Suitability of ERA5-Land reanalysis dataset for hydrological modelling in the Alpine region

Journal of Hydrology Regional Studies, Journal Year: 2024, Volume and Issue: 52, P. 101718 - 101718

Published: Feb. 26, 2024

Study region: The region of interest is the South-Tyrol in southeastern Alps, Italy. A comparison meteorological forcing performed with reference to this while hydrological simulations are conducted Passirio river basin. focus: objective work evaluate suitability ERA5-Land reanalysis product as a dataset for modelling topographically complex Alpine regions. compared observational gridded dataset, obtained by means Kriging interpolation, available at two contrasting spatial resolutions coarse grid size 11 × 8 kilometres and high-resolution 1 kilometres. coherence three datasets (ERA5-Land datasets) observed streamflow time series then assessed refer Passirio/Passer basin its nested snow-dominated sub-catchment Plan/Pfelders. New insights study assesses ERA5-Land's comparing outcomes. At annual scale, an overestimation precipitation about 40mm/month temperature underestimation 2.1 °C reported. These discrepancies influence simulations, resulting both snow water equivalent. It thus crucial consider limitations when using it application watersheds characterized terrains, such region.

Language: Английский

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Multi-decadal analysis of past winter temperature, precipitation and snow cover data in the European Alps from reanalyses, climate models and observational datasets

˜The œcryosphere, Journal Year: 2023, Volume and Issue: 17(8), P. 3617 - 3660

Published: Aug. 28, 2023

Abstract. Assessing past distributions, variability and trends in the mountain snow cover its first-order drivers, temperature precipitation, is key for a wide range of studies applications. In this study, we compare results various modeling systems (global regional reanalyses ERA5, ERA5-Land, ERA5-Crocus, CERRA-Land, UERRA MESCAN-SURFEX MTMSI climate model simulations CNRM-ALADIN CNRM-AROME driven by global reanalysis ERA-Interim) against observational references (in situ, gridded datasets satellite observations) across European Alps from 1950 to 2020. The comparisons are performed terms monthly seasonal variables (snow depth duration) their main atmospherical drivers (near-surface precipitation). We assess multi-annual averages subregional mean values, interannual variations, over timescales, mainly winter period (from November through April). MESCAN-SURFEX, CERRA-Land offer satisfying description evolution. However, spatial comparison observation indicates that all overestimate duration, especially melt-out date. ERA5-Land exhibit an overestimation accumulation during winter, increasing with elevations. analysis dynamics remains complex multiple scales none models evaluated here fully succeed reproduce compared reference datasets. Indeed, while most outputs perform well at representing multi-decadal precipitation variability, they often fail address duration. discuss several artifacts potentially responsible incorrect long-term products (ERA5 MESCAN-SURFEX), which attribute primarily heterogeneities assimilated. Nevertheless, many considered study line current state knowledge. Based on these datasets, last 50 years (1968–2017) scale, have experienced warming 0.3 0.4 ∘C per decade, stronger lower elevations, small reduction homogeneous elevation. decline duration ranges −7 % −15 decade −5 d respectively, both showing larger decrease low intermediate Overall, show no strategy outperforms others within our sample upstream choices (horizontal resolution, heterogeneity observations used data assimilation reanalyses, coupling between surface atmosphere, level complexity, configuration scheme, etc.) great consequences quality potential use. Despite limitations, cases can be characterize features

Language: Английский

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To the Origin of a Wintertime Screen-Level Temperature Bias at High Altitude in a Kilometric NWP Model

Journal of Hydrometeorology, Journal Year: 2022, Volume and Issue: 24(1), P. 53 - 71

Published: Oct. 26, 2022

Abstract High-resolution numerical weather prediction (NWP) systems present a strong potential to provide meteorological information in alpine terrain for diverse applications. However, they still suffer from biases highly detrimental practical purposes. In this study, we investigate the origin of significant wintertime screen-level temperature bias forecasts AROME-France NWP system high-altitude, snow-covered terrain. For purpose, thorough set and snow observations two high-altitude instrumental sites is used. Targeted simulations are carried out disentangle contributions coming atmospheric fields, scheme, coupling between snowpack atmosphere. At both sites, wind speed incoming longwave radiation appear significantly negatively biased AROME winter season. Using targeted offline simulations, show that simulation errors these fields contribute an average 67% AROME, while contribution shortwave negligible. Additionally, not majorly impacted by changes complexity especially vertical layering model. it appears particularly sensitive parameterization turbulent fluxes stable conditions. Evidence suggest findings could at least partially be generalized whole domain. Hence, reducing may great part proceed improving eliminating some compensations

Language: Английский

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Investigation on potential and limitations of ERA5 Reanalysis downscaled on Italy by a convection-permitting model

Climate Dynamics, Journal Year: 2023, Volume and Issue: 61(9-10), P. 4319 - 4342

Published: May 6, 2023

Abstract This study presents a comprehensive assessment of dynamical downscaling ERA5 Reanalysis recently performed over Italy through the COSMO-CLM model at convection-permitting scale (0.02°) period 1989–2020. Results are analysed against several independent observational datasets and reanalysis products. The capability to realistically represent climatology for 2 m temperature precipitation is whole peninsula subdomains. Hourly patterns, orography effects, urban climate dynamics also investigated, highlighting weaknesses strengths model. In particular, gains in performances achieved mountainous areas where characteristics correctly represented, as hourly characteristics. Losses occur coastal flat Italian peninsula, performance does not seem be satisfactory, opposed complex orographic areas. adopted parameterisation demonstrated simulate heat detection two cities: Rome Milan. Finally, subset extreme indicators evaluated, finding: ( i ) region-dependent response, ii notable iii discrepancies South, Central Insular Climate detect events detailed scale, becoming an important tool turning data into information.

Language: Английский

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Multi-decadal past winter temperature, precipitation and snow cover information over the European Alps using multiple datasets

Published: Feb. 8, 2023

Abstract. Assessing past distributions, variability and trends of the mountain snow cover its first order drivers, temperature precipitation, is key for a wide range studies applications. In this study, we compare results various modelling systems (global regional reanalyses ERA5, ERA5-Land, ERA5-Crocus, CERRA-Land, UERRA MESCAN-SURFEX, MTMSI, climate model simulations CNRM-ALADIN CNRM-AROME driven by global reanalysis ERA-Interim) against observational references (in-situ, kriged datasets satellite observations) across European Alps, from 1950 to 2020. The comparisons are performed in terms monthly seasonal variables (snow depth duration) their main atmospherical drivers (near-surface precipitation). We assess multi-annual averages sub-regional mean values, inter-annual variations, over time scales. simulations, ERA5-Land exhibit an overestimation accumulation during winter, increasing with elevations. CERRA-Land MTMSI offer satisfying description evolution albeit spatial comparison observation indicates that all overestimate duration cover, especially melt-out date. analysis indicate dynamics remain complex multiple scales, none models evaluated here fully succeed reproduce, compared reference datasets. Indeed, while most outputs perform well at representing multi-decadal winter precipitation variability, they often fail address duration. discuss several artifacts potentially responsible incorrect long-term products (ERA5 MESCAN-SURFEX), which attribute primarily heterogeneities assimilated. Reference some provides line current available literature. Over last 50 years (1968–2017) scale, Alps have experienced warming 0.3 0.4 °C per decade, weak reduction substantial decrease snowpack characteristics, decline reaching −10 % decade days respectively, low intermediate Overall, show no strategy outperforms others within our sample, upstream choices (horizontal resolution, heterogeneity observations used data assimilation reanalyses, coupling between surface atmosphere, level complexity configuration scheme etc.) great consequences on quality potential use. Despite limitations, many cases these modeling can be characterize features

Language: Английский

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Evaluation of the convection-permitting regional climate model CNRM-AROME41t1 over Northwestern Europe

Climate Dynamics, Journal Year: 2023, Volume and Issue: 62(6), P. 4587 - 4615

Published: Jan. 30, 2023

Abstract Since a decade, convection-permitting regional climate models (CPRCM) have emerged showing promising results, especially in improving the simulation of precipitation extremes. In this article, CPRCM CNRM-AROME developed at Centre National de Recherches Météorologiques (CNRM) since few years is described and evaluated using 2.5-km 19-year long hindcast over large northwestern European domain different observations through an added-value analysis which comparison with its driving 12-km RCM CNRM-ALADIN performed. The evaluation challenging due to lack high-quality both high temporal spatial resolutions. Thus, spatio-temporal observed gridded dataset was built from collection seven national datasets that helped identification added value CNRM-AROME. based on series standard climatic features include long-term means mean annual cycles near-surface temperature where shows little improvements compared CNRM-ALADIN. Additional indicators such as summer diurnal cycle indices extreme show, contrary, more realistic behaviour model. Moreover, snow cover clear simulation, principally improved description orography resolution. analyses incoming shortwave radiation, cloud satellite estimates. Overall, despite some systematic biases, indicates suitable superior many aspects

Language: Английский

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Evaluation of the convection permitting regional climate model CNRM-AROME on the orographically complex island of Corsica

Climate Dynamics, Journal Year: 2024, Volume and Issue: 62(6), P. 4673 - 4696

Published: May 11, 2024

Abstract Meteorological processes over islands with complex orography could be better simulated by Convection Permitting Regional Climate Models (CP-RCMs) thanks to an improved representation of the orography, land–sea contrasts, combination coastal and orographic effects, explicit deep convection. This paper evaluates ability CP-RCM CNRM-AROME (2.5-km horizontal resolution) simulate relevant meteorological characteristics Mediterranean island Corsica for 2000–2018 period. These hindcast simulations are compared their driving Model (RCM) CNRM-ALADIN (12.5-km resolution parameterised convection), weather stations precipitation wind gridded datasets. The main benefits found in (i) extremes resulting mainly from mesoscale convective systems affected steep mountains during autumn (ii) formation convection through thermally induced diurnal circulations interaction summer. Simulations hourly extremes, cycle precipitation, distribution intensities, duration events, sea breezes all 2.5-km respect RCM, confirming added value. However, existing differences between model observations difficult explain as biases related availability quality observations, particularly at high elevations. Overall, results resolution, increase our confidence CP-RCMs investigate future climate projections terrain.

Language: Английский

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Exploring the sensitivity to precipitation, blowing snow, and horizontal resolution of the spatial distribution of simulated snow cover

Published: Nov. 23, 2023

Abstract. Accurate snow cover modeling is a high stake for mountain regions. Alpine evolution and spatial variability result from multitude of complex processes including interactions between wind snow. The SnowPappus blowing model was designed to add capabilities the SURFEX/Crocus simulation system applications across large temporal extents. This paper presents very first spatialized evaluation this over 902 km2 domain in French Alps. Here we compare simulations distribution height obtained Pleiades satellites stereo-imagery Snow Melt-Out Dates Sentinel-2 time series three seasons. We analyzed sensitivity different precipitation datasets two horizontal resolutions. evaluations are presented as function elevation landform types. results show that forced with high-resolution fields enhances at elevations allowing better agreement observations above 2500 m near peaks ridges. Model improvements not obvious low medium altitudes where errors prevailing uncertainty. Our study illustrates necessity consider error contributions snow, forcings, unresolved subgrid robust simulations. Despite significant effect scales transport, 250 resolution using found be promising avenue large-scale alpine snowpacks.

Language: Английский

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Does a convection-permitting regional climate model bring new perspectives on the projection of Mediterranean floods?

Natural hazards and earth system sciences, Journal Year: 2024, Volume and Issue: 24(4), P. 1163 - 1183

Published: April 3, 2024

Abstract. Floods are the primary natural hazard in French Mediterranean area, causing damages and fatalities every year. These floods triggered by heavy precipitation events (HPEs) characterized limited temporal spatial extents. A new generation of regional climate models at kilometer scale have been developed, allowing an explicit representation deep convection improved simulations local-scale phenomena such as HPEs. Convection-permitting (CPMs) scarcely used hydrological impact studies, future projections remain uncertain with (RCMs). In this paper, we use CNRM-AROME CPM (2.5 km) its driving CNRM-ALADIN RCM (12 hourly timescale to simulate over Gardon d'Anduze catchment located region. Climate bias-corrected CDF-t method. Two models, a lumped conceptual model (GR5H) process-based distributed (CREST), forced historical from RCM, used. The confirms ability better reproduce extreme rainfall compared RCM. This added value is propagated on flood simulation reproduction peaks. Future consistent between but differ two models. Using magnitude all projected increase. With CPM, threshold effect found: largest expected intensify, while less severe decrease. addition, different event characteristics indicate that become flashier warmer climate, shorter lag time runoff peak smaller contribution base flow, regardless model. study first step for studies driven CPMs Mediterranean.

Language: Английский

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Spatial variability in the seasonal precipitation lapse rates in complex topographical regions – application in France

Hydrology and earth system sciences, Journal Year: 2024, Volume and Issue: 28(12), P. 2579 - 2601

Published: June 18, 2024

Abstract. Seasonal precipitation estimation in ungauged mountainous areas is essential for understanding and modeling a physical variable of interest many environmental applications (hydrology, ecology, cryospheric studies). Precipitation lapse rates (PLRs), defined as the increasing or decreasing rate amounts with elevation, play decisive role high-altitude estimation. However, documentation PLR regions remains weak even though their utilization frequent. This article intends to assess spatial variability spatial-scale dependence seasonal PLRs varied complex topographical region. At regional scale (10 000 km2), seven different products are compared ability reproduce altitude annual/seasonal 1836 stations located France. The convection-permitting climate model (CP-RCM) AROME best this regard, despite severe overestimation high altitudes. fine resolution allows precise assessment influence on winter summer 23 massifs at sub-regional (∼ 1000 km2) 2748 small catchments 100 through linear regressions. With AROME, often higher catchment scale. such French Alps, border than inside massifs. study emphasizes conducting investigation reduce heterogeneity precipitation–altitude relationships.

Language: Английский

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