scholarly journals Bias-corrected CMIP6 global dataset for dynamical downscaling of the historical and future climate (1979–2100)

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Zhongfeng Xu ◽  
Ying Han ◽  
Chi-Yung Tam ◽  
Zong-Liang Yang ◽  
Congbin Fu
Keyword(s):  
Large Scale ◽  
Dynamical Downscaling ◽  
Linear Trend ◽  
Coupled Model ◽  
Future Climate ◽  
Atmospheric Environment ◽  
Important Approach ◽  
Corrected Data ◽  
Mean Climate ◽  
The Individual

AbstractDynamical downscaling is an important approach to obtaining fine-scale weather and climate information. However, dynamical downscaling simulations are often degraded by biases in the large-scale forcing itself. We constructed a bias-corrected global dataset based on 18 models from the Coupled Model Intercomparison Project Phase 6 (CMIP6) and the European Centre for Medium-Range Weather Forecasts Reanalysis 5 (ERA5) dataset. The bias-corrected data have an ERA5-based mean climate and interannual variance, but with a non-linear trend from the ensemble mean of the 18 CMIP6 models. The dataset spans the historical time period 1979–2014 and future scenarios (SSP245 and SSP585) for 2015–2100 with a horizontal grid spacing of (1.25° × 1.25°) at six-hourly intervals. Our evaluation suggests that the bias-corrected data are of better quality than the individual CMIP6 models in terms of the climatological mean, interannual variance and extreme events. This dataset will be useful for dynamical downscaling projections of the Earth’s future climate, atmospheric environment, hydrology, agriculture, wind power, etc.

scholarly journals A bias-corrected CMIP6 global dataset for dynamical downscaling of future climate, 1979–2100

2021 ◽  
Author(s):  
Zhongfeng Xu ◽  
Ying Han ◽  
Chi-Yung Tam ◽  
Zong-Liang Yang ◽  
Congbin Fu
Keyword(s):  
Large Scale ◽  
Dynamical Downscaling ◽  
Coupled Model ◽  
Horizontal Resolution ◽  
Future Climate ◽  
Atmospheric Environment ◽  
Historical Period ◽  
Important Approach ◽  
Corrected Data ◽  
Mean Climate

Abstract Dynamical downscaling is an important approach to obtaining fine-scale weather and climate information. However, dynamical downscaling simulations are often degraded by biases in the large-scale forcing itself. Here, we construct a set of bias-corrected global dataset based on 18 models from the Coupled Model Intercomparison Project Phase 6 (CMIP6) and European Centre for Medium-Range Weather Forecasts Reanalysis 5 (ERA5). The bias-corrected data have an ERA5-based mean climate and interannual variance, but with a nonlinear trend from the mean of 18 CMIP6 models. The dataset spans the historical period of 1979–2014 and future scenarios (SSP245 and SSP585) of 2015–2100 with a horizontal resolution of 1.25° × 1.25° and 6-hourly intervals. Our evaluation suggests that the bias-corrected data shows clearly better quality than individual CMIP6 models evaluated in terms of climatological mean, interannual variance and extreme events. The presented dataset will be useful for the dynamical downscaling projections of future climate, atmospheric environment, hydrology, agriculture, wind power, etc.

Decadal North Atlantic Surface Temperature Prediction Skill in CMIP6

2020 ◽  
Author(s):  
Leonard Borchert ◽  
Matthew Menary ◽  
Didier Swingedouw ◽  
Giovanni Sgubin ◽  
Leon Hermanson ◽  
...  
Keyword(s):  
Surface Temperature ◽  
North Atlantic ◽  
Large Scale ◽  
Coupled Model ◽  
Surface Air Temperature ◽  
Climate Science ◽  
Prediction Skill ◽  
Oceanic Response ◽  
Decadal Variations ◽  
The Individual

<p>Due to its wide-ranging impacts, predicting decadal variations of sea surface temperature (SST) in the subpolar North Atlantic remains a key goal of climate science. Here, we compare the representation of observed subpolar SST variations since 1960 in initialized and uninitialized historical simulations from the 5th and 6th phases of the Coupled Model Intercomparison Project (CMIP5/6). CMIP6 simulations demonstrate improved skill in this region with 88% (initialized vs. 77% non-initialized) observed variance explained post-1980 compared to 42% (8%) in CMIP5. During this time, we find particularly high agreement between observations and historical simulations in CMIP6, indicating a more prominent role for forcing in driving observed subpolar SST changes than previously thought. Analysis of single-forcing experiments suggests much of this post-1980 agreement is due to natural forcings, explaining ~55% of the observed variance, consistent with a conceptual model of the large-scale oceanic response to volcanic forcing.<br />SPG SST skill differs between individual model ensemble means in CMIP6 hindcasts. Prediction skill for summer surface air temperature over Europe appears to be seasonally and regionally connected to the individual models’ skill at predicting SPG SST, illustrating the societal value of understanding SPG SST prediction skill.</p>

Eastern Mediterranean Drying: Projected Changes in Dynamics and Thermodynamics and Their Relation to Large-Scale Processes

2020 ◽  
Author(s):  
Eilat Elbaum ◽  
Chaim Garfinkel ◽  
Ori Adam ◽  
Efrat Morin
Keyword(s):  
Large Scale ◽  
Eastern Mediterranean ◽  
Coupled Model ◽  
Past Century ◽  
The Past ◽  
Intercomparison Project ◽  
The Individual ◽  
Projected Changes ◽  
Precipitation Changes

<p>Observations from the past century and projections for the end of this century exhibit a decrease in precipitation over the Eastern Mediterranean Sea and surrounding land areas, but the magnitude of the expected drying is unknown. Changes in precipitation are controlled by both thermodynamic (moist) and dynamic (dry) processes, but the relative contributions of these processes, in particular on regional scales, is not well understood. Previous studies have analyzed the ability of the fifth phase of the Coupled Model Intercomparison Project (CMIP5) multi-model mean to represent the spatial and seasonal patterns of the Mediterranean hydroclimate. A wide spread exists among the individual models, which can be exploited to better understand the factors controlling future climate. Garfinkel et al. (2020)<sup>[i]</sup> found that large-scale mechanisms contribute about 50% of the model spread in Eastern Mediterranean drying. This study further explores the variance across models in projected changes of the moisture budget by decomposing them into mean dynamic, mean thermodynamic and transient components. These components are then related to the variance across models in projected large-scale processes. Through these analyses, uncertainties regarding future changes in precipitation can be reduced.</p><p><sup>[i]</sup> Garfinkel, C. I. et al. (2020) ‘The role of zonally averaged climate change in contributing to inter-model spread in CMIP5 predicted local precipitation changes’, Journal of Climate, 33, pp. 1141–1154. doi: 10.1175/JCLI-D-19-0232.1.</p>

scholarly journals Hadley Circulation in the Present and Future Climate Simulations of the K-ACE Model

2021 ◽  
Author(s):  
Ije Hur ◽  
Minju Kim ◽  
Kyungmin Kwak ◽  
Hyun Min Sung ◽  
Young-Hwa Byun ◽  
...  
Keyword(s):  
Climate Models ◽  
Coupled Model ◽  
Hadley Circulation ◽  
Future Climate ◽  
The Pacific ◽  
Climate Simulations ◽  
Ace Model ◽  
Mean Climate ◽  
The Tropics ◽  
Component Models

AbstractHadley circulation (HC) is a planetary-scale overturning circulation in the tropics that transports momentum, heat, and moisture poleward. In this study, we evaluate the strength and extent of the HC in the historical and future climate simulations of the Korean Meteorological Administration (KMA) Advanced Community Earth system model (K-ACE), which was recently developed by the National Institute of Meteorological Sciences of Korea. Compared with a reanalysis product, the overall structure of the HC is reasonably reproduced by the K-ACE. At the same time, it is also found that the Northern Hemisphere HC in the K-ACE is shifted southward by a few degrees, while the strength of the Southern Hemisphere (SH) HC is under-represented by approximately 20%. These biases in the strength and extent of the HC can be explained by biases in the eddy momentum flux and precipitation in the tropics. In the future climate simulations under the Shared Socioeconomic Pathway 5-Representative Concentration Pathway 8.5 scenario, the HCs in the K-ACE show a weakening and widening trend in both hemispheres, which is consistent with the projections of many Coupled Model Intercomparison Project Phase 6 models. A notable feature of the K-ACE is the widening of the SH HC, which takes place at a rate that is about double the multi-model mean. Climate models that share the component models with the K-ACE, such as UKESM, HadGEM3-GC31-LL, and ACCESS-CM2/ESM1, also show enhanced poleward expansion of the HC in the SH. This strong expansion is shown to be dominated by the expansion of the regional HC over the Pacific.

The Structure and Properties of MoSi2 Thin Film in Mos Process

1980 ◽  
Vol 38 ◽  
pp. 326-327
Author(s):  
C.K. Wu ◽  
P. Chang ◽  
N. Godinho
Keyword(s):  
Thin Film ◽  
Integrated Circuits ◽  
High Performance ◽  
Large Scale ◽  
Process Development ◽  
Structure And Properties ◽  
Metal Silicides ◽  
High Oxidation ◽  
Important Approach ◽  
High Oxidation Resistance

Recently, the use of refractory metal silicides as low resistivity, high temperature and high oxidation resistance gate materials in large scale integrated circuits (LSI) has become an important approach in advanced MOS process development (1). This research is a systematic study on the structure and properties of molybdenum silicide thin film and its applicability to high performance LSI fabrication.

Models, Practices and Methods of Reading: Evolution in Time and Space

2009 ◽  
pp. 59-64
Author(s):  
Yulia P. Melentyeva
Keyword(s):  
Large Scale ◽  
Social Groups ◽  
National Program ◽  
Time And Space ◽  
Lack Of Information ◽  
The Individual

In recent years as public in general and specialist have been showing big interest to the matters of reading. According to discussion and launch of the “Support and Development of Reading National Program”, many Russian libraries are organizing the large-scale events like marathons, lecture cycles, bibliographic trainings etc. which should draw attention of different social groups to reading. The individual forms of attraction to reading are used much rare. To author’s mind the main reason of such an issue has to be the lack of information about forms and methods of attraction to reading.

scholarly journals Impact of air–sea coupling on the climate change signal over the Iberian Peninsula

2021 ◽  
Author(s):  
Alba de la Vara ◽  
William Cabos ◽  
Dmitry V. Sein ◽  
Claas Teichmann ◽  
Daniela Jacob
Keyword(s):  
Climate Change ◽  
Iberian Peninsula ◽  
Mediterranean Sea ◽  
Large Scale ◽  
Regional Distribution ◽  
Coupled Model ◽  
Climate Change Signal ◽  
The North ◽  
The Mediterranean ◽  
The Impact

AbstractIn this work we use a regional atmosphere–ocean coupled model (RAOCM) and its stand-alone atmospheric component to gain insight into the impact of atmosphere–ocean coupling on the climate change signal over the Iberian Peninsula (IP). The IP climate is influenced by both the Atlantic Ocean and the Mediterranean sea. Complex interactions with the orography take place there and high-resolution models are required to realistically reproduce its current and future climate. We find that under the RCP8.5 scenario, the generalized 2-m air temperature (T2M) increase by the end of the twenty-first century (2070–2099) in the atmospheric-only simulation is tempered by the coupling. The impact of coupling is specially seen in summer, when the warming is stronger. Precipitation shows regionally-dependent changes in winter, whilst a drier climate is found in summer. The coupling generally reduces the magnitude of the changes. Differences in T2M and precipitation between the coupled and uncoupled simulations are caused by changes in the Atlantic large-scale circulation and in the Mediterranean Sea. Additionally, the differences in projected changes of T2M and precipitation with the RAOCM under the RCP8.5 and RCP4.5 scenarios are tackled. Results show that in winter and summer T2M increases less and precipitation changes are of a smaller magnitude with the RCP4.5. Whilst in summer changes present a similar regional distribution in both runs, in winter there are some differences in the NW of the IP due to differences in the North Atlantic circulation. The differences in the climate change signal from the RAOCM and the driving Global Coupled Model show that regionalization has an effect in terms of higher resolution over the land and ocean.

scholarly journals Benchmarking homogenization algorithms for monthly data

2012 ◽  
Vol 8 (1) ◽  
pp. 89-115 ◽  
Author(s):  
V. K. C. Venema ◽  
O. Mestre ◽  
E. Aguilar ◽  
I. Auer ◽  
J. A. Guijarro ◽  
...  
Keyword(s):  
Time Series ◽  
Performance Metrics ◽  
Linear Trend ◽  
Simulated Data ◽  
Integrated Approach ◽  
Global Network ◽  
Temperature And Precipitation ◽  
Skill Scores ◽  
Simulated Network ◽  
The Individual

Abstract. The COST (European Cooperation in Science and Technology) Action ES0601: advances in homogenization methods of climate series: an integrated approach (HOME) has executed a blind intercomparison and validation study for monthly homogenization algorithms. Time series of monthly temperature and precipitation were evaluated because of their importance for climate studies and because they represent two important types of statistics (additive and multiplicative). The algorithms were validated against a realistic benchmark dataset. The benchmark contains real inhomogeneous data as well as simulated data with inserted inhomogeneities. Random independent break-type inhomogeneities with normally distributed breakpoint sizes were added to the simulated datasets. To approximate real world conditions, breaks were introduced that occur simultaneously in multiple station series within a simulated network of station data. The simulated time series also contained outliers, missing data periods and local station trends. Further, a stochastic nonlinear global (network-wide) trend was added. Participants provided 25 separate homogenized contributions as part of the blind study. After the deadline at which details of the imposed inhomogeneities were revealed, 22 additional solutions were submitted. These homogenized datasets were assessed by a number of performance metrics including (i) the centered root mean square error relative to the true homogeneous value at various averaging scales, (ii) the error in linear trend estimates and (iii) traditional contingency skill scores. The metrics were computed both using the individual station series as well as the network average regional series. The performance of the contributions depends significantly on the error metric considered. Contingency scores by themselves are not very informative. Although relative homogenization algorithms typically improve the homogeneity of temperature data, only the best ones improve precipitation data. Training the users on homogenization software was found to be very important. Moreover, state-of-the-art relative homogenization algorithms developed to work with an inhomogeneous reference are shown to perform best. The study showed that automatic algorithms can perform as well as manual ones.

Mechanisms Contributing to the Warming Hole and the Consequent U.S. East–West Differential of Heat Extremes

2012 ◽  
Vol 25 (18) ◽  
pp. 6394-6408 ◽  
Author(s):  
Gerald A. Meehl ◽  
Julie M. Arblaster ◽  
Grant Branstator
Keyword(s):  
United States ◽  
Twentieth Century ◽  
Linear Trend ◽  
Coupled Model ◽  
The United States ◽  
Convective Heating ◽  
Central Pacific ◽  
Southeastern Part ◽  
Climate System Model ◽  
East West

Abstract A linear trend calculated for observed annual mean surface air temperatures over the United States for the second-half of the twentieth century shows a slight cooling over the southeastern part of the country, the so-called warming hole, while temperatures over the rest of the country rose significantly. This east–west gradient of average temperature change has contributed to the observed pattern of changes of record temperatures as given by the ratio of daily record high temperatures to record low temperatures with a comparable east–west gradient. Ensemble averages of twentieth-century climate simulations in the Community Climate System Model, version 3 (CCSM3), show a slight west–east warming gradient but no warming hole. A warming hole appears in only several ensemble members in the Coupled Model Intercomparison Project phase 3 (CMIP3) multimodel dataset and in one ensemble member of simulated twentieth-century climate in CCSM3. In this model the warming hole is produced mostly from internal decadal time-scale variability originating mainly from the equatorial central Pacific associated with the Interdecadal Pacific Oscillation (IPO). Analyses of a long control run of the coupled model, and specified convective heating anomaly experiments in the atmosphere-only version of the model, trace the forcing of the warming hole to positive convective heating anomalies in the central equatorial Pacific Ocean near the date line. Cold-air advection into the southeastern United States in winter, and low-level moisture convergence in that region in summer, contribute most to the warming hole in those seasons. Projections show a disappearance of the warming hole, but ongoing greater surface temperature increases in the western United States compared to the eastern United States.

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