Accuracy of vertical velocity determination

Typical wind spectra taken at Poker Flat, Alaska, using the vertically oriented antenna show velocities of 10's of cm to meters per second and spectral widths winds of 0.5 to 1 m/s. The potential errors in such measurements can be broken down into three categories: (1) those due to instrumental parameters and data processing, (2) those due to specular returns from non-horizontal surfaces, and (3) those due to other physical effects. Error analysis in vertical velocity measurement is further discussed

Parameterization of spectrum

Many radars used for wind sounding generate Doppler power spectra as output. For compact data archiving purposes, as well as for data analysis, several parameters were produced to characterize each spectrum. The parameters chosen were noise level, echo signal strength, velocity, and width. Because the derived parameters may be the only quantities available for future analysis, it was important that they did not contain biases imposed by the derivation techniques. This consideration led to a processing scheme in which the parameters were derived independently for each spectrum

Use of the Sun to determine pointing of ST radar beams

Verification of the beam pointing direction for ST (stratosphere troposphere) radars is a technically difficult problem. Consequently it is not usually done. For measurement of horizontal wind, the lack of precise knowledge of the beam pointing direction is usually of little consequence as any errors cause only a small uncertainty in the measured velocity. However, instantaneous vertical velocities are typically more than an order of magnitude less than horizontal velocities and average vertical velocities are more than two orders of magnitude less than average horizontal velocities. Hence small pointing errors for vertical beams can result in large errors due to contamination by horizontal winds. Experimental confirmation of pointing accuracy using the measured winds is difficult but has been achieved where horizontal and vertical winds are measured at the same site. Using the techniques described by Balsley and Riddle, 1984 and Riddle and Balsley, 1985, pointing accuracy was measured at Ponape, Federated States of Micronesia. The experiment is described in detail

Archival of Poker Flat MST radar data

The Poker Flat MST (mesosphere stratosphere troposphere) radar has operated from early 1979 to 1985. The data recorded during that time resides on some 1100 magnetic tapes. A second set containing only the derived parameters of velocity, width and signal to noise of the primary echo at each height, plus the noise spectra, occupies another 250 tapes. While processing to generate the compressed data set does correct some known errors, no attempt has been made to identify or remove spurious echoes. Because the Poker Flat data set is such a unique and valuable resource, a proposal is made to archive the data in forms more useful for analysis. The archived data set would contain only the parameters for significant echoes with contamination from airplanes, unwanted ionospheric returns, frequently aliased Doppler signals and other sources removed. The archived set should be as good or better than the example shown and may occupy only 25 to 50 tapes

Tropospheric gravity waves observed by three closely spaced ST radars

Clear-air radar experiments were carried out on the southern coast of France during the (ALPEX) Alpine experiment program vertically directed stratosphere-troposphere-radars were set up with spacings of about 5 to 6 km. The temporal and spectral characteristics of the vertical velocity fluctuations were examined. The horizontal and vertical properties of gravity waves in the lower atmosphere were analyzed. The techniques used and the first results from this wave study are described

Direct measurements of the polarization of terrestrial kilometric radiation from Voyagers 1 and 2

Terrestrial radiation measurements obtained with planetary radio astronomy experiments on Voyager-1 and 2 during the early portions of each flight show the signals to be predominantly left-hand circularly polarized. Since these emissions were most probably generated above the Northern Hemisphere auroral zone, it is concluded that the radiation is emitted primarily in the extraordinary mode

Ambient loop district heating and cooling networks with integrated mobility, power and interseasonal storage

This paper describes a heat pump investigation for GreenSCIES (GS), a fifth Generation district heating and cooling (5DHC) network in Islington, London. The paper describes the GreenSCIES concept integrating Mobility, Power and Heat into a Smart Local Energy System (SLES). At the heart of the system is an ultra-low temperature ambient loop network, which permits bi-directional flow within the pipes to allow energy exchange between heating and cooling customers at different times and in different locations, depending on where demand is at any given time. An existing data centre provides the primary source of waste heat for the scheme. Heat pumps in distributed energy centres are utilised to amplify the temperature of the ambient loop to deliver heat in connected buildings. The energy centres integrate heat pumps with building-mounted solar photovoltaic (PV) systems and electric vehicle (EV) charging points. The paper provides an overview of the integrated SLES concept, focussing on the heat pump selection and the short and long-term thermal storage options designed for the scheme. The results show that even the smaller constructible ‘New River’ scheme will save 5,000 tons of CO2e annually. This will tend to 100% as the grid decarbonise further. Therefore, the GS SLES concept applied to urban areas could deliver significant carbon emission savings in the UK and elsewhere. Practical application: Project GreenSCIES, is a detailed design study to develop a Smart, Local Energy System (SLES) for a large community in the London Borough of Islington. Our consortium have developed an innovative SLES concept, centred around a fifth generation district heating and cooling network. The GS ambient loop systems have negligible losses and much greater efficiencies than traditional district heat networks. As recognised by the UK Government’s Heat and Buildings Strategy, ambient loop systems should be considered where large-scale neighbourhood regeneration occurs. The proposed SLES concept applied to wider urban areas could deliver significant carbon emission savings in the UK

Synoptic observations of Jupiter's radio emissions: Average Statistical properties observed by Voyager

Observations of Jupiter's low frequency radio emissions collected over one month intervals before and after each Voyager encounter were analyzed. Compilations of occurrence probability, average power flux density and average sense of circular polarization are presented as a function of central meridian longitude, phase of Io, and frequency. The results are compared with ground based observations. The necessary geometrical conditions are preferred polarization sense for Io-related decametric emission observed by Voyager from above both the dayside and nightside hemispheres are found to be essentially the same as are observed in Earth based studies. On the other hand, there is a clear local time dependence in the Io-independent decametric emission. Io appears to have an influence on average flux density of the emission down to below 2 MHz. The average power flux density spectrum of Jupiter's emission has a broad peak near 9MHz. Integration of the average spectrum over all frequencies gives a total radiated power for an isotropic source of 4 x 10 to the 11th power W

CLUSTERING A SERIES OF REPLICATED POLYPLOID GENE EXPRESSION EXPERIMENTS IN MAIZE

Ploidy level is defined as the number of individual sets of chromosomes contained in a single cell. Many important crop plants, such as potato, soybean and wheat are polyploid. Although it is widely known that polyploidy is a frequent evolutionary event, it is not fully understand why polyploids have been so successful. In this work cluster analysis is employed to study gene expression changes in a maize inbred line (B73) across a range of polyploidy levels. The B73 ploidy series includes monoploid, diploid, triploid and tetraploid plants and consists of biological and technical replicates as measured by microarray technology. An improved version of CORE (iCORE; improved Clustering of Repeat Expression) is presented to differentiate highly negatively correlated genes while taking advantage of the additional information that is provided by replication. The error information from the replicate experiments is utilized to cluster gene expression for both simulated and real ploidy-series data. Simulation results indicate that iCORE leads to an improvement in accuracy over both CORE and hierarchical clustering based on average gene expression only. When applied to the maize ploidy series, the iCORE results provide information that may aid in understanding of the effect of gene dose on gene expression in a ploidy series