Browsing Atmospheric sciences by Title
Now showing items 21-40 of 301
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Assimilation of Time-averaged Pseudoproxies for Climate Reconstruction
(2013-07-23)We examine the efficacy of a novel ensemble data assimilation (DA) technique in climate field reconstructions (CFR) of surface temperature. We perform four pseudoproxy experiments with both general circulation model (GCM) ... -
Asymmetric Patterns in the Atmosphere and Sea Ice During Polar Cyclones and Their Changes Under Global Warming
The spatial structure of polar cyclones is often considered to be largely symmetrical and distinct from that of midlatitude cyclones, however we use ERA5 reanalysis and a cyclone-centered compositing method to show that ... -
Atmospheric classification as a cloud and precipitation evaluation tool in models and observations
Atmospheric classifications are created for two regions using an automated clustering technique first described in Marchand et al. 2009. This method applies an iterative clustering algorithm to regional snapshots of dynamic ... -
The atmospheric energy constraint on precipitation change
(2014-02-24)How does rain change with global warming? This dissertation investigates the rate of global-mean precipitation increase, changes in atmospheric radiative cooling, and the changes in frequency and intensity of rain events. ... -
Atmospheric predictability is insensitive to the slope of the background kinetic energy spectrum
The sensitivity of atmospheric predictability to the slope of the background kinetic energy (KE) spectrum is investigated by adding low-level potential temperature perturbations of varying scales and amplitudes to ... -
Attributing Historical and Future Evolution of Radiative Feedbacks to Regional Warming Patterns using a Green's Function Approach: The Preeminence of the Western Pacific
Global radiative feedbacks have been found to vary in global climate model (GCM) simulations. Atmospheric GCMs (AGCMs) driven with historical patterns of sea-surface temperatures (SST) and sea-ice concentrations produce ... -
The Australian monsoon and its mesoscale convective systems
(1992)The 1987 Australian monsoon was observed with satellites, rawinsondes, radar and aircraft. These data are presented, with theory filling the gaps, in illustration of its dynamics.The engine of the monsoon is its embedded ... -
Beautiful Days in the Neighborhood: Modeling Self-Perpetuated Climate and Forest Expansion during the Mid-Holocene
At the end of glacial periods, warmer temperatures induce ice sheet retreat, exposing the land surface for forest establishment. The emergence of forest transforms the area from high to low albedo. Lowering land surface ... -
Biogeochemical cycling of mercury in the atmosphere-ocean-land system: Global and regional modeling
(2013-07-23)Mercury (Hg) is a ubiquitous trace metal in the environment originating from both natural and anthropogenic sources. It is a pollutant of concern because of the adverse human health effects caused by the consumption of ... -
Can the response to global warming be La Niña-like?
The majority of the models that participated in the Coupled Model Intercomparison Project Phase 5 global warming experiments warm faster in the eastern equatorial Pacific Ocean than in the west. GFDL-ESM2M is an exception ... -
Characterization of marine boundary layer aerosol from north Atlantic and European sources: physical and chemical properties and climate forcing parameters
(2002)This thesis focuses on aerosol properties measured in Southwestern Portugal during the second Aerosol Characterization Experiment. Fundamental aerosol physical properties such as particle size distribution and hygroscopic ... -
Characterizing Mesoscale Pressure Features with Bias Corrected Smartphone Pressures
With over a billion smartphones capable of measuring atmospheric pressure, a global mesoscale surface pressure network based on smartphone pressure sensors may be possible if key technical issues are solved, including ... -
Cirrus and water vapor transport in the tropical tropopause layer
(2012-08-10)Simulations of tropical-tropopause-layer (TTL) cirrus under the influence of a large-scale equatorial Kelvin wave have been performed in two dimensions. These simulations show that, even under the influence of the large-scale ... -
Climate driven changes in nitrate deposition and preservation over the West Antarctic Ice Sheet
Nitrate preserved in ice core records has the potential to be used as a proxy for historic atmospheric NO x concentrations and oxidant abundances. Nitrate deposited to ice sheets can undergo photolysis to NO x , oxidation, ... -
The climatic effects and requirements of arctic clouds
(1997)The climatic effect and requirements of clouds over the Arctic Ocean are examined using a pair of one-dimensional models. A coupled ice-atmosphere column model with prescribed cloud properties is used to examine the effect ... -
Cloud Feedbacks in Limited-Area and Near-Global Cloud-Resolving Simulations of an Aquaplanet in SAM
Global climate models (GCMs) with conventional cumulus parameterization produce a wide spread in cloud feedbacks due to uncertainty from low clouds. Cloud-resolving model (CRM) and large-eddy simulations (LES) can be used ... -
Cold air incursions into low-latitudes: global perspective and regional analysis over South America
(1998)This dissertation addresses several aspects of synoptic-scale incursions of cold air (cold surges) propagating equatorward along the east side of the Andes cordillera in South America. Similar cold surges are also a well ... -
Constraining storm-scale forecasts of deep convective initiation with surface weather observations
Successfully forecasting when and where individual convective storms will form remains an elusive goal for short-term numerical weather prediction. In this dissertation, the convective initiation (CI) challenge is considered ... -
Constraining the Surface Energy Balance of Snow in Complex Terrain
Physically-based snow models form the basis of our understanding of current and future water and energy cycles, especially in mountainous terrain. These models are poorly constrained and widely diverge from each other, ... -
Contributions of Dense Pressure Observations to Mesoscale Analyses and Forecasts
(2013-07-25)In an effort to improve the analysis and subsequent short-term forecast of mesoscale phenomena, the assimilation of dense surface pressure observations is examined using an ensemble Kalman filter. Over the Pacific Northwest, ...