Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
8,647
result(s) for
"Earth rotation"
Sort by:
Why we have day and night
Using an orange and a flashlight, a father explains to his children why the sun goes down.
Book
Improved 90-day Earth orientation predictions from angular momentum forecasts of atmosphere, ocean, and terrestrial hydrosphere
Short-term forecasts of atmospheric, oceanic, and hydrological effective angular momentum functions (EAM) of Earth rotation excitation are combined with least-squares extrapolation and autoregressive modeling to routinely predict polar motion (PM) and ΔUT1 for up to 90 days into the future. Based on hindcast experiments covering the years 2016 and 2017, a best performing parametrization was elaborated. At forecast horizons of 10 days, remaining prediction errors are 3.02 and 5.39 mas for PM and ΔUT1, respectively, corresponding to improvements of 34.5 and 44.7% when compared to predictions reported routinely in Bulletin A of the International Earth Rotation and Reference Systems Service. At forecast horizons of 60 days, prediction errors are 12.52 and 107.96 mas for PM and ΔUT1, corresponding to improvements of 34.5 and 8.2% over Bulletin A. The 90-day-long EAM forecasts leading to those improved EOP predictions are routinely published on a daily basis at isdc.gfz-potsdam.de/esmdata/eam.
Journal Article
Curious Pearl identifies the reason for seasons
\"What does Curious Pearl do with that notebook of hers? She tracks sunset times each day. When Pearl shows her friend how the sunset time changes each day, he asks why. As a lover of science, Pearl knows this is her chance to teach her friend all about the reason for seasons. With augmented reality access to videos through the Capstone 4D app, readers will have an enhanced learning experience\"--Amazon.com.
Book
Earth’s Rotation: Observations and Relation to Deep Interior
Observation of the variations in the Earth’s rotation at time scales ranging from subdiurnal to multidecadal allows us to learn about its deep interior structure. We review all three types of motion of the Earth’s rotation axis: polar motion (PM), length of day variations (ΔLOD) and nutations, with particular attention to how the combination of geodetic, magnetic and gravity observations provides insight into the dynamics of the liquid core, including its interactions with the mantle. Models of the Earth’s PM are able to explain most of the observed signal with the exception of the so-called Markowitz wobble. In addition, whereas the quasi-six year oscillations (SYO) observed in both ΔLOD and PM can be explained as the result of Atmosphere, Oceans and Hydrosphere Forcing (AOH) for PM, this is not true for ΔLOD where the subtraction of the AOH only makes the signal more visible. This points to a missing—possibly common—interpretation related to deep interior dynamics, the latter being also the most likely explanation of other oscillations in ΔLOD on interannual timescales. Deep Earth’s structure and dynamics also have an impact on the nutations reflected in the values of the Basic Earth Parameters (BEP). We give a brief review of recent works aiming to independently evaluate the BEP and their implications for the study of deep interior dynamics.
Journal Article
I know day and night
\"Readers will review objects that may be seen in the sky during the day and night as well as events that usually happen during these times, such as attending school and going to bed. They'll also consider what daily events they enjoy the most and when these happen, aiding them in connecting these actions to time\"--Provided by publisher.
Book
Combination strategy for consistent final, rapid and predicted Earth rotation parameters
The accurate knowledge of the Earth’s orientation and rotation in space is essential for a broad variety of scientific and societal applications. Among others, these include global positioning, near-Earth and deep-space navigation, the realisation of precise reference and time systems as well as studies of geodynamics and global change phenomena. In this paper, we present a refined strategy for processing and combining Very Long Baseline Interferometry (VLBI), Satellite Laser Ranging (SLR), Global Navigation Satellite Systems (GNSS), and Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS) observations at the normal equation level and formulate recommendations for a consistent processing of the space-geodetic input data. Based on the developed strategy, we determine final and rapid Earth rotation parameter (ERP) solutions with low latency that also serve as the basis for a subsequent prediction of ERPs involving effective angular momentum data. Realising final ERPs on an accuracy level comparable to the final ERP benchmark solutions IERS 14C04 and JPL COMB2018, our strategy allows to enhance the consistency between final, rapid and predicted ERPs in terms of RMS differences by up to 50% compared to existing solutions. The findings of the study thus support the ambitious goals of the Global Geodetic Observing System (GGOS) in providing highly accurate and consistent time series of geodetic parameters for science and applications.
Journal Article
Day and night
During the day, the sun shines, birds tweet, and bees buzz. Earth is awake! But what happens at night? The moon -- and a whole new group of animals come out to play!
Book
Structure, Materials and Processes in the Earth’s Core and Mantle
This paper reviews current knowledge about the Earth’s core and the overlying deep mantle in terms of structure, chemical and mineralogical compositions, physical properties, and dynamics, using information from seismology, geophysics, and geochemistry. High-pressure experimental techniques that can help to interpret and understand observations of these properties and compositions in the deep interior are summarized. The paper also examines the consequences of core flows on global observations such as variations in Earth’s rotation and orientation or variations in the Earth’s magnetic field. Processes currently active at the core-mantle boundary and the various coupling mechanisms between the core and the mantle are discussed, together with some evidence from magnetic field observations.
Journal Article
Sub-daily polar motion from GPS, GLONASS, and Galileo
We derive an empirical model of the sub-daily polar motion (PM) based on the multi-GNSS processing incorporating GPS, GLONASS, and Galileo observations. The sub-daily PM model is based on 3-year multi-GNSS solutions with a 2 h temporal resolution. Firstly, we discuss differences in sub-daily PM estimates delivered from individual GNSS constellations, including GPS, GLONASS, Galileo, and the combined multi-GNSS solutions. Secondly, we evaluate the consistency between the GNSS-based estimates of the sub-daily PM with three independent models, i.e., the model recommended in the International Earth Rotation and Reference Systems Service (IERS) 2010 Conventions, the Desai–Sibois model, and the Gipson model. The sub-daily PM estimates, which are derived from system-specific solutions, are inherently affected by artificial non-tidal signals. These signals arise mainly from the resonance between the Earth rotation period and the satellite revolution period. We found strong spurious signals in GLONASS-based and Galileo-based results with amplitudes up to 30 µas. The combined multi-GNSS solution delivers the best estimates and the best consistency of the sub-daily PM with external geophysical and empirical models. Moreover, the impact of the non-tidal spurious signals in the frequency domain diminishes in the multi-GNSS combination. After the recovery of the tidal coefficients for 38 tides, we infer better consistency of the GNSS-based empirical models with the new Desai–Sibois model than the model recommended in the IERS 2010 Conventions. The consistency with the Desai–Sibois model, in terms of the inter-quartile ranges of tidal amplitude differences, reaches the level of 1.6, 5.7, 6.3, 2.2 µas for the prograde diurnal tidal terms and 1.2/2.1, 2.3/6.0, 2.6/5.5, 2.1/5.1 µas for prograde/retrograde semi-diurnal tidal terms, for the combined multi-GNSS, GPS, GLONASS, and Galileo solutions, respectively.
Journal Article