Changes of Early Summer Precipitation in the Korean Peninsula and Nearby Regions Based on RCP Simulations

2015 ◽  
Vol 28 (9) ◽  
pp. 3557-3578 ◽  
Author(s):  
Ja-Young Hong ◽  
Joong-Bae Ahn
Keyword(s):  
Korean Peninsula ◽  
Large Scale ◽  
Climate Model ◽  
Circulation Model ◽  
Regional Model ◽  
Horizontal Resolution ◽  
Early Summer ◽  
Lower Atmosphere ◽  
Convective Precipitation ◽  
Global Circulation Model

Abstract In this study, the projected regional precipitation changes over northeast Asia (NEA) during early summer [May–July (MJJ)] for the late twenty-first century (2071–2100) were investigated using a high-resolution regional climate model (WRF3.4) based on the representative concentration pathways (RCPs) induced by the global circulation model (HadGEM2-AO). The increased horizontal resolution of the regional model with a 12.5-km horizontal resolution enabled it to reproduce the terrain-following features reasonably well compared to low-resolution reanalysis and HadGEM2-AO model data. The results of a regionally downscaled historical (1981–2010) experiment (D_Historical) demonstrated the model’s ability to capture the spatial and temporal variations of rainband migrating meridionally during MJJ over NEA. According to the regional model projection, intensive precipitation will increase and the rainband will affect the Korean Peninsula approximately 10 days earlier than in the D_Historical cases in both RCP4.5 and RCP8.5 (2071–2100). The precipitation will also increase in most of the domain, particularly in the southern Korean Peninsula and Kyushu, Japan. These increases in precipitation are attributed to increases in the northward moist transport coming from the lower latitudes and moist static instability in the lower atmosphere. According to this study, the convective precipitation contributes mainly to the increase in total precipitation. On the other hand, the large-scale nonconvective precipitation related to the stationary front will not change significantly but even tends to decrease approximately from the middle of July. The extreme precipitation intensity is also projected to increase by at least 22% (38%) in RCP4.5 (RCP8.5).

scholarly journals Future changes in the relationship of precipitation intensity in Eastern Mediterranean with large scale circulation

2010 ◽  
Vol 23 ◽  
pp. 31-36 ◽  
Author(s):  
M. Hatzaki ◽  
H. A. Flocas ◽  
C. Oikonomou ◽  
C. Giannakopoulos
Keyword(s):  
Large Scale ◽  
Climate Model ◽  
Eastern Mediterranean ◽  
Regional Climate ◽  
Circulation Model ◽  
Global Circulation Model ◽  
Intensity Index ◽  
Teleconnection Patterns ◽  
European Area ◽  
The Future

Abstract. The objective of this study is to investigate the linkage of large-scale upper air circulation over the greater European area with intense precipitation events over Eastern Mediterranean and then to estimate potential changes in the atmospheric patterns in the future, under global warming conditions. For this purpose, results from the regional climate model HadRM3P and Global Circulation Model HadAM3P have been used for the present period 1960–1990 (control run) and the future period 2070–2100 based on the B2a IPCC emission scenario. For the identification of the precipitation extremes the Simple Daily Intensity Index (SDII) was employed. Our analysis has shown a notable relation of extreme events with the East Atlantic and Scandinavia teleconnection patterns, as well as the Eastern Mediterranean Pattern (EMP) during the wet period. In the future, similar patterns are found, with different magnitude and position, following the projected changes in atmospheric circulation over Europe.

scholarly journals Utility of daily vs. monthly large-scale climate data: an intercomparison of two statistical downscaling methods

2007 ◽  
Vol 4 (5) ◽  
pp. 3413-3440 ◽  
Author(s):  
E. P. Maurer ◽  
H. G. Hidalgo
Keyword(s):  
Statistical Downscaling ◽  
General Circulation ◽  
Large Scale ◽  
Impact Analysis ◽  
Climate Model ◽  
Daily Precipitation ◽  
Circulation Model ◽  
Reanalysis Data ◽  
Temperature Extremes ◽  
Daily Data

Abstract. Downscaling of climate model data is essential to most impact analysis. We compare two methods of statistical downscaling to produce continuous, gridded time series of precipitation and surface air temperature at a 1/8-degree (approximately 140 km² per grid cell) resolution over the western U.S. We use NCEP/NCAR Reanalysis data from 1950–1999 as a surrogate General Circulation Model (GCM). The two methods included are constructed analogues (CA) and a bias correction and spatial downscaling (BCSD), both of which have been shown to be skillful in different settings, and BCSD has been used extensively in hydrologic impact analysis. Both methods use the coarse scale Reanalysis fields of precipitation and temperature as predictors of the corresponding fine scale fields. CA downscales daily large-scale data directly and BCSD downscales monthly data, with a random resampling technique to generate daily values. The methods produce comparable skill in producing downscaled, gridded fields of precipitation and temperatures at a monthly and seasonal level. For daily precipitation, both methods exhibit some skill in reproducing both observed wet and dry extremes and the difference between the methods is not significant, reflecting the general low skill in daily precipitation variability in the reanalysis data. For low temperature extremes, the CA method produces greater downscaling skill than BCSD for fall and winter seasons. For high temperature extremes, CA demonstrates higher skill than BCSD in summer. We find that the choice of most appropriate downscaling technique depends on the variables, seasons, and regions of interest, on the availability of daily data, and whether the day to day correspondence of weather from the GCM needs to be reproduced for some applications. The ability to produce skillful downscaled daily data depends primarily on the ability of the climate model to show daily skill.

scholarly journals Panama’s Current Climate Replicability in a Non-Hydrostatic Regional Climate Model Nested in an Atmospheric General Circulation Model

Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1543
Author(s):  
Reinhardt Pinzón ◽  
Noriko N. Ishizaki ◽  
Hidetaka Sasaki ◽  
Tosiyuki Nakaegawa
Keyword(s):  
Regional Climate Model ◽  
Air Temperature ◽  
General Circulation ◽  
Climate Model ◽  
Regional Climate ◽  
Surface Air Temperature ◽  
Circulation Model ◽  
Horizontal Resolution ◽  
Temperature And Precipitation ◽  
Current Climate

To simulate the current climate, a 20-year integration of a non-hydrostatic regional climate model (NHRCM) with grid spacing of 5 and 2 km (NHRCM05 and NHRCM02, respectively) was nested within the AGCM. The three models did a similarly good job of simulating surface air temperature, and the spatial horizontal resolution did not affect these statistics. NHRCM02 did a good job of reproducing seasonal variations in surface air temperature. NHRCM05 overestimated annual mean precipitation in the western part of Panama and eastern part of the Pacific Ocean. NHRCM05 is responsible for this overestimation because it is not seen in MRI-AGCM. NHRCM02 simulated annual mean precipitation better than NHRCM05, probably due to a convection-permitting model without a convection scheme, such as the Kain and Fritsch scheme. Therefore, the finer horizontal resolution of NHRCM02 did a better job of replicating the current climatological mean geographical distributions and seasonal changes of surface air temperature and precipitation.

A statistical framework for evaluating EURO-CORDEX simulations and derived drought characteristics

2021 ◽  
Author(s):  
David J. Peres ◽  
Alfonso Senatore ◽  
Paola Nanni ◽  
Antonino Cancelliere ◽  
Giuseppe Mendicino ◽  
...  
Keyword(s):  
Climate Change ◽  
Climate Models ◽  
Climate Model ◽  
Regional Climate ◽  
Circulation Model ◽  
Regional Climate Models ◽  
Monitoring Networks ◽  
Global Circulation Model ◽  
Drought Characteristics ◽  
Precipitation And Temperature

<p>Regional climate models (RCMs) are commonly used for assessing, at proper spatial resolutions, future impacts of climate change on hydrological events. In this study, we propose a statistical methodological framework to assess the quality of the EURO-CORDEX RCMs concerning their ability to simulate historic observed climate (temperature and precipitation). We specifically focus on the models’ performance in reproducing drought characteristics (duration, accumulated deficit, intensity, and return period) determined by the theory of runs at seasonal and annual timescales, by comparison with high-density and high-quality ground-based observational datasets. In particular, the proposed methodology is applied to the Sicily and Calabria regions (Southern Italy), where long historical precipitation and temperature series were recorded by the ground-based monitoring networks operated by the former Regional Hydrographic Offices. The density of the measurements is considerably greater than observational gridded datasets available at the European level, such as E-OBS or CRU-TS. Results show that among the models based on the combination of the HadGEM2 global circulation model (GCM) with the CLM-Community RCMs are the most skillful in reproducing precipitation and temperature variability as well as drought characteristics. Nevertheless, the ranking of the models may slightly change depending on the specific variable analysed, as well as the temporal and spatial scale of interest. From this point of view, the proposed methodology highlights the skills and weaknesses of the different configurations, aiding on the selection of the most suitable climate model for assessing climate change impacts on drought processes and the underlying variables.</p>

scholarly journals Characteristics of the Antarctic surface mass balance, 1958–2002, using a regional atmospheric climate model

2005 ◽  
Vol 41 ◽  
pp. 97-104 ◽  
Author(s):  
W.J. Van De Berg ◽  
M.R. Van Den Broeke ◽  
C.H. Reijmer ◽  
E. Van Meijgaard
Keyword(s):  
Mass Balance ◽  
Large Scale ◽  
Climate Model ◽  
Horizontal Resolution ◽  
Surface Mass Balance ◽  
Surface Mass ◽  
Solid Precipitation ◽  
Temporal And Spatial Characteristics ◽  
The Antarctic ◽  
Regional Atmospheric Climate Model

AbstractTemporal and spatial characteristics of the Antarctic specific surface mass balance (SSMB) are presented, including its components solid precipitation, sublimation/deposition and melt. For this purpose, we use the output of a regional atmospheric climate model (RACMO2/ANT, horizontal resolution of ~55 km) for the period 1958–2002. RACMO2/ANT uses European Centre for Medium-Range Weather Forecasts (ECMWF) 40 year re-analysis (ERA-40) fields as forcing at the lateral boundaries. RACMO2/ANT underestimates SSMB in the high interior of East and West Antarctica and overestimates SSMB on the steep coastal slopes. Otherwise, the modeled spatial pattern of SSMB is in good qualitative agreement with recent compilations of in situ observations. Large-scale patterns, like the precipitation shadow effect of the Antarctic Peninsula, are well reproduced, and mesoscale SSMB patterns, such as the strong precipitation gradients on Law Dome, are well represented in the model. The integrated SSMB over the grounded ice sheet is 153mmw.e. a–1 for the period 1958–2002, which agrees within 5% with the latest measurement compilations. Sublimation and melt remove 7% and <1% respectively of the solid precipitation. We found significant seasonality of solid precipitation, with a maximum in autumn and a minimum in summer. No meaningful trend was identified for the SSMB, because the time series of solid precipitation and SSMB are affected by an inhomogeneity in 1980 within the ERA-40 fields that drive RACMO2/ANT. Sublimation, melt and liquid precipitation increase in time, which is related to a modeled increase in 2m temperature.

scholarly journals Can Lagrangian Tracking Simulate Tracer Spreading in a High-Resolution Ocean General Circulation Model?

2019 ◽  
Vol 49 (5) ◽  
pp. 1141-1157 ◽  
Author(s):  
Patrick Wagner ◽  
Siren Rühs ◽  
Franziska U. Schwarzkopf ◽  
Inga Monika Koszalka ◽  
Arne Biastoch
Keyword(s):  
General Circulation ◽  
Large Scale ◽  
Circulation Model ◽  
Eddy Diffusivity ◽  
Ocean General Circulation Model ◽  
Horizontal Resolution ◽  
Ocean Model ◽  
Time Step ◽  
Lagrangian Particles ◽  
Cape Basin

AbstractTo model tracer spreading in the ocean, Lagrangian simulations in an offline framework are a practical and efficient alternative to solving the advective–diffusive tracer equations online. Differences in both approaches raise the question of whether both methods are comparable. Lagrangian simulations usually use model output averaged in time, and trajectories are not subject to parameterized subgrid diffusion, which is included in the advection–diffusion equations of ocean models. Previous studies focused on diffusivity estimates in idealized models but could show that both methods yield similar results as long as the deformations-scale dynamics are resolved and a sufficient amount of Lagrangian particles is used. This study compares spreading of an Eulerian tracer simulated online and a cloud of Lagrangian particles simulated offline with velocities from the same ocean model. We use a global, eddy-resolving ocean model featuring 1/20° horizontal resolution in the Agulhas region around South Africa. Tracer and particles were released at one time step in the Cape Basin and below the mixed layer and integrated for 3 years. Large-scale diagnostics, like mean pathways of floats and tracer, are almost identical and 1D horizontal distributions show no significant differences. Differences in vertical distributions, seen in a reduced vertical spreading and downward displacement of particles, are due to the combined effect of unresolved subdaily variability of the vertical velocities and the spatial variation of vertical diffusivity. This, in turn, has a small impact on the horizontal spreading behavior. The estimates of eddy diffusivity from particles and tracer yield comparable results of about 4000 m2 s−1 in the Cape Basin.

Global climate simulations at 2.8 km on GPU with the ICON model

2020 ◽  
Author(s):  
Xavier Lapillonne ◽  
William Sawyer ◽  
Philippe Marti ◽  
Valentin Clement ◽  
Remo Dietlicher ◽  
...  
Keyword(s):  
High Resolution ◽  
Large Scale ◽  
Climate Model ◽  
Global Climate ◽  
Weather Prediction ◽  
Time Integration ◽  
Horizontal Resolution ◽  
Performance Comparison ◽  
Quasi Biennial Oscillation ◽  
Numerical Weather

&lt;p&gt;The ICON modelling framework is a unified numerical weather and climate model used for applications ranging from operational numerical weather prediction to low and high resolution climate projection. In view of further pushing the frontier of possible applications and to make use of the latest evolution in hardware technologies, parts of the model were recently adapted to run on heterogeneous GPU system. This initial GPU port focus on components required for high-resolution climate application, and allow considering multi-years simulations at 2.8 km on the Piz Daint heterogeneous supercomputer. These simulations are planned as part of the QUIBICC project &amp;#8220;The Quasi-Biennial Oscillation (QBO) in a changing climate&amp;#8221;, which propose to investigate effects of climate change on the dynamics of the QBO.&lt;/p&gt;&lt;p&gt;Because of the low compute intensity of atmospheric model the cost of data transfer between CPU and GPU at every step of the time integration would be prohibitive if only some components would be ported to the accelerator. We therefore present a full port strategy where all components required for the simulations are running on the GPU. For the dynamics, most of the physical parameterizations and infrastructure code the OpenACC compiler directives are used. For the soil parameterization, a Fortran based domain specific language (DSL) the CLAW-DSL has been considered. We discuss the challenges associated to port a large community code, about 1 million lines of code, as well as to run simulations on large-scale system at 2.8 km horizontal resolution in terms of run time and I/O constraints. We show performance comparison of the full model on CPU and GPU, achieving a speed up factor of approximately 5x, as well as scaling results on up to 2000 GPU nodes. Finally we discuss challenges and planned development regarding performance portability and high level DSL which will be used with the ICON model in the near future.&lt;/p&gt;

Simulation of the Diurnal Cycle in Tropical Rainfall and Circulation during Boreal Summer with a High-Resolution GCM

2010 ◽  
Vol 138 (9) ◽  
pp. 3434-3453 ◽  
Author(s):  
Jeffrey J. Ploshay ◽  
Ngar-Cheung Lau
Keyword(s):  
Diurnal Cycle ◽  
General Circulation ◽  
Large Scale ◽  
Surface Wind ◽  
Circulation Model ◽  
Horizontal Resolution ◽  
Boreal Summer ◽  
Tropical Rainfall ◽  
Early Afternoon ◽  
Seaward Migration

Abstract The simulation of the diurnal cycle (DC) of precipitation and surface wind pattern by a general circulation model (GCM) with a uniform horizontal resolution of 50 km over the global domain is evaluated. The model output is compared with observational counterparts based on datasets provided by the Tropical Rainfall Measuring Mission and reanalysis products of the European Centre for Medium-Range Weather Forecasts. The summertime diurnal characteristics over tropical regions in Asia, the Americas, and Africa are portrayed using the amplitude and phase of the first harmonic of the 24-h cycle, departures of data fields during selected hours from the daily mean, and differences between extreme phases of the DC. There is general agreement between the model and observations with respect to the large-scale land–sea contrasts in the DC. Maximum land precipitation, onshore flows, and landward migration of rainfall signals from the coasts occur in the afternoon, whereas peak maritime rainfall and offshore flows prevail in the morning. Seaward migration of precipitation is discernible over the western Bay of Bengal and South China Sea during nocturnal and morning hours. The evolution from low-intensity rainfall in the morning/early afternoon to heavier precipitation several hours later is also evident over selected continental sites. However, the observed incidence of rainfall with very high intensity in midafternoon is not reproduced in the model atmosphere. Although the model provides an adequate simulation of the daytime upslope and nighttime downslope winds in the vicinity of mountain ranges, valleys, and basins, there are notable discrepancies between model and observations in the DC of precipitation near some of these orographic features. The model does not reproduce the observed seaward migration of precipitation from the western coasts of Myanmar (Burma) and India, and from individual islands of the Indonesian Archipelago at nighttime.

scholarly journals Atmospheric dynamics on tidally locked Earth-like planets in the habitable zone of an M dwarf star

2013 ◽  
Vol 8 (S299) ◽  
pp. 376-377 ◽  
Author(s):  
Ludmila Carone ◽  
Rony Keppens ◽  
Leen Decin
Keyword(s):  
Atmospheric Circulation ◽  
Large Scale ◽  
Rotation Period ◽  
Circulation Model ◽  
Return Flow ◽  
Parameter Study ◽  
Global Circulation Model ◽  
Dwarf Star ◽  
Global Circulation ◽  
M Dwarf

AbstractWe investigated the large scale atmospheric circulation of Gl581g, a potentially habitable planet around an M dwarf star, using an idealized dry global circulation model (GCM) with simplified thermal forcing as a first step towards a systematic extended parameter study. The results are compared with the work of Joshi et al. (1997) who investigated a tidally-locked habitable Earth analogue with less than half the rotation period of Gl581g. The extent, form and strength of the atmospheric circulation in each model generally agree with each other, even though the models differ in key parameters such as planetary radius, surface gravity, forcing scheme and rotation period. The substellar point is associated with an uprising direct circulation-branch of a Hadley-like cell with return flow over the poles. It is compelling to assume that the substellar point of a tidally locked terrestrial exoplanet behaves dynamically like the Earth's tropic associated with clouds and precipitation, making it an ideal target for habitability.

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