scholarly journals A First Look at Decadal Hydrological Predictability by Land Surface Ensemble Simulations

2018 ◽  
Vol 45 (5) ◽  
pp. 2362-2369 ◽  
Author(s):  
Xing Yuan ◽  
Enda Zhu
Keyword(s):  
Land Surface ◽  
Ensemble Simulations ◽  
Hydrological Predictability

scholarly journals GlobSim (v1.0): deriving meteorological time series for point locations from multiple global reanalyses

2019 ◽  
Vol 12 (11) ◽  
pp. 4661-4679 ◽  
Author(s):  
Bin Cao ◽  
Xiaojing Quan ◽  
Nicholas Brown ◽  
Emilie Stewart-Jones ◽  
Stephan Gruber
Keyword(s):  
Time Series ◽  
Land Surface ◽  
Ground Surface ◽  
Reanalysis Data ◽  
Meteorological Variables ◽  
Ensemble Simulations ◽  
Driving Time ◽  
Wide Range ◽  
Global Coverage ◽  
Uncertain Input

Abstract. Simulations of land-surface processes and phenomena often require driving time series of meteorological variables. Corresponding observations, however, are unavailable in most locations, even more so, when considering the duration, continuity and data quality required. Atmospheric reanalyses provide global coverage of relevant meteorological variables, but their use is largely restricted to grid-based studies. This is because technical challenges limit the ease with which reanalysis data can be applied to models at the site scale. We present the software toolkit GlobSim, which automates the downloading, interpolation and scaling of different reanalyses – currently ERA5, ERA-Interim, JRA-55 and MERRA-2 – to produce meteorological time series for user-defined point locations. The resulting data have consistent structure and units to efficiently support ensemble simulation. The utility of GlobSim is demonstrated using an application in permafrost research. We perform ensemble simulations of ground-surface temperature for 10 terrain types in a remote tundra area in northern Canada and compare the results with observations. Simulation results reproduced seasonal cycles and variation between terrain types well, demonstrating that GlobSim can support efficient land-surface simulations. Ensemble means often yielded better accuracy than individual simulations and ensemble ranges additionally provide indications of uncertainty arising from uncertain input. By improving the usability of reanalyses for research requiring time series of climate variables for point locations, GlobSim can enable a wide range of simulation studies and model evaluations that previously were impeded by technical hurdles in obtaining suitable data.

scholarly journals Use and uncertainty evaluation of a process-based model for assessing the methane budgets of global terrestrial ecosystems

2011 ◽  
Vol 8 (4) ◽  
pp. 7033-7070 ◽  
Author(s):  
A. Ito ◽  
M. Inatomi
Keyword(s):  
Land Surface ◽  
Meteorological Factors ◽  
Land Use Changes ◽  
Terrestrial Ecosystems ◽  
Atmospheric Composition ◽  
Primary Sources ◽  
Biogeochemical Model ◽  
Inventory Data ◽  
Sources And Sinks ◽  
Ensemble Simulations

Abstract. We assessed the global terrestrial budget of methane (CH4) using a process-based biogeochemical model (VISIT) and inventory data. Emissions from wetlands, paddy fields, biomass burning, and plants, and oxidative consumption by upland soils, were simulated by the model. Emissions from livestock ruminants and termites were evaluated by an inventory approach. These CH4 flows were estimated for each of the model's 0.5° × 0.5° grid cells from 1901 to 2009, while accounting for atmospheric composition, meteorological factors, and land-use changes. Estimation uncertainties were examined through ensemble simulations using different parameterization schemes and input data (e.g. different wetland maps and emission factors). From 1996 to 2005, the average global terrestrial CH4 budget was estimated on the basis of 576 simulations, and terrestrial ecosystems were found to be a net source of 320.4 ± 18.9 Tg CH4 yr−1. Wetland and ruminant emissions were the primary sources. The results of our simulations indicate that sources and sinks are distributed highly heterogeneously over the Earth's land surface. Seasonal and interannual variability in the terrestrial budget was assessed. The trend of increasing net terrestrial sources and its relationship with temperature variability imply that terrestrial CH4 feedbacks will play an increasingly important role as a result of future climatic change.

scholarly journals GlobSim (v1.0): Deriving meteorological time series for point locations from multiple global reanalyses

2019 ◽  
Author(s):  
Bin Cao ◽  
Xiaojing Quan ◽  
Nicholas Brown ◽  
Emilie Stewart-Jones ◽  
Stephan Gruber
Keyword(s):  
Time Series ◽  
Land Surface ◽  
Ground Surface ◽  
Reanalysis Data ◽  
Meteorological Variables ◽  
Ensemble Simulations ◽  
Driving Time ◽  
Wide Range ◽  
Global Coverage ◽  
Uncertain Input

Abstract. Simulations of land-surface processes and phenomena often require driving time series of meteorological variables. Corresponding observations, however, are unavailable in most locations, even more so, when considering the duration, continuity and data quality required. Atmospheric reanalyses provide global coverage of relevant meteorological variables, but their use is largely restricted to grid-based studies. This is because technical challenges limit the ease with which reanalysis data can be applied to models at the site scale. We present the software toolkit GlobSim, which automates the downloading, interpolation and scaling of different reanalyses – currently ERA-5, ERA-Interim, JRA-55 and MERRA-2 – to produce meteorological time series for user-defined point locations. The resulting data have consistent structure and units to efficiently support ensemble simulation. The utility of GlobSim is demonstrated using an application in permafrost research. We perform ensemble simulations of ground-surface temperature for ten terrain types in a remote tundra area in northern Canada and compare the results with observations. Simulation results reproduced seasonal cycles and variation between terrain types well, demonstrating that GlobSim can support efficient land-surface simulations. Ensemble means often yielded better accuracy than individual simulation and ensemble ranges additionally provide indications of uncertainty arising from uncertain input. By improving the usability of reanalyses for research requiring time-series of climate variables for point locations, GlobSim can enable a wide range of simulation studies and model evaluations that previously were impeded by technical hurdles in obtaining suitable data.

scholarly journals Use of a process-based model for assessing the methane budgets of global terrestrial ecosystems and evaluation of uncertainty

2012 ◽  
Vol 9 (2) ◽  
pp. 759-773 ◽  
Author(s):  
A. Ito ◽  
M. Inatomi
Keyword(s):  
Land Surface ◽  
Meteorological Factors ◽  
Land Use Changes ◽  
Terrestrial Ecosystems ◽  
Atmospheric Composition ◽  
Primary Sources ◽  
Biogeochemical Model ◽  
Inventory Data ◽  
Sources And Sinks ◽  
Ensemble Simulations

Abstract. We assessed the global terrestrial budget of methane (CH4) by using a process-based biogeochemical model (VISIT) and inventory data for components of the budget that were not included in the model. Emissions from wetlands, paddy fields, biomass burning, and plants, as well as oxidative consumption by upland soils, were simulated by the model. Emissions from ruminant livestock and termites were evaluated by using an inventory approach. These CH4 flows were estimated for each of the model's 0.5° × 0.5° grid cells from 1901 to 2009, while accounting for atmospheric composition, meteorological factors, and land-use changes. Estimation uncertainties were examined through ensemble simulations using different parameterization schemes and input data (e.g., different wetland maps and emission factors). From 1996 to 2005, the average global terrestrial CH4 budget was estimated on the basis of 1152 simulations, and terrestrial ecosystems were found to be a net source of 308.3 ± 20.7 Tg CH4 yr−1. Wetland and livestock ruminant emissions were the primary sources. The results of our simulations indicate that sources and sinks are distributed highly heterogeneously over the Earth's land surface. Seasonal and interannual variability in the terrestrial budget was also assessed. The trend of increasing net emission from terrestrial sources and its relationship with temperature variability imply that terrestrial CH4 feedbacks will play an increasingly important role as a result of future climatic change.

Land surface processes and Sahel climate

2000 ◽  
Vol 38 (1) ◽  
pp. 117-140 ◽  
Author(s):  
Sharon Nicholson
Keyword(s):  
Land Surface ◽  
Surface Processes ◽  
Land Surface Processes

STUDY OF POND STATUS IN INDIA : A REVIEW

2017 ◽  
Vol 23 (1) ◽  
Author(s):  
V.K. YADAV ◽  
SONAM SHARMA ◽  
A.K. SRIVASTAVA ◽  
P.K. KHARE
Keyword(s):  
Fresh Water ◽  
Land Surface ◽  
Human Population ◽  
Climate Changes ◽  
Hydrological Cycle ◽  
Habitat Destruction ◽  
Conservation Strategy ◽  
Goods And Services ◽  
Human Use ◽  
Over Exploitation

Ponds are an important fresh water critical ecosystem for plants and animals providing goods and services including food, fodder, fish, irrigation, hydrological cycle, shelter, medicine, culture, aesthetic and recreation. Ponds cover less than 2 percent of worlds land surface. Ponds are important source of fresh water for human use. These are threatened by urbanization, industrialization, over exploitation, fragmentation, habitat destruction, pollution, illegal capturing of land and climate changes. These above factors have been destroying ponds very rapidly putting them in danger of extinction of a great number of local biodiversity. It is necessary to formulate a correct conservation strategy for pond restoration in order to meet the growing needs of fresh water by increasing the human population. Some measures have been compiled and proposed in the present review.

THE IDENTIFICATION OF PARAMETERS OF THEORIES USED FOR PROGNOSES OF POST MINING DEFORMATIONS BY MEANS OF PRESENT SOFTWARE / IDENTYFIKACJA WARTOŚCI PARAMETRÓW TEORII PROGNOZOWANIA WPŁYWÓW PRZY WYKORZYSTANIU WSPÓŁCZESNYCH NARZĘDZI INFORMATYCZNYCH

2013 ◽  
Vol 58 (4) ◽  
pp. 1347-1357 ◽  
Author(s):  
Roman Ścigała
Keyword(s):  
Rock Mass ◽  
Land Surface ◽  
Underground Mining ◽  
Transient State ◽  
Computer Programs ◽  
Asymptotic State ◽  
Software System ◽  
Practical Utilization ◽  
Identification Of Parameters ◽  
Graphical Processing

Abstract The characteristic of specialized computer programs has been presented, serving for identification of W. Budryk-S. Knothe theory parameters, used for description of asymptotic state of post-mining deformations, as well as for transient state. The software is the result of several years of authors’ work. It is a part of complete software system designed for forecasting of underground mining influences on the rock mass and land surface and graphical processing of calculations results. Apart from software description, a short example of its practical utilization has been attached.

Spatial Hotspot Analysis of Bucharest’s Urban Heat Island (UHI) Using Modis Data

2018 ◽  
Vol 18 (1) ◽  
pp. 14-22 ◽  
Author(s):  
Georgiana Grigoraș ◽  
Bogdan Urițescu
Keyword(s):  
Surface Temperature ◽  
Air Temperature ◽  
Land Surface Temperature ◽  
Hot Spots ◽  
Land Surface ◽  
Hot Spot ◽  
Monitoring Network ◽  
Residential Areas ◽  
Hotspot Analysis ◽  
The City

Abstract The aim of the study is to find the relationship between the land surface temperature and air temperature and to determine the hot spots in the urban area of Bucharest, the capital of Romania. The analysis was based on images from both moderate-resolution imaging spectroradiometer (MODIS), located on both Terra and Aqua platforms, as well as on data recorded by the four automatic weather stations existing in the endowment of The National Air Quality Monitoring Network, from the summer of 2017. Correlation coefficients between land surface temperature and air temperature were higher at night (0.8-0.87) and slightly lower during the day (0.71-0.77). After the validation of satellite data with in-situ temperature measurements, the hot spots in the metropolitan area of Bucharest were identified using Getis-Ord spatial statistics analysis. It has been achieved that the “very hot” areas are grouped in the center of the city and along the main traffic streets and dense residential areas. During the day the "very hot spots” represent 33.2% of the city's surface, and during the night 31.6%. The area where the mentioned spots persist, falls into the "very hot spot" category both day and night, it represents 27.1% of the city’s surface and it is mainly represented by the city center.

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