41 research outputs found
Climatological lower thermosphere winds as seen by ground-based and space-based instruments
Comparisons are made between climatological dynamic fields obtained from ground-based (GB) and space-based (SB) instruments with a view towards identifying SB/GB intercalibration issues for TIMED and other future aeronomy satellite missions. SB measurements are made from the High Resolution Doppler Imager (HRDI) instrument on the Upper Atmosphere Research Satellite (UARS). The GB data originate from meteor radars at Obninsk, (55° N, 37° E), Shigaraki (35° N, 136° E) and Jakarta (6° S, 107° E) and MF spaced-antenna radars at Hawaii (22° N, 160° W), Christmas I. (2° N, 158° W) and Adelaide (35° S, 138° E). We focus on monthly-mean prevailing, diurnal and semidiurnal wind components at 96km, averaged over the 1991-1999 period. We perform space-based (SB) analyses for 90° longitude sectors including the GB sites, as well as for the zonal mean. Taking the monthly prevailing zonal winds from these stations as a whole, on average, SB zonal winds exceed GB determinations by ~63%, whereas meridional winds are in much better agreement. The origin of this discrepancy remains unknown, and should receive high priority in initial GB/SB comparisons during the TIMED mission. We perform detailed comparisons between monthly climatologies from Jakarta and the geographically conjugate sites of Shigaraki and Adelaide, including some analyses of interannual variations. SB prevailing, diurnal and semidiurnal tides exceed those measured over Jakarta by factors, on the average, of the order of 2.0, 1.6, 1.3, respectively, for the eastward wind, although much variability exists. For the meridional component, SB/GB ratios for the diurnal and semidiurnal tide are about 1.6 and 1.7. Prevailing and tidal amplitudes at Adelaide are significantly lower than SB values, whereas similar net differences do not occur at the conjugate Northern Hemisphere location of Shigaraki. Adelaide diurnal phases lag SB phases by several hours, but excellent agreement between the two data sources exists for semidiurnal tidal phases throughout the year. These results are consistent with phase retardation effects in the MF radar technique that are thought to exist above about 90km. Prevailing and tidal amplitudes from Shigaraki track year-to-year variations in SB fields, whereas in the Southern Hemisphere poorer agreement exists. The above hemispheric differences are due in part to MF vs. meteor radar techniques, but zonal asymmetries and day-to-day variability, combined with inadequate sampling, may also be playing a role. Based on these results, some obvious recommendations emerge that are relevant to combined GB/SB studies as part of TIMED and other future aeronomy missions.J. M. Forbes, Yu. I. Portnyagin, W. Skinner, R. A. Vincent, T. Solovjova, E. Merzlyakov, T. Nakamura, and S. Pal
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Monthly mean climatology of the prevailing winds and tides in the Artic mesosphere/lower thermosphere
The Arctic MLT wind regime parameters measured at the ground-based network of MF and meteor radar stations (Andenes 69° N, Tromsø 70° N, Esrange 68° N, Dixon 73.5° N, Poker Flat 65° N and Resolute Bay 75° N) are discussed and compared with those observed in the mid-latitudes. The network of the ground-based MF and meteor radars for measuring winds in the Arctic upper mesosphere and lower thermosphere provides an excellent opportunity for study of the main global dynamical structures in this height region and their dependence from longitude. Preliminary estimates of the differences between the measured winds and tides from the different radar types, situated 125-273km apart (Tromsø, Andenes and Esrange), are provided. Despite some differences arising from using different types of radars it is possible to study the dynamical wind structures. It is revealed that most of the observed dynamical structures are persistent from year to year, thus permitting the analysis of the Arctic MLT dynamics in a climatological sense. The seasonal behaviour of the zonally averaged wind parameters is, to some extent, similar to that observed at the moderate latitudes. However, the strength of the winds (except the prevailing meridional wind and the diurnal tide amplitudes) in the Arctic MLT region is, in general, less than that detected at the moderate latitudes, decreasing toward the pole. There are also some features in the vertical structure and seasonal variations of the Arctic MLT winds which are different from the expectations of the well-known empirical wind models CIRA-86 and HWM-93. The tidal phases show a very definite longitudinal dependence that permits the determination of the corresponding zonal wave numbers. It is shown that the migrating tides play an important role in the dynamics of the Arctic MLT region. However, there are clear indications with the presence in some months of non-migrating tidal modes of significant appreciable amplitude
Monthly mean climatology of the prevailing winds and tides in the Arctic mesosphere/lower thermosphere
Mesosphere/lower thermosphere prevailing wind model
The mesosphere/lower thermosphere (MLT) wind data from the 46 ground-based (GB) MF and meteor radar (MR) stations, located at the different latitudes over the globe, and the space-based (SB) HRDI data were used for constructing of the empirical global climatic 2-D prevailing wind model at 80-100 km heights for all months of the year. The main data set is obtained during 1990-2001 period. It is shown that the three datasets (MF, MR, HRDI) are mainly well correlated. However, a certain systematic bias between the GB and SB data at 96 km exists, as well as that between the MF and MR data higher 88 km. Simple correction factors are proposed to minimize these biases. The 2-D distant-weighted least-square interpolation procedure for some arbitrary collection of points was used for drawing model contour plots. The model is available in the computer readable form and may be used for construction of the new CIRA model. © 2004 COSPAR. Published by Elsevier Ltd. All rights reserved
Трубка ендотрахеальна з системою для екстратубажного введення речовини
Трубка ендотрахеальна з системою для екстратубажного введення речовин, що включає інтубаційну трубку із конектором та герметизуючою манжетою, яка відрізняється тим, що лікарські засоби вводяться через канал в порожнину герметизуючої манжети, у стінках якої виконані перфоративні зрошуючі отвори діаметром 0,3 мм
Haplotype analysis of the HFE gene among populations of Northern Eurasia, in patients with metabolic disorders or stomach cancer, and in long-lived people
Some Quantitative Aspects of Stability Management Strategy in a Bank
AbstractThe stability of commercial bank system is the result of balanced development, which can be characterised by equilibrium and security over a longer period of time. The history of commercial bank system development indicates that reaching and sustaining this qualitative and quantitative state requires regulations and management. One of the most important parts of commercial bank management system is correctly chosen strategy in the circumstances of a changing environment. Strategy gives a possibility to look into the future of the commercial bank, forecast its goals, areas, scale and potential operational results in relation to resource sources and expenses. Nowadays a commercial bank without a strategy is a body of assets, which is encumbered with liabilities. In the paper quantitative stability management aspects are being analysed – commercial bank profitability, liquidity, asset quality and recommendations are given for ensuring bank stability
Assessment of biotechnology capacity of various wheat varieties
Assess the ability to embryogenic callus formation and regeneration of plants of several varieties of soft and hard spring wheat breeding Egyptian and Russian in order to select genotypes suitable for biotechnology. Callus from mature embryos were isolated from dry seeds and immature embryos isolated from kernels at 10-12 days after pollination. The highest frequency of embryogenic callus production from mature embryos marked for cultivar Novosibirskaya-22 (71,4%), the lowest capacity for embryogenesis has the cultivar Sids-1 (4%). For some genotypes the higher frequency of production embryogenic callus obtained in the use of mature, but for others - immature embryos. For one genotypes higher frequency of embryogenic callus formation is received at use mature, and for others - immature embryos. With increase in age of culture the proportion of embryogenic calli was reduced at all cultivars, after four months of culturing it became close to zero. Novosibirskaya-22, Suhadzh-1, Gemmiza-1 can be used as sites of cell selection or genetic engineering
The killer shrimp Dikerogammarus villosus (Crustacea, Amphipoda) invades Lithuanian waters, South-Eastern Baltic Sea
The killer shrimp Dikerogammarus villosus was recorded for the
first time in
Lithuanian waters in 2015. The species was detected in three sites in the Curonian Lagoon
(on two buoys in the lagoon strait and the harbour, and one littoral sampling site) and in the mouth
of the Šventoji River. The species presence in the buoy fouling suggests the involvement of
shipping in species introduction. Most likely D. villosus has arrived to the Curonian Lagoon with
commercial ships, while the invasion into the mouth of the Šventoji River may be associated with
leisure shipping as the port situated therein is not currently functioning. Further northward
expansion of the killer shrimp in the Baltic Sea basin seems very probable. As the species is highly
aggressive, alterations of local macroinvertebrate assemblages can also be predicted
