Interrelationships between Length of the Day, Moon Distance, Phanerozoic Geodynamic Cycles, Tidal Dissipation and Earth’s Core: Review and Analysis

The rotation of the Earth and the related length of the day (LOD) are predominantly affected by tidal dissipation through the Moon and the growth of the Earth’s core. Due to the increased concentration of mass around the rotation axis of the spinning Earth during the growth of the core the rotation should have been accelerated. Controversially the tidal dissipation by the Moon, which is mainly dependent on the availability of open shallow seas and the kind of Moon escape from a nearby position, acts towards a deceleration of the rotating Earth. Measurements of LOD for Phanerozoic and Precambrian times open ways to solve questions concerning the geodynamical history of the Earth. These measurements encompass investigations of growth patterns in fossils and depositional patterns in sediments (Cyclostratigraphy, Tidalites, Stromatolites, Rhythmites). These patterns contain information on the LOD and on the changing distance between Earth and Moon and can be used as well for a discussion about the growth of the Earth’s core. By updating an older paper with its simple approach as well as incorporating newly published results provided by the geoscientific community, a moderate to fast growth of the core in a hot early Earth will be favored controversially to the assumption of a delayed development of the core in an originally cold Earth. Core development with acceleration of Earth’s rotation and the contemporaneous slowing down due to tidal dissipation during the filling of the ocean may significantly interrelate.

Detection of different-time-scale signals in the length of day variation based on EEMD analysis technique

Scientists pay great attention to different-time-scale signals in the lengllh of day （LOD） variations △LOD, which provide signatures of the Earth＇s interior structure, couplings among different layers, and potential excitations of ocean and atmosphere. In this study, based on the ensemble empirical mode decomposition （EEMD）, we analyzed the latest time series of △LOD data spanning from January 1962 to March 2015. We observed the signals with periods and amplitudes of about 0.5 month and 0.19 ms, 1.0 month and 0.19 ms, 0.5 yr and 0.22 ms, 1.0 yr and 0.18 ms, 2.28 yr and 0.03 ms, 5.48 yr and 0.05 ms, respectively, in coincidence with the results of predecessors. In addition, some signals that were previously not definitely observed by predecessors were detected in this study, with periods and amplitudes of 9.13 d and 0.12 ms, 13.69 yr and 0.10 ms, respectively. The mechanisms of the LOD fluctuations of these two signals are still open.

Activity budget of Rhinopithecus bieti at Tibet:Effects of day length,temperature and food availability

How animals allocate their time to various activities has significant consequences for their survival because they reflect the different constraints on time-energy balances. Many ecological variables, such as day length, temperature, food availabil- ity, are supposed to effect on activity budgets allocation of temperate primates. To examine the potential influence of these three variables, the activity budgets ofRhinopithecus bieti was studied at Xiaochangdu, Tibet from June 2003 to March 2005. Pearson correlations were utilized to assess potential relationships between activity budget and day length, food availability and temperature, and stepwise multiple regressions to identify the priority of resting and other activities （activities besides feeding, moving and resting）. Time spent resting and doing ＂other activities＂ is positively related to day length, temperature and food availability. No significant correlations were found between feeding/moving time and any of these variables. This suggests that foraging time （feeding ＋ moving） takes priority over rest and other activities. Day length and foraging time （as independent variables） were related to the time spent in the other two activities besides feeding/moving （as dependent variables）. Both time spent resting and in ＂other activities＂ were highly significant positive functions of day length, with the latter a highly significant negative function of feeding time and moving time. Resting time may therefore be interpreted as taking priority over ＂other activities＂ time. These results provide further evidence of the importance of day length, temperature and food availability to seasonal activity budgets [Current Zoology 56 （6）： 650q559, 2010].

Introducing atmospheric angular momentum into prediction of length of day change by generalized regression neural network model

The general regression neural network(GRNN) model was proposed to model and predict the length of day(LOD) change, which has very complicated time-varying characteristics. Meanwhile, considering that the axial atmospheric angular momentum(AAM) function is tightly correlated with the LOD changes, it was introduced into the GRNN prediction model to further improve the accuracy of prediction. Experiments with the observational data of LOD changes show that the prediction accuracy of the GRNN model is 6.1% higher than that of BP network, and after introducing AAM function, the improvement of prediction accuracy further increases to 14.7%. The results show that the GRNN with AAM function is an effective prediction method for LOD changes.

Prediction of length-of-day using extreme learning machine

Traditional artificial neural networks （ANN） such as back-propagation neural networks （BPNN） provide good predictions of length-of-day （LOD）. However, the determination of network topology is difficult and time consuming. Therefore, we propose a new type of neural network, extreme learning machine （ELM）, to improve the efficiency of LOD predictions. Earth orientation parameters （EOP） C04 time-series provides daily values from International Earth Rotation and Reference Systems Service （IERS）, which serves as our database. First, the known predictable effects that can be described by functional models-such as the effects of solid earth, ocean tides, or seasonal atmospheric variations--are removed a priori from the C04 time-series. Only the residuals after the subtraction of a priori model from the observed LOD data （i.e., the irregular and quasi-periodic variations） are employed for training and predictions. The predicted LOD is the sum of a prior extrapolation model and the ELM predictions of the residuals. Different input patterns are discussed and compared to optimize the network solution. The prediction results are analyzed and compared with those obtained by other machine learning-based prediction methods, including BPNN, generalization regression neural networks （GRNN）, and adaptive network-based fuzzy inference systems （ANFIS）. It is shown that while achieving similar prediction accuracy, the developed method uses much less training time than other methods. Furthermore, to conduct a direct comparison with the existing prediction tech- niques, the mean-absolute-error （MAE） from the proposed method is compared with that from the EOP prediction comparison campaign （EOP PCC）. The results indicate that the accuracy of the proposed method is comparable with that of the former techniques. The implementation of the proposed method is simple.

Effect of day length and temperature on the pollen fertility in photo(thermo)-sensitive genic male-sterile rice

The effect of day length and temperature on the pollen fertility of five photoperiod-sensitive genic male-sterile japonica rice lines (PGMSR) and three temperature-sensitive genic malesterile indica rice lines (TGMSR) were investigated in phytotron. The light source used for illumination was xenon lamp, and the light intensity which plant accepted on the leaf surface was 300—350μmol photons ms. The results indicated that pollens of PGMSR 7001S and E47S aborted completely whereas a little part of 31116S pollens appeared normal under long day photoperiod (LD,25℃,15h) (Table 1). High temperature (HT, 30℃, 12h) and lower temperature (LT,

Thermal and photoperiodic requirements of the seedling stage of three tropical forest species

Air temperature and photoperiod play an important role in the seedling development for tropical forest species.Both variables are sensitive to climate,and so evaluating thermal and photoperiodic effects on seedling development is fundamental,especially for climate change studies.Methods to quantify thermal time and the energy required for plants to reach a development stage include air temperature and cardinal temperatures.The photoperiod will also affect physiological reactions of a plant and thus its development.Here we evaluated the six thermal time methods widely used to compute thermal requirement,and identified the influence of the photoperiod from the 2015 and2016 growing seasons and 12 sowing dates in Itajubá,Minas Gerais state,Brazil,on seedling development of three native tropical forest species Psidium guajava L.(Myrtaceae),Citharexylum myrianthum Cham.(Verbenaceae),and Bixa orellana L.(Bixaceae).The method used to quantify thermal time influenced the analytical results of seedling development;the one that considered three cardinal temperatures and compared them with the mean air temperature(Method5)performed better in computing thermal requirements.The influence of photoperiod on seedling development was inconclusive for the three species,but all three developed better in mild temperatures(between 13.3℃and 26.9℃)with a photoperiod shorter than 13 h.

27.3-day and Average 13.6-day Periodic Oscillations in the Earth’s Rotation Rate and Atmospheric Pressure Fields Due to Celestial Gravitation Forcing

Variation in length of day of the Earth （LOD, equivalent to the Earth＇s rotation rate） versus change in atmospheric geopotential height fields and astronomical parameters were analyzed for the years 1962-2006. This revealed that there is a 27.3-day and an average 13.6-day periodic oscillation in LOD and atmospheric pressure fields following lunar revolution around the Earth. Accompanying the alternating change in celestial gravitation forcing on the Earth and its atmosphere, the Earth＇s LOD changes from minimum to maximum, then to minimum, and the atmospheric geopotential height fields in the tropics oscillate from low to high, then to low. The 27.3-day and average 13.6-day periodic atmospheric oscillation in the tropics is proposed to be a type of strong atmospheric tide, excited by celestial gravitation forcing. A formula for a Tidal Index was derived to estimate the strength of the celestial gravitation forcing, and a high degree of correlation was found between the Tidal Index determined by astronomical parameters, LOD, and atmospheric geopotential height. The reason for the atmospheric tide is periodic departure of the lunar orbit from the celestial equator during lunar revolution around the Earth. The alternating asymmetric change in celestial gravitation forcing on the Earth and its atmosphere produces a ＂modulation＂ to the change in the Earth＇s LOD and atmospheric pressure fields.

Phenological study of Sargassum thunbergii (Fucales, Phaeophyta) in Lidao Bay, Rongcheng, China

We conducted a phenological evaluation of Sargassum thunbergii, a common algal species, along the coast of Lidao Bay, Rongcheng, China. The local S. thunbergii population entered a maturation period from early June to mid-August, when seawater temperature was 14.4 to 25. 1℃. Our results suggest an increase in temperatttre and day length during this period initiated thalli maturation. Inhabitants of the low tidal zone had higher thalli length and biomass compared with those from the mid- and high tidal zones. We observed a switch in the length frequency distribution and contribution of length classes to biomass between the small （〈20 cm） and long （20-79.9 cm） length classes at the time of thallus maturity. This suggests there is a trade-off between sexual reproduction and vegetative regeneration.

Multichannel singular spectrum analysis of the axial atmospheric angular momentum

Earth＇s variable rotation is mainly produced by the variability of the AAM（atmospheric angular momentum）. In particular, the axial AAM component X_3, which undergoes especially strong variations,induces changes in the Earth＇s rotation rate. In this study we analysed maps of regional input into the effective axial AAM from 1948 through 2011 from NCEP/NCAR reanalysis. Global zonal circulation patterns related to the LOD（length of day） were described. We applied MSSA（Multichannel Singular Spectrum Analysis） jointly to the mass and motion components of AAM, which allowed us to extract annual, semiannual, 4-mo nth, quasi-biennial, 5-year, and low-frequency oscillations. PCs（Principal components） strongly related to ENSO（El Nino southern oscillation） were released. They can be used to study ENSO-induced changes in pressure and wind fields and their coupling to LOD. The PCs describing the trends have captured slow atmospheric circulation changes possibly related to climate variability.

Change monitoring of earth rotation parameter with Maglev gyroscope precessional torque

Through analyzing the relationship between gyro dynamic torques produced by the changes of earth rotation parameters (ERP), a method of measuring the earth rotation parameters was proposed and explored by using gyroscope. The preliminary experiments were carried out using GAT Maglev Gyro Station (which is self-developed by China). Considering the measurement and expanding-application of the earth rotation parameters, some ideas and opinions about the structure design, measurement methods and data processing of gyro were proposed, and some outlook of the expanding-application of the gyroscope in geodetic and geophysical fields were done. The experimental results show that using the high-precision gyroscope to determine the changes of ERP is feasible, with the emergence of ultra-high precision gyro; it is possible for determining the earth rotation parameters by gyro in stead of by current complex space surveying technology.

The Effects of Environmental Stressors on Aggregation in <i>Parachlorella kessleri</i>

The induction of biofilm formation has been explored as a means of harvesting microalgae for bioprocessing applications. Environmental stressors have been implicated in the induction of biofilm formation;however, it is unclear whether all stressors, or a select few, are responsible. This study aimed to investigate the effects of three stressors, nitrogen depletion, reduced or elongated day lengths, and increased culture turbulence on bio-film formation of Parachlorella kessleri. We also examined corresponding effects on growth and production of reactive oxygen species. Turbulence induced the greatest response in which a significant decrease in growth plus an increase in superoxide production and flocculation efficiency were seen for the 300-rpm treatment. For varying day lengths, stress response was not observed, however, a significant increase in EPS secretion was measured in both shorter and longer days. Nitrogen depletion induced a low-level stress response, in which superoxide production increased for the highest concentrations, while growth was not impacted. In contrast to previous studies on nitrogen depletion, a significant increase in EPS secretion was not observed. Results indicate that stress response varies according to type and magnitude. EPS production and thus biofilm formation are not linked to the stress indicators investigated. P. kessleri uses small quantities of EPS to contribute to cell stickiness, but not necessarily to the full formation of a biofilm;however, cell stickiness served as a mechanism for substrate adherence and cellular aggregation none the less.

Effects of Sowing Time on the Seed Yield of Quinoa (Chenopodium quinoa Willd) in South Kanto, Japan

The objective of the present study was to determine the optimum sowing time of three quinoa ecotypes (Altipllano, sea level, and valley) for high seed yields in south Kanto, Japan. Pot experiments were conducted in the experimental field at Nihon University during 2011, 2012, 2013, and 2014. In this experiment, the following quinoa varieties were used NL-6, Baer Cajon and Cauquenes (sea-level type), Amarilla de Marangani, Blanca de Junin, CICA-127, ECU-420, ECU-525, Ingapirica, and Narino (valley type), 94R and Isluga (Altiplano type). The quinoa seeds were sown on March 29, June 17 and September 22, 2011;March 27, June 17 and August 28, 2012;March 26, June 15 and 5 September 5, 2013;and March 27, June 17 and August 28, 2014. When the sea-level type and Altiplano type seeds were sowed from March to September, the seeds could be gained in all sowing plots. However, the seed weights of all varieties were the highest in the sowing plots of March. And the seed weights in the sowing plot of March were significantly higher than that in the other sowing plots. The sea-level type and Altiplano type quinoa had almost the same seed growth reaction for day length and day temperature. Thus, to gain a high seed yield of the sea-level and Altiplano type quinoa, March was the optimum sowing time in south Kanto, Japan. When the valley-type seeds were sowed from March to June, the seeds could not be gained, except in 2012. In 2012, the seed weights and seed numbers in sowing plots of March and June were significantly lower than those in the sowing plot of September. Thus, to obtain a high seed yield of the valley type quinoa, the optimum sowing time in south Kanto, Japan was from August to September.

Growing Season and Phenological Stages of Small Grain Crops in Response to Climate Change in Alaska

The climate change in Alaska has caused earlier spring snowmelt and the growing season expanded. However, the effect of climate change on crop phenological stages, heading (BBCH 55) and maturity (BBCH 85), is unknown. In this study, the trends of growing-season length (GSL), phenological stages of crops and climatic parameters, and the correlations between climatic parameters and the phenological stages were analyzed using the climate data and crop data over the period of 1978 to 2016. The longer GSL was found in Fairbanks (64.83˚N, 147.77˚W) and in Delta Junction (64.05˚N, 145.60˚W) but not in Palmer (61.60˚N, 149.11˚W). Sowing dates did not change significantly in three locations. The decreasing trends of heading and maturity of crops were observed but varied with location. Heading of barley and oat significantly advanced 3 and 3.1 d decade-1, respectively from 1989 to 2016 in Fairbanks while no change of heading was observed in Delta Junction and Palmer. Maturity of barley, oat and wheat significantly advanced 2.6, 3.8 and 3.9 d decade-1, respectively from 1978 to 2016 in Fairbanks (P < 0.05);maturity of oat and wheat significantly advanced 4.4 and 3.4 d decade-1 from 1978 to 2015, respectively in Delta Junction (P < 0.05). The increasing temperature trends and decreasing precipitation trends were found in Fairbanks and Delta Junction but varied with phenological stages of crops. Sowing was more important for heading than for maturity of crops. The effect of climate change on heading was less important than that on maturity. Earlier maturity of crops in Fairbanks may be attributed to increased temperatures, that in Delta Junction to both increased minimum temperature and decreased precipitation and that in Palmer to temperature and precipitation.

利用1984~2022年日长实测值对其变化的时序分析和拟合研究

利用IERS(International Earth Rotation and Reference Systems Service)发布的EOP 14 C04产品中1984~2022年LOD实测值进行频谱分析及周期项提取,并采用最小二乘外推模型联合多项式曲线拟合模型方法将提取到的周期项应用于对LOD序列的拟合。实验结果表明,相比于单一的LS外推模型拟合,新方法拟合序列的RMSE从0.0003 s下降至0.0001 s,且新方法将确定系数从0.80提高到0.97左右。该研究结果可为LOD序列的预报研究提供参考。

The Coincidence of Critical Day Length Recognition for Florigen Gene Expression and Floral Transition under Long-Day Conditions in Rice

The photoperiodic control of flowering time is essential for the adaptation of plants to variable environments and for successful reproduction. The identification of genes encoding florigens, which had been elusive but were supposedly synthesized in leaves and then transmitted to shoot apices to induce floral transitions, has greatly advanced our understanding of the photoperiodic regulation of flowering. Studies on the photoperiodism of Arabidopsis, a model long-day plant, revealed the molecular mechanisms regulating the expression of the Arabidopsis florigen gene FT, which is gradually induced in response to increase in day length. By contrast, in rice, a model short-day plant, the expression of the florigen gene Hd3a （an FTortholog in rice） is regulated in an on/off fashion, with strong induction under short-day conditions and repression under long-day conditions. This critical day length dependence of Hd3a expression enables rice to recognize a slight change in the photoperiod as a trigger to initiate floral induction. Rice possesses a second florigen gene, RFT1, which can be expressed to induce floral transition under non-inductive long-day conditions. The complex transcriptional regulation of florigen genes and the resulting precise control over flowering time provides rice with the adaptability required for a crop species of increasing global importance.

Spatial and Temporal Variations of Atmospheric Angular Momentum and Its Relation to the Earth Length of Day

The characteristics of atmospheric-angular-momentum （AAM） and length-of-day （LOD） on different timescales are investigated in this paper, on the basis of the NECP/NCAR reanalysis data and an LOD dataset for 1962-2010. The variation and overall trend of the AAM anomaly （AAMA） at different latitudes are presented, and the relationship between AAMA and LOD is discussed. The AAMAs in different latitude regions exhibit different patterns of variation, and the AAMA in the tropics makes a dominant contribution to the global AAMA. In the tropics, the AAMA propagates poleward to the extratropical regions. It is confirmed that a downward propagation of the AAMA occurs in the lower stratosphere. Correlation analysis shows that the relationship between AAMA and LOD varies significantly on different timescales. Specifically, the tropical AAMA is positively correlated with LOD on short timescales, but they are not obviously correlated on long timescales. This indicates that the interaction between AAM and the earth＇s angular momentum follows the conservative restriction on short timescales, but the influence of the earth angular momentum on that of the atmosphere depends on the interaction process on long timescales.

PREDICTION OF EL NINO EVENTS BY THE ASTRONOMICAL OBSERVATION OF THE LENGTH OF DAY

Ⅰ. INTRODUCTIONSince the strong El Nio event occurred at the end of 1982, which was characterized by the anomalous warming up of the sea surface water in equatorial area of eastern Pacific, the relationship between the variation of the rate of Earth rotation and the El Nio event has attracted more and more attention and some significant studies have been made. How-

Interannual variations in the length of day and ENSO events in 1982-1983 and 1997-1998

The length of day series during the period of 1962.0-2000.0, the atmospheric angular momentum and the Southern Oscillation Index are adopted to analyze the relationships among the EN-SO events that have occurred since 1960, the changes in the length of day and the atmospheric angular momentum. Attention is particularly given to the different effects of the 1982-1983 and 1997-1998 ENSO events on the variations of Earth rotation. The synthetic excitation effects of multi-scale atmospheric oscillations on the anomalous variations of the interannual rates of Earth rotation are revealed by means of the time-frequency spectrum of the wavelet transform.

Interannual variations in length of day and atmospheric angular momentum, and their seasonal associations with El Ni^o/Southern Oscillation-like sea surface temperature patterns

This study examines the seasonal connections between the interannual variations in LOD （length of day）/ AAMglobe （the relative atmospheric angular momentum for the whole globe） and the ENSO-like SST （El Nifio/ Southern Oscillation-like sea surface temperature） pattern and corresponding zonal and vertical circulations. Consistent with previous studies, the ENSO-like SST impact the following season LOD/AAMglobe, with the strongest correlations in DJF （December, January, and February）, when it is likely to be the peak E1 Nino/La Nifia period. Lag correlations between the interannual variations in LOD/AAMglobe and surface temperature, and the interannual variations in LOD and both zonal circulation and vertical airflow around the equator, consistently indicate that the LOD/AAMglobe reflect the potential impacts of variations in the Earth＇s rotation rate on the following season＇s sea surface temperatures （SST） over the tropical central and eastern pattern is located）. Pacific （where the ENSO-like SST Moreover, the centers of strongest variation in the AAMcolumn （the relative atmospheric angular momentum for an air column and the unit mass over a square meter） are located over the mid-latitudinal North Pacific in DJF and MAM （March, April, and May）, and over the mid-latitudinal South Pacific in JJA （June, July, and August） and SON （September, October, and November）. This suggests that the AAMcolumn over the mid-latitudinal Pacific around 30°N （30~S） dominate the modulation of Earth＇s rotation rate, and then impact the variations in LOD during DJF and MAM （JJA and SON）.