1,765 research outputs found

    Sustaining permafrost observations: priorities and needs of the Global Terrestrial Network for Permafrost (GTN-P)

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    The Global Terrestrial Network for Permafrost (GTN-P) is the primary international programme concerned with sustained long-term monitoring of permafrost. GTN-P was developed in the 1990s by the International Permafrost Association (IPA) under the Global Terrestrial Observing System (GTOS) as part of the Global Climate Observing System (GCOS). The two major components of GTN-P (Essential Climate Variables) are: (a) long-term monitoring of the thermal state of permafrost in an extensive borehole network, the Thermal State of Permafrost - TSP; and (b) monitoring of the Active-layer thickness - ALT. Long-term monitoring of permafrost generates essential baseline information for the assessment of climate change impacts in polar and high mountain regions

    Climate Observing Systems in The Netherlands – National Activities Contributing to GCOS

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    Climate monitoring is a multidisciplinary and international activity. KNMI and partner institutes in the Netherlands contribute to climate monitoring and coordinate their actions based on a national implementation in accordance to the Implementation Plan of the WMO Global Climate Observing System (GCOS). Here we summarize the contribution of governmental institutes and universities in the Netherlands to climate monitoring activities

    The Spaceborne Global Climate Observing Center (SGCOC): Executive summary

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    Conceptual planning of the Spaceborne portion of the Global Climate Observing Systems (SGCOS) is reviewed. Fundamentals of the SGCOS are summarized

    Managing the transition from Vaisala RS92 to RS41 radiosondes within the Global Climate Observing System Reference Upper-Air Network (GRUAN): a progress report

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    open13This paper describes the Global Climate Observing System (GCOS) Reference Upper-Air Network (GRUAN) approach to managing the transition from the Vaisala RS92 to the Vaisala RS41 as the operational radiosonde. The goal of GRUAN is to provide long-term high-quality reference observations of upper-air essential climate variables (ECVs) such as temperature and water vapor. With GRUAN data being used for climate monitoring, it is vital that the change of measurement system does not introduce inhomogeneities to the data record. The majority of the 27 GRUAN sites were launching the RS92 as their operational radiosonde, and following the end of production of the RS92 in the last quarter of 2017, most of these sites have now switched to the RS41. Such a large-scale change in instrumentation is unprecedented in the history of GRUAN and poses a challenge for the network. Several measurement programs have been initiated to characterize differences in biases, uncertainties, and noise between the two radiosonde types. These include laboratory characterization of measurement errors, extensive twin sounding studies with RS92 and RS41 on the same balloon, and comparison with ancillary data. This integrated approach is commensurate with the GRUAN principles of traceability and deliberate redundancy. A 2-year period of regular twin soundings is recommended, and for sites that are not able to implement this, burden-sharing is employed such that measurements at a certain site are considered representative of other sites with similar climatological characteristics. All data relevant to the RS92-RS41 transition are archived in a database that will be accessible to the scientific community for external scrutiny. Furthermore, the knowledge and experience gained regarding GRUAN's RS92-RS41 transition will be extensively documented to ensure traceability of the process. This documentation will benefit other networks in managing changes in their operational radiosonde systems.Preliminary analysis of the laboratory experiments indicates that the manufacturer's calibration of the RS41 temperature and humidity sensors is more accurate than for the RS92, with uncertainties of < 0.2 K for the temperature and < 1.5 % RH (RH: relative humidity) for the humidity sensor. A first analysis of 224 RS92-RS41 twin soundings at Lindenberg Observatory shows nighttime temperature differences < 0.1 K between the Vaisala-processed temperature data for the RS41 (T-RS41) and the GRUAN data product for the RS92 (TRS92-GDP.2). However, daytime temperature differences in the stratosphere increase steadily with altitude, with TRS92-GDP.2 up to 0.6 K higher than T-RS41 at 35 km. RHRS41 values are up to 8 % higher, which is consistent with the analysis of satellite-radiosonde collocations.openRuud J. Dirksen; Greg E. Bodeker; Peter W. Thorne; Andrea Merlone; Tony Reale; Junhong Wang; Dale F. Hurst; Belay B. Demoz; Tom D. Gardiner; Bruce Ingleby; Michael Sommer; Christoph von Rohden; Thierry LeblancDirksen, Ruud J.; Bodeker, Greg E.; Thorne, Peter W.; Merlone, Andrea; Reale, Tony; Wang, Junhong; Hurst, Dale F.; Demoz, Belay B.; Gardiner, Tom D.; Ingleby, Bruce; Sommer, Michael; von Rohden, Christoph; Leblanc, Thierr

    Assessment of Satellite Radiometry in the Visible Domain

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    Marine reflectance and chlorophyll-a concentration are listed among the Essential Climate Variables by the Global Climate Observing System. To contribute to climate research, the satellite ocean color data records resulting from successive missions need to be consistent and well characterized in terms of uncertainties. This chapter reviews various approaches that can be used for the assessment of satellite ocean color data. Good practices for validating satellite products with in situ data and the current status of validation results are illustrated. Model-based approaches and inter-comparison techniques can also contribute to characterize some components of the uncertainty budget, while time series analysis can detect issues with the instrument radiometric characterization and calibration. Satellite data from different missions should also provide a consistent picture in scales of variability, including seasonal and interannual signals. Eventually, the various assessment approaches should be combined to create a fully characterized climate data record from satellite ocean color

    Development of a Low-Cost Weather Station to Measure in Situ Essential Climate Variables

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    A weather station is proposed especially designed for developing countries, and to meet the standards of the international scientific community making research on the earth system. The station would measure in situ several ECV (essential climate variables). These data may enable an agricultural breakthrough in countries lacking meteorological infrastructure, help in climate change monitoring, and facilitate diffusion of wind energy. A pre-feasibility analysis is presented. It appears interesting that the station is supplied by a social enterprise. A research to establish the best shelter design using computational fluid dynamics is also reported. The criterion is the accuracy with which the surface air temperature is reproduced inside the shelter. A design following recommendations by the WMO (World Meteorological Organization), a smaller design with identical geometry, and two alternative small designs are analyzed. All four designs are simulated in PVC, natural rubber and wood, with and without white paint coating. The smaller shelters perform better. The influence of the material, dimensions and design is smaller than that of the white paint. Shelters made of PVC or rubber, and/or in alternative designs, may be more interesting if other criteria are considered, like whether logistics, manufacturing, etc. are more sustainable, easier and/or cheaper.Peer ReviewedPostprint (published version

    Briefing on meetings at & reports by the 65th & 66th United Nations General Assembly

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    Briefing on meetings at & reports by the 65th & 66th United Nations General AssemblyNo relevant differences are observed or identified after perusal of the space-related resolutions and documents issued by the UN System between 2010 and 2011. The most remarkable statements remain virtually unchanged in this time period. For instance, the UN GA recognizes the common interest of all mankind in the exploration and use of outer space for peaceful purposes, and reaffirms that these shall be carried out for the benefit and in the interest of all countries, irrespective of their degree of development. Also, the growing use of outer space increases the need for greater transparency and better information on the part of the international community. Again in 2011, the UN GA stated that it is deeply convinced of the important role that science and technology play in promoting sustained economic growth and sustainable development and that their use and applications in areas such as telemedicine, tele-education, disaster management, environmental protection and other EO applications, contribute to achieve the objectives in various aspects of economic, social and cultural development and welfare, particularly poverty eradication and mitigation of the consequences of disasters. It is necessary to continue to examine how space science and technology and their applications could contribute to achieve the UN MDG, since space tools are indispensable not only in areas linked to disasters, but also in climate change, food security, opportunities for education and global health. In 2011, 12 April was declared as the International Day of Human Space Flight to celebrate each year at the international level the beginning of the space era for mankind, reaffirming the important contribution of space science and technology in achieving sustainable development goals and increasing the well-being of States and peoples, as well as ensuring the realization of their aspiration to maintain outer space for peaceful purposes. We congratulate SGAC people working on the project YGNSS as their contribution [8] to the 2011 HLS AMR of the UN ECOSOC was accepted for distribution to all participants of the HLS in Geneva, July 2011. In this a written statement, the YNSS team informed the HLS AMR that SGAC “is focused on cultivating the next generation of space leaders and increasing awareness of the educational and societal benefits of space technology” and that “Within SGAC, the project YGNSS aims to present to youth the benefits of GNSS and how various such systems applications are able to benefit a nation’s economy and society”. Also, it is mentioned that “YGNSS has supported the educational outreach of GNSS applications”, that YGNSS has spread “the word that GNSS can be used for precision timing, agricultural and disaster management, and a wide variety of items that need accurate positioning, navigation, and timing”, that YGNSS has recommended “that the international community continue to foster the education of GNSS and the utilities of space technology”. Finally, the written statement informs that SGAC “is committed to providing a network for university students and young professionals in the international space sector to collaborate and contribute their international knowledge and skills to foster development”. As per the report from the IAF GEOSS Workshop, Space Sensors for Climate Monitoring [9], it is worth noting that satellite data are required to effectively monitor, characterize and predict changes in the Earth system, and particularly in the climate. Earth Observation (EO) satellites are essential as they provide the only realistic means to obtain the necessary global coverage. With well-calibrated measurements, e.g. using in situ data, space-based sensors will become a critical contribution to global observations for climate.Preprin
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