Reflection halo twins: subsun and supersun.

From an aircraft, a short distinct vertical structure is sometimes seen above the setting sun. Such a feature can be understood as a halo, which is the counterpart of the well-known subsun. Whereas the latter arises from reflections off basal faces of plate-oriented ice crystals illuminated from above, what we call the supersun emerges when these crystals are illuminated from below.

Noninverted images in inferior mirages.

Inferior mirages over sun-exposed roads often appear in isolated strips at their near sides and the reflected scenery exhibits multiple images. This effect is explained as due to slight undulations of the road's surface. At the same time, some of these images, although they are reflections, are not inverted.

Comment on "improved ray tracing air mass numbers model".

Air mass numbers have traditionally been obtained by techniques that use height as the integration variable. This introduces an inherent singularity at the horizon, and ad hoc solutions have been invented to cope with it. A survey of the possible options including integration by height, zenith angle, and horizontal distance or path length is presented.

Random-mood interpretation of determinants for major depression.

Background: It has recently been proposed that major depression disorder (MDD) may, in a heterogeneous population-based cohort, be interpreted in terms of a random-mood model. Mood fluctuations are thought to result from stressors that occur randomly in time. We have investigated whether this concept also holds for more homogeneous groups, defined by known determinants for MDD, and whether the model's parameters, susceptibility (Z) and relaxation time (T), may be evaluated and used to differentiate between subcohorts.

Major depressive episodes and random mood.

Context: Mathematical models describing changes in mood in affective disorders may assist in the identification of underlying pathologic and neurobiologic mechanisms and in differentiating between alternative interpretations of psychiatric data.

Objective: Using time-to-event data from a large epidemiologic survey on recovery from major depression, to model the survival probability, in terms of an underlying process, with parameters which might be recognized and influenced in clinical practice.

Design: We present a sequential-phase model for survival analysis, which describes depression as a state with or without an additional incubation phase.

The toboggan sun.

Special variants of the Novaya Zemlya effect may arise from localized temperature inversions that follow the height profile of hills or mountains. Rather than following its natural path, the rising or setting Sun may, under such circumstances, appear to slide along a distant mountain slope. We found early observations of this effect in the literature by Willem Barents (1597) and by Captain Scott and H.

Gerrit de Veer's true and perfect description of the Novaya Zemlya effect, 24-27 January 1597.

The first recordings of the Novaya Zemlya (NZ) effect were made during Willem Barents' third Arctic expedition. Ray-tracing analyses of the three key observations, on 24-27 January 1597, show that all the reported details can be explained by adopting one common and realistic type of temperature inversion. In particular, the Moon-Jupiter conjunction could have been visible over the central mountain ridge of the island.

Novaya Zemlya effect and sunsets.

Systematics of the Novaya Zemlya (NZ) effect are discussed in the context of sunsets. We distinguish full mirages, exhibiting oscillatory light paths and their onsets, the subcritical mirages. Ray-tracing examples and sequences of solar images are shown.

Ray tracing and refraction in the modified US1976 atmosphere.

A new and flexible ray-tracing procedure for calculating astronomical refraction is outlined and applied to the US1976 standard atmosphere. This atmosphere is generalized to allow for a free choice of the temperature and pressure at sea level, and in this form it has been named the modified US1976 (MUSA76) atmosphere. Analytical expressions and numerical procedures are presented for calculating dry-air refractions and for the water-vapor correction.

Search for isovector giant monopole resonances via the Pb(3He,tp) reaction.

The (nat)Pb(3He,tp) reaction at E(3He) = 177 MeV was studied to identify 2Planck's over 2piomega isovector monopole strength in Bi isotopes. Monopole strength was found in the region -45 View Article and Find Full Text PDF

Three-nucleon force and the A(y) puzzle in intermediate energy p--> + d and d--> + p elastic scattering.

New vector analyzing-power data on p-->+d elastic scattering at E(p) = 150 and 190 MeV have been measured. These are presented together with existing data and with recent d-->+p vector and tensor analyzing power data at E(d) = 270 MeV. The strong negative extremum of both vector analyzing powers A(p)(y) and A(d)(y) at straight theta(c.