current research examines the mediational role of self-esteem variables in the relationship between age of initiation and IGD symptomatology. Data were analyzed from 1,044 adult participants (mean age = 30.90; standard deviation: 9.28; 35.0% female) recruited from Amazon Mechanical Turk who reported playing massively multiplayer online role-playing games. Age of gaming initiation is directly linked to IGD, as earlier age predicted overall IGD symptom severity (b = -0.10, 95% confidence interval [CI: -0.17, -0.03]), controlling for self-esteem factors. In addition, self-esteem factors emerged as mediators of the effect, where global self-esteem served as a protective factor (b = -0.05, 95% CI: [-0.07, -0.02]) and high gaming-contingent self-worth (GCSW; b = -0.10, 95% CI: [-0.15, -0.04]) was associated with more negative outcomes. Earlier age of gaming initiation is associated with IGD symptomatology. Although risks of screen time are often referred to in terms of physical consequences, the present study provides support regarding the inclusion of self-esteem factors in the link between early use and IGD. © Copyright 2017, Mary Ann Liebert, Inc. 2017

Supplement 1. R code used to perform simulations.

<h2>File List</h2><div> <p><a href="simulations.R">simulations.R</a> (MD5: bdda5503ab6ec0d1374d340d60f562d6)</p> </div><h2>Description</h2><div> <p>This comment used the attached R script to conduct simulation studies of spatial component regression (SCR). The file simulations.R contain all code needed to run the simulations to test SCR performance for three objectives: (1) inference under the null hypothesis; (2) inference when the predictor of inference does have an effect on the outcome; and (3) matrix selections. The code will simulate 16 sets of 1000 data sets each. The 16 data sets represent all possible combinations of 2 different spatial predictor types 4 autocorrelation types and 2 effect sizes for the spatial predictor.</p> </div

Appendix A. Simulation descriptions and results.

Simulation descriptions and results

Tree-ring history of Swiss needle cast impact on Douglas-fir growth in Western Oregon: correlations with climatic variables

The fungal pathogen, Nothophaeocryptopus gaeumannii, occurs wherever Douglas-fir is found but disease damage is believed to be limited to the Coast Range and is of no concern outside the coastal fog zone (Shaw, et al., 2011). However, knowledge remains limited on the history and spatial distribution of Swiss Needle Cast (SNC) impacts in the Pacific Northwest (PNW). We reconstructed the history of SNC impacts on mature Douglas-fir trees based on tree ringwidth chronologies from the west slope of the Coast Range to the high Cascades of Oregon. Our findings show that SNC impacts on growth occur wherever Douglas-fir is found in western Oregon and is not limited to the coastal fog zone. The spatiotemporal patterns of growth impact from SNC disease were synchronous across the region, displayed periodicities of 25-30 years, strongly correlated with winter and summer temperatures and summer precipitation, and matched the patterns of enriched cellulosic stable carbon isotope indicative of physiological stress. While winter and summer temperature and summer precipitation influenced pathogen dynamics at all sites, the primary climatic factor of these three limiting factors varied spatially by location, topography, and elevation. In the 20th century, SNC impacts at low- to mid-elevations were least severe during the warm phase of the Pacific Decadal Oscillation (PDO, 1924-1945) and most severe in 1984-1986, following the cool phase of the PDO (1945-1977). At high elevations on the west slope of the Cascade Mountains, SNC impacts were the greatest in the 1990s and 2000s, a period of warmer winter temperatures associated with climate change. Warmer winters will likely continue to increase SNC severity at higher elevations, north along the coast from northern Oregon to British Columbia, and inland where low winter temperatures currently limit growth of the pathogen. Surprisingly, tree-ring records of ancient Douglas-fir logs dated ~53K radioactive years B.P. from Eddyville, OR displayed 7.5- and 20-year periodicities of low growth, similar to those found in modern day coastal Douglas-fir tree-ring records which we interpret as being due to cyclic fluctuations in SNC severity. Our findings indicate that SNC has persisted for as long as its host, and as a result of changing climate, may become a significant forest health problem in areas of the PNW beyond the coastal fog zone