Lunar Declination Research Articles

Vertical Distribution of Rocky Intertidal Organisms Shifts With Sea-Level Variability on the Northeast Pacific Coast.

Disentangling the effects of cyclical variability in environmental forcing and long-term climate change on natural communities is a major challenge for ecologists, managers, and policy makers across ecosystems. Here we examined whether the vertical distribution of rocky intertidal taxa has shifted with sea-level variability occurring at multiple temporal scales and/or long-term anthropogenic sea-level rise (SLR). Because of the distinct zonation characteristic of intertidal communities, any shift in tidal dynamics or average sea level is expected to have large impacts on community structure and function. We found that across the Northeast Pacific Coast (NPC), sea level exhibits cyclical seasonal variability, tidal amplitude exhibits ecologically significant variability coherent with the 18.6-year periodicity of lunar declination, and long-term sea-level rise is occurring. Intertidal taxa largely do not exhibit significant vertical distribution shifts coherent with short-term (monthly to annual) sea-level variability but do exhibit taxa-specific vertical distribution shifts coherent with cyclical changes in lunar declination and long-term SLR at decadal timescales. Finally, our results show that responses to cyclical celestial mechanics and SLR vary among taxa, primarily according to their vertical distribution. Long-term SLR is occurring on ecologically relevant scales, but the confounding effects of cyclical celestial mechanics make interpreting shifts in zonation or community structure challenging. Such cyclical dynamics alternatingly amplify and dampen long-term SLR impacts and may modify the impacts of other global change related stressors, such as extreme heat waves and swell events, on intertidal organisms living at the edge of their physiological tolerances. As a result, intertidal communities will likely experience cyclical periods of environmental stress and concomitant nonlinear shifts in structure and function as long-term climate change continues. Our results demonstrate that consistent, large-scale monitoring of marine ecosystems is critical for understanding natural variability in communities and documenting long-term change.

Mixed‐diurnal tidal record from a Palaeoproterozoic embayment in the Par Formation, Gwalior Group, Central India

The Palaeoproterozoic Par Formation, Gwalior Group, central India contains a mixed, predominantly diurnal, tidal record in an embayment‐like estuarine setting where flood energy exceeded the ebb energy. From two order differences in set thickness between flood‐ and ebb‐generated bedforms an asymmetry in peak tidal current velocity of flood and ebb is inferred with domination of flood current. From the presence of crossover in successive neap records and 27.75 neap‐spring cycles per year, an unambiguous clue for tidal forcing by lunar declination rather than lunar phase is inferred. Harmonic analysis of foreset‐lamina thickness from tidal sand waves suggests that a tropical month of minimum 26 lunar days was in effect at the Gwalior Sea during the late Palaeoproterozoic (2,000–1,791 Ma).

VARIABILITY AND INTERRELATION OF THE BASIC CLIMATE INDICES FOR THE NORTH PACIFIC: TRENDS, CLIMATE SHIFTS, SPECTRA, CORRELATIONS

The study is continuing, which first results were published in 2019 [Khen et al., 2019]. The main patterns of long-term variability are considered for selected climate indices in the North Pacific and links between them are identified on the common methodological basis. The following indices are analyzed: AO (Arctic Oscillation), PDO (Pacific Decadal Oscillation), Nino 3.4 (index of El-Nino — South Oscillation), ALPI (Aleutian Low Pressure index), NPI (North Pacific index), PNA (Pacific/North American index), SHI (Siberian High index), and WP (West Pacific index). Their time-series are provided on websites of the world climate centers, with exception of the Siberian High index that was calculated from the reanalysis data on the sea level pressure provided by the USA National Center for Environmental Prediction (NCEP) — National Center for Atmospheric Research (NCAR) for 1950–2018. Data were analysed using standard statistical methods. Regime shifts are detected using Rodionov’s method of sequential regime shift detection including the regime shift index (RSI) and tools of automatic detection of the regime shifts with improved performance at the ends of time series. Variations of all indices since the middle 20th century correspond to warming that is not monotonous but combines phases of quick transition from one climatic regime to another — climate shifts and periods of relatively stable state between them. The most important climate shifts happened in 1977 and 1989 and they were noted for majority of the considered indices. Values of the indices heightened in the former shift and slightly lowered in the latter one, except of NPI that had opposite changes. PDO, WP and NPI had another positive shift in the recent years (2015–2017) that allows to assume transition to a new climate regime which will be warmer than the previous one in the last two decades. Long-term periodicity coincided with the 19-year cycle of lunar declination is revealed for PDO, ALPI, NPI and PNA; its spectral power amplifies considerably after removing of high-frequency variability by running 5-year averaging of the time series. Nino 3.4 showed a prominent 11-year cycle, possibly associated with the solar activity. SHI, AO and WP changed with periods about two decades: the main frequency is 26 years for SHI, 20 years for AO, and 17 years for WP, but the peaks of spectral power for the two latter indices is low, i.e. non-periodic oscillations dominate for them. Secondary peaks of spectral power are much lower than the main ones, they correspond to cycles of 7–8 years for AO and PDO, 11 years for WP, and 15 years for SHI. The indices of the North Pacific quartette (PDO, ALPI, NPI and PNA) are closely related between each other with high correlation coefficients (0.67–0.96). The Nino 3.4 index is also linked with them, but with lower correlation (0.45–0.56). SHI has statistically significant relationship with AO only, and WP correlates with Nino 3.4. Contribution of the large-scale climate processes to environmental variability in the Far-Eastern Seas of Russia and the Northwestern Pacific will be considered in the next issue.

The Semiannual and 4.4‐Year Modulations of Extreme High Tides

AbstractIn most places extreme high tides undergo a clear seasonal variation. It is well known that semidiurnal tides tend to peak during equinox seasons, and diurnals during solstice seasons. This is a consequence of the solar and lunar declinations, which when large maximize diurnal tides at the expense of semidiurnals. The semiannual range modulation of tidal extremes for a pure semidiurnal tide is determined mainly by the amplitude of the K2 constituent; a pure diurnal is determined mainly by P1. Mixed tidal regimes tend to experience maxima very roughly around the times of solstice, but not always, with the semiannual modulation generally a complicated function of constituent amplitudes and phases. These modulations are here mapped worldwide by analyzing tidal extremes predicted with a global tide model. The known 4.4‐year modulation in extreme tides is a consequence of declinational and perigean effects coming in and out of phase. The phase of the 4.4‐year modulation is controlled by the phase of the semiannual modulation, irrespective of whether the tide is diurnal, semidiurnal, or mixed.

Improving the Definition and Algorithms of China’s Coastline Considering the Diversity of Tidal Characteristics

Two commonly used definitions of coastline are compared and analyzed in this article. To build a more perfect digital tide-coordinated coastline model in China, we should first solve the problems of the existing definition and unclear algorithms of China’s coastline. On the basis of defining the coastline in China as the intersection of coastal land and the mean high water spring (MHWS), it should be further revised, and defined either as an intersection of coastal land and the MHWS or as a mean higher high water level (MHHWL) considering the diversity of tidal characteristics in China Sea areas. Since MHWS is related to the extreme of the lunar phase and MHHWL is related to the extreme of the angle of the lunar declination elevation, the algorithms to obtain them are more complicated than that of mean high water (MHW) used in the United States. We should consider the specific law of tidal movement in different tide types of the predominantly semidiurnal or diurnal sea areas in China when studying the precise algorithms for MHWS and MHHWL. Several experiments show that the difference between the two types of calculations of coastal height, such as water level observations and tidal predictions, is within centimeter level. The research results of this article have a certain reference value for countries with similar coastline features as in China.

Insight-building models for lunar range and range rate

The analysis of range or Doppler data between sites on the Earth and Moon requires an accurate computation of the lunar orbit and detailed models of the orientation of the Earth and Moon. Models constructed to understand range and range rate can lack detail, but if they include the largest lunar orbit variations, tracking stations on a rotating Earth, and lunar sites on a synchronously rotating Moon, then they will display the largest effects for orbit elements, Earth orientation, tracking station locations, and lunar site coordinates. The range and range rate are expanded into periodic series. To understand accurate solutions, the largest periodic terms that are sensitive to various solution parameters indicate the sensitivity of data to solution parameters and the time spans needed for their determination. Conclusions include: cylindrical coordinates work well for sites on the rapidly rotating Earth, but Cartesian coordinates are more natural for the synchronously rotating Moon since the series for the three coordinate projections are distinct. For range and range rate data, daily, semimonthly, monthly, and longer periods are present. For Doppler data, the daily periods may be stronger and more useful than the long periods, particularly for terms associated with the terrestrial tracking station. Doppler data do not determine the lander coordinate toward the Earth well. Observational strategies for range and Doppler data are not identical. For all data types, one wishes a variety of hour angles, lunar declinations, times of month, and longer periods. A long span of high-quality range data can improve the lunar orbit, orientation of the Earth’s equator, and physical librations. The locations of new lunar sites or new tracking stations can be determined from shorter spans of data.

THE ARCHITECTONIC ENCODING OF THE MINOR LUNAR STANDSTILLS IN THE HORIZON OF THE GIZA PYRAMIDS

The paper is an attempt to show the architectonic method of the ancient Egyptian designers for encoding the horizontal-projections of the moon’s declinations during two events of the minor lunar standstills, in the design of the site-plan of the horizon of the Giza pyramids, using the methods of descriptive geometry. It shows that the distance of the eastern side of the second Giza pyramid from the north-south axis of the great pyramid encodes a projection of a lunar declination, when earth’s obliquity-angle was ~24.10°. Besides, it shows that the angle of inclination of the causeway of the second Giza pyramid, of ~13.54° south of the cardinal east, encodes the projection of another lunar declination when earth’s obliquity-angle reaches ~22.986°. In addition, it shows the encoded coordinate system in the site-plan of the horizon of the Giza pyramids.

Sunspot numbers: Implications on Eastern African rainfall

Following NASA’s prediction of sunspot numbers for the current sunspot cycle, Cycle 24, we now include
 sunspot numbers as an explanatory variable in a statistical model. This model is based on fitting monthly
 rainfall values with factors and covariates obtained from solar–lunar geometry values and sunspot numbers.
 The model demonstrates high predictive skill in estimating monthly values by achieving a correlation
 coefficient of 0.9 between model estimates and the measurements. Estimates for monthly total rainfall for the
 period from 1901 to 2020 for Kenya indicate that the model can be used not only to estimate historical values
 of rainfall, but also to predict monthly total rainfall. We have found that the 11-year solar sunspot cycle has
 an influence on the frequency and timing of extreme hydrology events in Kenya, with these events occurring
 every 5±2 years after the turning points of sunspot cycles. While solar declination is the major driver of
 monthly variability, sunspots and the lunar declinations play a role in the annual variability and may have
 influenced the occurrence of the Sahelian drought of the mid-1980s that affected the Sahel region including
 the Greater Horn of Africa. Judging from the reflection symmetry, the trend of the current maximum and the
 turning point of the sunspot minimum at the end of the Modern Maximum, with a 95% level of confidence,
 drought conditions similar to those of the early 1920s may reoccur in the year 2020±2.

Lunar influence on human visual acuity: effects during the lunar quarters

We have previously shown that, in an eye affected by macular edema, visual acuity is better at the time of the full moon, with respect to the new moon, whereas there is no difference in the normal eye. In the present paper we report that in both the normal and the edematous eyes visual acuity is affected by the Moon at the lunar quarters. There are both increases and decreases of acuity but they occur rarely, only once or twice in a year. It is necessary for a lunar zero declination to coincide with a quarter for there to be a response. There is correlation between these events and changes in the atmospheric pressure. An increase in atmospheric pressure is associated with a decrease in visual acuity, whereas a decrease in atmospheric pressure correlates with an increase in acuity. These results may be of relevance to many marine animals.

Lunar perturbations in variations of earth angular velocity and atmospheric pressure

The analysis of the contribution of lunar declination variations to the total variance of air pressure anomalies at meteorological stations of the global network is carried out on the basis of the data of daily observations. It is demonstrated that the changes in the declination of the Moon while moving around the Earth is accompanied by nonrandom variations of atmospheric pressure. Their manifestation depends significantly on the season and geographic latitude. The contribution of the lunar effect to the total variance of pressure anomalies is spatially inhomogeneous and amounts to 40% and more in the basic centers. The maximum effect is reached in the late spring or early summer in the corresponding hemisphere: in May and June in the Northern Hemisphere and in October and November in the Southern Hemisphere.

Effect of orientation of lunar apse on earthquakes

There were 6563 earthquakes of magnitude 1.0 - 2.9 in 1993 and 10233 in 2003. The lunar apse was at about 90° to the axis of rotation of the earth. The number of earthquakes of magnitude 3.0 to 4.9 between 2000 and 2005 increased when the minimum perigee moved from North Pole to South Pole. The decrease in earthquakes of magnitude 1.0- 2.9 after 2003 in Mediterranean region was accompanied by an increase of earthquakes of magnitude 3.0 - 4.9 in Pacific sea region. The minimum perigee nearer to South Pole of Earth decreased the number of earthquakes of magnitude 5.0 to 5.9 from 1542 in 1994 to 979 in 1998. The minimum perigee nearer to North Pole of Earth increased the number of earthquakes of magnitude 5.0 to 5.9 from 979 in 1998 to 1203 in 2003. The apse parallel to the axis of rotation of earth in 1990, 1995, 1999, 2004 and 2008 increased the number of large earthquakes in these years. From 2004 - 2008 (April-September), 33 out of 34 large earthquakes were close to 28, 0, -28 and -0° lunar declinations. During the same year (October - March), 29 out of 39 large earthquakes were close to above lunar declinations. Key words: Plate tectonics, mantle convection, Sun-Earth-Moon interaction, perigee-apogee, lunar phases, lunar declination, earthquake triggering.

Monthly lunar declination extremes' influence on tropospheric circulation patterns

[1] Short-term tidal variations occurring every 27.3 days from southern (negative) to northern (positive) maximum lunar declinations (MLDs), and back to southern declination of the moon have been overlooked in weather studies. These short-term MLD variations' significance is that when lunar declination is greatest, tidal forces operating on the high latitudes of both hemispheres are maximized. We find that such tidal forces deform the high latitude Rossby longwaves. Using the NCEP/NCAR reanalysis data set, we identify that the 27.3 day MLD cycle's influence on circulation is greatest in the upper troposphere of both hemispheres' high latitudes. The effect is distinctly regional with high impact over central North America and the British Isles. Through this lunar variation, midlatitude weather forecasting for two-week forecast periods may be significantly improved.

Lunar semimonthly signal in cloudiness: Lunar-phase or lunar-declination effect?

The cloud amount summer nighttime data obtained from the 1994 to 2007 NASA satellite infrared and visible range measurements taken within the framework of the International Satellite Cloud Climatology Project (ISCCP) were analyzed, and the contribution by lunar signal to the cloud amount was extracted. Although the fact of lunar influence on cloudiness is known, this investigation has made it possible to separate the lunar-phase and lunar-declination effects on cloudiness. The relative cloud amount tends to grow with a change in lunar phase from a quadrature to the New Moon or Full Moon and with an increase in lunar declination by absolute value. Both the effects are statistically significant, the lunar-declination effect is a little stronger. The obtained results do not seem to contradict the theory of lunar tides.

Period is Going to be Faster When the Earth-Moon Distance Increased According to IERS Actual Data

If a small body of mass (m) orbits a large body of mass (M) then, the sidereal rotation period of the large body (M) may be calculated by the rotational equation.The earth rotation period is going to be faster when the earth-moon distance increased according to IERS actual data. Earthquakes of the upper range are distinctly related to rotational parameters of the Earth lunar declination.The earthquakes increased when the lunar declination is moving toward the earth equator (when the earth rotation are going to be faster).A perfect correlation between lunar declination and the changes of leap seconds.(UT1-UTC)-(UT1- UTC).A very good correlation between earthquakes and the changes of leap seconds.(UT1-UTC)-(UT1-UTC).The Earth rotation acceleration of 29 degree declination is more that of 18.6 declination, this lead to more earthquakes in 29 degree lunar declination.

27.3-day and 13.6-day atmospheric tide

An analysis of time variations in the earth’s length of day (LOD) for 25 years (1973–1998) versus atmospheric circulation changes and lunar phase is presented. It is found that, on the average, there is a 27.3-day and 13.6-day period oscillation in global zonal wind speed, atmospheric geopotential height, and LOD following alternating changes in lunar phase. Every 5–9 days (6.8 days on average), the fields of global atmospheric zonal wind and geopotential height and LOD undergo a sudden change in relation to a change in lunar declination. The observed atmospheric oscillation with this time period may be viewed as a type of atmospheric tide.

27.3-day and 13.6-day atmospheric tide and lunar forcing on atmospheric circulation

An analysis of time variations of the earth’s length of day (LOD) versus atmospheric geopotential height fields and lunar phase is presented. A strong correlation is found between LOD and geopotential height from which a close relationship is inferred and found between atmospheric circulation and the lunar cycle around the earth. It is found that there is a 27.3-day and 13.6-day east-west oscillation in the atmospheric circulation following the lunar phase change. The lunar revolution around the earth strongly influences the atmospheric circulation. During each lunar cycle around the earth there is, on average, an alternating change of 6.8-day-decrease, 6.8-day-increase, 6.8-day-decrease and 6.8-day-increase in atmospheric zonal wind, atmospheric angular momentum and LOD. The dominant factor producing such an oscillation in atmospheric circulation is the periodic change of lunar declination during the lunar revolution around the earth. The 27.3-day and 13.6-day atmospheric oscillatory phenomenon is akin to a strong atmospheric tide, which is different from the weak atmospheric tides, diurnal and semidiurnal, previously documented in the literature. Also it is different from the tides in the ocean in accordance with their frequency and date of occurrence. Estimation shows that the 27.3-day lunar forcing produces a 1–2 m s−1 change in atmospheric zonal wind. Therefore, it should be considered in models of atmospheric circulation and short and middle term weather forecasting. The physical mechanism and dynamic processes in lunar forcing on atmospheric circulation are discussed.

Modulation of shallow water tides in an inlet‐basin system with a mixed tidal regime

During the autumn of 1999 a 56‐day‐long observational study of sea surface elevation and currents was made in Yavaros Bay, a shallow inlet‐basin system with a mixed tidal regime in the Gulf of California. During the late spring of 1998 a similar experiment was performed at the same coastal lagoon as well, although it was shorter. The measurements are used to investigate the modulation of the shallow water tides. The complex demodulation approach revealed that not only the Moon's path cycle modified the generation of shallow water tides but also the lunar declination and the solar declination. The sixth‐diurnal tides showed a spring‐neap modulation. The fifth‐diurnal tides were above the noise level only close to the summer solstice. The fourth‐diurnal tides were modulated by the spring‐neap cycle at the basin, but this modulation was changed by friction at the inlet. At this site the fourth‐diurnal band of the tidal current had a maximum in amplitude during neap tides. The third‐diurnal tides were irregularly modulated. The advection and the nonlinear continuity terms were correlated with the third‐ and fourth‐diurnal bands of the tidal current at the inlet. The quadratic friction terms were correlated with the sixth‐, fourth‐, and third‐diurnal bands of the tidal current. The semidiurnal tides mainly provided the energy of the tidal residual current during the autumnal equinox of 1999. Near the summer solstice of 1998 the semidiurnal band induced a residual current seaward oriented, while the diurnal band induced a residual current landward oriented.

The Tonkin tides revisited

A description of the once-daily tides of the Gulf of Tonkin in 1678 came at an awkward time for natural philosophers, before Newton's Principia had been published. Halley (in 1684) noticed the strong dependence on lunar declination (not phase), but was over-hasty in trying to reduce the varying amplitudes to a simple rule. Newton proposed a mechanism for the absence of the half-daily tide, but admitted that further observations were required to confirm it. Another explanation was made by Euler in 1740. The exact site of the original observations is obscure but is here identified through Dampier's Voyages . The subsequent history of prediction practice is briefly summarized, and attention is drawn to a recent computer model of the South China Sea that belatedly solves all the outstanding problems.

Settlement Patterns of Brachyuran Megalopae in a Louisiana Estuary

Artificial substrate collectors were used to sample settled brachyuran megalopae in Terrebonne Bay, Louisiana, northern Gulf of Mexico. Three taxa,Callinectes sapidus, Uca spp., andRhithropanopeus harrisii, were the most common settlers. Settlement occurred almost year-round, although settlement densities were highest in late summer and early fall. In 1990, all three taxa had several simultaneous settlement peaks; in 1991, one simultaneous settlement peak occurred. FewerC. sapidus andUca spp. settled in 1991 than in 1990, but settlement abundance ofR. harrissii was similar between years. Local weather events, such as heavy precipitation, may have influenced the lower abundances ofC. sapidus andUca spp. in 1991. The megalopae ofC. sapidus andUca spp., which re-invade the estuary from higher salinity offshore waters where larval development occurs, may have been more affected by the lower 1991 estuarine salinity values than the larvae ofR. harrissii, which are retained within the estuary throughout larval development. Settlement ofC. sapidus andUca spp. was correlated with maximum tidal height, tidal amplitude, salinity, temperature, and lunar phase. In 1990, settlement ofC. sapidus was correlated with lunar declination cycles; settlement peaks occurred during equatorial minimum amplitude tides. The settlement ofR. harrisii was associated with tidal amplitude and lunar phase. Associations between environmental variables and settlement of megalopae were not consistent between the two years sampled. The opposing or reinforcing effects of various environmental variables on settlement, e.g., tidal height and rainfall, are superimposed on long-term hydrologic cycles so that dramatically altered cycles of settlement occur among years.

The Moon and El Niño

Regional climates around the world display cycles corresponding to the 18.61‐year maximum lunar declination (MLD) periodicity. We suggest that these cycles are created by a relationship between MLD and El Niño / Southern Oscillation (ENSO). Both equatorial Pacific sea‐surface temperature and South Pacific atmospheric pressure significantly correlate with maximum lunar declination. Low MLDs are associated with warmer equatorial Pacific sea‐surface temperatures and negative values of the Southern Oscillation Index. A lunar‐influenced change in the Pacific gyre circulation presents a viable physical mechanism for explaining these relationships. We suggest that the gyre is enhanced by tidal forces under high MLDs, inducing cold‐water advection into the equatorial region but is restricted by the weak tidal forcing of low MLDs thereby favoring El Niño episodes. An astronomical model utilizing this relationship produces a forecast of increased non‐El Niño (either La Niña or neutral) activity for the early part of this decade.