Showing papers on "Longitude published in 1977"
TL;DR: SMS-1 infrared brightness was estimated subjectively for each 1° square for the area from the equator to 20°N latitude and from 10°E to 30°W longitude for Phase III of GATE and the previous interphase period at 6 h intervals as discussed by the authors.
Abstract: SMS-1 infrared brightness was estimated subjectively for each 1° square for the area from the equator to 20°N latitude and from 10°E to 30°W longitude for Phase III of GATE and the previous interphase period at 6 h intervals. Each grid square was assigned one of the following brightness categories: 0, no clouds or clouds with low tops; 1, clouds with tops at middle heights; or 2, clouds with coldest tops—presumably of convective origin. The percentage of area covered by category 2 clouds was then computed for squares 3° an a side. The data were filtered with respect to time to isolate 3–4 day period wave-related oscillations. In addition, over 160 individual cloud clusters, including a special type of “squall” cluster, were identified in the IR images and tracked on a 3 h basis. A progressive pattern of 3–4 day period fluctuations in convective activity was observed. A comparison of this pattern with time-filtered 700 mb wind data indicates a correspondence of convective activity to wave trough a...
134 citations
TL;DR: In this paper, the equatorial counter-electrojet corresponds to a westward flow of currents within a narrow latitude band on either side of the dip-equator and negative depressions of the regular daily variation SR in the horizontal component which it induces at these latitudes can be considered as an unexpected and abnormal reversal of the SR.
118 citations
TL;DR: In this paper, the authors present many examples of downstream amplification over the monsoonal belt, based on 43 years of data, showing that during northern summer pressure drops in the vicinity of the North Vietnam coast (near 20°N) as a typhoon or a tropical storm arrives, during the ensuing week pressure rises over Indochina and Burma by some 5-7 mb.
Abstract: In this paper we present many examples (based on 43 years of data) of a phenomenon of downstream amplification over the monsoonal belt. The specific finding here is the following sequence of events: 1) During northern summer pressure drops in the vicinity of the North Vietnam coast (near 20°N) as a typhoon or a tropical storm arrives; 2) during the ensuing week pressure rises over Indochina and Burma by some 5–7 mb; and 3) during the following week a monsoon disturbance forms near the northern part of the Bay of Bengal. On an x-t (or Hovmoller) diagram this sequence of low-high-low formation is similar to the downstream amplification phenomenon of the middle latitudes. The following are some interesting differences: over the middle latitudes the eastward propagating phase velocity is of the order of 10° longitude day−1, while the eastward propagating group velocity (the speed of propagation of the amplification) is around 30° longitude day−1. The tropical counterparts are westward propagating, an...
67 citations
TL;DR: The phase and amplitude of the annual, semiannual, and quasi-biennial oscillations to total ozone data for the Northern Hemisphere in the period 1957-1972 and for Northern Hemisphere ozonesonde data for variable periods from 1962-1974 have been plotted as functions of latitude, longitude, and altitude.
Abstract: The phase and amplitude of the annual, semiannual, and quasi-biennial oscillations to total ozone data for the Northern Hemisphere in the period 1957-1972 and for Northern Hemisphere ozonesonde data for variable periods from 1962-1974 have been plotted as functions of latitude, longitude, and altitude. The largest annual wave amplitude in total ozone occurs over eastern Siberia. In total ozone, the region of maximum quasi-biennial oscillation (QBO) coincides with that of the annual wave. The major feature of the QBO in the vertical distribution is the maximum amplitude in the arctic just above the tropopause. As for the semiannual wave, the maximum in total ozone lies in the arctic, displaced slightly to the Siberian side. In the vertical, its maximum amplitude is near 18 km. The phase appears to progress poleward, with maxima at high latitudes occurring in March-April.
55 citations
TL;DR: In this paper, the International Astronomical Union has adopted a new longitude system for Jupiter, labelled System III(1965), to replace the provisional system III(19570) The specification of the prime meridian and epoch for the new system differs slightly from that recently published Its rotation rate implies a period of 9 hr 55 min 29711 (plus or minus 004) sec.
Abstract: Commission 40 of the International Astronomical Union has adopted a new longitude system for Jupiter, labelled System III(1965), to replace the provisional System III(19570) The specification of the prime meridian and epoch for the new system differs slightly from that recently published Its rotation rate implies a period of 9 hr 55 min 29711 (plus or minus 004) sec, consistent with recent determinations from decimetric and decametric data For both the new and older systems, equations are provided which are useful in the evaluation of longitudes for the analysis of Jupiter radio, particle, and field data from earth and spacecraft observations
38 citations
34 citations
TL;DR: The time variation in size and location of the 300 mb north circumpolar vortex has been estimated from mean monthly polar stereographic maps for the years 1963-75, both by planimetering the area north of height contours in the main belt of westerlies and by determining the colatitude of these contours at 30° longitude intervals and squaring the average value as mentioned in this paper.
Abstract: The time variation in size and location of the 300 mb north circumpolar vortex has been estimated from mean monthly polar stereographic maps for the years 1963–75, both by planimetering the area north of height contours in the main belt of westerlies and by determining the colatitude of these contours at 30° longitude intervals and squaring the average value. It is shown that the vortex areas determined by the two independent techniques are in excellent agreement, but that the vortex-center locations (based on equalization of arms) determined by the two techniques are in only fair agreement. The change in vortex area appears mainly to reflect a change in mean tropospheric temperature, but with some modification caused by a change in mean surface pressure in temperate latitudes. Since 1970 the yearly averaged vortex area has increased by almost 2%, but that increase apparently ended in 1975, suggesting that the cooling in north temperate latitudes has also ended. During this same five-year period ...
31 citations
TL;DR: The preferred longitude effect was most pronounced from 1970 onward but was also evident in the years preceding 1970 as discussed by the authors, when it was assumed that the synodic rotation period of the sun is 27.025 days.
Abstract: During the 11 1/2-year period from July 1964 through December 1975, high- and low-speed solar wind flows originated from preferred solar longitudes. The preferred longitude effect was most pronounced from 1970 onward but was also evident in the years preceding 1970. The most pronounced modulation in average solar wind speed with longitude (approximately 20%) was obtained when it was assumed that the synodic rotation period of the sun is 27.025 days. Some deep internal structure in the sun must ultimately be responsible for these long-lived longitudinal effects, which appear to rotate rigidly with the sun.
20 citations
TL;DR: In this article, the authors examined long-term averages of solar-wind-speed data obtained in the ecliptic plane from July 1964 through December 1975 for a regular variation in flow speed associated with earth's yearly excursion to latitudes of plus or minus 7.25 deg about the solar equator.
Abstract: Long-term averages of solar-wind-speed data obtained in the ecliptic plane from July 1964 through December 1975 have been examined for a regular variation in flow speed associated with earth's yearly excursion to latitudes of plus or minus 7.25 deg about the solar equator. Regular speed modulations of about 70 km/s peaking at the highest latitudes are discernible from mid-1964 through 1966 and from early 1969 to early 1971. During the remainder of this 11.5-year interval, the modulations in speed seem to be aperiodic. A superposed epoch analysis of all the data fails to reveal a general solar latitude gradient in the solar-wind flow for these 11.5 years. It is concluded that with near-earth observations, a latitude dependence of the flow speed is too small to be detected on a regular basis against a background 'noise' of solar-wind streams, which vary in longitude, latitude, and time.
19 citations
TL;DR: In this paper, a large-scale longitudinal variation in surface temperature in the North Pacific is described by an analysis of some existing data and some newer data, showing that there is nearly always a temperature maximum in the eastern Pacific and a minimum in the central Pacific.
Abstract: A large-scale longitudinal variation in surface temperature in the North Pacific is described by an analysis of some existing data and some newer data. When monthly mean surface temperatures are plotted against longitude at mid-latitudes there is nearly always a temperature maximum in the eastern Pacific and a minimum in the central Pacific. Long-term averages of monthly mean temperature data, as well as independent surface temperature data from individual cruises, show a similar maximum and minimum. At 35°N and 40°N the mean positions of the maximum and minimum are further west in summer than in winter, and for a given month are further west at 35°N than at 40°N. The east-west scale of the temperature feature is defined to be the longitudinal distance between the positions of the adjacent temperature extremes and is shown to have an average value of about 2000 km nearly independent of season and latitude. The temperature scale is defined to be the difference between the maximum and minimum tempe...
13 citations
TL;DR: In this paper, the positions of the current system foci were found to vary much more with longitude than with season, and the observed seasonal changes in the foci must be due to changes in winds rather than in conductivities.
TL;DR: A planetwide control net of Mars has been computed by a single large-block analytical triangulation derived from 17,224 measurements of 3,037 control points on 928 Mariner 9 pictures.
Abstract: A planetwide control net of Mars has been computed by a single large-block analytical triangulation derived from 17,224 measurements of 3,037 control points on 928 Mariner 9 pictures. The computation incorporated the Viking-determined direction of the spin axis and rotation rate of Mars. The angle measured from the vernal equinox to the prime meridian (areocentric right ascension) of Mars was determined to be 148.368 deg + 350.891986 deg (JD - 2433282.5), where JD refers to the Julian date. The prime meridian of Mars passes through the center of the small crater Airy-O. The longitudes of the Viking landers are 47.82 + or - 0.1 deg for Lander 1 and 225.59 + or - 0.1 deg for Lander 2.
TL;DR: In this article, the monthly median NmF 2 values during the high sunspot period 1958 from a number of low latitude stations in the American zone are subjected to harmonic analysis.
01 Mar 1977
TL;DR: In this article, a comparative survey of monthly and seasonal climatic data for the middle and higher latitude southern hemisphere islands is made, where differences of mean pressure between station pairs are used to determine seasonal indices of the strength of the broad westerly stream.
Abstract: In order to establish the distribution of element variability and its possible relation to broad scale circulation patterns a comparative survey is made of monthly and seasonal climatic data for the middle and higher latitude southern hemisphere islands. Variability of mean temperature between the same seasons of different years is low except for the winter pack ice fringe of the Weddell Sea; in general, precipitation decreases with island latitude, shows some longitude dependence at lower latitudes but exhibits relatively low interseasonal and interannual variability. Differences of mean pressure between station pairs are used to determine seasonal indices of the strength of the broad westerly stream. The zonal flow is strongest and most variable in spring and displays greatest regional variability south east of Australia and north of the Weddell Sea. Variations in the strength of the broad zonal westerlies cannot be correlated with corresponding precipitation anomalies on the islands, but for an average of well exposed stations in western Tasmania the precipitation in spring increases with increasing local pressure gradient and a weakening gradient to the south. No significant trend in island temperature and precipitation or in broad zonal pressure or temperature gradient is descernible over the period of record. though a decreasing meridional temperature gradient over the Weddell Sea in spring is observed during the latter part of the 1960's.
TL;DR: The ionospheric storm of 4-5 August 1972 was analyzed using data from 35 middle and low latitude ionosphere stations and 7 magnetic stations in the Asia-Australia-Pacific longitude sector as discussed by the authors.
TL;DR: In this article, preliminary results obtained from a network of air sampling stations located between 9° S and 43° S along about 150° E longitude indicate that the "spring" maximum in tropospheric radioactivity concentrations propagates poleward at a rate of about 35 cm s -1.
Abstract: Preliminary results obtained from a network of air sampling stations located between 9° S and 43° S along about 150° E longitude indicate that the “spring” maximum in tropospheric radioactivity concentrations propagates poleward at a rate of about 35 cm s -1 . The peak appears to be associated with an injection of air enriched with Be-7, presumably stratospheric, at about 20°S during September-October. A secondary injection of air containing high concentrations of Be-7 is suggested by the results, occurring southward of 35° S during November-December. Use of artificial radionuclide concentrations as southern hemispheric tracers is severely hampered by continuing weapons testing in the south Pacific region. A complete comparison between the various models of the atmospheric general circulation and the results from studies such as the present awaits the collection of data unaffected by weapons testing programs. DOI: 10.1111/j.2153-3490.1977.tb00722.x
TL;DR: In this paper, a study of data from the cylindrical electrostatic probe and the topside sounder aboard the Alouette 2 satellite reveals the existence of nighttime Ne enhancements at mid-latitudes, at altitudes 1, 000-3, 000km.
Abstract: A study of data from the cylindrical electrostatic probe and the topside sounder aboard the Alouette 2 satellite reveals the existence of nighttime Ne enhancements at mid-latitudes, at altitudes 1, 000-3, 000km. The peaks seem to approach the equator with increasing altitude, and appear to lie on a specific set of geomagnetic field lines. The intensity and location of these nocturnal Ne peaks, as well as the electron density in the entire low- to mid-latitude range, show a marked dependence on geomagnetic longitude. These observations are interpreted in terms of field-aligned flow of thermal plasma from the protonosphere above 3, 000km in the presence of a westward electric field at L≈2.
TL;DR: Cross sections of the mean meridional wind for winter and summer along five latitudes (15°, 30°, 45°, 60° and 75°N) are presented, and their salient features described.
Abstract: Cross sections of the mean meridional wind for winter and summer along five latitudes (15°, 30°, 45°, 60° and 75°N) are presented, and their salient features described.
Patent•
26 Feb 1977
TL;DR: In this article, an annular gear in a plane at right angles with a virtual axis in parallel with the earth's axis was used to automatically trace the position of the solar longitude by rotating by 15 degrees per hour.
Abstract: PURPOSE:To automatically trace the position of the solar longitude by rotating by 15 deg. per hour an annular gear in a plane at right angles with a virtual axis in parallel with the earth's axis.
TL;DR: In this article, the authors reported a magnitude of 3.5 to 3.7 with a focal depth of about 5 km and the maximum intensity was V MM and the earthquake was felt over about 5,620 sq. km.
Abstract: The earthquake in southern Georgia on December 27, 1976 occured about 1:57 a.m., EST. The hypocenter was located near 32.05° north latitude and 82.3° west longitude. Instrumental data indicate a magnitude of 3.5 to 3.7 with a focal depth of about 5-km. The maximum epicenteral intensity was V MM and the earthquake was felt over about 5,620 sq. km.
TL;DR: In this paper, a method of simultaneous determination of astronomic latitude, azimuth and longitude from observations of a star-pair near their times of east and west elongations and a south star near its time of meridian transit was proposed.
Abstract: This paper endeavours to evolve a method of simultaneous determination of astronomic latitude, azimuth and longitude from observations of a star-pair near their times of east and west elongations and a south star near its time of meridian transit. The star-pair of observation being within a short distance of elongation, either east or west, their motion in azimuth then is extremely slow and the small error in time has therefore insignificant effect on their azimuth, and in addition, the south star with its azimuth known from observations of the previous star-pair, being very fast-moving, the method is especially suitable for determining the astronomic latitude, azimuth and longitude by observing only the time and horizontal angees between them, and also a reference mark for ensuring the orientation of the horizontal circle side by side.