scholarly journals ECLAT Cluster Spacecraft Magnetotail Plasma Region Identifications (2001–2009)

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
P. D. Boakes ◽  
R. Nakamura ◽  
M. Volwerk ◽  
S. E. Milan
Keyword(s):  
Solar Wind ◽  
Scientific Community ◽  
Large Scale ◽  
Energy Transport ◽  
System Level ◽  
Earth System ◽  
Plasma Region ◽  
Near Earth Space ◽  
The Earth ◽  
Cluster Data

The European Space Agency’s four-spacecraft Cluster mission has been observing the Earth’s dynamical magnetotail region since early 2001. The magnetotail, and in particular the hot trapped plasma sheet, is a critical region in the coupled Sun-Earth system. Changes in the solar wind have direct influence on the properties and dynamical processes occurring in this region, which in turn directly influence operational near-Earth space, the upper atmosphere, and even induce large-scale currents in the ground. As part of the European Cluster Assimilation Technology (ECLAT) project, a magnetotail plasma region dataset has been produced to facilitate magnetospheric research and further our understanding of the important processes linking the solar wind-magnetospheric-ionospheric system. The dataset consists of a comprehensive list of plasma regions encountered in the nightside magnetosphere of the Earth by each of the four Cluster spacecraft in the years 2001–2009. The regions identified are those where major energy transport/conversion processes take place and are important regions for system level science. Characteristic averaged parameters describing the behavior of each region are provided for further understanding. The dataset facilitates the use of the large repository of Cluster data by the wider scientific community.

Dryland Degradation and Expansion: Implications for Mexican Policies from the Earth System Perspective

2020 ◽  
pp. 1-4
Author(s):  
Gabriel Lopez Porras
Keyword(s):  
Climate Change ◽  
Ecosystem Services ◽  
Science Policy ◽  
Land Degradation ◽  
Water Scarcity ◽  
Large Scale ◽  
Earth System ◽  
Sustainable Land Management ◽  
System Perspective ◽  
The Earth

Despite international efforts to stop dryland degradation and expansion, current dryland pathways are predicted to result in large-scale migration, growing poverty and famine, and increasing climate change, land degradation, conflicts and water scarcity. Earth system science has played a key role in analysing dryland problems, and has been even incorporated in global assessments such as the ones made by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services. However, policies addressing dryland degradation, like the ‘Mexican programme for the promotion of sustainable land management’, do not embrace an Earth system perspective, so they do not consider the complexity and non-linearity that underlie dryland problems. By exploring how this Mexican programme could integrate the Earth system perspective, this paper discusses how ’Earth system’ policies could better address dryland degradation and expansion in the Anthropocene.

Preliminary monthly gravity field models from kinematic orbits of SWARM Satellites

2021 ◽  
Author(s):  
Xingfu Zhang ◽  
Qiujie Chen ◽  
Yunzhong Shen
Keyword(s):  
Gravity Field ◽  
Large Scale ◽  
Earth System ◽  
The Earth ◽  
Swarm Satellites ◽  
Variable Gravity ◽  
Data Gap ◽  
One Year ◽  
Gravity Recovery ◽  
Gravity Field Models

<p>      Although the Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow-On (GRACE FO) satellite missions play an important role in monitoring global mass changes within the Earth system, there is a data gap of about one year spanning July 2017 to May 2018, which leads to discontinuous gravity observations for monitoring global mass changes. As an alternative mission, the SWARM satellites can provide gravity observations to close this data gap. In this paper, we are dedicated to developing alternative monthly time-variable gravity field solutions from SWARM data. Using kinematic orbits of SWARM from ITSG for the period January 2015 to September 2020, we have generated a preliminary time series of monthly gravity field models named Tongji-Swarm2019 up to degree and order 60. The comparisons between Tongji-Swarm2019 and GRACE/GRACE-FO monthly solutions show that Tongji-Swarm2019 solutions agree with GRACE/GRACE-FO models in terms of large-scale mass change signals over amazon, Greenland and other regions. We can conclude that Tongji-Swarm2019 monthly gravity field models are able to close the gap between GRACE and GRACE FO.</p>

scholarly journals Earth System Model Evaluation Tool (ESMValTool) v2.0 – an extended set of large-scale diagnostics for quasi-operational and comprehensive evaluation of Earth system models in CMIP

2020 ◽  
Vol 13 (7) ◽  
pp. 3383-3438 ◽  
Author(s):  
Veronika Eyring ◽  
Lisa Bock ◽  
Axel Lauer ◽  
Mattia Righi ◽  
Manuel Schlund ◽  
...  
Keyword(s):  
Model Evaluation ◽  
Large Scale ◽  
Performance Metrics ◽  
Earth System Model ◽  
System Model ◽  
Earth System ◽  
Evaluation Tool ◽  
The Earth ◽  
And Performance ◽  
Earth System Models

Abstract. The Earth System Model Evaluation Tool (ESMValTool) is a community diagnostics and performance metrics tool designed to improve comprehensive and routine evaluation of Earth system models (ESMs) participating in the Coupled Model Intercomparison Project (CMIP). It has undergone rapid development since the first release in 2016 and is now a well-tested tool that provides end-to-end provenance tracking to ensure reproducibility. It consists of (1) an easy-to-install, well-documented Python package providing the core functionalities (ESMValCore) that performs common preprocessing operations and (2) a diagnostic part that includes tailored diagnostics and performance metrics for specific scientific applications. Here we describe large-scale diagnostics of the second major release of the tool that supports the evaluation of ESMs participating in CMIP Phase 6 (CMIP6). ESMValTool v2.0 includes a large collection of diagnostics and performance metrics for atmospheric, oceanic, and terrestrial variables for the mean state, trends, and variability. ESMValTool v2.0 also successfully reproduces figures from the evaluation and projections chapters of the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5) and incorporates updates from targeted analysis packages, such as the NCAR Climate Variability Diagnostics Package for the evaluation of modes of variability, the Thermodynamic Diagnostic Tool (TheDiaTo) to evaluate the energetics of the climate system, as well as parts of AutoAssess that contains a mix of top–down performance metrics. The tool has been fully integrated into the Earth System Grid Federation (ESGF) infrastructure at the Deutsches Klimarechenzentrum (DKRZ) to provide evaluation results from CMIP6 model simulations shortly after the output is published to the CMIP archive. A result browser has been implemented that enables advanced monitoring of the evaluation results by a broad user community at much faster timescales than what was possible in CMIP5.

scholarly journals Advances in Collaborative Documentation Support for CMIP6

2020 ◽  
Author(s):  
Charlotte Pascoe ◽  
David Hassell ◽  
Martina Stockhause ◽  
Mark Greenslade
Keyword(s):  
Science Communication ◽  
Scientific Community ◽  
Climate Models ◽  
Coupled Model ◽  
Automatic Generation ◽  
Earth System ◽  
The Earth ◽  
Data Citation ◽  
On Line ◽  
Intercomparison Project

<div>The Earth System Documentation (ES-DOC) project aims to nurture an ecosystem of tools & services in support of Earth System documentation creation, analysis and dissemination. Such an ecosystem enables the scientific community to better understand and utilise Earth system model data.</div><div>The ES-DOC infrastructure for the Coupled Model Intercomparison Project Phase 6 (CMIP6) modelling groups to describe their climate models and make the documentation available on-line has been available for 18 months, and more recently the automatic generation of documentation of every published simulation has meant that every CMIP6 dataset within the Earth System Grid Federation (ESGF) is now immediately connected to the ES-DOC description of the entire workflow that created it, via a “further info URL”.</div><div>The further info URL is a landing page from which all of the relevant CMIP6 documentation relevant to the data may be accessed, including experimental design, model formulation and ensemble description, as well as providing links to the data citation information.</div><div>These DOI landing pages are part of the Citation Service, provided by DKRZ. Data citation information is also available independently through the ESGF Search portal or in the DataCite search or Google’s dataset search. It provides users of CMIP6 data with the formal citation that should accompany any use of the datasets that comprise their analysis.</div><div>ES-DOC services and the Citation Service form a CMIP6 project  collaboration, and depend upon structured documentation provided by the scientific community. Structured scientific metadata has an important role in science communication, however it’s creation and collation exacts a cost in time, energy and attention.  We discuss progress towards a balance between the ease of information collection and the complexity of our information handling structures.</div><div> </div><div>CMIP6: https://pcmdi.llnl.gov/CMIP6/</div><div>ES-DOC: https://es-doc.org/</div><div>Further Info URL: https://es-doc.org/cmip6-ensembles-further-info-url</div><div> <p>Citation Service: http://cmip6cite.wdc-climate.de</p> </div>

scholarly journals Measurement of geologic nitrogen using mass spectrometry, colourimetry, and a newly adapted fluorometry technique

2016 ◽  
Author(s):  
Benjamin W. Johnson ◽  
Natashia Drage ◽  
Jody Spence ◽  
Nova Hanson ◽  
Rana El-Sabaawi ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Continental Crust ◽  
Large Scale ◽  
Organic N ◽  
Stable Form ◽  
Earth System ◽  
N Budget ◽  
Rock Types ◽  
The Earth ◽  
Assess Quality

Abstract. Long viewed as a mostly noble, atmospheric species, recent work demonstrates that nitrogen in fact cycles throughout the Earth system, including the atmosphere, biosphere, oceans, and solid Earth. Despite this new-found behaviour, more thorough investigation of N in geologic materials is limited due to its low concentration (1 to 10 s ppm) and difficulty in analysis. In addition, N can exist in multiple species (NO3−, NH4+, N2, organic-N), and determining which species is actually quantified can be difficult. In rocks and minerals, NH4+ is the most stable form of N over geologic time scales. As such, techniques designed to measure NH4+ can be particularly useful. We measured a number of geochemical rock standards using three different techniques: mass spectrometry, colourimetry, and fluorometry. The fluorometry approach is a novel adaptation of a technique commonly used in biologic science, applied herein to geologic NH4+. Briefly, NH4+ can be quantified by HF-dissolution, neutralization, addition of a fluorescing reagent, and analysis on a standard fluorometer. We reproduce published values for several rock standards (BCR-2, BHVO-2, and G-2), especially if an additional distillation step is performed. While it is difficult to assess quality of each method, due to lack of international geologic N standards, fluorometry appears better suited to analyzing mineral-bound NH4+ than mass spectrometry, and is a simpler, quicker alternative to colourimetry. To demonstrate a potential application of fluorometry, we calculated a continental crust N budget based on new measurements. We used glacial tills as a proxy for upper crust and analyzed several poorly constrained rock types (volcanics, mid-crustal xenoliths) to determine that the continental crust contains ∼ 2 × 1018 kg N. This estimate is consistent with recent budget estimates, and shows that fluorometry is appropriate for large-scale questions where high sample throughput is helpful. Lastly, we report the first δ15N values of six rock standards: BCR-2 (1.05 ± 0.4 ‰), BHVO-2 (−0.3 ± 0.2 ‰), G-2 (1.23 ± 1.32 ‰), LKSD-4 (3.59 ± 0.1 ‰), Till-4 (6.33 ± 0.1 ‰), and SY-4 (2.13 ± 0.5 ‰). The need for international geologic N standards is crucial for further investigation of the Earth system N cycle, and we suggest that existing rock standards may be suited to this need.

scholarly journals The mechanical advantage of the magnetosphere: solar-wind-related forces in the magnetosphere-ionosphere-Earth system

2007 ◽  
Vol 25 (1) ◽  
pp. 255-269 ◽  
Author(s):  
V. M. Vasyliūnas
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Lorentz Force ◽  
Linear Momentum ◽  
Neutral Atmosphere ◽  
Earth System ◽  
Mechanical Advantage ◽  
The Earth ◽  
Earth’S Interior ◽  
Earth's Interior

Abstract. Magnetosphere-ionosphere interactions involve electric currents that circulate between the two regions; the associated Lorentz forces, existing in both regions as matched opposite pairs, are generally viewed as the primary mechanism by which linear momentum, derived ultimately from solar wind flow, is transferred from the magnetosphere to the ionosphere, where it is further transferred by collisions to the neutral atmosphere. For a given total amount of current, however, the total force is proportional to ℒB and in general, since ℒ2B~ constant by flux conservation, is much larger in the ionosphere than in the magnetosphere (ℒ = effective length, B = magnetic field). The magnetosphere may be described as possesing a mechanical advantage: the Lorentz force in it is coupled with a Lorentz force in the ionosphere that has been amplified by a factor given approximately by the square root of magnetic field magnitude ratio (~20 to 40 on field lines connected to the outer magnetosphere). The linear momentum transferred to the ionosphere (and thence to the atmosphere) as the result of magnetic stresses applied by the magnetosphere can thus be much larger than the momentum supplied by the solar wind through tangential stress. The added linear momentum comes from within the Earth, extracted by the Lorentz force on currents that arise as a consequence of magnetic perturbation fields from the ionosphere (specifically, the shielding currents within the Earth that keep out the time-varying external fields). This implies at once that Fukushima's theorem on the vanishing of ground-level magnetic perturbations cannot be fully applicable, a conclusion confirmed by re-examining the assumptions from which the theorem is derived. To balance the inferred Lorentz force within the Earth's interior, there must exist an antisunward mechanical stress there, only a small part of which is the acceleration of the entire Earth system by the net force exerted on it by the solar wind. The solar-wind interaction can thus give rise to internal forces, significantly larger than the force exerted by the solar wind itself, between the ionosphere and the neutral atmosphere as well as within the current-carrying regions of the Earth's interior.

scholarly journals On inclusion of water resource management in Earth System models – Part 1: Problem definition and representation of water demand

2014 ◽  
Vol 11 (7) ◽  
pp. 8239-8298 ◽  
Author(s):  
A. Nazemi ◽  
H. S. Wheater
Keyword(s):  
Resource Management ◽  
Water Resource ◽  
Water Demand ◽  
Water Resource Management ◽  
Large Scale ◽  
Earth System ◽  
Water Demands ◽  
The Earth ◽  
Scale Models ◽  
Earth System Models

Abstract. Human activities have caused various changes in the Earth System, and hence, the interconnections between humans and the Earth System should be recognized and reflected in models that simulate the Earth System processes. One key anthropogenic activity is water resource management that determines the dynamics of human–water interactions in time and space. There are various reasons to include water resource management in Earth System models. First, the extent of human water requirements is increasing rapidly at the global scale and it is crucial to analyze the possible imbalance between water demands and supply under various scenarios of climate change and across various temporal and spatial scales. Second, recent observations show that human–water interactions, manifested through water resource management, can substantially alter the terrestrial water cycle, affect land-atmospheric feedbacks and may further interact with climate and contribute to sea-level change. Here, we divide the water resource management into two interdependent elements, related to water demand as well as water supply and allocation. In this paper, we survey the current literature on how various water demands have been included in large-scale models, including Land Surface Schemes and Global Hydrological Models. The available algorithms are classified based on the type of demand, mode of simulation and underlying modeling assumptions. We discuss the pros and cons of available algorithms, address various sources of uncertainty and highlight limitations in current applications. We conclude that current capability of large-scale models in terms of representing human water demands is rather limited, particularly with respect to future projections and online simulations. We argue that current limitations in simulating various human demands and their impact on the Earth System are mainly due to the uncertainties in data support, demand algorithms and large-scale models. To fill these gaps, the available models, algorithms and data for representing various water demands should be systematically tested, intercompared and improved and human water demands should be considered in conjunction with water supply and allocation, particularly in the face of water scarcity and unknown future climate.

scholarly journals Applying the concept of "energy return on investment" to desert greening of the Sahara/Sahel using a global climate model

2014 ◽  
Vol 5 (1) ◽  
pp. 43-53 ◽  
Author(s):  
S. P. K. Bowring ◽  
L. M. Miller ◽  
L. Ganzeveld ◽  
A. Kleidon
Keyword(s):  
Return On Investment ◽  
Energy Input ◽  
Large Scale ◽  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Earth System ◽  
Energy Return On Investment ◽  
The Earth ◽  
Sahel Region

Abstract. Altering the large-scale dynamics of the Earth system through continual and deliberate human intervention now seems possible. In doing so, one should question the energetic sustainability of such interventions. Here, from the basis that a region might be unnaturally vegetated by employing technological means, we apply the metric of "energy return on investment" (EROI) to benchmark the energetic sustainability of such a scenario. We do this by applying EROI to a series of global climate model simulations where the entire Sahara/Sahel region is irrigated with increased rates of desalinated water to produce biomass. The energy content of this biomass is greater than the energy input rate for a minimum irrigation rate of about 200 mm yr−1 in the winter and 500 mm yr−1 in the summer, thereby yielding an EROI ratio >1 : 1, expressing energetic sustainability. Quantified annually, the EROI was >1 : 1 for irrigation rates more than 500 mm yr−1, progressively increasing to a maximum of 1.8 : 1 with 900 mm yr−1, and then decreasing with further increases in the irrigation rate. Including the precipitation feedback arising from changes in moisture recycling within the study region approximately doubles these EROI ratios. This overall result varies spatially and temporally, so while the entire Sahara/Sahel region is irrigated equally, the western coastal region from June to August had the highest EROI. Other factors would complicate such a large-scale modification of the Earth system, but this sensitivity study concludes that with a required energy input, desert greening may be energetically sustainable. More specifically, we have shown how this type of EROI analysis could be applied as a metric to assess a diverse range of human alterations to, and interventions within, the Earth system.

scholarly journals Satellite observations of currents and waves in space plasmas

1988 ◽  
Vol 6 (3) ◽  
pp. 503-511 ◽  
Author(s):  
T. A. Potemra ◽  
M. J. Engebretson ◽  
L. J. Zanetti ◽  
R. E. Erlandson ◽  
P. F. Bythrow
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Geomagnetic Field ◽  
Large Scale ◽  
Field Experiments ◽  
Outer Space ◽  
Solar Wind Plasma ◽  
Field Configuration ◽  
The Earth ◽  
Field Lines

When viewed from outer space, the earth's magnetic field does not resemble a simple dipole, but is severely distorted into a comet-shaped configuration by the continuous flow of solar wind plasma. A complicated system of currents flows within this distorted magnetic field configuration called the ‘magnetosphere’ (See figure 1). For example, the compression of the geomagnetic field by the solar wind on the dayside of the earth is associated with a large-scale current flowing across the geomagnetic field lines, called the ‘Chapman-Ferraro’ or magnetopause current. The magnetospheric system includes large-scale currents that flow in the ‘tail’, the ring current that flows at high altitudes around the equator of the earth, field-aligned ‘Birkeland’ currents that flow along geomagnetic field lines into and away from the two auroral regions, and a complex system of currents that flows completely within the layers of the ionosphere, the earth's ionized atmosphere. The intensities of these various currents reach millions of amperes and are closely related to solar activity. The geomagnetic field lines can also oscillate, like giant vibrating strings, at specified resonant frequencies. The effects of these vibrations, sometimes described as ‘standing Alfvén waves’, have been observed on the ground in magnetic field recordings dating back to the beginning of the century. Observations of currents and waves with satellite-borne magnetic field experiments have provided a new perspective on the complicated plasma processes that occur in the magnetosphere. Some of the new observations are described here.

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