IEM_Final_Report-draft-29sep16 - UAF SNAP
... available to support the proposed modeling efforts. This included a survey into the strengths and weaknesses of historically observed vs historical reanalysis data. Climatic Research Unit (CRU) high resolution climate data (Harris et al. 2014) was chosen due to long record, a relatively rapid update ...
... available to support the proposed modeling efforts. This included a survey into the strengths and weaknesses of historically observed vs historical reanalysis data. Climatic Research Unit (CRU) high resolution climate data (Harris et al. 2014) was chosen due to long record, a relatively rapid update ...
Future climate in world regions - the IPCC Data Distribution Centre
... on natural and human systems are likely to become profound. In order to improve our understanding of the likely regional distribution of these impacts, information on projected future climate is therefore needed at a regional scale. The tools most commonly adopted for projecting future climate are c ...
... on natural and human systems are likely to become profound. In order to improve our understanding of the likely regional distribution of these impacts, information on projected future climate is therefore needed at a regional scale. The tools most commonly adopted for projecting future climate are c ...
Pacific Islands Meteorological Strategy 2012
... a Chair from an atoll country, the severe impacts of these and climate change provide more than enough motivation to ensure that our NMSs continue to grow in providing time critical and relevant data and information services to the public. The growth and sustenance of NMSs must be a priority for our ...
... a Chair from an atoll country, the severe impacts of these and climate change provide more than enough motivation to ensure that our NMSs continue to grow in providing time critical and relevant data and information services to the public. The growth and sustenance of NMSs must be a priority for our ...
Diagnosing Present and Future Permafrost from Climate Models
... Permafrost is a characteristic aspect of the terrestrial Arctic and the fate of near-surface permafrost over the next century is likely to exert strong controls on Arctic hydrology and biogeochemistry. Using output from the fifth phase of the Coupled Model Intercomparison Project (CMIP5), the author ...
... Permafrost is a characteristic aspect of the terrestrial Arctic and the fate of near-surface permafrost over the next century is likely to exert strong controls on Arctic hydrology and biogeochemistry. Using output from the fifth phase of the Coupled Model Intercomparison Project (CMIP5), the author ...
Recent developments on the South American monsoon system
... The SAMS is part of the monsoon system of the Americas. In the upper troposphere, the wet summer season is characterised by an anticyclonic circulation over Bolivia and a trough over the tropical and sub-tropical South Atlantic, near the coast of Northeast Brazil (Figure 1A). Prominent low-level fea ...
... The SAMS is part of the monsoon system of the Americas. In the upper troposphere, the wet summer season is characterised by an anticyclonic circulation over Bolivia and a trough over the tropical and sub-tropical South Atlantic, near the coast of Northeast Brazil (Figure 1A). Prominent low-level fea ...
Marine productivity response to Heinrich events
... the data, whereas in other regions they do not agree with the marine response seen in data (Eastern Equatorial Pacific, Southern Ocean, see Table 1). These regional differences between model results and marine sediment records suggest that physical or biogeochemical processes might be missing or und ...
... the data, whereas in other regions they do not agree with the marine response seen in data (Eastern Equatorial Pacific, Southern Ocean, see Table 1). These regional differences between model results and marine sediment records suggest that physical or biogeochemical processes might be missing or und ...
Mixed Cumulative Distribution Networks
... multivariate binary case (Richardson, 2009, Evans and Richardson, 2010), our construction has complementary properties: while it provides only a subclass of all binary ADMG models compatible with a given graph (hence less attractive in applications such as joint hypothesis testing of ADMG constraint ...
... multivariate binary case (Richardson, 2009, Evans and Richardson, 2010), our construction has complementary properties: while it provides only a subclass of all binary ADMG models compatible with a given graph (hence less attractive in applications such as joint hypothesis testing of ADMG constraint ...
Use of models in detection and attribution of climate change
... to assess9 ). Another important uncertainty affecting the accuracy of model simulations is radiative forcing uncertainty. Forcing uncertainty is generally understood to be small in the case of well-mixed greenhouse gases10 that have well understood effects on the planet’s radiative balance. Uncertai ...
... to assess9 ). Another important uncertainty affecting the accuracy of model simulations is radiative forcing uncertainty. Forcing uncertainty is generally understood to be small in the case of well-mixed greenhouse gases10 that have well understood effects on the planet’s radiative balance. Uncertai ...
Impact of Antarctic Ozone Depletion and Recovery on Southern
... Precipitation Climatology Project version-2 (GPCP) precipitation (Adler et al. 2003) and Objectively Analyzed Air–Sea Heat Fluxes version-3 (OAFlux) global ocean evaporation data (Yu et al. 2008). Those models with significant biases are discarded, and 19 models are selected for the analyses as desc ...
... Precipitation Climatology Project version-2 (GPCP) precipitation (Adler et al. 2003) and Objectively Analyzed Air–Sea Heat Fluxes version-3 (OAFlux) global ocean evaporation data (Yu et al. 2008). Those models with significant biases are discarded, and 19 models are selected for the analyses as desc ...
Climate change impacts on Yangtze River discharge at the Three
... a 4 m deep aquifer produced the best fit. Snow accumulation depends on both precipitation and air temperature with snowmelt calculated using a degree-day method (as there were insufficient data to use the more complex energy budget methods) with the melt dependent on the sum of the positive air temp ...
... a 4 m deep aquifer produced the best fit. Snow accumulation depends on both precipitation and air temperature with snowmelt calculated using a degree-day method (as there were insufficient data to use the more complex energy budget methods) with the melt dependent on the sum of the positive air temp ...
How is the stratosphere-troposphere coupling af
... possibly resolves the discrepancies between the observed and simulated tropospheric signal is the influence of stratospheric conditions on baroclinic instability in the troposphere (Wittman et al., 2004). Synoptic-scale tropospheric responses to stratospheric changes were also found by Charlton et a ...
... possibly resolves the discrepancies between the observed and simulated tropospheric signal is the influence of stratospheric conditions on baroclinic instability in the troposphere (Wittman et al., 2004). Synoptic-scale tropospheric responses to stratospheric changes were also found by Charlton et a ...
Peru-Chile upwelling dynamics under climate change - HAL-Insu
... The influence of the steep topography of the Andes and of the oceanic slope cannot be accurately simulated. In order to reach a higher spatial resolution, regional downscaling must be considered. Garreaud and Falvey [2008] studied wind changes off Chile using a regional atmospheric model (PRECIS) [Jo ...
... The influence of the steep topography of the Andes and of the oceanic slope cannot be accurately simulated. In order to reach a higher spatial resolution, regional downscaling must be considered. Garreaud and Falvey [2008] studied wind changes off Chile using a regional atmospheric model (PRECIS) [Jo ...
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.