Showing papers on "Longitude published in 2009"

Climatological mean and decadal change in surface ocean pCO2, and net sea–air CO2 flux over the global oceans

Abstract: A climatological mean distribution for the surface water pCO2 over the global oceans in non-El Nino conditions has been constructed with spatial resolution of 4° (latitude) ×5° (longitude) for a reference year 2000 based upon about 3 million measurements of surface water pCO2 obtained from 1970 to 2007. The database used for this study is about 3 times larger than the 0.94 million used for our earlier paper [Takahashi et al., 2002. Global sea–air CO2 flux based on climatological surface ocean pCO2, and seasonal biological and temperature effects. Deep-Sea Res. II, 49, 1601–1622]. A time-trend analysis using deseasonalized surface water pCO2 data in portions of the North Atlantic, North and South Pacific and Southern Oceans (which cover about 27% of the global ocean areas) indicates that the surface water pCO2 over these oceanic areas has increased on average at a mean rate of 1.5 μatm y−1 with basin-specific rates varying between 1.2±0.5 and 2.1±0.4 μatm y−1. A global ocean database for a single reference year 2000 is assembled using this mean rate for correcting observations made in different years to the reference year. The observations made during El Nino periods in the equatorial Pacific and those made in coastal zones are excluded from the database. Seasonal changes in the surface water pCO2 and the sea-air pCO2 difference over four climatic zones in the Atlantic, Pacific, Indian and Southern Oceans are presented. Over the Southern Ocean seasonal ice zone, the seasonality is complex. Although it cannot be thoroughly documented due to the limited extent of observations, seasonal changes in pCO2 are approximated by using the data for under-ice waters during austral winter and those for the marginal ice and ice-free zones. The net air–sea CO2 flux is estimated using the sea–air pCO2 difference and the air–sea gas transfer rate that is parameterized as a function of (wind speed)2 with a scaling factor of 0.26. This is estimated by inverting the bomb 14C data using Ocean General Circulation models and the 1979–2005 NCEP-DOE AMIP-II Reanalysis (R-2) wind speed data. The equatorial Pacific (14°N–14°S) is the major source for atmospheric CO2, emitting about +0.48 Pg-C y−1, and the temperate oceans between 14° and 50° in the both hemispheres are the major sink zones with an uptake flux of −0.70 Pg-C y−1 for the northern and −1.05 Pg-C y−1 for the southern zone. The high-latitude North Atlantic, including the Nordic Seas and portion of the Arctic Sea, is the most intense CO2 sink area on the basis of per unit area, with a mean of −2.5 tons-C month−1 km−2. This is due to the combination of the low pCO2 in seawater and high gas exchange rates. In the ice-free zone of the Southern Ocean (50°–62°S), the mean annual flux is small (−0.06 Pg-C y−1) because of a cancellation of the summer uptake CO2 flux with the winter release of CO2 caused by deepwater upwelling. The annual mean for the contemporary net CO2 uptake flux over the global oceans is estimated to be −1.6±0.9 Pg-C y−1, which includes an undersampling correction to the direct estimate of −1.4±0.7 Pg-C y−1. Taking the pre-industrial steady-state ocean source of 0.4±0.2 Pg-C y−1 into account, the total ocean uptake flux including the anthropogenic CO2 is estimated to be −2.0±1.0 Pg-C y−1 in 2000.

Solar release times of energetic particles in ground-level events

Abstract: We study the onset times of energetic particles of various species and velocities, v, in large solar energetic particle events with sufficiently hard spectra that are seen by neutron monitors at ground level. Observations of He, O, and Fe from the Wind spacecraft provide especially well-defined sequences of onset times, and data from IMP-8, GOES, and neutron monitors contribute importantly at higher energies. Plotting onset times versus v –1 yields a line with the initial solar particle release (SPR) time as the intercept and the magnetic path length as the slope. We find consistent results for 13 of the 16 ground-level events that occurred from 1994 to 2007, in solar cycle 23. Path lengths vary from 1.1 to 2.2 AU in the 13 events. In all of the events, SPR times occur after the onset of the shock wave-induced type II radio emission. Events with well-defined SPR times are found over a wide span of solar longitude, suggesting that all ion species and energies are released together, even far from the source longitude, with no evidence of energy- or rigidity-dependent coronal transport. If the SPR time is converted to a radial distance of the source shock wave from the Sun and plotted against longitude, acceleration for well-connected events is found to begin at 2-4 solar radii over a longitude span of ~ 100° and to rise to greater heights only at longitudes more distant from the source, as would be expected from shock-acceleration models.

Surface-exosphere coupling due to thermal tides

Abstract: [1] Using densities measured by accelerometers on the CHAMP and GRACE satellites, and taking advantage of the local time precession characteristics of these near-polar orbiting satellites, exosphere temperatures are derived as a function of local time, longitude and latitude. Significant longitude variability (e.g., ±25K maximum to minimum over the equator) in geomagnetically-quiet exosphere temperatures is shown to exist, and is attributed to a spectrum of diurnal and semidiurnal thermal tides that are excited in the troposphere and strongly influenced by the global land-sea distribution. Since exosphere temperatures are independent of height, this discovery constitutes evidence that exosphere variability is linked to surface variability. Recent evidence suggests that analogous effects exist at Mars.

African CO emissions between years 2000 and 2006 as estimated from MOPITT observations

Abstract: The space-time variations of the carbon budget at the Earth's surface are highly variable and quantifying them represents a major scientific challenge One strategy consists in inferring the carbon surface fluxes from the atmospheric concentrations An inversion scheme for the hydrocarbon oxidation chain, that includes CO and CH4, is presented here with a focus on the African continent It is based on a variational principle The multi-tracer system has been built as an extension of a system initially developed for CO2 and includes a new simplified non-linear chemistry module Individual in situ measurements of methyl-chloroform and individual retrievals of CO concentrations from the Measurements Of Pollution In The Troposphere (MOPITT) space-born instrument have been processed by the new system for the period 2000–2006 to infer the time series of CO emissions at the resolution of 25°×375° (latitude, longitude) It is shown that the analysed concentrations improve the fit to five independent surface measurement stations located in or near Africa by up to 28% compared to standard inventories, which confirms that significant information about CO emissions can be obtained from MOPITT data In practice, the inversion reduces the amplitude and the interannual variability of the seasonal cycle in the northern part of Africa, with a longer burning season In the southern part, the inversion mainly shifts the emission peak by one month later in the season, consistent with previously-published inversion results

Characterizing the 10 November 2004 storm‐time middle‐latitude plasma bubble event in Southeast Asia using multi‐instrument observations

Abstract: [1] The development and dynamics of ionospheric plasma bubble (PB) irregularity during the super storm of 7–11 November 2004 are investigated using the data from a multi-instrument network operated in Southeast Asia. Analysis of fluctuations in Global Positioning System total electron content (GPS TEC), ionosonde, GPS scintillation, and in situ satellite density data indicates a series of intense PB-associated irregularities at equatorial, low, and middle latitudes in the Japanese longitude on 10 November. However, in the Chinese sector, the scintillations and PB irregularities are confined within the range of 20–50°N in geographic latitude and 110–125°E in geographic longitude. The absence of equatorial PB irregularities in this sector shows a major difference from that in the close-by longitude Japanese sector. In the Southern Hemisphere Australian sector, the irregularities occurrence is present as a symmetrical distribution at conjugate latitudes. Combined analysis of the data from Osan and Wuhan ionosondes illustrates that the middle-latitude spread F irregularities initially develop at the lower part of the F region and then distribute in the whole F region. This initiation of spread F at lower altitudes indicates that the middle-latitude PB-associated irregularities are locally generated. These results together with the irregularities occurrence sequence from higher to lower latitudes, and the onset time delay of several hours implies that the presence of PB-associated irregularities within a latitude range of 20–50°N in the Chinese sector cannot be attributed to the effects of prompt penetration electric fields (PPEFs), although the equatorial PBs in the close-by longitude are seen to be associated with PPEFs. The possible mechanism is the F region plasma instabilities triggered by wave structures, which act as an external driving force and seed active plasma dynamics and instability growth at middle latitude.

A Mercury orientation model including non-zero obliquity and librations

Abstract: Planetary orientation models describe the orientation of the spin axis and prime meridian of planets in inertial space as a function of time. The models are required for the planning and execution of Earth-based or space-based observational work, e.g. to compute viewing geometries and to tie observations to planetary coordinate systems. The current ori- entation model for Mercury is inadequate because it uses an obsolete spin orientation, neglects oscillations in the spin rate called longitude librations, and relies on a prime meridian that no longer reflects its intended dynamical significance. These effects result in positional errors on the surface of ! 1.5 km in latitude and up to several km in longitude, about two orders of magnitude larger than the finest image resolution currently attainable. Here we present an updated orientation model which incorporates modern values of the spin orientation, includes a formulation for longitude librations, and restores the dynamical significance to the prime meridian. We also use modern values of the orbit normal, spin axis orientation, and preces- sion rates to quantify an important relationship between the obliquity and moment of inertia differences.

Development of new solar exergy maps

Abstract: In this paper, we develop a solar exergy map concept and conduct a comprehensive case study to show how it is utilized and how it is significant for practical solar applications. Based on the exergy content of the solar radiation, the performance of a photovoltaic thermal (PV/T) system is evaluated for different Indian cities, namely Bangalore (latitude 12°58′N, longitude 77°38′E), Jodhpur (latitude 26°18′N, longitude 73°04′E), Mumbai (latitude 18°55′N, longitude 72°54′E), New Delhi (latitude 28°35′N, longitude 77°12′E) and Srinagar (latitude 34°08′N, longitude 74°51′E) for a year and for different cities of U.S.A., namely Chicago (latitude 41°50′N, longitude 87°37′W), Las Vegas (latitude 36°10′N, longitude 115°12′W), Miami (latitude 25°46′N, longitude 80°12′W), New York (latitude 40°47′N, longitude 73°58′E), Portland (latitude 43°40′N, longitude 70°15′W), San Antonio (latitude 29°23′N, longitude 98°33′W), San Francisco (latitude 37°47′N, longitude 122°26′W), Tucson (latitude 32°7′N, longitude 110°56′W) and Tulsa (latitude 36°09′N, longitude 95°59′W) for different months of January, April, June and October. For the first time, the development of exergy maps for the exergy of solar radiation as well as the exergy efficiency of PV/T system is done for the above-mentioned Indian and American climatic conditions. It is found that the predicted exergy efficiency is in good agreement with the experimental results for the climatic conditions of New Delhi, India. It is observed that the average exergy efficiency is highest in Bangalore from January (28%) to April (32.6%) and from September (32.5%) to December (32.4%) and it is highest in Srinagar from May (29.5%) to August (26.8%) for Indian climatic conditions and for American climatic conditions, the PV/T system gives the best performance in terms of exergy efficiency in Las Vegas (32%) and Tucson (32.5–31.5%) in April and June. Copyright © 2009 John Wiley & Sons, Ltd.

Large-scale spatial patterns in the distribution of Collembola (Hexapoda) species in Antarctic terrestrial ecosystems

Abstract: Aim We tested whether the distribution of three common springtail species (Gressittacantha terranova, Gomphiocephalus hodgsoni and Friesea grisea) in Victoria Land (Antarctica) could be modelled as a function of latitude, longitude, altitude and distance from the sea. Location Victoria Land, Ross Dependency, Antarctica. Methods Generalized linear models were constructed using species presence/absence data relative to geographical features (latitude, longitude, altitude, distance from sea) across the species’ entire ranges. Model results were then integrated with the known phylogeography of each species and hypotheses were generated on the role of climate as a major driver of Antarctic springtail distribution. Results Based on model selection using Akaike’s information criterion, the species’ distributions were: hump-shaped relative to longitude and monotonic with altitude for Gressittacantha terranova; hump-shaped relative to latitude and monotonic with altitude for Gomphiocephalus hodgsoni; and hump-shaped relative to longitude and monotonic with latitude, altitude and distance from the sea for Friesea grisea. Main conclusions No single distributional pattern was shared by the three species. While distributions were partially a response to climatic spatial clines, the patterns observed strongly suggest that past geological events have influenced the observed distributions. Accordingly, present-day spatial patterns are likely to have arisen from the interaction of historical and environmental drivers. Future studies will need to integrate a range of spatial and temporal scales to further quantify their respective roles.

In situ observations from STEREO/PLASTIC: a test for L5 space weather monitors

Abstract: . Stream interaction regions (SIRs) that corotate with the Sun (corotating interaction regions, or CIRs) are known to cause recurrent geomagnetic storms. The Earth's L5 Lagrange point, separated from the Earth by 60 degrees in heliographic longitude, is a logical location for a solar wind monitor – nearly all SIRs/CIRs will be observed at L5 several days prior to their arrival at Earth. Because the Sun's heliographic equator is tilted about 7 degrees with respect to the ecliptic plane, the separation in heliographic latitude between L5 and Earth can be more than 5 degrees. In July 2008, during the period of minimal solar activity at the end of solar cycle 23, the two STEREO observatories were separated by about 60 degrees in longitude and more than 4 degrees in heliographic latitude. This time period affords a timely test for the practical application of a solar wind monitor at L5. We compare in situ observations from PLASTIC/AHEAD and PLASTIC/BEHIND, and report on how well the BEHIND data can be used as a forecasting tool for in situ conditions at the AHEAD spacecraft with the assumptions of ideal corotation and minimal source evolution. Preliminary results show the bulk proton parameters (density and bulk speed) are not in quantitative agreement from one observatory to the next, but the qualitative profiles are similar.

Observations of near‐surface wind and temperature structures and their variations with topography and latitude in East Antarctica

Abstract: Received 10 December 2008; revised 30 March 2009; accepted 5 June 2009; published 15 September 2009. [1] The first multiyear surface meteorological observations over Dome A, the highest ice feature in the entire Antarctica continent, are analyzed to understand the surface wind, temperature, and stability climatology over Dome A and how it differs from the surface climatology at two lower-latitude/lower-elevation sites along similar longitude in East Antarctica. The climatology is also compared with that over Dome C. In contrast to the surface winds at lower sites, where moderate to strong northeasterly winds prevail with a distinct diurnal oscillation in wind speed in response to the diurnal change in katabatic forcing, summertime surface winds over Dome A are very weak, are variable in direction, and show little diurnal variation. Although both temperature and temperature gradient oscillate diurnally, the gradient over Dome A remained positive all day long, indicating a persistent surface inversion, while at the two lower sites, as well as over Dome C, sufficient insolation leads to the breakup of inversion and the development of a convective boundary layer in the afternoon. Wavelet analysis of near-surface stability revealed that besides the strong diurnal signal, the near-surface stability also exhibits annual, semiannual, and interseasonal (period 50 days) oscillations at all locations. These oscillations in near-surface stability are linked to the same peaks in the 500-hPa geopotential height spectra and therefore are believed to be caused by variations of synoptic conditions.

In Situ Observations of Solar Wind Stream Interface Evolution

Abstract: The heliocentric orbits of the two STEREO satellites are similar in radius and ecliptic latitude, with separation in longitude increasing by about 45° per year. This arrangement provides a unique opportunity to study the evolution of stream interfaces near 1 AU over time scales of hours to a few days, much less than the period of a Carrington rotation. Assuming nonevolving solar wind sources that corotate with the Sun, we calculated the expected time and longitude of arrival of stream interfaces at the Ahead observatory based on the in situ solar wind speeds measured at the Behind observatory. We find agreement to within 5° between the expected and actual arrival longitude until the spacecraft are separated by more than 20° in heliocentric inertial longitude. This corresponds to about one day between the measurement times. Much larger deviations, up to 25° in longitude, are observed after 20° separation. Some of the deviations can be explained by a latitude difference between the spacecraft, but other deviations most likely result from evolution of the source region. Both remote and in situ measurements show that changes at the source boundary can occur on a time scale much shorter than one solar rotation. In 32 of 41 cases, the interface was observed earlier than expected at STEREO/Ahead.

Equatorial and low‐latitude ionosphere‐thermosphere system response to the space weather event of August 2005

Abstract: [1] The response of the equatorial and low-latitude ionosphere-thermosphere system to the geomagnetic storm during 23–26 August 2005 is investigated. The study is carried out using the vertical total electron content (VTEC) measured by GPS receivers along the 77–78°E longitude and the O/N2 ratio obtained from the Global Ultraviolet Imager instrument on board the TIMED satellite. The equatorial ionization anomaly (EIA) shows a poleward latitudinal expansion on 24 August, probably associated with an eastward prompt-penetration electric field. The equatorial and low latitudes show an increase in VTEC during the main phase of the storm on 24 August. The prompt-penetration eastward electric field, along with an increase in the O/N2 ratio, could be responsible for this observed positive phase. The VTEC variations on 24 August also reveal the signature of a large-scale acoustic gravity wave/traveling atmospheric disturbance propagating with a horizontal velocity of ∼750 m/s. Suppression of the EIA is observed during the storm recovery phase on 25 August, which probably is associated with the westward disturbance dynamo electric field and the equatorward expansion of the neutral composition changes (O/N2 depletion).

Climate change related rise of extreme typhoon power and duration over south-east asia seas

Abstract: The paper presents an analysis of 40 years of measurements of geographic location (longitude, latitude) and power (wind speed) of tropical storms and typhoons over South-East Asia seas, mainly the South China Sea and the Philippine Sea. The results demonstrate the growing intensity of duration of the most severe events. The analysis includes singular spectrum analysis of wind speed series in the period 1960–2000 to identify two sub-periods of roughly similar behavior. Then, the recorded events and occurrences are classified statistically. The most extreme ones from the 1st and 2nd sub-period are plotted as functions of their geographic co-ordinates to assess the spatial evolution of their location. Next, the escalating power and mostly duration of the most extreme typhoons are examined with extreme probability distributions to quantify the resulting climate change consequences in the studied region. Finally, all results are reiterated in the form of conclusions and suggestions for potential follow-up rese...

Technical Note: Perturbations on a Stationary Satellite by the Longitude-Dependent Terms in Mars’ Gravitational Field

Abstract: In analogy with geostationary satellites, an areostationary satellite (a stationary satellite of Mars) will tend to drift in longitude, and in fact, it will tend to oscillate like a pendulum around two stable longitudinal points. In this article we provide a first-order analysis of such motion and provide estimates of the locations of the equilibrium points, the period of libration (130 days for small amplitudes), and the amount of corrective station keeping Δv needed to counteract such drift.

Strategies for high-latitude northern hemisphere CO2 sampling now and in the future

Abstract: A sampling strategy to determine the annual mean air–sea CO 2 fluxes in the high-latitude North Pacific and North Atlantic was developed using a combination of signal-to-noise ratios and 2D Fourier transforms in conjunction with a coupled climate carbon model. To account for unresolved mesoscale variability in our simulations, we used summer and winter cruises to determine the magnitude of this variability and estimate its impact on the air–sea fluxes. From our analysis, we propose a regular sampling strategy of every 6° in latitude and 10° in longitude every 3 months for the North Pacific and North Atlantic. Applying this sampling strategy to the simulation returned an annual mean air–sea flux value within ±15% of the total simulated value, when applied now and into the future. Our study highlights several key points for measuring annual mean basin-scale CO 2 fluxes: (1) the combination of temporal and spatial sampling dramatically reduces the noise in the observations and provides a good representation of the fluxes with far fewer measurements than required for resolving the spatial or temporal signals independently; (2) that sampling at higher than recommended frequencies in time and space provides little improvement in the estimated annual mean flux; (3) the uncertainty in the decadal annual mean uptake is limited by interannual variability and not by sampling error or unresolved mesoscale variability; and (4) our high-latitude sampling strategies remain valid until at least the end of this century.

Traffic condition management method and system

Abstract: The invention discloses a method and a system for managing traffic condition. The method is characterized in that a traffic road network file containing a detailed data area and a logic grid area is established in advance, wherein, serial numbers of all roads within a designated area and corresponding traffic condition are stored in the detailed data area; the designated area is divided into grids which are equal in size and correspond to various latitude and longitude ranges; and latitudes, longitudes and serial numbers of all roads within each grid are stored in the logic grid area. The method comprises the following steps: according to the latitude and the longitude of a road to be located, a grid in which the road to be located is positioned can be located in the logic grid area; according to the latitude and the longitude of the road to be located, the serial number of a road matched with the road to be located can be found within the located grid; and according to the found serial number, traffic condition corresponding to the road is sought in the detailed data area. The scheme provided by the invention improves the efficiency of seeking traffic condition.

Lunar pole illumination and communications maps computed from GSSR elevation data

Abstract: A Digital Elevation Model of the lunar south pole was produced using Goldstone Solar System RADAR (GSSR) data obtained in 2006.12 This model has 40-meter horizontal resolution and about 5-meter relative vertical accuracy [Ref 1]. This Digital Elevation Model was used to compute average solar illumination and Earth visibility with 100 km of the lunar south pole. The elevation data were converted into local terrain horizon masks, then converted into lunar-centric latitude and longitude coordinates. The horizon masks were compared to latitude, longitude regions bounding the maximum Sun and Earth motions relative to the moon. Estimates of Earth visibility were computed by integrating the area of the region bounding the Earth's motion that was below the horizon mask. Solar illumination and other metrics were computed similarly. Proposed lunar south pole base sites were examined in detail, with the best site showing yearly solar power availability of 92% and Direct-To-Earth (DTE) communication availability of about 50%. Similar analysis of the lunar south pole used an older GSSR Digital Elevation Model with 600-meter horizontal resolution. The paper also explores using a heliostat to reduce the photovoltaic power system mass and complexity.

Internal wave observations in the northern South China Sea from satellite ocean color imagery

Abstract: The northern South China Sea (SCS) including the Luzon Strait, from around 19° to 22°N latitude and from 114° to 122°E longitude, is an ocean area where energetic internal waves occur frequently. In this study, satellite ocean color products from SeaWiFS (Sea-viewing Wide Field-of-view Sensor) and MODIS (Moderate Resolution Imaging Spectroradiometer) including true color and chlorophyll images are used for the statistical analysis of internal wave occurrence. For spatial distribution, fewer internal waves distributed in the east of 118°E obviously originate from the Luzon Strait, and more internal waves in the west of 118°E may propagate from the east or evolve into solitons originating from the eastern boundary owing to the fission effect of the shoaling thermocline. No internal wave is found east of the Luzon Strait. The lunar daily observed internal wave occurrence frequencies show that more internal waves are found after full moon and new moon, that is the spring tide. This indicates that the generation of internal waves in the northern SCS may relate to the internal tide. The monthly distribution of internal wave occurrence frequencies reveals that the high frequencies are distributed from May to August and reach a peak in July with a maximum frequency of 21.5%. The low occurrence frequencies are found in winter from November to February with a minimum frequency of 0.5% in January.

Validating and assessing the sensitivity of the climate model with an ocean general circulation model developed at the Institute of Atmospheric Physics, Russian Academy of Sciences

Abstract: A new version of the Institute of Atmospheric Physics, Russian Academy of Sciences (IAP RAS), climate model (CM) has been developed using an ocean general circulation model instead of the statistical-dynamical ocean model applied in the previous version. The spatial resolution of the new ocean model is 3° in latitude and 5° in longitude, with 25 unevenly spaced vertical levels. In the previous version of the oceanic model, as in the atmospheric model, the horizontal resolution was 4.5° in latitude and 6° in longitude, with four vertical levels (the upper quasi-homogeneous layer, seasonal thermocline, abyssal ocean, and bottom friction layer). There is no correction for the heat and momentum fluxes between the atmosphere and ocean in the new version of the IAP RAS CM. Numerical experiments with the IAP RAS CM have been performed under current initial and boundary conditions, as well as with an increasing concentration of atmospheric carbon dioxide. The main simulated atmospheric and oceanic fields agree quite well with observational data. The new version’s equilibrium temperature sensitivity to atmospheric CO2 doubling was found to be 2.9 K. This value lies in the mid-range of estimates (2–4.5 K) obtained from simulations with state-of-the-art models of different complexities.

Quasiperiodic ULF-pulsations in Saturn's magnetosphere

Abstract: . Recent magnetic field investigations made onboard the Cassini spacecraft in the magnetosphere of Saturn show the existence of a variety of ultra low frequency plasma waves. Their frequencies suggest that they are presumably not eigenoscillations of the entire magnetospheric system, but excitations confined to selected regions of the magnetosphere. While the main magnetic field of Saturn shows a distinct large scale modulation of approximately 2 nT with a periodicity close to Saturn's rotation period, these ULF pulsations are less obvious superimposed oscillations with an amplitude generally not larger than 3 nT and show a package-like structure. We have analyzed these wave packages and found that they are correlated to a certain extent with the large scale modulation of the main magnetic field. The spatial localization of the ULF wave activity is represented with respect to local time and Kronographic coordinates. For this purpose we introduce a method to correct the Kronographic longitude with respect to a rotation period different from its IAU definition. The observed wave packages occur in all magnetospheric regions independent of local time, elevation, or radial distance. Independent of the longitude correction applied the wave packages do not occur in an accentuated Kronographic longitude range, which implies that the waves are not excited or confined in the same selected longitude ranges at all times or that their lifetime leads to a variable phase with respect to the longitudes where they have been exited.

Active longitudes of sunspots

Abstract: The inhomogeneity of the sunspot group longitude distribution has been determined depending on the rotation period used to determine a longitude. The statistical significance of the found active longitudes has been estimated. It has been indicated that a rather high reliability is reached only when the synodic rotation period is close to 27 and 28 days. In this case active longitudes show the long-term variation related to the north-south asymmetry of the sunspot formation. It is assumed that active longitudes are related to the relic magnetic field frozen in a uniformly rotating solar radiative zone.