A5058371561- Climate variability and models
- Climate change and permafrost
- Cryospheric studies and observations
- Atmospheric and Environmental Gas Dynamics
- Plant Water Relations and Carbon Dynamics
- Meteorological Phenomena and Simulations
- Hydrology and Watershed Management Studies
- Arctic and Antarctic ice dynamics
- Atmospheric chemistry and aerosols
- Fire effects on ecosystems
- Geophysics and Gravity Measurements
- Geology and Paleoclimatology Research
- Methane Hydrates and Related Phenomena
- Peatlands and Wetlands Ecology
- Soil Moisture and Remote Sensing
- Atmospheric aerosols and clouds
- Aeolian processes and effects
- Climate change impacts on agriculture
- Geological Studies and Exploration
- Geochemistry and Geologic Mapping
- Flood Risk Assessment and Management
- Water-Energy-Food Nexus Studies
- Geological and Geochemical Analysis
- Tree-ring climate responses
- Climate Change Policy and Economics
NSF National Center for Atmospheric Research
2016-2025
Climate and Global Dynamics Laboratory
2016-2025
Barrick Gold (Canada)
2023-2024
U.S. National Science Foundation
2024
University of Lapland
2022
AngloGold Ashanti (South Africa)
2015-2017
Massachusetts Institute of Technology
2011-2017
Kingston University
2013-2014
Oak Ridge National Laboratory
2014
University of Reading
2001-2013
The fourth version of the Community Climate System Model (CCSM4) was recently completed and released to climate community. This paper describes developments all CCSM components, documents fully coupled preindustrial control runs compared previous version, CCSM3. Using standard atmosphere land resolution 1° results in sea surface temperature biases major upwelling regions being comparable 1.4°-resolution Two changes deep convection scheme component result CCSM4 producing El Niño–Southern...
Previous estimates of land-atmosphere interaction (the impact soil moisture on precipitation) have been limited by a lack observational data and the model dependence computational estimates. To counter second limitation, dozen climate-modeling groups recently performed same highly controlled numerical experiment as part coordinated comparison project. This allows multimodel estimation regions Earth where precipitation is affected anomalies during Northern Hemisphere summer. Potential...
The Community Earth System Model (CESM) is a flexible and extensible community tool used to investigate diverse set of system interactions across multiple time space scales. This global coupled model significantly extends its predecessor, the Climate Model, by incorporating new simulation capabilities. These comprise ability simulate biogeochemical cycles, including those carbon nitrogen, variety atmospheric chemistry options, Greenland Ice Sheet, an atmosphere that lower thermosphere. other...
An overview of the Community Earth System Model Version 2 (CESM2) is provided, including a discussion challenges encountered during its development and how they were addressed. In addition, an evaluation pair CESM2 long preindustrial control historical ensemble simulations presented. These performed using nominal 1° horizontal resolution configuration coupled model with both "low-top" (40 km, limited chemistry) "high-top" (130 comprehensive versions atmospheric component. contains many...
Abstract While internal climate variability is known to affect projections, its influence often underappreciated and confused with model error. Why? In general, modeling centers contribute a small number of realizations international assessments [e.g., phase 5 the Coupled Model Intercomparison Project (CMIP5)]. As result, error are difficult, at times impossible, disentangle. response, Community Earth System (CESM) community designed CESM Large Ensemble (CESM-LE) explicit goal enabling...
The Community Land Model (CLM) is the land component of Earth System (CESM) and used in several global regional modeling systems. In this paper, we introduce model developments included CLM version 5 (CLM5), which default for CESM2. We assess an ensemble simulations, including prescribed prognostic vegetation state, multiple forcing data sets, CLM4, CLM4.5, CLM5, against a range metrics from International Benchmarking (ILAMBv2) package. CLM5 includes new updated processes parameterizations:...
The Community Land Model is the land component of Climate System Model.Here, we describe a broad set model improvements and additions that have been provided through CLM development community to create CLM4.The extended with carbon-nitrogen (CN) biogeochemical prognostic respect vegetation, litter, soil carbon nitrogen states vegetation phenology.An urban canyon added transient cover use change (LCLUC) capability, including wood harvest, introduced, enabling study historic future LCLUC on...
We present the design and performance of multi-object fiber spectrographs for Sloan Digital Sky Survey (SDSS) their upgrade Baryon Oscillation Spectroscopic (BOSS). Originally commissioned in Fall 1999 on 2.5-m aperture Telescope at Apache Point Observatory, produced more than 1.5 million spectra SDSS SDSS-II surveys, enabling a wide variety Galactic extra-galactic science including first observation baryon acoustic oscillations 2005. The were upgraded 2009 are currently use BOSS, flagship...
The Community Land Model version 3 (CLM3) is the land component of Climate System (CCSM). CLM3 has energy and water biases resulting from deficiencies in some its canopy soil parameterizations related to hydrological processes. Recent research by community that utilizes family CCSM models indicated several promising approaches alleviating these biases. This paper describes implementation a selected set their effects on simulated cycle. modifications consist surface data sets based Moderate...
The Community Land Model is the land component of Climate System Model.Here, we describe a broad set model improvements and additions that have been provided through CLM development community to create CLM4.The extended with carbon-nitrogen (CN) biogeochemical prognostic respect vegetation, litter, soil carbon nitrogen states vegetation phenology.An urban canyon added transient cover use change (LCLUC) capability, including wood harvest, introduced, enabling study historic future LCLUC on...
Abstract. Human land use activities have resulted in large changes to the biogeochemical and biophysical properties of Earth's surface, with consequences for climate other ecosystem services. In future, are likely expand and/or intensify further meet growing demands food, fiber, energy. As part World Climate Research Program Coupled Model Intercomparison Project (CMIP6), international community has developed next generation advanced Earth system models (ESMs) estimate combined effects human...
Abstract The Global Land–Atmosphere Coupling Experiment (GLACE) is a model intercomparison study focusing on typically neglected yet critical element of numerical weather and climate modeling: land–atmosphere coupling strength, or the degree to which anomalies in land surface state (e.g., soil moisture) can affect rainfall generation other atmospheric processes. 12 AGCM groups participating GLACE performed series simple experiments that allow objective quantification this for boreal summer....
[1] The Community Land Model version 4 (CLM4) overestimates gross primary production (GPP) compared with data-driven estimates and other process models. We use global, spatially gridded GPP latent heat flux upscaled from the FLUXNET network of eddy covariance towers to evaluate improve canopy processes in CLM4. investigate differences arising model parameterizations (termed structural error) uncertainty photosynthetic parameter Vcmax uncertainty). errors entail radiative transfer, leaf...
Abstract Many of the scientific and societal challenges in understanding preparing for global environmental change rest upon our ability to understand predict water cycle at large river basin, continent, scales. However, current large‐scale land models (as a component Earth System Models, or ESMs) do not yet reflect best hydrologic process utilize amount observations model testing. This paper discusses opportunities key improve representations benchmarking ESM models, suggesting that (1)...
Abstract Earth System Models (ESMs) are essential tools for understanding and predicting global change, but they cannot explicitly resolve hillslope‐scale terrain structures that fundamentally organize water, energy, biogeochemical stores fluxes at subgrid scales. Here we bring together hydrologists, Critical Zone scientists, ESM developers, to explore how hillslope may modulate grid‐level fluxes. In contrast the one‐dimensional (1‐D), 2‐ 3‐m deep, free‐draining soil hydrology in most land...
The current distribution and future projections of permafrost are examined in a fully coupled global climate model, the Community Climate System Model, version 3 (CCSM3) with explicit treatment frozen soil processes. spatial extent simulated present‐day CCSM3 agrees well observational estimates – an area, excluding ice sheets, 10.5 million km 2 . By 2100, as little 1.0 near‐surface remains. Freshwater discharge to Arctic Ocean rises by 28% over same period, largely due increases...
Abstract. Results from the fully and biogeochemically coupled simulations in which CO2 increases at a rate of 1 % yr−1 (1pctCO2) its preindustrial value are analyzed to quantify magnitude carbon–concentration carbon–climate feedback parameters measure response ocean terrestrial carbon pools changes atmospheric concentration resulting change global climate, respectively. The results based on 11 comprehensive Earth system models most recent (sixth) Coupled Model Intercomparison Project (CMIP6)...
Abstract The authors investigate the atmospheric response to projected Arctic sea ice loss at end of twenty-first century using an general circulation model (GCM) coupled a land surface model. was obtained from two 60-yr integrations: one with repeating seasonal cycle specified conditions for late twentieth (1980–99) and that (2080–99). In both integrations, SSTs 1980–99 prescribed isolate impact future loss. Note greenhouse gas concentrations remained fixed levels in sets experiments....
We conducted a model-based assessment of changes in permafrost area and carbon storage for simulations driven by RCP4.5 RCP8.5 projections between 2010 2299 the northern region. All models simulating represented soil with depth, critical structural feature needed to represent carbon-climate feedback, but that is not universal all climate models. Between 2299, indicated losses 3 5 million km2 6 16 climate. For projection, cumulative change varied 66-Pg C (1015-g carbon) loss 70-Pg gain. 74...
Abstract Although the global partitioning of evapotranspiration (ET) into transpiration, soil evaporation, and canopy evaporation is not well known, most current land surface schemes few available observations indicate that transpiration dominant component on scale, followed by evaporation. The Community Land Model version 3 (CLM3), however, does reflect this view ET partitioning, with far outweighing transpiration. One consequence unrealistic in CLM3 photosynthesis, which linked to through...
Abstract. Human land-use activities have resulted in large changes to the Earth's surface, with resulting implications for climate. In future, are likely expand and intensify further meet growing demands food, fiber, energy. The Land Use Model Intercomparison Project (LUMIP) aims advance understanding of impacts land-cover change (LULCC) on climate, specifically addressing following questions. (1) What effects LULCC climate biogeochemical cycling (past–future)? (2) land management surface...
Abstract. Soils are a crucial component of the Earth system; they comprise large portion terrestrial carbon stocks, mediate supply and demand nutrients, influence overall response ecosystems to perturbations. In this paper, we develop new soil biogeochemistry model for Community Land Model, version 4 (CLM4). The includes vertical dimension (C) nitrogen (N) pools transformations, more realistic treatment mineral N pools, flexible dynamics decomposing carbon, radiocarbon (14C) tracer. We...