Integration of nitrogen dynamics into the Noah-MP land model v1.1 for climate and environmental predictions
Summary: A terrestrial nitrogen dynamics model is integrated into Noah-MP. The new model performs well in capturing the major nitrogen state/flux variables (e.g., soil nitrate and nitrate leaching). The addition of nitrogen dynamics improves the modeling of the carbon and water cycles (e.g., net primary productivity and evapotranspiration). This improvement advances the capability of Noah-MP to simultaneously predict weather and water quality.
Geosci. Model Dev. Discuss., 8, 4113-4153, doi:10.5194/gmdd-8-4113-2015, 2015
A fully coupled Atmosphere–Ocean Wave modeling system (WEW) for the Mediterranean Sea: interactions and sensitivity to the resolved scales and mechanisms
Summary: This paper includes the entire steps and processes to develop a two-way fully coupled atmosphere-ocean wave model (WEW) aiming a better description and understanding of the exchange processes near the ocean surface. WEW offers a more realistic representation of the extreme weather and sea state events over the ocean bodies and finally leads in an overall improved simulations.
Geosci. Model Dev. Discuss., 8, 4075-4112, doi:10.5194/gmdd-8-4075-2015, 2015
Photolysis rates in correlated overlapping cloud fields: Cloud-J 7.3
Geosci. Model Dev. Discuss., 8, 4051-4073, doi:10.5194/gmdd-8-4051-2015, 2015
Improved simulation of precipitation in the tropics using a modified BMJ scheme in WRF model
Summary: In this study the BMJ scheme, a convective adjustment scheme where temperature and humidity are relaxed towards reference profiles, as implemented in the WRF model version 3.3.1, is modified so that the precipitation produced by the model is in better agreement with that observed as given by the Tropical Rainfall Measuring Mission (TRMM) 3B42 dataset. The "modified BMJ" scheme gives a better representation of the observed rainfall for the whole tropics in both winter and summer seasons.
Geosci. Model Dev. Discuss., 8, 4019-4049, doi:10.5194/gmdd-8-4019-2015, 2015
S4CAST v2.0: sea surface temperature based statistical seasonal forecast model
Geosci. Model Dev. Discuss., 8, 3971-4018, doi:10.5194/gmdd-8-3971-2015, 2015
A global empirical system for probabilistic seasonal climate prediction
Summary: Our paper reports on a simple regression-based system for producing probabilistic forecasts of seasonal climate. We discuss the physical motivation behind the statistical relationships underpinning our empirical model and provide a validation of hindcasts produced for the last half century. The generation of probabilistic forecasts on a global scale along with the use of the long-term trend as a source of skill constitutes a novel approach to empirical forecasting of seasonal climate.
Geosci. Model Dev. Discuss., 8, 3941-3970, doi:10.5194/gmdd-8-3941-2015, 2015
Updating sea spray aerosol emissions in the Community Multiscale Air Quality (CMAQ) model version 5.0.2
Geosci. Model Dev. Discuss., 8, 3905-3939, doi:10.5194/gmdd-8-3905-2015, 2015
Evaluation of the Community Multiscale Air Quality (CMAQ) model v5.0 against size-resolved measurements of inorganic particle composition across sites in North America
Summary: This study is the most comprehensive evaluation of CMAQ inorganic aerosol size-composition distributions conducted to date. We compare two methods of inferring PM2.5 concentrations from the model: (1) based on the sum of the masses in the fine aerosol modes, as is most commonly done in CMAQ model evaluation; and (2) computed using the simulated size distributions. Differences are generally less than 1microgram/m3, and are largest over the eastern United States during the summer.
Geosci. Model Dev. Discuss., 8, 3861-3904, doi:10.5194/gmdd-8-3861-2015, 2015
A new ensemble-based consistency test for the Community Earth System Model
Summary: Climate simulations codes are especially complex, and their on-going state of development requires frequent software quality assurance to both preserve code quality and instill model confidence. To formalize and simplify this previously subjective and expensive process, we have developed a new tool for evaluating climate consistency. The tool has proven its utility in detecting errors in software and hardware environments and providing rapid feedback to model developers.
Geosci. Model Dev. Discuss., 8, 3823-3859, doi:10.5194/gmdd-8-3823-2015, 2015
An automatic and effective parameter optimization method for model tuning
Summary: A “three-step” methodology is proposed to effectively obtain the optimum combination of some key parameters in cloud and convective parameterizations according to a comprehensive objective evaluation metrics. The optimal results improve the metrics performance by 9%. A software framework can automatically execute any part of the “three-step” calibration strategy. The proposed methodology and framework can be easily applied to other GCMs to speed up the model development process.
Geosci. Model Dev. Discuss., 8, 3791-3822, doi:10.5194/gmdd-8-3791-2015, 2015
PLUME-MoM 1.0: a new 1-D model of volcanic plumes based on the method of moments
Summary: In this paper a new mathematical model of volcanic plume, named PlumeMoM, is presented. The model is based on the method of moments and it is able to describe the continuous variability in the grain size distribution (GSD) of the pyroclastic mixture ejected at the vent, crucial to characterize the source conditions of ash dispersal models. Results show that the GSD at the top of the plume is similar to that at the base and that plume height is weakly affected by the parameters of the GSD.
Geosci. Model Dev. Discuss., 8, 3745-3790, doi:10.5194/gmdd-8-3745-2015, 2015
ECCO version 4: an integrated framework for non-linear inverse modeling and global ocean state estimation
Summary: The ECCO v4 nonlinear inverse modeling framework and its reference solution are made publicly available. The inverse estimate of ocean physics and atmospheric forcing yields a dynamically consistent and global state estimate without unidentified sources of heat and salt that closely fits in-situ and satellite data. Any user can reproduce it accurately. Parametric and external model uncertainties are of comparable magnitudes and generally exceed structural model uncertainties.
Geosci. Model Dev. Discuss., 8, 3653-3743, doi:10.5194/gmdd-8-3653-2015, 2015
Simulating Secondary Inorganic Aerosols using the chemistry transport model MOCAGE version R2.15.0
Geosci. Model Dev. Discuss., 8, 3593-3651, doi:10.5194/gmdd-8-3593-2015, 2015
Using satellite-based estimates of evapotranspiration and groundwater changes to determine anthropogenic water fluxes in land surface models
Summary: 1. Current land surface models (LSMs) poorly represent irrigation impacts on regional hydrology. 2. Approaches to include irrigation in LSMs are based on either potentially outdated irrigation inventory data or soil moisture curves that are not constrained by regional water balances. 3. We use satellite remote sensing of actual ET and groundwater depletion to develop recent estimates of regional irrigation data. 4. Remote-sensing parameterizations of irrigation improve model performance.
Geosci. Model Dev. Discuss., 8, 3565-3592, doi:10.5194/gmdd-8-3565-2015, 2015
A 3-D RBF-FD elliptic solver for irregular boundaries: modeling the atmospheric global electric circuit with topography
Geosci. Model Dev. Discuss., 8, 3523-3564, doi:10.5194/gmdd-8-3523-2015, 2015
The Explicit Wake Parametrisation V1.0: a wind farm parametrisation in the mesoscale model WRF
Summary: We introduce a wind farm parametrisation for mesoscale models. The formulation accounts explicitly for the unresolved wake expansion within a turbine containing grid-cell. Turbulence Kinetic Energy (TKE) production results only from a changed shear in velocity. The modelled wind speed recovery behind an offshore wind farm agrees well with observations from mast measurements. The vertical structure of the TKE and the velocity profile correspond qualitatively to that simulated with LES model.
Geosci. Model Dev. Discuss., 8, 3481-3522, doi:10.5194/gmdd-8-3481-2015, 2015
The GRENE-TEA Model Intercomparison Project (GTMIP): overview and experiment protocol for Stage 1
Summary: The paper provides the experiment protocol of the stage 1 (site simulations) of an open model intercomparison project for Arctic terrestrial (GTMIP), planned and conducted as an activity of the Japan-funded Arctic Climate Change Research Project (GRENE-TEA). Models are driven by 33-year data created with the GRENE-TEA observations at four sites in Finland, Siberia and Alaska, and evaluated for physico-ecological key processes: energy budgets, snow, permafrost, phenology, and carbon budgets.
Geosci. Model Dev. Discuss., 8, 3443-3479, doi:10.5194/gmdd-8-3443-2015, 2015
The Louvain-la-Neuve sea ice model LIM3.5: global and regional capabilities
Geosci. Model Dev. Discuss., 8, 3403-3441, doi:10.5194/gmdd-8-3403-2015, 2015
An open and extensible framework for spatially explicit land use change modelling in R: the lulccR package (0.1.0)
Summary: The contribution of lulccR is to provide a free and open source framework for land use change modelling. The software, which is provided as an R package, addresses problems associated with the current paradigm of closed source, specialised land use change modelling software which disrupt the scientific process. lulccR is an attempt to move the discipline towards open and transparent science and to ensure land use change models are accessible to scientists working across the geosciences.
Geosci. Model Dev. Discuss., 8, 3359-3402, doi:10.5194/gmdd-8-3359-2015, 2015
Taking off the training wheels: the properties of a dynamic vegetation model without climate envelopes
Summary: Predicting the distribution of vegetation under novel climates is important, both to understand how climate change will impact ecosystem services, but also for understanding how vegetation changes might affect the carbon, energy and water cycles. Historically, predictions have been heavily dependent upon observations of existing vegetation boundaries. In this paper, we attempt to predict ecosystem boundaries from the 'bottom up', and illustrate the complexities and promise of this approach.
Geosci. Model Dev. Discuss., 8, 3293-3357, doi:10.5194/gmdd-8-3293-2015, 2015
Using field observations to inform thermal hydrology models of permafrost dynamics with ATS (v0.83)
Summary: Development and calibration of a process-rich model representation of thaw-depth dynamics in Arctic tundra is presented. Improved understanding of polygonal tundra thermal hydrology processes, of thermal conduction, surface and subsurface saturation and snowpack dynamics is gained by using measured field data to calibrate and refine model structure. The refined model is then used identify future data needs and observational studies.
Geosci. Model Dev. Discuss., 8, 3235-3292, doi:10.5194/gmdd-8-3235-2015, 2015
Evaluation of modeled surface ozone biases as a function of cloud cover fraction
Summary: This study focuses on the evaluation of regional air quality model's performance based on the cloud information from satellite. While cloud information is crucial in photochemistry model, the definition of cloud fraction from model and satellite are not physically consistent. We demonstrate that improper model of cloud fraction is correlated with surface ozone bias, and also show that current model cloud field might be too bright, causing an overestimation of surface ozone-level.
Geosci. Model Dev. Discuss., 8, 3219-3233, doi:10.5194/gmdd-8-3219-2015, 2015
Representation of vegetation effects on the snow-covered albedo in the Noah land surface model with multiple physics options
Summary: Snow albedo varies with snow grain size, snow cover thickness, etc. It also depends on the spatial characteristics of land cover and on the canopy density and structure. The Noah-MP model shows a bias error of albedo in winter due to no proper reflection of the vegetation effect. We developed new parameters, called leaf index and stem index, which reflect the vegetation effect on winter albedo. The Noah-MP's performance in albedo has prominently improved with about 73% decrease in the RMS error.
Geosci. Model Dev. Discuss., 8, 3197-3218, doi:10.5194/gmdd-8-3197-2015, 2015
The Yale Interactive terrestrial Biosphere model: description, evaluation and implementation into NASA GISS ModelE2
Summary: The Yale Interactive Terrestrial Biosphere Model (YIBs) predicts land carbon fluxes and tree growth based on mature schemes but with special updates in phenology, ozone vegetation damage, and photosynthetic-dependent biogenic volatile organic compound. Evaluations with data from 145 flux tower sites and multiple satellite products show that the model predicts reasonable magnitude, seasonality, and spatial distribution of land carbon fluxes.
Geosci. Model Dev. Discuss., 8, 3147-3196, doi:10.5194/gmdd-8-3147-2015, 2015
Revision of the convective transport module CVTRANS 2.4 in the EMAC atmospheric chemistry–climate model
Geosci. Model Dev. Discuss., 8, 3117-3145, doi:10.5194/gmdd-8-3117-2015, 2015
A new sub-grid surface mass balance and flux model for continental-scale ice sheet modelling: validation and last glacial cycle
Summary: A long-term challenge for any model of complex large-scale processes is accounting for the impact of unresolved sub-grid (SG) processes. We quantify the impact of SG mass-balance and ice fluxes on glacial cycle ensemble results for North America. We find no easy solutions to accurately capture these impacts. We show that SG process representation and associated parametric uncertainties can have significant impact on coarse resolution model results for glacial cycle ice sheet evolution.
Geosci. Model Dev. Discuss., 8, 3037-3077, doi:10.5194/gmdd-8-3037-2015, 2015
Increasing vertical mixing to reduce Southern Ocean deep convection in NEMO
Summary: Most ocean models, including NEMO, have unrealistic Southern Ocean deep convection. That is, through extensive areas of the Southern Ocean, they exhibit convection from the surface of the ocean to the sea floor. We find this convection to be an issue as it impacts the whole ocean circulation, notably strengthening the Antarctic Circumpolar Current. Using sensitivity experiments, we show that counter-intuitively the vertical mixing needs to be enhanced to reduce this spurious convection.
Geosci. Model Dev. Discuss., 8, 2949-2972, doi:10.5194/gmdd-8-2949-2015, 2015
Methods for automatized detection of rapid changes in lateral boundary condition fields for NWP limited area models
Geosci. Model Dev. Discuss., 8, 2691-2737, doi:10.5194/gmdd-8-2691-2015, 2015
Enhancement for bitwise identical reproducibility of Earth system modeling on the C-Coupler platform
Geosci. Model Dev. Discuss., 8, 2403-2435, doi:10.5194/gmdd-8-2403-2015, 2015
A parallelization scheme to simulate reactive transport in the subsurface environment with OGS#IPhreeqc
Summary: This technical paper presents a new tool to simulate reactive transport processes in subsurface systems, which couples the open source software packages OpenGeoSys and IPhreeqc. A flexible parallelization scheme was developed and implemented to enable an optimized allocation of computer resources. The performance tests of the coupling interface and parallelization scheme illustrate the promising efficiency of this generally valid approach to simulate reactive transport problems.
Geosci. Model Dev. Discuss., 8, 2369-2402, doi:10.5194/gmdd-8-2369-2015, 2015
Impact of climate, vegetation, soil and crop management variables on multi-year ISBA-A-gs simulations of evapotranspiration over a Mediterranean crop site
Summary: This paper investigates the impacts of errors in climate, vegetation, soil and irrigation drivers on the simulation of evapotranspiration (ET) from the ISBA-A-gs land surface model over a 12-year Mediterranean crop succession. Vegetation dynamic and irrigation have the greatest impact on simulated evapotranspiration. Differences in climate datasets slightly influence simulated ET. Errors in the forcing variables generate smaller impact on simulated ET than errors in the soil parameters.
Geosci. Model Dev. Discuss., 8, 2053-2100, doi:10.5194/gmdd-8-2053-2015, 2015
MOPS-1.0: modelling the regulation of the global oceanic nitrogen budget by marine biogeochemical processes
Geosci. Model Dev. Discuss., 8, 1945-2010, doi:10.5194/gmdd-8-1945-2015, 2015
EwE-F 1.0: an implementation of Ecopath with Ecosim in Fortran 95/2003 for coupling
Summary: Marine ecosystem-based management requires integrating multiple models in one unified scheme. Being the most widely used food web model, Ecopath with Ecosim (EwE) is potentially a crucial component of such schemes. Written in Visual Basic for the .NET framework, integration of EwE with physical and/or biogeochemical oceanographic models, which are mostly in Fortran, is complicated. We release a re-coding of EwE in Fortran (EwE-F) so as to facilitate integrating EwE in coupled modelling schemes.
Geosci. Model Dev. Discuss., 8, 1511-1537, doi:10.5194/gmdd-8-1511-2015, 2015
Analysis of the impact of inhomogeneous emissions in a semi-parameterized street canyon model
Summary: Semi-parameterized street canyon models are popular due to their speed and low input requirements. One often used assumption is that emissions are homogeneously distributed in the entire length and width of the street. It is thus the aim of the present study to analyse the impact of this assumption by implementing an inhomogeneous emission geometry scheme and validating it. The results show an improved performance, however confounded by challenges estimating the emissions accurately.
Geosci. Model Dev. Discuss., 8, 935-977, doi:10.5194/gmdd-8-935-2015, 2015
CH4 parameter estimation in CLM4.5bgc using surrogate global optimization
Summary: We tune the CH4-related parameters of the Community Land Model (CLM) using surrogate global optimization in order to reduce the discrepancies between the CLM predictions and observed CH4 emissions. This is the first application of a surrogate optimization method to calibrate a global climate model. We found that the observation data drives the model to predict more CH4 emissions in the northern latitudes and less in the tropics.
Geosci. Model Dev. Discuss., 8, 141-207, doi:10.5194/gmdd-8-141-2015, 2015
Thermo-hydro-mechanical processes in fractured rock formations during glacial advance
Summary: The paper examines the coupled thermo-hydro-mechanical (THM) processes that develop in a fractured rock region within a fluid-saturated rock mass due to loads imposed by an advancing glacier. This scenario needs to be examined in order to assess the suitability of potential sites for the location of deep geologic repositories for the storage of high-level nuclear waste. The THM processes are examined using a computational multiphysics approach.
Geosci. Model Dev. Discuss., 7, 7351-7394, doi:10.5194/gmdd-7-7351-2014, 2014