• Caballero, R.; Huber, M.; Hanley, J. 2012-04-01 Recent paleoclimate proxy reconstructions indicate that global-mean surface temperatures in past warm climates may have been some 10-15°C higher than today.

Little is known about atmospheric dynamics at temperatures this warm. In particular, is it possible that the general circulation may transition to a qualitatively different state at warm enough temperatures? We study this question in a set of simulations using NCAR's Community Climate System Model in both full- and slab-ocean configurations with a range of atmospheric CO2 concentrations extending from preindustrial values (280 ppm) up to 8960 ppm (5 doublings).

We find that the simulation at 4480 ppm CO2 gives a remarkably good fit to recent surface temperature reconstructions of the early Eocene, and does not suffer from the classical 'low gradient' problem. We also find that the atmospheric general circulation in this and warmer simulations differs qualitatively from the modern regime in at least two major ways: 1) When equatorial surface temperatures exceed ~33°C, the model undergoes a transition to equatorial superrotation, a state with strong annual- and zonal-mean westerlies on the equator. The transition is driven by zonal momentum convergence due to large-amplitude transient eddies on the equator. These eddies have a structure similar to the observed Madden-Julian Oscillation (MJO).

The model's MJO variability is weaker than observed when simulating the modern climate but increases sharply with temperature, coming to dominate the tropical variability and mean state of the warmest climates. 2) Poleward atmospheric moisture transport across midlatitudes decreases with increasing temperature, the opposite behaviour to that at temperatures close to modern. We account for this non-monotonic behaviour in terms of a simple diffusive model of the oceanic storm tracks which suggests that it is due mostly to the drop in mean eddy amplitudes as temperature increases. • Jablonowski, Christiane 2015-12-14 The goals of this project were to (1) assess and quantify the sensitivity and scale-dependency of unresolved subgrid-scale mixing processes in NCAR’s Community Earth System Model (CESM), and (2) to improve the accuracy and skill of forthcoming CESM configurations on modern cubed-sphere and variable-resolution computational grids. The research thereby contributed to the description and quantification of uncertainties in CESM’s dynamical cores and their physics-dynamics interactions. L.; Dattore, R.

2014-12-01 Wind energy cost models incur inaccuracies from uncertainty in ambient wind measurements and estimates. This inhibits the best possible investment in wind energy infrastructure and management systems.

High-resolution temporal and spatial wind data needed for wind availability analysis—usually created with regional-scale models—have traditionally been proprietary and costly to obtain. Freely available global model data suffers from either lower spatial or temporal resolution, or both. Low spatial resolution fails to realistically represent wind speeds in complex terrain. Low temporal resolution fails to capture the full diurnal cycle of wind behavior.

Grib1 To Grib2 Converter Weight. Convert grib2 to grib1. How to convert NetCDF file to Grib2 or Grib files. Alien package converter. Wgrib2: changes since 5/2012. Catalyst is a light-weight version of the ParaView server library that is designed to be directly embedded into parallel.

The NCAR Global Climate Four-Dimensional Data Assimilation (CFDDA) Hourly 40 km Reanalysis was developed in 2009-2010 by the Research Applications Laboratory (RAL) to provide the most accurate boundary layer wind estimates available at that time. CFDDA used 28 sigma levels, with 19 between the surface and 700 hPa, a four-fold improvement over the contemporary NWP models. The dataset spans 21 years, 1985-2005, providing hourly atmospheric parameters, including winds, on 28 vertical levels on a global 40 km grid. This presentation will introduce the modeling and assimilation strategy, highlight the available data content including the parameter set, and review the data access options available from the RDA. CFDDA project partners, Defense Threat Reduction Agency (DTRA), NCAR RAL and NCAR Mesoscale & Microscale Meteorology (MMM) divisions are offering this dataset to the public for free with minor restrictions.

NCAR Research Data Archive (RDA), hosted by the Computational and Information Systems Laboratory, provides data support. It is available at • Lai-Chen, C. Severe weather, such as cyclones, heavy rainfall, outburst of cold air, etc., results in great disaster all the world. It is the mission for the scientists to design a warning system, to predict the severe weather systems and to reduce the damage of the society.

In Taiwan, National Satellite Project Office (NSPO) initiated ROCSAT-3 program at 1997. She scheduled the Phase I conceptual design to determine the mission for observation weather system.

Cooperating with National Center of Atmospheric Research ( NCAR), NSPO involved an international cooperation research and operation program to build a 32 GPS satellites system. NCAR will offer 24 GPS satellites. The total expanse will be US 100 millions. NSPO also provide US 80 millions for launching and system engineering operation. And NCAR will be responsible for Payload Control Center and Fiducial Network. The cooperative program contract has been signed by Taiwan National Science Council, Taipei Economic Cultural Office of United States and American Institute in Taiwan. One of the payload is COSMIC, Constellation Observation System for Meteorology, Ionosphere and Climate.

It is a GPS meteorology instrument system. The system will observe the weather information, e. Electron density profiles, horizontal and vertical TEC and CFT scintillation and communication outage maps. The mission is to obtain the weather data such as vertical temperature profiles, water vapor distribution and pressure distribution over the world for global weather forecasting, especially during the severe weather period.

The COSMIC Conference held on November, 1998. The export license was also issued by Department of Commerce of Unites States at November, 1998. Recently, NSPO begun to train their scientists to investigate the system. Scientists simulate the observation data to combine the existing routine satellite infrared cloud maps, radar echo and synoptic weather analysis for severe weather forecasting. It is hopeful to provide more accurate • Kiehl, J.T.; Hack, J.J.; Bonan, G.B.; Boville, B.A.; Briegleb, B.P. 1996-09-01 This repor presents the details of the governing equations, physical parameterizations, and numerical algorithms defining the version of the NCAR Community Climate Model designated CCM3. The material provides an overview of the major model components, and the way in which they interact as the numerical integration proceeds.

This version of the CCM incorporates significant improvements to the physic package, new capabilities such as the incorporation of a slab ocean component, and a number of enhancements to the implementation (e.g., the ability to integrate the model on parallel distributed-memory computational platforms). • Dickinson, R.E.; Henderson-Sellers, A.; Kennedy, P.J. 1993-08-01 A comprehensive model of land-surface processes has been under development suitable for use with various National Center for Atmospheric Research ( NCAR) General Circulation Models (GCMs). Special emphasis has been given to describing properly the role of vegetation in modifying the surface moisture and energy budgets. The result of these efforts has been incorporated into a boundary package, referred to as the Biosphere-Atmosphere Transfer Scheme (BATS). The current frozen version, BATS1e is a piece of software about four thousand lines of code that runs as an offline version or coupled to the Community Climate Model (CCM). • Tzeng, Ren-Yow; Bromwich, David H.; Parish, Thomas R.

1993-01-01 The ability of the NCAR Community Climate Model Version 1 (CCM1) with R 15 resolution to simulate the present-day climate of Antarctica was evaluated using the five-year seasonal cycle output produced by the CCM1 and comparing the model results with observed horizontal syntheses and point data. The results showed that the CCM1 with R 15 resolution can simulate to some extent the dynamics of Antarctic climate on the synoptic scale as well as some mesoscale features. The model can also simulate the phase and the amplitude of the annual and semiannual variation of the temperature, sea level pressure, and zonally averaged zonal (E-W) wind. The main shortcomings of the CCM1 model are associated with the model's anomalously large precipitation amounts at high latitudes, due to the tendency of the scheme to suppress negative moisture values.

• Radakovich, Jon D.; Wang, Guiling; Chern, Jiundar; Bosilovich, Michael G.; Lin, Shian-Jiann; Nebuda, Sharon; Shen, Bo-Wen 2002-01-01 In this study, the NCAR CLM version 2.0 land-surface model was integrated into the NASA/ NCAR fvGCM. The CLM was developed collaboratively by an open interagency/university group of scientists and based on well-proven physical parameterizations and numerical schemes that combine the best features of BATS, NCAR-LSM, and IAP94. The CLM design is a one-dimensional point model with 1 vegetation layer, along with sub-grid scale tiles. The features of the CLM include 10-uneven soil layers with water, ice, and temperature states in each soil layer, and five snow layers, with water flow, refreezing, compaction, and aging allowed. In addition, the CLM utilizes two-stream canopy radiative transfer, the Bonan lake model and topographic enhanced streamflow based on TOPMODEL. The DAO fvGCM uses a genuinely conservative Flux-Form Semi-Lagrangian transport algorithm along with terrain- following Lagrangian control-volume vertical coordinates. The physical parameterizations are based on the NCAR Community Atmosphere Model (CAM-2).

For our purposes, the fvGCM was run at 2 deg x 2.5 deg horizontal resolution with 55 vertical levels. The 10-year climate from the fvGCM with CLM2 was intercompared with the climate from fvGCM with LSM, ECMWF and NCEP. We concluded that the incorporation of CLM2 did not significantly impact the fvGCM climate from that of LSM. The most striking difference was the warm bias in the CLM2 surface skin temperature over desert regions. We determined that the warm bias can be partially attributed to the value of the drag coefficient for the soil under the canopy, which was too small resulting in a decoupling between the ground surface and the canopy.

We also discovered that the canopy interception was high compared to observations in the Amazon region. A number of experiments were then performed focused on implementing model improvements. In order to correct the warm bias, the drag coefficient for the soil under the canopy was considered a function of LAI (Leaf • Radakovich, Jon D.; Wang, Guiling; Chern, Jiundar; Bosilovich, Michael G.; Lin, Shian-Jiann; Nebuda, Sharon; Shen, Bo-Wen 2002-01-01 In this study, the NCAR CLM version 2.0 land-surface model was integrated into the NASA/ NCAR fvGCM. The CLM was developed collaboratively by an open interagency/university group of scientists and based on well-proven physical parameterizations and numerical schemes that combine the best features of BATS, NCAR-LSM, and IAP94. The CLM design is a one-dimensional point model with 1 vegetation layer, along with sub-grid scale tiles. The features of the CLM include 10-uneven soil layers with water, ice, and temperature states in each soil layer, and five snow layers, with water flow, refreezing, compaction, and aging allowed.

In addition, the CLM utilizes two-stream canopy radiative transfer, the Bonan lake model and topographic enhanced streamflow based on TOPMODEL. The DAO fvGCM uses a genuinely conservative Flux-Form Semi-Lagrangian transport algorithm along with terrain- following Lagrangian control-volume vertical coordinates.

The physical parameterizations are based on the NCAR Community Atmosphere Model (CAM-2). For our purposes, the fvGCM was run at 2 deg x 2.5 deg horizontal resolution with 55 vertical levels. The 10-year climate from the fvGCM with CLM2 was intercompared with the climate from fvGCM with LSM, ECMWF and NCEP. We concluded that the incorporation of CLM2 did not significantly impact the fvGCM climate from that of LSM. The most striking difference was the warm bias in the CLM2 surface skin temperature over desert regions. We determined that the warm bias can be partially attributed to the value of the drag coefficient for the soil under the canopy, which was too small resulting in a decoupling between the ground surface and the canopy. We also discovered that the canopy interception was high compared to observations in the Amazon region.

A number of experiments were then performed focused on implementing model improvements. In order to correct the warm bias, the drag coefficient for the soil under the canopy was considered a function of LAI (Leaf • Hahmann, A.N.; Dickinson, R.E. 1996-12-31 Model validation and results are briefly presented for a simulation of deforestation of the Amazon rainforest.

This initial study is made using assumptions regarding deforestation similar to those in earlier studies with several versions of the NCAR Community Climate Model (CCM) couples to the Biosphere-Atmosphere Transfer Scheme (BATS). The model used is a revised version of the NCAR CCM Version 2 coupled to BATS Version 1e. This paper discusses the portion of validation dealing with the distribution of precipitation; the simulation displays very good agreement with observed rainfall rates for the austral summer.

Preliminary results from an 8-year simulation of deforestation are similar to that of previous studies. Annual precipitation and evaporation are reduced, while surface air temperatures show a slight increase. A substantial bimodal pattern appears in the results, with the Amazon decrease of precipitation and temperature increase accompanied by changes in the opposite sign to the southeast of the Amazon. Similar patterns have occurred in other studies, but not always in exactly the same locations. Evidently, how much of the region of rainfall increase occurs in the deforested area over the Amazon strongly affects the inferred statistics. It is likely that this pattern depends on the model control climatology and possibly other features. 16 refs., 2 figs., 2 tabs.

• Zeng, Xubin; Troch, Peter; Pelletier, Jon; Niu, Guo-Yue; Gochis, David 2015-11-15 This is the Final Report of our four-year (3-year plus one-year no cost extension) collaborative project between the University of Arizona (UA) and the National Center for Atmospheric Research ( NCAR). The overall objective of our project is to develop and evaluate the first hybrid 3-D hydrological model with a horizontal grid spacing of 1 km for the NCAR Community Earth System Model (CESM). Stihl Ms170 Chainsaw Manual. • Bromwich, D.H.; Tzeng, R.Y. ); Parish, T.R.

) 1994-07-01 The NCAR CCM1's simulation of the modern arctic climate is evaluated by comparing a five-year seasonal cycle simulation with the ECMWF global analyses. The sea level pressure (SLP), storm tracks, vertical cross section of height, 500-hPa height, total energy budget, and moisture budget are analyzed to investigate the biases in the simulated arctic climate.

Brauer Handbuch Der Prparativen Anorganischen Chemielaborant. The results show that the model simulates anomalously low SLP, too much activity, and anomalously strong baroclinicity to the west of Greenland and vice versa to the east of Greenland. This bias is mainly attributed to the model's topographic representation of Greenland.

First, the broadened Greenland topography in the model distorts the path of cyclone waves over the North Atlantic Ocean. Second, the model oversimulates the ridge over Greenland, which intensifies its blocking effect and steers the cyclone waves clockwise around it and hence produces an artificial [open quotes]circum-Greenland[close quotes] trough. These biases are significantly alleviated when the horizontal resolution increases to T42.

Over the Arctic basin, the modal simulates large amounts of low-level (stratus) clouds in winter and almost no stratus in summer, which is opposite to the observations. This bias is mainly due to the location of the simulated SLP features and the negative anomaly of storm activity, which prevent the transport of moisture into this region during summer but favor this transport in winter. 26 refs., 14 figs., 42 tabs. • Schwartz, C. S.; Romine, G. S.; Sobash, R.; Fossell, K.