scholarly journals Bias in the variance of gridded data sets leads to misleading conclusions about changes in climate variability

2015 ◽  
Vol 36 (9) ◽  
pp. 3413-3422 ◽  
Author(s):  
Santiago Beguería ◽  
Sergio M. Vicente-Serrano ◽  
Miquel Tomás-Burguera ◽  
Marco Maneta
Keyword(s):  
Climate Variability ◽  
Data Sets ◽  
Gridded Data

scholarly journals Correction: Brodzik, M.J., et al. EASE-Grid 2.0: Incremental but Significant Improvements for Earth-Gridded Data Sets. ISPRS International Journal of Geo-Information 2012, 1, 32–45

2014 ◽  
Vol 3 (3) ◽  
pp. 1154-1156 ◽  
Author(s):  
Mary Brodzik ◽  
Brendan Billingsley ◽  
Terry Haran ◽  
Bruce Raup ◽  
Matthew Savoie
Keyword(s):  
Data Sets ◽  
Gridded Data

Visualizing sparse gridded data sets

2000 ◽  
Vol 20 (5) ◽  
pp. 52-57 ◽  
Author(s):  
S. Djurcilov ◽  
A. Pang
Keyword(s):  
Data Sets ◽  
Gridded Data

scholarly journals Multi-annual modes in the 20th century temperature variability in reanalyses and CMIP5 models

2016 ◽  
Vol 9 (11) ◽  
pp. 4097-4109
Author(s):  
Heikki Järvinen ◽  
Teija Seitola ◽  
Johan Silén ◽  
Jouni Räisänen
Keyword(s):  
Climate Variability ◽  
20Th Century ◽  
Climate Models ◽  
Spectral Power ◽  
Singular Spectrum Analysis ◽  
Reanalysis Data ◽  
Cmip5 Models ◽  
Data Sets ◽  
Near Surface ◽  
Annual Variability

Abstract. A performance expectation is that Earth system models simulate well the climate mean state and the climate variability. To test this expectation, we decompose two 20th century reanalysis data sets and 12 CMIP5 model simulations for the years 1901–2005 of the monthly mean near-surface air temperature using randomised multi-channel singular spectrum analysis (RMSSA). Due to the relatively short time span, we concentrate on the representation of multi-annual variability which the RMSSA method effectively captures as separate and mutually orthogonal spatio-temporal components. This decomposition is a unique way to separate statistically significant quasi-periodic oscillations from one another in high-dimensional data sets.The main results are as follows. First, the total spectra for the two reanalysis data sets are remarkably similar in all timescales, except that the spectral power in ERA-20C is systematically slightly higher than in 20CR. Apart from the slow components related to multi-decadal periodicities, ENSO oscillations with approximately 3.5- and 5-year periods are the most prominent forms of variability in both reanalyses. In 20CR, these are relatively slightly more pronounced than in ERA-20C. Since about the 1970s, the amplitudes of the 3.5- and 5-year oscillations have increased, presumably due to some combination of forced climate change, intrinsic low-frequency climate variability, or change in global observing network. Second, none of the 12 coupled climate models closely reproduce all aspects of the reanalysis spectra, although some models represent many aspects well. For instance, the GFDL-ESM2M model has two nicely separated ENSO periods although they are relatively too prominent as compared with the reanalyses. There is an extensive Supplement and YouTube videos to illustrate the multi-annual variability of the data sets.

scholarly journals A novel hydrographic gridded data set for the northern Antarctic Peninsula

2021 ◽  
Vol 13 (2) ◽  
pp. 671-696
Author(s):  
Tiago S. Dotto ◽  
Mauricio M. Mata ◽  
Rodrigo Kerr ◽  
Carlos A. E. Garcia
Keyword(s):  
Southern Ocean ◽  
Antarctic Peninsula ◽  
Initial Conditions ◽  
Transitional Zone ◽  
Water Masses ◽  
Easy Access ◽  
Data Sets ◽  
Gridded Data ◽  
Data Set ◽  
Early 21St Century

Abstract. The northern Antarctic Peninsula (NAP) is a highly dynamic transitional zone between the subpolar-polar and oceanic-coastal environments, and it is located in an area affected by intense climate change, including intensification and spatial shifts of the westerlies as well as atmospheric and oceanic warming. In the NAP area, the water masses originate mainly from the Bellingshausen and Weddell seas, which create a marked regional dichotomy thermohaline characteristic. Although the NAP area has relatively easy access when compared to other Southern Ocean environments, our understanding of the water masses' distribution and the dynamical processes affecting the variability of the region is still limited. That limitation is closely linked to the sparse data coverage, as is commonly the case in most Southern Ocean environments. This work provides a novel seasonal three-dimensional high-resolution hydrographic gridded data set for the NAP (version 1), namely the NAPv1.0. Hydrographic measurements from 1990 to 2019 comprising data collected by conductivity, temperature, depth (CTD) casts; sensors from the Marine Mammals Exploring the Oceans Pole to Pole (MEOP) consortium; and Argo floats have been optimally interpolated to produce maps of in situ temperature, practical salinity, and dissolved oxygen at ∼ 10 km spatial resolution and 90 depth levels. The water masses and oceanographic features in this regional gridded product are more accurate than other climatologies and state estimate products currently available. The data sets are available in netCDF format at https://doi.org/10.5281/zenodo.4420006 (Dotto et al., 2021). The novel and comprehensive data sets presented here for the NAPv1.0 product are a valuable tool to be used in studies addressing climatological changes in the unique NAP region since they provide accurate initial conditions for ocean models and improve the end of the 20th- and early 21st-century ocean mean-state representation for that area.

scholarly journals Imprints of climate forcings in global gridded temperature data

2016 ◽  
Vol 7 (1) ◽  
pp. 231-249 ◽  
Author(s):  
Jiří Mikšovský ◽  
Eva Holtanová ◽  
Petr Pišoft
Keyword(s):  
Climate Variability ◽  
20Th Century ◽  
Southern Oscillation ◽  
Atlantic Multidecadal Oscillation ◽  
Temperature Data ◽  
Data Sets ◽  
Near Surface ◽  
Anthropogenic Forcing ◽  
Internal Climate Variability ◽  
Climate Forcings

Abstract. Monthly near-surface temperature anomalies from several gridded data sets (GISTEMP, Berkeley Earth, MLOST, HadCRUT4, 20th Century Reanalysis) were investigated and compared with regard to the presence of components attributable to external climate forcings (associated with anthropogenic greenhouse gases, as well as solar and volcanic activity) and to major internal climate variability modes (El Niño/Southern Oscillation, North Atlantic Oscillation, Atlantic Multidecadal Oscillation, Pacific Decadal Oscillation and variability characterized by the Trans-Polar Index). Multiple linear regression was used to separate components related to individual explanatory variables in local monthly temperatures as well as in their global means, over the 1901–2010 period. Strong correlations of temperature and anthropogenic forcing were confirmed for most of the globe, whereas only weaker and mostly statistically insignificant connections to solar activity were indicated. Imprints of volcanic forcing were found to be largely insignificant in the local temperatures, in contrast to the clear volcanic signature in their global averages. Attention was also paid to the manifestations of short-term time shifts in the responses to the forcings, and to differences in the spatial fingerprints detected from individual temperature data sets. It is shown that although the resemblance of the response patterns is usually strong, some regional contrasts appear. Noteworthy differences from the other data sets were found especially for the 20th Century Reanalysis, particularly for the components attributable to anthropogenic forcing over land, but also in the response to volcanism and in some of the teleconnection patterns related to the internal climate variability modes.

scholarly journals Synthesis and evaluation of historical meridional heat transport from midlatitudes towards the Arctic

2020 ◽  
Vol 11 (1) ◽  
pp. 77-96
Author(s):  
Yang Liu ◽  
Jisk Attema ◽  
Ben Moat ◽  
Wilco Hazeleger
Keyword(s):  
Climate Variability ◽  
Heat Transport ◽  
Climate Models ◽  
Energy Transport ◽  
Reanalysis Data ◽  
Arctic Climate ◽  
The Arctic ◽  
Global Ocean ◽  
Data Sets ◽  
Sea Ice Concentration

Abstract. Meridional energy transport (MET), both in the atmosphere (AMET) and ocean (OMET), has significant impact on the climate in the Arctic. In this study, we quantify AMET and OMET at subpolar latitudes from six reanalysis data sets. We investigate the differences between the data sets and we check the coherence between MET and the Arctic climate variability at interannual timescales. The results indicate that, although the mean transport in all data sets agrees well, the spatial distributions and temporal variations of AMET and OMET differ substantially among the reanalysis data sets. For the ocean, only after 2007, the low-frequency signals in all reanalysis products agree well. A further comparison with observed heat transport at 26.5∘ N and the subpolar Atlantic, and a high-resolution ocean model hindcast confirms that the OMET estimated from the reanalysis data sets are consistent with the observations. For the atmosphere, the differences between ERA-Interim and the Japanese 55-year Reanalysis (JRA-55) are small, while the Modern-Era Retrospective analysis for Research and Applications version 2 (MERRA-2) differs from them. An extended analysis of linkages between Arctic climate variability and AMET shows that atmospheric reanalyses differ substantially from each other. Among the chosen atmospheric products, ERA-Interim and JRA-55 results are most consistent with those from coupled climate models. For the ocean, the Ocean Reanalysis System 4 (ORAS4) and Simple Ocean Data Assimilation version 3 (SODA3) agree well on the relation between OMET and sea ice concentration (SIC), while the GLobal Ocean reanalyses and Simulations version 3 (GLORYS2V3) deviates from those data sets. The regressions of multiple fields in the Arctic on both AMET and OMET suggest that the Arctic climate is sensitive to changes of meridional energy transport at subpolar latitudes in winter. Given the good agreement on the diagnostics among assessed reanalysis products, our study suggests that the reanalysis products are useful for the evaluation of energy transport. However, assessments of products with the AMET and OMET estimated from reanalysis data sets beyond interannual timescales should be conducted with great care and the robustness of results should be evaluated through intercomparison, especially when studying variability and interactions between the Arctic and midlatitudes.

Environmental Electronic Sensing Systems

Geography ◽  
2021 ◽  
Keyword(s):  
Mathematical Models ◽  
Remote Sensing Data ◽  
Sensor Calibration ◽  
Scaling Analysis ◽  
Data Sets ◽  
Gridded Data ◽  
Environmental Processes ◽  
Sensing Systems ◽  
Electronic Sensing ◽  
Selection Of

Although environmental measurement instrumentation has been utilized by human civilizations for thousands of years, the use of electronics to conduct measurements closely parallels the development of electrical theory from the 19th century to the present. Environmental electronic sensing systems have been created to automate measurement tasks that are difficult for humans to repeat in a precise and synchronous fashion or to measure phenomena that cannot be manually observed at scales ranging from the microscopic to the planetary. The collection and recording of data at regular timesteps enable inputs to mathematical models that provide predictions and forecasts of environmental processes; moreover, these models can be used to better understand planetary systems. Data measurements conducted at different scales can be subjected to statistical or scaling analysis to provide gridded data sets for application of mathematical models. Point measurements made at a single geographic location provide calibration or validation for satellite remote sensing data products. Measurements made by different sensors can be utilized along with sensor fusion algorithms to calculate indexes or gridded data sets. The sources in this article have been selected to provide an overview of the sensors and associated sensing systems that measure components of the environment on or near the surface of the Earth. Each first-level heading demarcates different environmental components. The final section of the article provides a selection of references pertaining to the engineering of sensor networks that are used to obtain areal measurements of environmental processes. Each section contains a series of subsections that divide the literature according to the type of sensor or measurement. An emphasis is placed on the selection of references that provide insight into the measurement physics of the sensor and the environmental physics of the phenomena being measured. Moreover, references are selected that provide schematic diagrams and engineering design considerations suitable for replication and development of new sensors. Papers on sensor calibration and error analysis as well as case studies are included for operational use and field deployment applications. Due to the numerous papers that have been published on environmental sensing systems, it is not possible to cite all available literature pertaining to a certain type of sensor. To close gaps in the literature and to provide ideas for students, instrument developers, engineers, and environmental scientists, overview papers are also provided in this article. These overview papers often present ideas in a succinct fashion and the associated sensor mathematics, design, and signal processing are provided in a manner to enhance pedagogical value.

scholarly journals Stochastic temporal disaggregation of monthly precipitation for regional gridded data sets

2014 ◽  
Vol 50 (11) ◽  
pp. 8714-8735 ◽  
Author(s):  
Stephan Thober ◽  
Juliane Mai ◽  
Matthias Zink ◽  
Luis Samaniego
Keyword(s):  
Data Sets ◽  
Monthly Precipitation ◽  
Gridded Data ◽  
Temporal Disaggregation
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