Extent and Causes of Chesapeake Bay Warming

Coastal environments such as the Chesapeake Bay have long been impacted by eutrophication stressors resulting from human activities, and these impacts are now being compounded by global warming trends. However, there are few studies documenting long-term estuarine temperature change and the relative contributions of rivers, the atmosphere, and the ocean. In this study, Chesapeake Bay warming, since 1985, is quantified using a combination of cruise observations and model outputs, and the relative contributions to that warming are estimated via numerical sensitivity experiments with a watershed–estuarine modeling system. Throughout the Bay’s main stem, similar warming rates are found at the surface and bottom between the late 1980s and late 2010s (0.02 +/- 0.02C/year, mean +/- 1 standard error), with elevated summer rates (0.04 +/- 0.01C/year) and lower rates of winter warming (0.01 +/- 0.01C/year). Most (~85%) of this estuarine warming is driven by atmospheric effects. The secondary influence of ocean warming increases with proximity to the Bay mouth, where it accounts for more than half of summer warming in bottom waters. Sea level rise has slightly reduced summer warming, and the influence of riverine warming has been limited to the heads of tidal tributaries. Future rates of warming in Chesapeake Bay will depend not only on global atmospheric trends, but also on regional circulation patterns in mid-Atlantic waters, which are currently warming faster than the atmosphere. Supporting model data available at: https://doi.org/10.25773/c774-a36

Spin-orbit splitting in the N-Δ spectra and the deformed baryon model

The absence of appreciable spin-orbit splitting in the low-lying even and odd parity states of the nucleon and delta is puzzling in conventional quark models. A constitutent quark model, in which the quarks interact through gluon as well as pion exchange, and the baryon is allowed to deform in the excited states, may provide a solution to the problem

Introduction to solar magnetism: the early years

The year 2008 marked the one hundredth anniversary of the observational discovery by George Ellery Hale of magnetic field in sunspots (Hale in Astrophys. J. 28:315–343, 1908). This observation, the first to suggest a direct link between the best-known variable features on the Sun and magnetism, started a line of research that has widened considerably over the last 100 years and is continuing today. Knowledge about all aspects of the Sun has increased in a remarkable way over the past few decades. Variations in the appearance of the Sun and its corona, as well as deeper sources of quasi-regular and chaotic changes that make up solar variability have been extensively documented by both ground-based and space-based solar observatories. It has been recognized that solar magnetism is the key phenomenon that drives solar variability. The workshop devoted to the origin and dynamics of solar magnetism held in the International Space Science Institute in Bern, Switzerland, from 21 to 25 January 2008 reviewed the status of the field and has led to this volume that brings together the best available knowledge and understanding of solar magnetism 100 years after Hale’s pioneering paper. This introductory paper gives an outline of the history of research into solar variability up to the work of Hale and his colleagues. The achievements of the past decades are discussed extensively in the other contributions to this volume

Stress response of juvenile rainbow trout (Oncorhynchus mykiss)to chemical cues released from stressed conspecifics

The objective of this study was to determine whether exposure of rainbow trout (Oncorhynchus mykiss) to water containing a stressed trout or skin extract from stressed and non-stressed trout would elicit a stress response in conspecifics. Juvenile rainbow trout were exposed for 1 hour to water containing a stressed fish, homogenized skin extracts from a non-stressed fish, skin extract from a stressed fish and water with none of these factors. The stress response was measured over a 24-h period (1, 6, 12, 24 h after exposure). Plasma cortisol levels increased at 12 h in fish exposed to water from a stressed fish and skin extract from a stressed fish. Plasma glucose and hepatic hsp70 levels were not affected by treatments. The results suggest that rainbow trout elicit a stress response when exposed to stress-related alarm cues released from conspecifics

Discovery of Jovian Dust Streams and Interstellar Grains by the Ulysses Spacecraft

On 8 February 1992, the Ulysses spacecraft flew by Jupiter at a distance of 5.4 AU from the Sun. During the encounter, the spacecraft was deflected into a new orbit, inclined at about 80-degrees to the ecliptic plane, which will ultimately lead Ulysses over the polar regions of the Sun1. Within 1 AU from Jupiter, the onboard dust detector2 recorded periodic bursts of submicrometre dust particles, with durations ranging from several hours to two days, and occurring at approximately monthly intervals (28 +/- 3 days). These particles arrived at Ulysses in collimated streams radiating from close to the line-of-sight direction to Jupiter, suggesting a jovian origin for the periodic bursts. Ulysses also detected a flux of micrometre-sized dust particles moving in high-velocity (greater-than-or-equal-to 26 km s-1) retrograde orbits (opposite to the motion of the planets); we identify these grains as being of interstellar origin