Technical Summary - Climate Change 2013
... Intergovernmental Panel on Climate Change (IPCC). This comprehensive assessment of the physical aspects of climate change puts a focus on those elements that are relevant to understand past, document current and project future climate change. The assessment builds on the IPCC Fourth Assessment Repor ...
... Intergovernmental Panel on Climate Change (IPCC). This comprehensive assessment of the physical aspects of climate change puts a focus on those elements that are relevant to understand past, document current and project future climate change. The assessment builds on the IPCC Fourth Assessment Repor ...
Uncertainty contributions to low
... model forcing from a delta change approach. This concept allows one to remove biases resulting from simulations when regional climate model (RCM) outputs are used as an input in hydrologic modelling. Instead of using RCM simulations of daily air temperature and precipitation for hydrologic model cal ...
... model forcing from a delta change approach. This concept allows one to remove biases resulting from simulations when regional climate model (RCM) outputs are used as an input in hydrologic modelling. Instead of using RCM simulations of daily air temperature and precipitation for hydrologic model cal ...
Regulation of atmospheric CO2 by deep
... not an important source of error. The reason why the closed system produces a reasonable approximation of (steady state) sediment composition in an open system is that most (7080%) of the CaCO3 rain flux reaching the sediment surface dissolves and is returned to the ocean anyway, so that the impac ...
... not an important source of error. The reason why the closed system produces a reasonable approximation of (steady state) sediment composition in an open system is that most (7080%) of the CaCO3 rain flux reaching the sediment surface dissolves and is returned to the ocean anyway, so that the impac ...
A Review of Downscaling Methods for Climate
... the projections are made. It is important to recognize the variety of assumptions behind the techniques used to derive such information and the limitations they impose on the results. The main tools used to project climate are General Circulation Model (GCMs), which are computer models that mathemat ...
... the projections are made. It is important to recognize the variety of assumptions behind the techniques used to derive such information and the limitations they impose on the results. The main tools used to project climate are General Circulation Model (GCMs), which are computer models that mathemat ...
Inferred gas hydrate and permafrost stability history models linked to
... change. In addition, ice melting and GH dissociation are endothermic and the latent heat effects should delay, additionally, any phase changes at depth, such that even where the GH destabilization mechanism is pressure reduction (Kennett et al., 2003) GH destabilization would be an unlikely major co ...
... change. In addition, ice melting and GH dissociation are endothermic and the latent heat effects should delay, additionally, any phase changes at depth, such that even where the GH destabilization mechanism is pressure reduction (Kennett et al., 2003) GH destabilization would be an unlikely major co ...
challenges of hydrological analysis for water resources
... runoff at a daily time scale. BTOPMC was also capable to simulate seasonal discharge with snowpack and snowmelt processes in wet winter and recession of low flows in dry summer, which are indispensable for analyzing multi seasonal dam reservoir use in long-term simulation. Next, data availability fr ...
... runoff at a daily time scale. BTOPMC was also capable to simulate seasonal discharge with snowpack and snowmelt processes in wet winter and recession of low flows in dry summer, which are indispensable for analyzing multi seasonal dam reservoir use in long-term simulation. Next, data availability fr ...
How well do we understand and evaluate climate change feedback
... is not a new issue. It is a long-standing problem that is central to discussions about the uncertainty of climate change projections. A number of reasons for the slow progress in this area are proposed. First, climate feedback studies have long been focused on the derivation of global estimates of t ...
... is not a new issue. It is a long-standing problem that is central to discussions about the uncertainty of climate change projections. A number of reasons for the slow progress in this area are proposed. First, climate feedback studies have long been focused on the derivation of global estimates of t ...
Comparative carbon cycle dynamics of the present and last interglacial
... during glacial cycles (Ciais et al., 2012), no direct proxy exists for the past amount of carbon stored in terrestrial ecosystems. However, pollen-based reconstructions of terrestrial vegetation cover reveal changes in plant composition over the Holocene with up to decadal scale precision. During th ...
... during glacial cycles (Ciais et al., 2012), no direct proxy exists for the past amount of carbon stored in terrestrial ecosystems. However, pollen-based reconstructions of terrestrial vegetation cover reveal changes in plant composition over the Holocene with up to decadal scale precision. During th ...
CLIVAR Research Foci Development Team ENSO in a changing
... simulations of present-day El Niño characteristics indicate current limitations in our ability to model this climate phenomenon and anticipate changes in its properties on short and long time scales. Since the establishment of the basic physical mechanisms 30 years ago, major progress in ENSO resear ...
... simulations of present-day El Niño characteristics indicate current limitations in our ability to model this climate phenomenon and anticipate changes in its properties on short and long time scales. Since the establishment of the basic physical mechanisms 30 years ago, major progress in ENSO resear ...
Climate Models: An Assessment of Strengths and Limitations
... sensitivity in isolation. Studies in which multiple tests of model climate responses are considered simultaneously are essential when analyzing these constraints on sensitivity. Improvements in our confidence in estimates of climate sensitivity are most likely to arise from new data streams such as ...
... sensitivity in isolation. Studies in which multiple tests of model climate responses are considered simultaneously are essential when analyzing these constraints on sensitivity. Improvements in our confidence in estimates of climate sensitivity are most likely to arise from new data streams such as ...
Rapid attribution of the August 2016 flood
... flooding caused by conditions downstream) in many neighborhoods (Burton and Demas, 2016). Further downstream on the Amite River, provisional data showed that water levels exceeded the NWS flood stage from 13 to 23 August and also exceeded the previous height record (set 25 April 1977). Its levels de ...
... flooding caused by conditions downstream) in many neighborhoods (Burton and Demas, 2016). Further downstream on the Amite River, provisional data showed that water levels exceeded the NWS flood stage from 13 to 23 August and also exceeded the previous height record (set 25 April 1977). Its levels de ...
Global Meteorological Drought: A Synthesis of Current
... assessment of the dominant large-scale forcing of meteorological drought on seasonal and longer time scales—the response of the atmosphere to SST anomalies (e.g., Hoerling and Kumar 2003; Schubert et al. 2004; Seager et al. 2005). This assessment is based on AMIP-style simulations using prescribed S ...
... assessment of the dominant large-scale forcing of meteorological drought on seasonal and longer time scales—the response of the atmosphere to SST anomalies (e.g., Hoerling and Kumar 2003; Schubert et al. 2004; Seager et al. 2005). This assessment is based on AMIP-style simulations using prescribed S ...
PDF - AMS Journals - American Meteorological Society
... Updated and improved satellite retrievals of the temperature of the mid-to-upper troposphere (TMT) are used to address key questions about the size and significance of TMT trends, agreement with model-derived TMT values, and whether models and satellite data show similar vertical profiles of warming ...
... Updated and improved satellite retrievals of the temperature of the mid-to-upper troposphere (TMT) are used to address key questions about the size and significance of TMT trends, agreement with model-derived TMT values, and whether models and satellite data show similar vertical profiles of warming ...
Numerical weather prediction
Numerical weather prediction uses mathematical models of the atmosphere and oceans to predict the weather based on current weather conditions. Though first attempted in the 1920s, it was not until the advent of computer simulation in the 1950s that numerical weather predictions produced realistic results. A number of global and regional forecast models are run in different countries worldwide, using current weather observations relayed from radiosondes, weather satellites and other observing systems as inputs.Mathematical models based on the same physical principles can be used to generate either short-term weather forecasts or longer-term climate predictions; the latter are widely applied for understanding and projecting climate change. The improvements made to regional models have allowed for significant improvements in tropical cyclone track and air quality forecasts; however, atmospheric models perform poorly at handling processes that occur in a relatively constricted area, such as wildfires.Manipulating the vast datasets and performing the complex calculations necessary to modern numerical weather prediction requires some of the most powerful supercomputers in the world. Even with the increasing power of supercomputers, the forecast skill of numerical weather models extends to about only six days. Factors affecting the accuracy of numerical predictions include the density and quality of observations used as input to the forecasts, along with deficiencies in the numerical models themselves. Post-processing techniques such as model output statistics (MOS) have been developed to improve the handling of errors in numerical predictions.A more fundamental problem lies in the chaotic nature of the partial differential equations that govern the atmosphere. It is impossible to solve these equations exactly, and small errors grow with time (doubling about every five days). Present understanding is that this chaotic behavior limits accurate forecasts to about 14 days even with perfectly accurate input data and a flawless model. In addition, the partial differential equations used in the model need to be supplemented with parameterizations for solar radiation, moist processes (clouds and precipitation), heat exchange, soil, vegetation, surface water, and the effects of terrain. In an effort to quantify the large amount of inherent uncertainty remaining in numerical predictions, ensemble forecasts have been used since the 1990s to help gauge the confidence in the forecast, and to obtain useful results farther into the future than otherwise possible. This approach analyzes multiple forecasts created with an individual forecast model or multiple models.