The impact of precipitation evaporation on the atmospheric aerosol distribution in EC-Earth v3.2.0

Abstract. The representation of aerosol-cloud interaction in global climate models (GCMs) remains a large source of uncertainty in climate projections. Due to its complexity, precipitation evaporation is either ignored or taken into account in a simplified manner in GCMs. This research explores various ways to treat aerosol resuspension and determines the possible impact of precipitation evaporation and subsequent aerosol resuspension on global aerosol burdens and distribution. The representation of wet deposition of aerosols by large-scale precipitation in the EC-Earth model has been improved by utilising additional precipitation related 3-D fields from the dynamical core IFS in the chemistry and aerosol module TM5. A simple approach of scaling aerosol release with evaporated precipitation fraction leads to an increase in the global aerosol burden (+7.8 to +15 %, for different aerosol species). However, when taking into account the different sizes and evaporation rate of raindrops following Gong et al. (2006), the release of aerosols is strongly reduced, and the total aerosol burden decreases by −3.0 to −8.5 %. Moreover, inclusion of cloud processing based on observations by Mitra et al. (1992) transforms scavenged small aerosol to coarse particles, which enhances removal by sedimentation and hence leads to a lower burden of small size aerosol by −10 to −11 %. Finally, when these two effects are combined the global aerosol burden decreases by −11 to −19 %. Compared to MODIS satellite observations, AOD is generally underestimated in most parts of the world in all model set-ups and although the representation is now physically more realistic, global AOD shows no large improvements in spatial patterns. Similarly, the agreement of the vertical profile with CALIOP satellite measurements does not improve significantly. However, aerosol resuspension after precipitation evaporation has a considerable impact on the modelled aerosol distribution and needs to be taken into account.

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The impact of precipitation evaporation on the atmospheric aerosol distribution in EC-Earth v3.2.0

Geoscientific Model Development ◽

10.5194/gmd-11-1443-2018 ◽

2018 ◽

Vol 11 (4) ◽

pp. 1443-1465 ◽

Cited By ~ 3

Author(s):

Marco de Bruine ◽

Maarten Krol ◽

Twan van Noije ◽

Philippe Le Sager ◽

Thomas Röckmann

Keyword(s):

General Circulation ◽

Large Scale ◽

Climate Models ◽

Circulation Model ◽

Global Climate Models ◽

Orthogonal Polarization ◽

Earth Model ◽

Climate Projections ◽

Aerosol Distribution ◽

The Impact

Abstract. The representation of aerosol–cloud interaction in global climate models (GCMs) remains a large source of uncertainty in climate projections. Due to its complexity, precipitation evaporation is either ignored or taken into account in a simplified manner in GCMs. This research explores various ways to treat aerosol resuspension and determines the possible impact of precipitation evaporation and subsequent aerosol resuspension on global aerosol burdens and distribution. The representation of aerosol wet deposition by large-scale precipitation in the EC-Earth model has been improved by utilising additional precipitation-related 3-D fields from the dynamical core, the Integrated Forecasting System (IFS) general circulation model, in the chemistry and aerosol module Tracer Model, version 5 (TM5). A simple approach of scaling aerosol release with evaporated precipitation fraction leads to an increase in the global aerosol burden (+7.8 to +15 % for different aerosol species). However, when taking into account the different sizes and evaporation rate of raindrops following Gong et al. (2006), the release of aerosols is strongly reduced, and the total aerosol burden decreases by −3.0 to −8.5 %. Moreover, inclusion of cloud processing based on observations by Mitra et al. (1992) transforms scavenged small aerosol to coarse particles, which enhances removal by sedimentation and hence leads to a −10 to −11 % lower aerosol burden. Finally, when these two effects are combined, the global aerosol burden decreases by −11 to −19 %. Compared to the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite observations, aerosol optical depth (AOD) is generally underestimated in most parts of the world in all configurations of the TM5 model and although the representation is now physically more realistic, global AOD shows no large improvements in spatial patterns. Similarly, the agreement of the vertical profile with Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) satellite measurements does not improve significantly. We show, however, that aerosol resuspension has a considerable impact on the modelled aerosol distribution and needs to be taken into account.

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Assessing the effects of climate change on US West Coast sablefish productivity and on the performance of alternative management strategies

ICES Journal of Marine Science ◽

10.1093/icesjms/fsz029 ◽

2019 ◽

Vol 76 (6) ◽

pp. 1524-1542

Author(s):

Melissa A Haltuch ◽

Z Teresa A’mar ◽

Nicholas A Bond ◽

Juan L Valero

Keyword(s):

Climate Change ◽

West Coast ◽

Large Scale ◽

Climate Models ◽

Global Climate ◽

Management Strategies ◽

Climate Impacts ◽

Global Climate Models ◽

The Impact ◽

Us West

Abstract US West Coast sablefish are economically valuable, with landings of 11.8 million pounds valued at over $31 million during 2016, making assessing and understanding the impact of climate change on the California Current (CC) stock a priority for (1) forecasting future stock productivity, and (2) testing the robustness of management strategies to climate impacts. Sablefish recruitment is related to large-scale climate forcing indexed by regionally correlated sea level (SL) and zooplankton communities that pelagic young-of-the-year sablefish feed upon. This study forecasts trends in future sablefish productivity using SL from Global Climate Models (GCMs) and explores the robustness of harvest control rules (HCRs) to climate driven changes in recruitment using management strategy evaluation (MSE). Future sablefish recruitment is likely to be similar to historical recruitment but may be less variable. Most GCMs suggest that decadal SL trends result in recruitments persisting at lower levels through about 2040 followed by higher levels that are more favorable for sablefish recruitment through 2060. Although this MSE suggests that spawning biomass and catches will decline, and then stabilize, into the future under both HCRs, the sablefish stock does not fall below the stock size that leads to fishery closures.

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Process-oriented analysis of aircraft soot-cirrus interactions constrains the climate impact of aviation

Communications Earth & Environment ◽

10.1038/s43247-021-00175-x ◽

2021 ◽

Vol 2 (1) ◽

Author(s):

Bernd Kärcher ◽

Fabian Mahrt ◽

Claudia Marcolli

Keyword(s):

Radiative Forcing ◽

Large Scale ◽

Climate Models ◽

Climate Model ◽

Global Climate ◽

Climate Impact ◽

Global Climate Models ◽

Soot Particles ◽

Cloud Ice ◽

The Impact

AbstractFully accounting for the climate impact of aviation requires a process-level understanding of the impact of aircraft soot particle emissions on the formation of ice clouds. Assessing this impact with the help of global climate models remains elusive and direct observations are lacking. Here we use a high-resolution cirrus column model to investigate how aircraft-emitted soot particles, released after ice crystals sublimate at the end of the lifetime of contrails and contrail cirrus, perturb the formation of cirrus. By allying cloud simulations with a measurement-based description of soot-induced ice formation, we find that only a small fraction (<1%) of the soot particles succeeds in forming cloud ice alongside homogeneous freezing of liquid aerosol droplets. Thus, soot-perturbed and homogeneously-formed cirrus fundamentally do not differ in optical depth. Our results imply that climate model estimates of global radiative forcing from interactions between aircraft soot and large-scale cirrus may be overestimates. The improved scientific understanding reported here provides a process-based underpinning for improved climate model parametrizations and targeted field observations.

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Estimating the potential impact of climate change on sunflower yield in the Konya province of Turkey

The Journal of Agricultural Science ◽

10.1017/s0021859621000101 ◽

2021 ◽

pp. 1-13

Author(s):

Hudaverdi Gurkan ◽

Vakhtang Shelia ◽

Nilgun Bayraktar ◽

Y. Ersoy Yildirim ◽

Nebi Yesilekin ◽

...

Keyword(s):

Climate Change ◽

Climate Models ◽

Global Climate ◽

Model Performance ◽

Global Climate Models ◽

Climate Projections ◽

Climate Change Scenarios ◽

Adaptation To Climate Change ◽

Impact Of Climate Change ◽

The Impact

Abstract The impact of climate change on agricultural productivity is difficult to assess. However, determining the possible effects of climate change is an absolute necessity for planning by decision-makers. The aim of the study was the evaluation of the CSM-CROPGRO-Sunflower model of DSSAT4.7 and the assessment of impact of climate change on sunflower yield under future climate projections. For this purpose, a 2-year sunflower field experiment was conducted under semi-arid conditions in the Konya province of Turkey. Rainfed and irrigated treatments were used for model analysis. For the assessment of impact of climate change, three global climate models and two representative concentration pathways, i.e. 4.5 and 8.5 were selected. The evaluation of the model showed that the model was able to simulate yield reasonably well, with normalized root mean square error of 1.3% for the irrigated treatment and 17.7% for the rainfed treatment, a d-index of 0.98 and a modelling efficiency of 0.93 for the overall model performance. For the climate change scenarios, the model predicted that yield will decrease in a range of 2.9–39.6% under rainfed conditions and will increase in a range of 7.4–38.5% under irrigated conditions. Results suggest that temperature increases due to climate change will cause a shortening of plant growth cycles. Projection results also confirmed that increasing temperatures due to climate change will cause an increase in sunflower water requirements in the future. Thus, the results reveal the necessity to apply adequate water management strategies for adaptation to climate change for sunflower production.

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Summer Season Squall-Line Simulations: Sensitivity of Gravity Waves to Physics Parameterization and Implications for Their Parameterization in Global Climate Models

Journal of the Atmospheric Sciences ◽

10.1175/jas-d-13-0380.1 ◽

2014 ◽

Vol 71 (9) ◽

pp. 3376-3391 ◽

Cited By ~ 14

Author(s):

Claudia Stephan ◽

M. Joan Alexander

Keyword(s):

Gravity Waves ◽

Momentum Flux ◽

Large Scale ◽

Climate Models ◽

Climate Model ◽

Middle Atmosphere ◽

Global Climate ◽

Global Climate Models ◽

Squall Line ◽

The Impact

Abstract Gravity waves have important effects on the middle atmosphere circulation, and those generated by convection are prevalent in the tropics and summer midlatitudes. Numerous case studies have been carried out to investigate their characteristics in high-resolution simulations. Here, the impact of the choice of physics parameterizations on the generation and spectral properties of these waves in models is investigated. Using the Weather Research and Forecasting Model (WRF) a summertime squall line over the Great Plains is simulated in a three-dimensional, nonlinear, and nonhydrostatic mesoscale framework. The distributions of precipitation strength and echo tops in the simulations are compared with radar data. Unsurprisingly, those storm features are most sensitive to the microphysics scheme. However, it is found that these variations in storm morphology have little influence on the simulated stratospheric momentum flux spectra. These results support the fundamental idea behind climate model parameterizations: that the large-scale storm conditions can be used to predict the spectrum of gravity wave momentum flux above the storm irrespective of the convective details that coarse-resolution models cannot capture. The simulated spectra are then contrasted with those obtained from a parameterization used in global climate models. The parameterization reproduces the shape of the spectra reasonably well but their magnitudes remain highly sensitive to the peak heating rate within the convective cells.

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Differential Credibility Assessment for Statistical Downscaling

Journal of Applied Meteorology and Climatology ◽

10.1175/jamc-d-19-0296.1 ◽

2020 ◽

Vol 59 (8) ◽

pp. 1333-1349

Author(s):

S. C. Pryor ◽

J. T. Schoof

Keyword(s):

Large Scale ◽

Climate Models ◽

Linear Models ◽

Transfer Functions ◽

Global Climate ◽

Global Climate Models ◽

Maximum Temperature ◽

Climate Projections ◽

Climate Extreme ◽

Credibility Assessment

AbstractClimate science is increasingly using (i) ensembles of climate projections from multiple models derived using different assumptions and/or scenarios and (ii) process-oriented diagnostics of model fidelity. Efforts to assign differential credibility to projections and/or models are also rapidly advancing. A framework to quantify and depict the credibility of statistically downscaled model output is presented and demonstrated. The approach employs transfer functions in the form of robust and resilient generalized linear models applied to downscale daily minimum and maximum temperature anomalies at 10 locations using predictors drawn from ERA-Interim reanalysis and two global climate models (GCM; GFDL-ESM2M and MPI-ESM-LR). The downscaled time series are used to derive several impact-relevant Climate Extreme (CLIMDEX) temperature indices that are assigned credibility based on 1) the reproduction of relevant large-scale predictors by the GCMs (i.e., fraction of regression beta weights derived from predictors that are well reproduced) and 2) the degree of variance in the observations reproduced in the downscaled series following application of a new variance inflation technique. Credibility of the downscaled predictands varies across locations and between the two GCM and is generally higher for minimum temperature than for maximum temperature. The differential credibility assessment framework demonstrated here is easy to use and flexible. It can be applied as is to inform decision-makers about projection confidence and/or can be extended to include other components of the transfer functions, and/or used to weight members of a statistically downscaled ensemble.

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Impact of large-scale future floods on the railway system

10.5194/egusphere-egu2020-6376 ◽

2020 ◽

Author(s):

Weiping Wang ◽

Saini Yang ◽

Huijun Sun ◽

Jianjun Wu ◽

Jianxi Gao

Keyword(s):

Large Scale ◽

Climate Models ◽

Negative Impact ◽

Global Climate ◽

Global Climate Models ◽

Policy Implications ◽

Transport Sector ◽

Railway Network ◽

Railway System ◽

The Impact

Increasing flood risk was caused by expanding climate change. The floods directly or indirectly disrupt the railway system and arise a significant negative impact on our social-economic system. This study developed an integrated approach to explore the impact of large-scale future floods on railway system. Firstly, A three layered traffic flow simulation model was constructed to study propagation and amplification effects of component failure after the event of flooding in the system. Secondly, future runoff scenarios were produced by using five global climate models and three different representative concentration pathways. The future floods was simulated by using CaMa-Flood model after inputting future runoff scenarios. Furthermore, we imposing simulated future floods into traffic simulation system and develop two measurements to evaluate the impact of floods on the railway system as the perspective of the entire system. Here we explore the impact of floods on the real-world highway network of China. The results illustrate that: (i) Unprecedented uncertainty. The damage of the flood to the railway system is not linearly and positively correlated with representative concentration pathway and the year within different global climate models; Floods in different years have different impacts in connections among regions; (ii) Unacceptable damage. 59.76 % of railway segments inundated and 98.61461% of large cities could not be reached by extreme floods. These results have critical policy implications for the transport sector in reference to railway location and design, railway network optimization and protection and can be also easily adapted to analyze other spatial damages for valuable protection suggestions.

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An Assessment of Land–Atmosphere Interactions over South America Using Satellites, Reanalysis, and Two Global Climate Models

Journal of Hydrometeorology ◽

10.1175/jhm-d-20-0132.1 ◽

2021 ◽

Vol 22 (4) ◽

pp. 905-922

Author(s):

Jessica C. A. Baker ◽

Dayana Castilho de Souza ◽

Paulo Y. Kubota ◽

Wolfgang Buermann ◽

Caio A. S. Coelho ◽

...

Keyword(s):

South America ◽

Large Scale ◽

Climate Models ◽

Hydrological Cycle ◽

Global Climate ◽

Atlantic Coast ◽

Global Climate Models ◽

Climate Projections ◽

Median Response ◽

Model Version

AbstractIn South America, land–atmosphere interactions have an important impact on climate, particularly the regional hydrological cycle, but detailed evaluation of these processes in global climate models has been limited. Focusing on the satellite-era period of 2003–14, we assess land–atmosphere interactions on annual to seasonal time scales over South America in satellite products, a novel reanalysis (ERA5-Land), and two global climate models: the Brazilian Global Atmospheric Model version 1.2 (BAM-1.2) and the U.K. Hadley Centre Global Environment Model version 3 (HadGEM3). We identify key features of South American land–atmosphere interactions represented in satellite and model datasets, including seasonal variation in coupling strength, large-scale spatial variation in the sensitivity of evapotranspiration to surface moisture, and a dipole in evaporative regime across the continent. Differences between products are also identified, with ERA5-Land, HadGEM3, and BAM-1.2 showing opposite interactions to satellites over parts of the Amazon and the Cerrado and stronger land–atmosphere coupling along the North Atlantic coast. Where models and satellites disagree on the strength and direction of land–atmosphere interactions, precipitation biases and misrepresentation of processes controlling surface soil moisture are implicated as likely drivers. These results show where improvement of model processes could reduce uncertainty in the modeled climate response to land-use change, and highlight where model biases could unrealistically amplify drying or wetting trends in future climate projections. Finally, HadGEM3 and BAM-1.2 are consistent with the median response of an ensemble of nine CMIP6 models, showing they are broadly representative of the latest generation of climate models.

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A different perspective on how parameterized orographic gravity waves influence atmospheric transport and dynamics in current generation global climate models

10.5194/egusphere-egu2020-4171 ◽

2020 ◽

Author(s):

Harald Rieder ◽

Petr Šácha ◽

Roland Eichinger ◽

Aleš Kuchař ◽

Nadja Samtleben ◽

...

Keyword(s):

Gravity Waves ◽

Large Scale ◽

Climate Models ◽

Atmospheric Transport ◽

Global Climate ◽

Internal Gravity Waves ◽

Global Climate Models ◽

Current Generation ◽

The Individual ◽

The Impact

In the atmosphere, internal gravity waves (GWs) are a naturally occurring and ubiquitous, though intermittent phenomenon. In addition, GWs (especially orographic; OGWs) are asymmetrically distributed around the globe. In current generation global climate models (GCMs), GWs are usually smaller than the model grid resolution and the majority of their spectrum therefore must be parameterized. To some extent, the intermittency and asymmetry of a spatial distribution of the resulting OGW drag (OGWD) is present also in GCMs. As the GW parameterization schemes in GCMs are usually tuned to get the zonal mean climatology of particular features right, an important question emerges: what kind of influence do GW parameterizations have on the individual models atmosphere locally? Here we focus on answering this question regarding the impact of spatiotemporally intermittent OGW forcing in the extra-tropical lower stratosphere region (LS). The LS region is characterized by a strong interplay of chemical, physical and dynamical processes. To date, the representation of this dynamically active region in models frequently mismatches observations. Although we can find a climatological maximum of oGWD in the LS, the role of OGW forcing for the transport and composition in this region is poorly understood. We combine observational evidence, idealized modeling and statistical analysis of GCM outputs to study both the short-term and long-term model response to the OGW forcing. The results presented will question the relationship between the advective part of the Brewer- Dobson circulation and the zonally asymmetric GW forcing, and a so-far neglected link between oGWD and large-scale quasi-isentropic stirring will be discussed.

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Risk for large-scale fires in boreal forests of Finland under changing climate

Natural Hazards and Earth System Sciences Discussions ◽

10.5194/nhessd-3-4753-2015 ◽

2015 ◽

Vol 3 (8) ◽

pp. 4753-4795

Author(s):

I. Lehtonen ◽

A. Venäläinen ◽

M. Kämäräinen ◽

H. Peltola ◽

H. Gregow

Keyword(s):

Forest Fires ◽

Large Scale ◽

Climate Models ◽

Global Climate ◽

Mapping Method ◽

Global Climate Models ◽

Burned Area ◽

Fire Weather Index ◽

Short Period ◽

The Impact

Abstract. The target of this work was to assess the impact of projected climate change on the number of large forest fires (over 10 ha fires) and burned area in Finland. For this purpose, we utilized a strong relationship between fire occurrence and the Canadian fire weather index (FWI) during 1996–2014. We used daily data from five global climate models under representative concentration pathway RCP4.5 and RCP8.5 scenarios. The model data were statistically downscaled onto a high-resolution grid using the quantile-mapping method before performing the analysis. Our results suggest that the number of large forest fires may double or even triple during the present century. This would increase the risk that some of the fires could develop into real conflagrations which have become almost extinct in Finland due to active and efficient fire suppression. Our results also reveal substantial inter-model variability in the rate of the projected increase in forest-fire danger. We moreover showed that the majority of large fires occur within a relatively short period in May and June due to human activities and that FWI correlates poorer with the fire activity during this time of year than later in summer when lightning is more important cause of fires.

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