scholarly journals Issues in Simulating the Annual Precipitation of a Semiarid Region in Central Spain

2005 ◽  
Vol 6 (4) ◽  
pp. 409-422 ◽  
Author(s):  
N. Hasler ◽  
R. Avissar ◽  
G. E. Liston
Keyword(s):  
High Resolution ◽  
Climate Models ◽  
Domain Size ◽  
Atmospheric Modeling ◽  
Annual Rainfall ◽  
Semiarid Region ◽  
Central Spain ◽  
Small Domain ◽  
The Impact ◽  
Dry Bias

Abstract Running regional climate models at a high resolution may improve their ability to simulate regional precipitation patterns, making them suitable for studying the impact of human-induced land-cover changes on hydrometeorology. The performance of the Regional Atmospheric Modeling System (RAMS) run in the high-resolution climate mode (4-km grid mesh) has been tested over a small domain in a semiarid region in central Spain. Three 1-yr simulations representing dry, intermediate, and wet conditions were compared to observations collected in 35 rain gauges. The model captured general spatiotemporal features of precipitation, such as the timing of precipitation events and approximate location of storms. A high correlation (0.82) between monthly domain-averaged observed and modeled precipitation was obtained. However, the model had a systematic dry bias, averaging −0.29 mm day−1, equivalent to 26% of annual rainfall. The small domain size, chosen because of computational limits, induced strong lateral boundary forcing, which, combined with uncertainty in NCEP relative humidity fields, was a likely cause for this dry bias.

scholarly journals Numerical analysis of the impact of agricultural emissions on PM<sub>2.5</sub> in China using a high-resolution ammonia emissions inventory

2020 ◽  
Author(s):  
Xiao Han ◽  
Lingyun Zhu ◽  
Mingxu Liu ◽  
Yu Song ◽  
Meigen Zhang
Keyword(s):  
Air Quality ◽  
High Resolution ◽  
Source Apportionment ◽  
Mass Concentration ◽  
Atmospheric Modeling ◽  
Central China ◽  
High Mass ◽  
Emissions Inventory ◽  
Aerosol Mass Concentration ◽  
The Impact

Abstract. China is one of the largest agricultural countries in the world. The NH3 emissions from agricultural activities in China significantly affect regional air quality and horizontal visibility. To reliably estimate the influence of NH3 on agriculture, a high-resolution agricultural NH3 emissions inventory, compiled with a 1 km × 1 km horizontal resolution, was applied to calculate the NH3 mass burden in China. The key emission factors of this inventory were enhanced by considering the results of many native experiments, and the activity data of spatial and temporal information were updated using statistical data from 2015. Fertilizer and husbandry, as well as farmland ecosystems, livestock waste, crop residue burning, fuel wood combustion, and other NH3 emission sources were included in the inventory. Furthermore, a source apportionment tool, ISAM (Integrated Source Apportionment Method), coupled with the air quality modeling system RAMS-CMAQ (Regional Atmospheric Modeling System and Community Multiscale Air Quality), was applied to capture the contribution of NH3 emitted from total agriculture (Tagr) in China. The aerosol mass concentration in 2015 was simulated, and the results showed that a high mass concentration of NH3, which exceeded 10 μg m−3, appeared mainly in the North China Plain (NCP), Central China (CNC), the Yangtz River Delta (YRD), and the Sichan Basin (SCB), and the annual average contribution of Tagr NH3 to PM2.5 mass burden in China was 14–18 %. Specific to the PM2.5 components, Tagr NH3 provided a major contribution to ammonium formation (87.6 %) but a tiny contribution to sulfate (2.2 %). In addition, several brute-force sensitivity tests were conducted to estimate the impact of Tagr NH3 emissions reduction on the PM2.5 mass burden. Compared with the results of ISAM, it was found that even though the Tagr NH3 only contributed 10.1 % of nitrate under current emissions scenarios, the reduction of nitrate could reach 98.8 % upon removal of the Tagr NH3 emissions. The main reason for this deviation could be that the NH3 contribution to nitrate is small under rich NH3 conditions and large in poor NH3 environments. Thus, the influence of NH3 on nitrate formation could be enhanced with the decrease of ambient NH3 mass concentration.

scholarly journals Reconstructing Flood Events in Mediterranean Coastal Areas Using Different Reanalyses and High-Resolution Meteorological Models

2020 ◽  
Vol 21 (8) ◽  
pp. 1865-1887
Author(s):  
A. Senatore ◽  
S. Davolio ◽  
L. Furnari ◽  
G. Mendicino
Keyword(s):  
High Resolution ◽  
Climate Models ◽  
Hydrological Model ◽  
Numerical Models ◽  
Heavy Precipitation ◽  
High Impact ◽  
Added Value ◽  
Distributed Hydrological Model ◽  
The Impact ◽  
Small Catchments

AbstractReliable reanalysis products can be exploited to drive mesoscale numerical models and generate high-resolution reconstructions of high-impact weather events. Within this framework, regional weather and climate models may greatly benefit from the recent release of the ERA5 product, an improvement to the ERA-Interim dataset. In this study, two different convection-permitting models driven by these two reanalysis datasets are used to reproduce three heavy precipitation events affecting a Mediterranean region. Moreover, different sea surface temperature (SST) initializations are tested to assess how higher-resolution SST fields improve the simulation of high-impact events characterized by strong air–sea interactions. Finally, the coupling with a distributed hydrological model allows evaluating the impact at the ground, specifically assessing the possible added value of the ERA5 dataset for the high-resolution simulation of extreme hydrometeorological events over the Calabria region (southern Italy). Results, based on the comparison against multiple-source precipitation observations, show no clear systematic benefit to using the ERA5 dataset; moreover, intense convective activity can introduce uncertainties masking the signal provided by the boundary conditions of the different reanalyses. The effect of the high-resolution SST fields is even more difficult to detect. The uncertainties propagate and amplify along the modeling chain, where the spatial resolution increases up to the hydrological model. Nevertheless, even in very small catchments, some of the experiments provide reasonably accurate results, suggesting that an ensemble approach could be suitable to cope with uncertainties affecting the overall meteo-hydrological chain, especially for small catchments.

scholarly journals High-Resolution Climate Change Impact Analysis on Medium-Sized River Catchments in Germany: An Ensemble Assessment

2013 ◽  
Vol 14 (4) ◽  
pp. 1175-1193 ◽  
Author(s):  
Irena Ott ◽  
Doris Duethmann ◽  
Joachim Liebert ◽  
Peter Berg ◽  
Hendrik Feldmann ◽  
...  
Keyword(s):  
Climate Change ◽  
High Resolution ◽  
Impact Analysis ◽  
Climate Models ◽  
Global Climate Models ◽  
Climate Change Signal ◽  
Climate Modelling ◽  
Community Land Model ◽  
The Impact ◽  
River Catchments

Abstract The impact of climate change on three small- to medium-sized river catchments (Ammer, Mulde, and Ruhr) in Germany is investigated for the near future (2021–50) following the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) A1B scenario. A 10-member ensemble of hydrological model (HM) simulations, based on two high-resolution regional climate models (RCMs) driven by two global climate models (GCMs), with three realizations of ECHAM5 (E5) and one realization of the Canadian Centre for Climate Modelling and Analysis version 3 (CCCma3; C3) is established. All GCM simulations are downscaled by the RCM Community Land Model (CLM), and one realization of E5 is downscaled also with the RCM Weather Research and Forecasting Model (WRF). This concerted 7-km, high-resolution RCM ensemble provides a sound basis for runoff simulations of small catchments and is currently unique for Germany. The hydrology for each catchment is simulated in an overlapping scheme, with two of the three HMs used in the project. The resulting ensemble hence contains for each chain link (GCM–realization–RCM–HM) at least two members and allows the investigation of qualitative and limited quantitative indications of the existence and uncertainty range of the change signal. The ensemble spread in the climate change signal is large and varies with catchment and season, and the results show that most of the uncertainty of the change signal arises from the natural variability in winter and from the RCMs in summer.

scholarly journals Climate changes of hydrometeorological and hydrological extremes in the Paute basin, Ecuadorean Andes

2014 ◽  
Vol 18 (2) ◽  
pp. 631-648 ◽  
Author(s):  
D. E. Mora ◽  
L. Campozano ◽  
F. Cisneros ◽  
G. Wyseure ◽  
P. Willems
Keyword(s):  
Climate Change ◽  
Climate Models ◽  
Potential Evapotranspiration ◽  
High Peak ◽  
Annual Rainfall ◽  
Climate Change Signal ◽  
Perturbation Approach ◽  
Peak Flows ◽  
Ipcc Sres ◽  
The Impact

Abstract. Investigation was made on the climate change signal for hydrometeorological and hydrological variables along the Paute River basin, in the southern Ecuador Andes. An adjusted quantile perturbation approach was used for climate downscaling, and the impact of climate change on runoff was studied for two nested catchments within the basin. The analysis was done making use of long daily series of seven representative rainfall and temperature sites along the study area and considering climate change signals of global and regional climate models for IPCC SRES scenarios A1B, A2 and B1. The determination of runoff was carried out using a lumped conceptual rainfall–runoff model. The study found that the range of changes in temperature is homogeneous for almost the entire region with an average annual increase of approximately +2.0 &amp;degC. However, the warmest periods of the year show lower changes than the colder periods. For rainfall, downscaled results project increases in the mean annual rainfall depth and the extreme daily rainfall intensities along the basin for all sites and all scenarios. Higher changes in extreme rainfall intensities are for the wetter region. These lead to changes in catchment runoff flows, with increasing high peak flows and decreasing low peak flows. The changes in high peak flows are related to the changes in rainfall extremes, whereas the decreases in the low peak flows are due to the increase in temperature and potential evapotranspiration together with the reduction in the number of wet days.

Examining the vulnerability of Australian eucalypts to future drought-induced tree mortality

2021 ◽  
Author(s):  
Martin De Kauwe ◽  
Manon Sabot ◽  
Andrew Pitman ◽  
Sami Rifai ◽  
Patrick Meir ◽  
...  
Keyword(s):  
Climate Change ◽  
Land Surface ◽  
Tree Mortality ◽  
Climate Models ◽  
Global Climate Models ◽  
Annual Rainfall ◽  
Surface Model ◽  
Eucalyptus Species ◽  
Drought Risk ◽  
The Impact

&lt;p&gt;Australia is the driest inhabited continent. Annual rainfall is low and is accompanied by marked inter-annual variability, leading to multi-year droughts. Climate change is expected to alter the frequency, magnitude, and intensity of future droughts, with potentially major environmental and socio-economic consequences for Australia. However, Australian vegetation is well adapted to extended dry periods, thus, the likelihood of drought-induced mortality in the future depends both on the severity of future drought events and inherent vegetation resilience. Here, we used the Community Atmosphere Biosphere Land Exchange (CABLE) land surface model, coupled with a stomatal optimisation scheme, to examine the projected impact of future drought for 24 Eucalyptus species. We forced CABLE with future climate from four global climate models (MIROC, ECHAM, CCCMA, and CSIRO) dynamically downscaled by three regional climate models. We separated the impact of climate change (e.g. increasing VPD, precipitation variability) from rising CO&lt;sub&gt;2&lt;/sub&gt; (increasing water use-efficiency) to provide the first assessment of future drought risk to Australian trees.&lt;/p&gt;

Meridional distribution of moisture transport associated to Tropical Cyclones

2020 ◽  
Author(s):  
Daniele Peano ◽  
Enrico Scoccimarro ◽  
Alessio Bellucci ◽  
Malcolm Roberts ◽  
Annalisa Cherchi ◽  
...  
Keyword(s):  
Water Vapor ◽  
High Resolution ◽  
Tropical Cyclones ◽  
Moisture Transport ◽  
Climate Models ◽  
Climate Model ◽  
Water Vapor Transport ◽  
The North ◽  
Good Ability ◽  
The Impact

&lt;p&gt;Tropical cyclones (TCs) transport energy and moisture along their pathways interacting with the climate system and TCs activities are expected to extend further poleward during the 21&lt;sup&gt;st&lt;/sup&gt; century.&lt;/p&gt;&lt;p&gt;For this reason, it is important to assess the ability of state-of-the-art climate models in reproducing an accurate meridional distribution of TCs as well as a reasonable meridional portrait of moisture transport associated with TCs.&lt;/p&gt;&lt;p&gt;Since high resolutions are required to reconstruct observed TCs activity, the present work is based on the simulations performed as part of HighResMIP in the framework of the community CMIP6 effort. To inspect this feature, two horizontal resolutions for each climate model are considered. Besides, the impact of boundary conditions, i.e. observed ocean surface state, is examined by considering both coupled and atmosphere-only configurations.&lt;/p&gt;&lt;p&gt;In the present work, the north Atlantic region is analyzed as a sample region, while the same approach is applied on a multi-basin basis. In the sample area, climate models present a good ability in reproducing the TCs distribution, with a general underestimation at lower latitudes and a slight overestimation at high-latitudes compared to observed TCs tracks (e.g. IBTRACK).&lt;/p&gt;&lt;p&gt;The meridional distribution of moisture transport associated with TCs is evaluated by considering the radial average of the integrated water vapor transport along the TC tracks. When compared to observation (IBTRACS and JRA-55 reanalysis), the simulated moisture transport associated with TCs displays reasonably good performance in atmosphere-only high-resolution models configuration. The interannual variability of water vapor associated with TCs, instead, is poorly represented in climate models.&lt;/p&gt;&lt;p&gt;Climate models in high-resolution configuration can then be used in estimating future TCs meridional distribution and changes in meridional moisture transport associated with TCs.&lt;/p&gt;&lt;p&gt;This effort is part of HighResMIP and it is developed in the framework of the EU-funded PRIMAVERA project.&amp;#160;&amp;#160;&amp;#160;&lt;/p&gt;

The Forcing of Southwestern Asia Teleconnections by Low-Frequency Sea Surface Temperature Variability during Boreal Winter

2015 ◽  
Vol 28 (4) ◽  
pp. 1511-1526 ◽  
Author(s):  
Andrew Hoell ◽  
Chris Funk ◽  
Mathew Barlow
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Land Surface ◽  
Climate Models ◽  
Empirical Orthogonal Functions ◽  
Sea Surface ◽  
Annual Rainfall ◽  
Semiarid Region ◽  
Boreal Winter ◽  
Sst Variability

Abstract Southwestern Asia, defined here as the domain bounded by 20°–40°N and 40°–70°E, which includes the nations of Iraq, Iran, Afghanistan, and Pakistan, is a water-stressed and semiarid region that receives roughly 75% of its annual rainfall during November–April. The November–April climate of southwestern Asia is strongly influenced by tropical Indo-Pacific variability on intraseasonal and interannual time scales, much of which can be attributed to sea surface temperature (SST) variations. The influences of lower-frequency SST variability on southwestern Asia climate during November–April Pacific decadal SST (PDSST) variability and the long-term trend in SST (LTSST) is examined. The U.S. Climate Variability and Predictability Program (CLIVAR) Drought Working Group forced global atmospheric climate models with PDSST and LTSST patterns, identified using empirical orthogonal functions, to show the steady atmospheric response to these modes of decadal to multidecadal SST variability. During November–April, LTSST forces an anticyclone over southwestern Asia, which results in reduced precipitation and increases in surface temperature. The precipitation and tropospheric circulation influences of LTSST are corroborated by independent observed precipitation and circulation datasets during 1901–2004. The decadal variations of southwestern Asia precipitation may be forced by PDSST variability, with two of the three models indicating that the cold phase of PDSST forces an anticyclone and precipitation reductions. However, there are intermodel circulation variations to PDSST that influence subregional precipitation patterns over the Middle East, southwestern Asia, and subtropical Asia. Changes in wintertime temperature and precipitation over southwestern Asia forced by LTSST and PDSST imply important changes to the land surface hydrology during the spring and summer.

scholarly journals Climatic impact of Arctic Ocean methane hydrate dissociation in the 21<sup>st</sup>-century

2017 ◽  
Author(s):  
Sunil Vadakkepuliyambatta ◽  
Ragnhild B. Skeie ◽  
Gunnar Myhre ◽  
Stig B. Dalsøren ◽  
Anna Silyakova ◽  
...  
Keyword(s):  
Arctic Ocean ◽  
21St Century ◽  
Gas Hydrates ◽  
Climate Models ◽  
Atmospheric Modeling ◽  
Climate Feedback ◽  
The Arctic ◽  
Atmospheric Methane ◽  
The Impact ◽  
Hydrate Stability

Abstract. Greenhouse gas methane trapped in sub-seafloor gas hydrates may play an important role in a potential climate feedback system. The impact of future Arctic Ocean warming on the hydrate stability and its contribution to atmospheric methane concentrations remains an important and unanswered question. Here, we estimate the climate impact of released methane from oceanic gas hydrates in the Arctic to the atmosphere towards the end of the 21st century, integrating hydrate stability and atmospheric modeling. Based on future climate models, we estimate that increasing ocean temperatures over the next 100 years could release up to 17 ± 6 Gt C into the Arctic Ocean. However, the released methane has a limited or minor impact on the global mean surface temperature, contributing only 0.1 % of the projected anthropogenic influenced warming over the 21st century.

scholarly journals On the Link between Summer Dry Bias over the U.S. Great Plains and Seasonal Temperature Prediction Skill in a Dynamical Forecast System

2019 ◽  
Vol 34 (4) ◽  
pp. 1161-1172 ◽  
Author(s):  
Constantin Ardilouze ◽  
Lauriane Batté ◽  
Bertrand Decharme ◽  
Michel Déqué
Keyword(s):  
Great Plains ◽  
Land Surface ◽  
Climate Models ◽  
Warm Season ◽  
Seasonal Temperature ◽  
Forecast System ◽  
Temperature And Precipitation ◽  
The Impact ◽  
The U.S ◽  
Dry Bias

Abstract Soil moisture anomalies are expected to be a driver of summer predictability for the U.S. Great Plains since this region is prone to intense and year-to-year varying water and energy exchange between the land and the atmosphere. However, dynamical seasonal forecast systems struggle to deliver skillful summer temperature forecasts over that region, otherwise subject to a consistent warm-season dry bias in many climate models. This study proposes two techniques to mitigate the impact of this precipitation deficit on the modeled soil water content in a forecast system based on the CNRM-CM6-1 model. Both techniques lead to increased evapotranspiration during summer and reduced temperature and precipitation bias. However, only the technique based on a correction of the precipitation feeding the land surface throughout the forecast integration enables skillful summer prediction. Although this result cannot be generalized for other parts of the globe, it confirms the link between bias and skill over the U.S. Great Plains and pleads for continued efforts of the modeling community to tackle the summer bias affecting that region.

scholarly journals Deep mixed ocean volume in the Labrador Sea in HighResMIP models

2021 ◽  
Author(s):  
Torben Koenigk ◽  
Ramon Fuentes-Franco ◽  
Virna L. Meccia ◽  
Oliver Gutjahr ◽  
Laura C. Jackson ◽  
...  
Keyword(s):  
High Resolution ◽  
Climate Models ◽  
Deep Convection ◽  
Deep Ocean ◽  
Meridional Overturning Circulation ◽  
Labrador Sea ◽  
Surface Salinity ◽  
Data Set ◽  
Standard Resolution ◽  
The Impact

AbstractSimulations from seven global coupled climate models performed at high and standard resolution as part of the high resolution model intercomparison project (HighResMIP) are analyzed to study deep ocean mixing in the Labrador Sea and the impact of increased horizontal resolution. The representation of convection varies strongly among models. Compared to observations from ARGO-floats and the EN4 data set, most models substantially overestimate deep convection in the Labrador Sea. In four out of five models, all four using the NEMO-ocean model, increasing the ocean resolution from 1° to 1/4° leads to increased deep mixing in the Labrador Sea. Increasing the atmospheric resolution has a smaller effect than increasing the ocean resolution. Simulated convection in the Labrador Sea is mainly governed by the release of heat from the ocean to the atmosphere and by the vertical stratification of the water masses in the Labrador Sea in late autumn. Models with stronger sub-polar gyre circulation have generally higher surface salinity in the Labrador Sea and a deeper convection. While the high-resolution models show more realistic ocean stratification in the Labrador Sea than the standard resolution models, they generally overestimate the convection. The results indicate that the representation of sub-grid scale mixing processes might be imperfect in the models and contribute to the biases in deep convection. Since in more than half of the models, the Labrador Sea convection is important for the Atlantic Meridional Overturning Circulation (AMOC), this raises questions about the future behavior of the AMOC in the models.

Sign in / Sign up

Export Citation Format

Share Document