The intense interest in possible climate change has led to increasing scrutiny of relatively long time series for indications of secular trends in climate indicators. Changes in mean levels of simple fields such as temperature, or shifts in the apparent return times (or oscillation periods) of various phenomena such as the El Niño–Southern Oscillation (ENSO) or the North Atlantic oscillation (N...

Causal discovery seeks to recover cause–effect relationships from statistical data using graphical models. One goal of this paper is to provide an accessible introduction to causal discovery methods for climate scientists, with a focus on constraint-based structure learning. Second, in a detailed case study constraintbased structure learning is applied to derive hypotheses of causal relationshi...

The classic 10-year population cycle of snowshoe hares (Lepus americanus, Erxleben 1777) and Canada lynx (Lynx canadensis, Kerr 1792) in the boreal forests of North America has drawn much attention from both population and community ecologists worldwide; however, the ecological mechanisms driving the 10-year cyclic dynamic pattern are not fully revealed yet. In this study, by the use of histori...

We characterized fire history and examined climate–fire relationships in dry ponderosa pine (Pinus ponderosa) forests in the Zuni Mountains of northwestern New Mexico. Our findings indicate that the historical wildfire regime for the study area was typified by high-frequency, low-severity surface fires. Climate–wildfire relationships were assessed using both Superposed Epoch Analysis (SEA) and ...

Accurate projections of future temperature and precipitation patterns in many regions of the world depend on quantifying anthropogenic signatures in tropical Pacific climate against its rich background of natural variability. However, the detection of anthropogenic signatures in the region is hampered by the lack of continuous, century-long instrumental climate records. This study presents cora...

1. Introduction The US CLIVAR (Climate Variability and Prediction) Program, now in its eighth year, was designed to investigate the season-to-season, year-to-year, and decade-to-decade fluctuations in the climate. These climate variations influence nearly all spheres of human activity: our clothing, shelter, and energy needs; our ability to grow crops and raise livestock for food and fiber; and...

The useful lifespan of hydroelectric power infrastructure is 50 years or more; this is long enough that long-term climate change and shorter-term climate variability should be considered when planning new facilities and maintaining existing ones. This study examines observed historical climate variability in Southeast, Alaska, where several new and expanded hydropower facilities are proposed. A...

The Arctic Oscillation (AO) and the Antarctic Oscillation (AAO) are the leading modes of high-latitude variability in each hemisphere as characterized by the first EOF of mean sea-level pressure. Observations suggest a recent positive trend in the AO and it is speculated that this may be related to global warming. The CCCma coupled general circulation model control simulation exhibits a robust ...

Long-term estimation of extreme wave height remains a key challenge because of the short duration of available wave data, and also because of the possible impact of climate variability on ocean waves. Here, we analyse storm-based statistics to obtain estimates of extreme wave height at locations in the northeast Atlantic and North Sea using the NORA10 wave hindcast (1958-2011), and use a 5 year...