scholarly journals Hydrologic-land surface modelling of the Canadian sporadic-discontinuous permafrost: initialization and uncertainty propagation

2021 ◽  
Author(s):  
Mohamed Abdelhamed ◽  
Mohamed Elshamy ◽  
Howard Wheater ◽  
Saman Razavi
Keyword(s):  
Land Surface ◽  
Near Field ◽  
Field Capacity ◽  
Climatic Conditions ◽  
Active Layer Thickness ◽  
Climate Conditions ◽  
Discontinuous Permafrost ◽  
Initial Soil ◽  
Model Initialization ◽  
The Impact

Permafrost thaw has been observed in recent decades in the Northern Hemisphere and is expected to accelerate with continued global warming. Predicting the future of permafrost requires proper representation of the interrelated surface/subsurface thermal and hydrologic regimes. Land surface models (LSMs) are well suited for such predictions, as they couple heat and water interactions across soil-vegetation-atmosphere interfaces and can be applied over large scales. LSMs, however, are challenged by the long-term thermal and hydraulic memories of permafrost and the paucity of historical records to represent permafrost dynamics under transient climate conditions. In this study, we address the challenge of model initialization by characterizing the impact of initial climate conditions and initial soil frozen and liquid water contents on the simulation length required to reach equilibrium. Further, we quantify how the uncertainty in model initialization propagates to simulated permafrost dynamics. Modelling experiments are conducted with the Modélisation Environmentale Communautaire – Surface and Hydrology (MESH) framework and its embedded Canadian Land Surface Scheme (CLASS). The study area is in the Liard River basin in the Northwest Territories of Canada with sporadic and discontinuous regions. Results show that uncertainty in model initialization controls various attributes of simulated permafrost, especially the active layer thickness, which could change by 0.5-1.5m depending on the initial condition chosen. The least number of spin-up cycles is achieved with near field capacity condition, but the number of cycles varies depending on the spin-up year climate. We advise an extended spin-up of 200-1000 cycles to ensure proper model initialization under different climatic conditions and initial soil moisture contents.

Land-surface feedbacks on temperature and precipitation in CMIP6-LS3MIP projections

2021 ◽  
Author(s):  
Franco Catalano ◽  
Andrea Alessandri ◽  
Wilhelm May ◽  
Thomas Reerink
Keyword(s):  
Climate Change ◽  
Soil Moisture ◽  
Land Surface ◽  
Hydrological Cycle ◽  
Climate Change Signal ◽  
Moisture Change ◽  
Climate Conditions ◽  
Temperature And Precipitation ◽  
Systematic Biases ◽  
The Impact

<p align="justify"><span>The Land Surface, Snow and Soil Moisture Model Intercomparison Project (LS3MIP) aims at diagnosing systematic biases in the land models of CMIP6 Earth System Models and assessing the role of land-atmosphere feedbacks on climate change. Two components of experiments have been designed: the first is devoted to the assessment of the systematic land biases in offline mode (LMIP) while the second component is dedicated to the analysis of the land feedbacks in coupled mode (LFMIP). Here we focus on the LFMIP experiments. In the LFMIP protocol (van den Hurk et al. 2016), which builds upon the GLACE-CMIP configuration, two sets of climate-sensitivity projections have been carried out in amip mode: in the first set (amip-lfmip-pdLC) the land feedbacks to climate change have been disabled by prescribing the soil-moisture states from a climatology derived from “present climate conditions” (1980-2014) while in the second set (amip-lfmip-rmLC) 30-year running mean of land-surface state from the corresponding ScenarioMIP experiment (O’Neill et al., 2016) is prescribed. The two sensitivity simulations span the period 1980-2100 with sea surface temperature and sea-ice conditions prescribed from the first member of historical and ScenarioMIP experiments. Two different scenarios are considered: SSP1-2.6 (f1) and SSP5-8.5 (f2).</span></p><p align="justify"><span>In this analysis, we focus on the differences between amip-lfmip-rmLC and amip-lfmip-pdLC at the end of the 21st Century (2071–2100) in order to isolate the impact of the soil moisture changes on surface climate change. The (2071-2100) minus (1985-2014) temperature change is positive everywhere over land and the climate change signal of precipitation displays a clear intensification of the hydrological cycle in the Northern Hemisphere. Warming and hydrological cycle intensification are larger in SSP5-8.5 scenario. Results show large differences in the feedbacks between wet, transition and semi-arid climates. In particular, over the regions with negative soil moisture change, the 2m-temperature increases significantly while the cooling signal is not significant over all the regions getting wetter. In agreement with Catalano et al. (2016), the larger effects on precipitation due to soil moisture forcing occur mostly over transition zones between dry and wet climates, where evaporation is highly sensitive to soil moisture. The sensitivity of both 2m-temperature and precipitation to soil moisture change is much stronger in the SSP5-8.5 scenario.</span></p>

Data collections of ESA DUE GlobPermafrost and ESA CCI+ Permafrost

2020 ◽  
Author(s):  
Annett Bartsch ◽  
Keyword(s):  
Time Series ◽  
Information System ◽  
Land Surface ◽  
Surface Deformation ◽  
Data Access ◽  
Active Layer Thickness ◽  
Rock Glacier ◽  
Borehole Data ◽  
Data Repositories ◽  
The Impact

<p>A Permafrost Information System (PerSys) based on satellite data has been setup as part of the ESA DUE GlobPermafrost project (2016-2019, www.globpermafrost.info). This includes a data catalogue as well as a WebGIS, both linked to the Pangaea repository for easy data access.</p><p>The thematic products available include InSAR-based land surface deformation maps, rock glacier velocity fields, spatially distributed permafrost model outputs, land surface properties and changes, and ground-fast lake ice. Extended permafrost modelling (time series) is implemented in the new ESA CCI+ Permafrost project (2018-2021, http://cci.esa.int/Permafrost), which will provide the key for our understanding of the changes of surface features over time. Special emphasis in CCI+ Permafrost is on the evaluation and development of land surface models to gain better understanding of the impact of climate change on permafrost and land-atmosphere exchange. Additional focus will be on documentation of kinematics from rock glaciers in several mountain regions across the world supporting the International Permafrost Association (IPA) action group ‘rock glacier kinematics as an essential climate variable’.</p><p>We will present the Permafrost Information System including the time series (2003-2017) of the first version of ground temperatures and active layer thickness for the entire Arctic from the ESA CCI+ Permafrost project. Further on, details on the user requirements collection process will be provided. Ground temperature is calculated for 0, 1m, 2m, 5m, and 10 m depth and has been assessed based on a range of borehole data. A survey regarding data repositories containing for validation relevant borehole data has been conducted. The records have been evaluated for the project purpose and harmonized. The resulting database will be eventually also made publicly available.</p>

scholarly journals The Impact of a Mobile Shading System and a Phase-Change Heat Store on the Thermal Functioning of a Transparent Building Partition

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2512
Author(s):  
Michał Musiał ◽  
Lech Lichołai
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Climatic Conditions ◽  
Temperate Climate ◽  
Summer Period ◽  
Heat Accumulator ◽  
Climate Conditions ◽  
Empirical Results ◽  
The Impact ◽  
Change Material

The article presents the results of multi-month field tests and numerical analyses describing the thermal functioning of mobile shading systems for building windows containing a phase-change heat accumulator. The experiments were conducted in the summer period with temperate climate conditions in Rzeszów (Poland). The tested shading system was dedicated to the daily life cycle of residents, taking into account both the need to illuminate the rooms with natural light and reducing the undesirable overheating of the rooms in the summer. The obtained empirical results showed a reduction in room overheating in the summer period by 29.4% from composite windows with a phase-change heat accumulator and a mobile shading system as compared to the reference composite window with an analogous mobile shading system. The database of empirical results allowed for the creation and verification of a numerical model of heat conversion, storage and distribution within the composite window containing phase change material and a mobile shading system. The verified model made it possible to analyse the thermal functioning of the modified transparent partitions in cool temperate, temperate and subtropical climates. The article is a solution to the problem of undesirable overheating of transparent building partitions by efficient storage and distribution of solar radiation energy thanks to the use of a mobile shading system and a phase change material, while presenting a useful tool enabling the prediction of energy gains in different climatic conditions.

scholarly journals Ensemble Modeling of the Impact of Climate Warming and Increased Frequency of Extreme Climatic Events on the Thermal Characteristics of a Sub-Tropical Lake

Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1982 ◽  
Author(s):  
Gideon Gal ◽  
Gilboa Yael ◽  
Schachar Noam ◽  
Estroti Moshe ◽  
Dirk Schlabing
Keyword(s):  
Climate Changes ◽  
Heat Waves ◽  
Thermal Characteristics ◽  
Large Degree ◽  
Climatic Conditions ◽  
Tropical Lake ◽  
Gradual Change ◽  
Lake Ecosystems ◽  
Climate Conditions ◽  
The Impact

Lake ecosystems are impacted by changes in climatic conditions. Climate changes forecasted to occur are reflected in models by slow gradual changes over extended periods of time. Output from weather generators, on the other hand, can simulate short-term extreme conditions and weather patterns. In order to evaluate the likely impact of climate changes on a large sub-tropical lake, specifically the thermal regime of the lake, we constructed climate scenarios using a weather generator. The 30-year scenarios included no change in climate conditions, a gradual change, increased frequency of heat waves and a merging of the latter two. The projected impact on the lake’s physical properties was evaluated using an ensemble of 1-D hydrodynamic lake models. The gradual increase scenario had the largest impact on annual temperatures and stratification period; however, increased heat waves had a large effect on the summer lake conditions and introduced a larger degree of variability in water temperature. The use of the ensemble of models resulted in variability in the projected impacts; yet, the large degree of similarity between projected trends and patterns increased confidence in the results. The projected effect the heat waves will have on the lake conditions highlights the need to include heat waves in climate studies and the need for impact studies in order to better understand possible consequences for lake ecosystems.

scholarly journals Weather and climate conditions for recreational and sports activities in the Ukrainian Carpathians

2014 ◽  
pp. 268-274
Author(s):  
Natalia Michajlenko ◽  
Iryna Scherban
Keyword(s):  
Atmospheric Pressure ◽  
Climatic Conditions ◽  
Cold Period ◽  
Mountainous Areas ◽  
Climate Conditions ◽  
Pressure Oxygen ◽  
Weather And Climate ◽  
Snow Storm ◽  
The Impact ◽  
Sports Activities

The analysis of contributing weather and climate in recreation and sport competitions during the cold period in Ukrainian Carpathians held. The results of the evaluation of the impact of weather and climate on the general condition and State of health of the person received. Reviewed by: day-to-day variability of atmospheric pressure, oxygen content. The conditions of the snow cover in mountainous areas and future trends of solid precipitation (snow, snow storm) during the cold period of the year described. Key words: recreation, weather types, climatic conditions, the cold period of the year.

scholarly journals Suitability dynamics of winter-spring period for pear cultivation in Krasnodar Region

2019 ◽  
pp. 39-46
Author(s):  
I. A. Dragavtseva ◽  
N. V. Mozhar ◽  
A. S. Romanenko ◽  
I. Yu. Savin ◽  
E. Yu. Prudnikova
Keyword(s):  
Climatic Conditions ◽  
Winter Hardiness ◽  
Capital Investments ◽  
Climate Conditions ◽  
Digital Maps ◽  
Spring Period ◽  
Scientific Approach ◽  
Phases Of Development ◽  
Krasnodar Region ◽  
The Impact

The reaction of two pear varieties (Kieffer with reduced winter hardiness and Leven with increased winter hardiness) on the changing climatic conditions of winter-spring period from 1986 to 2018 on the territory of Krasnodar region was studied. The critical minimum temperature is detrimental to flower buds of the studied varieties in different phases of the winter-spring period. Thermal stress manifestation in time and space is calculated. Digital maps of dynamic changes in the periodicity of the temperature conditions in the winter-spring period for the analyzed pear varieties are compiled. A digital computer analysis of the evaluation of frost hazard territories of Krasnodar region for pears in changing climate conditions was carried out. The proposed scientific approach suggests the need for a transition from registering the impact on the productivity of fruit crops and their varieties of individual environmental factors to evaluate their relationship and interdependence over specific phases of development. It will allow more efficient use the natural potentials of crops, varieties and growing environments without additional capital investments.

scholarly journals High Spatial Resolution Climate Scenarios to Analyze Madrid Building Energy Demand

2020 ◽  
Author(s):  
Roberto San José ◽  
Juan Luis Pérez ◽  
Rosa María Gonzalez-Barras
Keyword(s):  
Spatial Resolution ◽  
Energy Demand ◽  
Dynamical Downscaling ◽  
Economic Cost ◽  
Climatic Conditions ◽  
Climate Scenarios ◽  
Climate Conditions ◽  
Rcp 8.5 ◽  
Dynamics Models ◽  
The Impact

We have modelled the energy consumption of prototype and real buildings under present and future climatic conditions with the EnergyPlus model to develop a better understanding of the relationship between changing climate conditions and energy demand. We have produced detailed meteorological information with 50 meters of spatial resolution through dynamical downscaling process combining regional, urban and computational fluid dynamics models which include the effects of the buildings on urban wind patterns. The city of Madrid has been chosen for our experiment. The impact on energy demand and their respective economic cost are calculated for year 2100 versus 2011 based on two IPCC climate scenarios, RCP 4.5 (stabilization of emissions) and RCP 8.5 (not reduction of emissions). Findings show that climate change will have a significant impact on the energy demand for buildings. Space heating demand will be increased by the RCP 4.5 and cooling demand will be increased for the RCP 8.5 in the analysed buildings.

scholarly journals Uncertainty in the Number of Calibration Repetitions of a Hydrologic Model in Varying Climatic Conditions

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2362
Author(s):  
Patrik Sleziak ◽  
Ladislav Holko ◽  
Michal Danko ◽  
Juraj Parajka
Keyword(s):  
Differential Evolution Algorithm ◽  
Model Performance ◽  
Hydrologic Model ◽  
Climatic Conditions ◽  
Data Set ◽  
Climate Conditions ◽  
Daily Data ◽  
Model Efficiency ◽  
The Difference ◽  
The Impact

The objective of this study is to examine the impact of the number of calibration repetitions on hydrologic model performance and parameter uncertainty in varying climatic conditions. The study is performed in a pristine alpine catchment in the Western Tatra Mountains (the Jalovecký Creek catchment, Slovakia) using daily data from the period 1989–2018. The entire data set has been divided into five 6-years long periods; the division was based on the wavelet analysis of precipitation, air temperature and runoff data. A lumped conceptual hydrologic model TUW (“Technische Universität Wien”) was calibrated by an automatic optimisation using the differential evolution algorithm approach. To test the effect of the number of calibrations in the optimisation procedure, we have conducted 10, 50, 100, 300, 500 repetitions of calibrations in each period and validated them against selected runoff and snow-related model efficiency criteria. The results showed that while the medians of different groups of calibration repetitions were similar, the ranges (max–min) of model efficiency criteria and parameter values differed. An increasing number of calibration repetitions tend to increase the ranges of model efficiency criteria during model validation, particularly for the runoff volume error and snow error, which were not directly used in model calibration. Comparison of model efficiencies in climate conditions that varied among the five periods documented changes in model performance in different periods but the difference between 10 and 500 calibration repetitions did not change much between the selected time periods. The results suggest that ten repetitions of model calibrations provided the same median of model efficiency criteria as a greater number of calibration repetitions and model parameter variability and uncertainty were smaller.

 Land-atmosphere coupling in operational NCUM forecasts during the 2020 monsoon season

2021 ◽  
Author(s):  
Emma Barton ◽  
Chris Taylor ◽  
A. Jayakumar ◽  
Ashis Mitra ◽  
T. Arulalan
Keyword(s):  
Soil Moisture ◽  
Land Surface ◽  
Monsoon Season ◽  
Atmospheric Temperature ◽  
Summer Monsoon Rainfall ◽  
Initial Soil Moisture ◽  
Initial Soil ◽  
Temperature And Pressure ◽  
Moisture State ◽  
The Impact

<p>The onset, persistence and variability of summer monsoon rainfall impacts over a billion people. Advance knowledge is critical for agricultural planning and hazard mitigation, yet forecasting remains a challenge. Sources of error that have been identified in forecast models include the representation of the land surface and subsequent coupling with the boundary layer and convection. This study presents an analysis of land-atmosphere coupling in the operational Indian 4km convective scale regional model configuration of the Unified Model (NCUM-R), used by NCMRWF to provide daily forecasts. An earlier study (Barton et al, QJRMS 2019) analysed the coupling in this model for a single forecast when research aircraft observations were available. It revealed rapidly evolving biases in the monsoon trough linked to errors in the representation of soil moisture. Our current work aims to understand whether this behavior is typical of the monsoon season. This matters because the trough is an important dynamical feature and a key driver of regional rainfall. Here we provide a more comprehensive analysis by assessing the impact of initial soil moisture state on a full season of operational three day forecasts. NCUM-R output is evaluated by comparison to ERA5 reanalysis (atmospheric temperature and pressure) and satellite observations from AMSR2 (land surface temperature) and SMAP (soil moisture).  Correlations between surface and atmospheric variables in the model are computed using linear regression. Our results suggest that systematic biases in the evolution of atmospheric temperature and pressure over three days are indeed linked to errors in the initial soil moisture state. These biases likely impact rainfall predictions derived from the forecasts throughout the monsoon season. This work highlights the importance for realistic soil moisture initialisation in high resolution operational forecasts.</p>

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