scholarly journals The Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2)

2017 ◽  
Vol 30 (14) ◽  
pp. 5419-5454 ◽  
Author(s):  
Ronald Gelaro ◽  
Will McCarty ◽  
Max J. Suárez ◽  
Ricardo Todling ◽  
Andrea Molod ◽  
...  

The Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2), is the latest atmospheric reanalysis of the modern satellite era produced by NASA’s Global Modeling and Assimilation Office (GMAO). MERRA-2 assimilates observation types not available to its predecessor, MERRA, and includes updates to the Goddard Earth Observing System (GEOS) model and analysis scheme so as to provide a viable ongoing climate analysis beyond MERRA’s terminus. While addressing known limitations of MERRA, MERRA-2 is also intended to be a development milestone for a future integrated Earth system analysis (IESA) currently under development at GMAO. This paper provides an overview of the MERRA-2 system and various performance metrics. Among the advances in MERRA-2 relevant to IESA are the assimilation of aerosol observations, several improvements to the representation of the stratosphere including ozone, and improved representations of cryospheric processes. Other improvements in the quality of MERRA-2 compared with MERRA include the reduction of some spurious trends and jumps related to changes in the observing system and reduced biases and imbalances in aspects of the water cycle. Remaining deficiencies are also identified. Production of MERRA-2 began in June 2014 in four processing streams and converged to a single near-real-time stream in mid-2015. MERRA-2 products are accessible online through the NASA Goddard Earth Sciences Data Information Services Center (GES DISC).

2011 ◽  
Vol 24 (14) ◽  
pp. 3624-3648 ◽  
Author(s):  
Michele M. Rienecker ◽  
Max J. Suarez ◽  
Ronald Gelaro ◽  
Ricardo Todling ◽  
Julio Bacmeister ◽  
...  

Abstract The Modern-Era Retrospective Analysis for Research and Applications (MERRA) was undertaken by NASA’s Global Modeling and Assimilation Office with two primary objectives: to place observations from NASA’s Earth Observing System satellites into a climate context and to improve upon the hydrologic cycle represented in earlier generations of reanalyses. Focusing on the satellite era, from 1979 to the present, MERRA has achieved its goals with significant improvements in precipitation and water vapor climatology. Here, a brief overview of the system and some aspects of its performance, including quality assessment diagnostics from innovation and residual statistics, is given. By comparing MERRA with other updated reanalyses [the interim version of the next ECMWF Re-Analysis (ERA-Interim) and the Climate Forecast System Reanalysis (CFSR)], advances made in this new generation of reanalyses, as well as remaining deficiencies, are identified. Although there is little difference between the new reanalyses in many aspects of climate variability, substantial differences remain in poorly constrained quantities such as precipitation and surface fluxes. These differences, due to variations both in the models and in the analysis techniques, are an important measure of the uncertainty in reanalysis products. It is also found that all reanalyses are still quite sensitive to observing system changes. Dealing with this sensitivity remains the most pressing challenge for the next generation of reanalyses. Production has now caught up to the current period and MERRA is being continued as a near-real-time climate analysis. The output is available online through the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC).


2017 ◽  
Vol 17 (19) ◽  
pp. 12081-12096 ◽  
Author(s):  
Anne R. Douglass ◽  
Susan E. Strahan ◽  
Luke D. Oman ◽  
Richard S. Stolarski

Abstract. Constituent evolution for 1990–2015 simulated using the Global Modeling Initiative chemistry and transport model driven by meteorological fields from the Modern-Era Retrospective analysis for Research and Applications version 2 (MERRA-2) is compared with three sources of observations: ground-based column measurements of HNO3 and HCl from two stations in the Network for the Detection of Atmospheric Composition Change (NDACC, ∼ 1990–ongoing), profiles of CH4 from the Halogen Occultation Experiment (HALOE) on the Upper Atmosphere Research Satellite (UARS, 1992–2005), and profiles of N2O from the Microwave Limb Sounder on the Earth Observing System satellite Aura (2005–ongoing). The differences between observed and simulated values are shown to be time dependent, with better agreement after ∼ 2000 compared with the prior decade. Furthermore, the differences between observed and simulated HNO3 and HCl columns are shown to be correlated with each other, suggesting that issues with the simulated transport and mixing cause the differences during the 1990s and that these issues are less important during the later years. Because the simulated fields are related to mean age in the lower stratosphere, we use these comparisons to evaluate the time dependence of mean age. The ongoing NDACC column observations provide critical information necessary to substantiate trends in mean age obtained using fields from MERRA-2 or any other reanalysis products.


Diabetes ◽  
2019 ◽  
Vol 68 (Supplement 1) ◽  
pp. 393-P
Author(s):  
KHAWLA F. ALI ◽  
LIMA LAWRENCE ◽  
LAUREN A. BUEHLER ◽  
RONALD R. GAMBINO ◽  
MARWAN HAMATY

2020 ◽  
Vol 26 (3) ◽  
pp. 698-720
Author(s):  
E.V. Lobkova ◽  
A.S. Petrichenko

Subject. This article studies the mechanism of State health regulation and methods of management of efficiency of regional healthcare institutions. Objectives. The article aims to analyze the territorial health system in the context of the urgent need to optimize budget expenditures and address public health problems, as well as develop directions to improve the effectiveness of the regional health system of the Krasnoyarsk Krai. Methods. For the study, we used the method of index numbers and calculation of dynamics indicators using official statistics data. Results. We have developed and now present a system of indicators of regional health efficiency assessment, focused mainly on public health indicators and quality of medical services. We also offer our own version of the Luenberger observer modification adapted to the objectives of the regional health system analysis. Conclusions and Relevance. The article concludes that it is necessary to optimize the regional health system using the parameters of medical and social efficiency of the system. The proposed approach to assessing the effectiveness of regional health system can be used as a mechanism to develop recommendations for the management of the network of medical and prophylactic institutions of the region.


2017 ◽  
Vol 1 (3) ◽  
pp. 54
Author(s):  
BOUKELLOUZ Wafa ◽  
MOUSSAOUI Abdelouahab

Background: Since the last decades, research have been oriented towards an MRI-alone radiation treatment planning (RTP), where MRI is used as the primary modality for imaging, delineation and dose calculation by assigning to it the needed electron density (ED) information. The idea is to create a computed tomography (CT) image or so-called pseudo-CT from MRI data. In this paper, we review and classify methods for creating pseudo-CT images from MRI data. Each class of methods is explained and a group of works in the literature is presented in detail with statistical performance. We discuss the advantages, drawbacks and limitations of each class of methods. Methods: We classified most recent works in deriving a pseudo-CT from MR images into four classes: segmentation-based, intensity-based, atlas-based and hybrid methods. We based the classification on the general technique applied in the approach. Results: Most of research focused on the brain and the pelvis regions. The mean absolute error (MAE) ranged from 80 HU to 137 HU and from 36.4 HU to 74 HU for the brain and pelvis, respectively. In addition, an interest in the Dixon MR sequence is increasing since it has the advantage of producing multiple contrast images with a single acquisition. Conclusion: Radiation therapy field is emerging towards the generalization of MRI-only RT thanks to the advances in techniques for generation of pseudo-CT images. However, a benchmark is needed to set in common performance metrics to assess the quality of the generated pseudo-CT and judge on the efficiency of a certain method.


Author(s):  
Ashashri Shinde ◽  
Pankaj Gupta ◽  
Sudipt Rath

A quality drug is central to the success of any therapeutic plan. The quality of drug is determined right from the collection to delivery to the patients. The commonest problem involving the medicinal plant stating materials is intentional or unintentional substitution and adulteration owing to multiple reasons like unavailability, higher costs, unfair trade etc. This trend was also present in the olden days, as evident from the concept of substitute drugs (Pratinidhi Dravya) as available in Yogratanakara, Bhavaprakasha and Bhaishajyaratnawali. Therefore, Charka and later Acharyas also have dealt with authentication and standardization of herbal drugs and formulations in detail by using four Pramanas (tools of knowledge) Ch.Vi.8/87. Nowadays the concept of substitution is entirely converted into intentional and unintentional malpractices of adulteration. The established authenticity parameters for plant material identification and standardization like organoleptic, physical, chemical and genetic parameters are relatively inaccessible for routine use. Not withstanding the accuracy and usefulness of these lab parameters and delay in the development of easy to perform parameters for reasonable drug authentication. These adulteration malpractices spoils the market of herbal industries. In this article we discuss about concept of substitution in ancient Ayurveda and at present intentional and unintentional adulteration practices.


2021 ◽  
Vol 15 (4) ◽  
pp. 10-23
Author(s):  
Eka Chandra Ramdhani ◽  
Juniarti Eka Safitri ◽  
Selamat Abdurrahman Fahmi ◽  
Asep Asep

The inventory system is a system that has a very important role in a company. Inventory systems have been widely used or developed in a place with various technologies and systems. Problems at PT. Sanghiang Perkasa is due to the fact that the data has not been stored in a good file and the management and processing of inventory data is still processed in a conventional way, which has a very significant effect on the quality of the data and information produced. The main objective of this research is to produce an inventory system that is powerful and in accordance with the needs of the users associated with the inventory system. The system development method in this inventory system uses the waterfall method which consists of six stages. The stages are System Analysis and Design, software requirements analysis, system design, coding, system testing and maintenance. This system was built using the PHP programming language, DataBase MySQL. It is hoped that with the implementation of this inventory system at PT. Sanghiang Perkasa can make it easier to store and process data and information such as stock-taking data, information on incoming and outgoing goods transactions, purchase and sales return data, managing customer and supplier data to making product stock reports and assembly reports. Keywords: Information System; Inventory, Web


2018 ◽  
Vol 7 (2.26) ◽  
pp. 25
Author(s):  
E Ramya ◽  
R Gobinath

Data mining plays an important role in analysis of data in modern sensor networks. A sensor network is greatly constrained by the various challenges facing a modern Wireless Sensor Network. This survey paper focuses on basic idea about the algorithms and measurements taken by the Researchers in the area of Wireless Sensor Network with Health Care. This survey also catego-ries various constraints in Wireless Body Area Sensor Networks data and finds the best suitable techniques for analysing the Sensor Data. Due to resource constraints and dynamic topology, the quality of service is facing a challenging issue in Wireless Sensor Networks. In this paper, we review the quality of service parameters with respect to protocols, algorithms and Simulations. 


2017 ◽  
Author(s):  
Anne R. Douglass ◽  
Susan E. Strahan ◽  
Luke D. Oman ◽  
Richard S. Stolarski

Abstract. Constituent evolution for 1990–2015 simulated using the Global Modeling Initiative Chemistry and Transport Model driven by meteorological fields from the Modern Era Retrospective analysis for Research and Applications Version 2 (MERRA-2) is compared with three sources of observations: ground based column measurements of HNO3 and HCl from two stations in the Network for Detection of Atmospheric Composition Change (NDACCC, ~ 1990–ongoing); profiles of CH4 from the HALogen Occultation Experiment (HALOE) on the Upper Atmosphere Research Satellite (UARS, 1992–2005); profiles of N2O from the Microwave Limb Sounder on the Earth Observing System satellite Aura (2015–ongoing). The differences between observed and simulated values are shown to be time dependent, with better agreement after ~2000 compared with the prior decade. Furthermore, the differences between observed and simulated HNO3 and HCl columns are shown to be correlated with each other, suggesting that issues with the simulated transport and mixing cause the differences during the 1990s and these issues are less important during the later years. Because the simulated fields are related to mean age in the lower stratosphere, we use these comparisons to evaluate the time dependence of mean age. We use these relationships to account for dynamical variability when determining decadal scale trends in constituents and mean age. The ongoing NDACC column observations provide critical information necessary to substantiate trends in mean age obtained using fields from MERRA-2 or any other reanalysis products.


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