The sacred 260-day Mesoamerican calendar probably originated near a latitude of 15 degrees N, where there is a 260-day interval between transits of the zenithal sun. Archeological and faunal evidence favors an origin in the Pacific lowlands rather than in the highlands near Copán, Honduras, although Copán, which is located at the 15th parallel of latitude, later became the principal Mayan astro...

[1] Recent paleoproxy records suggest that the mean latitude of the Atlantic Intertropical Convergence Zone (ITCZ) varied synchronously with North Atlantic climate over a range of timescales throughout the Holocene and Last Glacial Maximum. We show that the present-day ‘‘meridional mode’’ of atmosphere-ocean variability in the tropical Atlantic is a potentially useful model for understanding th...

Is the transport of heat northward by the Gulf Stream and North Atlantic Drift, and its subsequent release into the midlatitude westerlies, the reason why Europe’s winters are so much milder than those of eastern North America and other places at the same latitude? Here, it is shown that the principal cause of this temperature difference is advection by the mean winds. South-westerlies bring wa...

Olindias sambaquiensis, known as agua viva, is an endemic hydromedusa that is distributed from latitude 23 degrees to 42 degrees south in the southwestern Atlantic Ocean and is known to cause severe stings. This is the first report of the use of vinegar in disarming O sambaquiensis nematocysts and includes preliminary observations on its use in managing the stings of hydromedusae.

Several computational experiments were carried out with a state-of-the-art ocean general circulation model to identify the northward directed Ekman transport of Antarctic and Subantarctic origin surface water as a mechanism which forces mid-latitude convection. The results indicate that the wind-driven transport of water in the surface layer is most efficient at increasing the depth of convecti...

Short-term constituents of the secular variation, at inter-decadal (20–30 years) and sub-centennial (60–90 years) time scales, present in observatory data and main field models, are also found in the radial field evolution at core surface. The paper is focused on the sub-centennial constituent in the gufm1 model. Time–Longitude (t–λ) plots, covering the 400 years time span of the model, at vari...

This study examines the productivity and resilience of agroecosystems in the Korean Peninsula. Having learned valuable lessons from a Chapman University project funded by the United States Department of Agriculture which concentrated on the semi-arid region of southwestern United States, our joint Korea—Chapman University team has applied similar methodologies to the Korean Peninsula, which is ...

The Late Cretaceous 'greenhouse' world witnessed a transition from one of the warmest climates of the past 140 million years to cooler conditions, yet still without significant continental ice. Low-latitude sea surface temperature (SST) records are a vital piece of evidence required to unravel the cause of Late Cretaceous cooling, but high-quality data remain illusive. Here, using an organic ge...

We present software for spherical harmonic analysis (SHA) and spherical harmonic synthesis (SHS), which can be used for essentially arbitrary degrees and all co-latitudes in the interval (0◦, 180◦). The routines use extended-range floating-point arithmetic, in particular for the computation of the associated Legendre functions. The price to be paid is an increased computation time; for degree 3...