The prevention of deforestation and promotion afforestation have often been cited as strategies to slow global warming. Deforestation releases CO(2) the atmosphere, which exerts a warming influence on Earth's climate. However, biophysical effects deforestation, include changes in land surface albedo, evapotranspiration, cloud cover also affect Here we present results from several large-scale experiments performed with three-dimensional coupled carbon-cycle climate model. These simulations...

The Atmospheric Model Intercomparison Project (AMIP), initiated in 1989 under the auspices of World Climate Research Programme, undertook systematic validation, diagnosis, and intercomparison performance atmospheric general circulation models. For this purpose all models were required to simulate evolution climate during decade 1979–88, subject observed monthly average temperature sea ice a common prescribed CO2 concentration solar constant. By 1995, 31 modeling groups, representing...

While numerous studies have addressed changes in climate extremes, analyses of concurrence extremes are scarce, and change effects on joint rarely considered. This study assesses the occurrence (concurrent) monthly continental precipitation temperature Climate Research Unit (CRU) University Delaware (UD) observations, 13 Coupled Model Intercomparison Project Phase 5 (CMIP5) global simulations. The occurrences simulated by CMIP5 models compared with those derived from CRU UD observations for...

When changing from grass and croplands to forest, there are two competing effects of land cover change on climate: an albedo effect which leads warming evapotranspiration tends produce cooling. It is not clear would dominate. We have performed simulations global using the NCAR CAM3 atmospheric general circulation model coupled a slab ocean model. find that replacement current vegetation by trees lead mean 1.3°C, nearly 60% produced under doubled CO 2 concentration, while grasslands result in...

To significantly improve the simulation of climate by general circulation models (GCMs), systematic errors in representations relevant processes must first be identified, and then reduced. This endeavor demands that GCM parameterizations unresolved processes, particular, should tested over a wide range time scales, not just simulations. Thus, numerical weather prediction (NWP) methodology for evaluating model gaining insights into their behavior may prove useful, provided suitable...

Abstract A global climate model experiment is performed to evaluate the effect of irrigation on temperatures in several major irrigated regions world. The Community Atmosphere Model, version 3.3, was modified represent for fraction each grid cell equipped according datasets from Food and Agriculture Organization. Results indicate substantial regional differences magnitude irrigation-induced cooling, which are attributed three primary factors: extent area, simulated soil moisture control...

There is a growing body of empirical evidence documenting the expansion shrub vegetation in circumpolar Arctic response to climate change. Here, we conduct series idealized experiments with Community Climate System Model analyze potential impact on boreal large-scale tundra-to-shrub conversion. The model responds an increase abundance substantial atmospheric heating arising from two seasonal land–atmosphere feedbacks: decrease surface albedo and evapotranspiration-induced moisture content....

In this study, a Bayesian maximum‐likelihood method is used to estimate local probability distributions of projected climate changes in continental temperature T and precipitation P under greenhouse emission scenarios two different severity levels. These estimates are derived from multimodel simulations the 20th 21st centuries. Bayesian‐weighted consensus climate‐change signal noise determined statistical agreement each model's simulation historical with observations its 21st‐century...

The terrestrial phase of the water cycle can be seriously impacted by management and human use behavior (e.g., reservoir operation, irrigation withdrawals). Here we outline a method for assessing availability in changing climate, while explicitly considering anthropogenic demand scenarios supply infrastructure designed to cope with climatic extremes. framework brings top-down bottom-up approach provide localized assessment based on local projected demands. When our is applied southeastern...

The influence of the El Nino/Southern Oscillation (ENSO) on terrestrial water storage is analyzed for time period 2003–2010 using monthly estimates continental from Gravity Recovery and Climate Experiment (GRACE). Peak correlation between NOAA's Multivariate ENSO Index (MEI) measured mass anomaly timeseries shows an R 2 0.65 Amazon Basin Borneo in Southeast Asia. By including a Hilbert transformation MEI to account lag, improved 0.76. Tropical regions show strong negative with arid are...

Abstract Assessing the uncertainties and understanding deficiencies of climate models are fundamental to developing adaptation strategies. The objective this study is understand how well Coupled Model Intercomparison‐Phase 5 (CMIP5) model simulations replicate ground‐based observations continental drought areas their trends. CMIP5 multimodel ensemble encompasses Climatic Research Unit (CRU) area under at all time steps. However, most members overestimate extreme drought, particularly in...

Coherent fluctuations between extratropical circulation and tropical conviction in the intraseasonal time scale are studied. Possible relationships 500-mb height field outgoing longwave radiation (OLR) examined using correlation, complex EOF composite techniques. Results show that 20-70 day bands data, there is a systematic evolution of wavetrains from Eurasia across Pacific to North America Atlantic 5 10 days. Over tropics, dominant mode variation convection an east-west dipole-like feature...

In support of the Intergovernmental Panel on Climate Change (IPCC), simulations 20th century climate have been performed recently with some 20 global coupled ocean‐atmosphere models. view its central importance for biological and socioeconomic systems, model‐simulated continental precipitation is evaluated relative to three observational estimates at both regional scales. Many models are found display systematic biases, deviating markedly from observed spatial variability amplitude/phase...

As extreme heat and weather events are predicted to increase due global warming, the risk of human stress within buildings will increase. To be resilient, need capacity provide habitable indoor conditions without power for limited amounts time. Additional thermal standards required public health address 'passive habitability' during outages. Current research on building-related numerous indices is examined in relation development a new heat-safety metric use passively conditioned buildings....

Abstract We present an improved procedure of generating initial conditions (ICs) for climate model hindcast experiments with specified sea surface temperature and ice. The motivation is to minimize errors in the ICs lead a better evaluation atmospheric parameterizations' performance mode. apply state variables (horizontal velocities, temperature, specific humidity) from operational analysis/reanalysis states. Without data assimilation system, we two‐step process obtain other necessary...

Abstract Precipitation and temperature are physically related to each other with significant dependences that vary seasons at regional global scales. The dependence between precipitation (P–T dependence) plays a central role in characterizing the joint behaviour of two variables. Along extensive studies on variation mean, variance, or extremes under warming, it is particular interest understand climate‐change impacts covariability temperature. aim this study therefore assess climate change...

Abstract El Niño–Southern Oscillation (ENSO) is an important driver of regional hydroclimate variability through far-reaching teleconnections. This study uses simulations performed with coupled general circulation models (CGCMs) to investigate how precipitation in the twenty-first century may be affected by changes both ENSO-driven and slowly evolving mean rainfall. First, a dominant, time-invariant pattern canonical ENSO (cENSO) identified observed SST data. Next, fidelity which 33...

CO₂ fertilization affects plant growth, which modifies surface physical properties, altering the albedo, and fluxes of sensible latent heat. We investigate how such CO₂-fertilization effects on vegetation properties would affect climate system. Using a global three-dimensional climate-carbon model that simulates dynamics, we compare two multicentury simulations: 'Control' simulation with no emissions 'Physiol-noGHG' where physiological changes occur as result prescribed...

Abstract Several independent measurements of warm‐season soil moisture and surface atmospheric variables recorded at the ARM Southern Great Plains (SGP) research facility are used to estimate terrestrial component land‐atmosphere coupling (LAC) strength its regional uncertainty. The observations reveal substantial variation in strength, as estimated from three a single site, well across six other sites having varied land cover types. observational estimates then serve references for...

Abstract This study examines several observational aspects of land‐atmosphere coupling on daily average time scales during warm seasons the years 1997 to 2008 at Department Energy Atmospheric Radiation Measurement Program's Southern Great Plains (SGP) Central Facility site near Lamont, Oklahoma. Characteristics local are inferred by analyzing covariability selected land and atmospheric variables that include precipitation soil moisture, surface air temperature, relative humidity, radiant...