Diurnal variation of mountain waves

Mountain waves could be modified as the boundary layer varies between stable and convective. However case studies show mountain waves day and night, and above e.g. convective rolls with precipitation lines over mountains. VHF radar measurements of vertical wind (1990–2006) confirm a seasonal variation of mountain-wave amplitude, yet there is little diurnal variation of amplitude. Mountain-wave azimuth shows possible diurnal variation compared to wind rotation across the boundary layer

VHF volume-imaging radar observation of aspect-sensitive scatterers tilted in mountain waves above a convective boundary layer

International audienceThin stable atmospheric layers cause VHF radars to receive increased echo power from near zenith. Layers can be tilted from horizontal, for instance by gravity waves, and the direction of VHF "glinting" is measurable by spatial domain interferometry or many-beam Doppler beam swinging (DBS). This paper uses the Middle and Upper atmosphere (MU) radar, Shigaraki, Japan as a volume-imaging radar with 64-beam DBS, to show tilting of layers and air flow in mountain waves. Tilt of aspect-sensitive echo power from horizontal is nearly parallel to air flow, as assumed in earlier measurements of mountain-wave alignment. Vertical-wind measurements are self-consistent from different beam zenith angles, despite the combined effects of aspect sensitivity and horizontal-wind gradients

All-weather volume imaging of the boundary layer and troposphere using the MU radar

International audienceThis paper shows the first volume-imaging radar that can run in any weather, revealing the turbulent three-dimensional structure and airflow of convective cells, rain clouds, breaking waves and deep convection as they evolve and move. Precipitation and clear air can be volume-imaged independently. Birds are detected as small high-power echoes moving near horizontal, at different speeds and directions from background wind. The volume-imaging method could be used to create a real-time virtual-reality view of the atmosphere, in effect making the invisible atmosphere visible in any weather

The Behavior of Confined Calves Raised for Veal: Are These Animals Distressed?

The behavior of twelve calves confined in crates was recorded at 1-minute intervals for 12-hour periods. These recordings were made at fortnightly intervals from approximately 2 to 16 weeks of age. In all, 864 hours of observations were recorded. The activities performed and the amount of time spent doing each are outlined. Circadian rhythms were mainly controlled by feeding time, although there was a difference between diurnal and nocturnal behavior. Individual calves varied in how they adapted to the restricted environment. Individual personality profiles and data on the ontogeny of behavior under these conditions are presented. At ten weeks of age, the calves were transferred to a different shed, where they were further restricted and yoked. This transfer had a significant effect on most behaviors. The redistribution of time for the confined and restricted calves, as compared with calves who remain with mothers in fields, is discussed, along with other aspects of welfare. Seven possible criteria related to behavioral distress (defined in functional terms) are suggested and discussed in relation to these results

The Behavior of Confined Calves Raised for Veal: Are These Animals Distressed?

The behavior of 12 calves confined in crates was recorded at 1-minute intervals for 12-hour periods. These recordings were made at fortnightly intervals from approximately 2 to 16 weeks of age. In all, 864 hours of observations were recorded. The activities that were performed and the amount of time spent doing each are outlined. Circadian rhythms were controlled largely by feeding time, although there was a difference between diurnal and nocturnal behavior. Individual calves vaned tn how they adapted to the restricted environment. Individual personality profiles and data on the ontogeny of behavior under these conditions are presented. At 10 weeks of age, the calves were transferred to a different shed, where they were further restricted and yoked. This had a significant effect on most behavtors. The redistribution of time for the confined and restricted calves, as compared with calves who remain with mothers in fields, is discussed, along with other aspects of welfare. Seven possible criteria related to behavioral distress (defined in functional terms) are suggested and discussed in relation to these results