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Atmospheric intensive modeling of the wind field in the Santa Barbara channel and Santa Maria basin
P.I.: D. Koracin
Duration: 2002/2003 (extended)
Sponsor: DOI - MMS - Scripps Institution of Oceanography, San Diego, CA

This is a cooperative project among the Scripps Institution of Oceanography, Princeton University, the State University of New York, and DRI. By using high-resolution MM5 predictions with horizontal resolutions of 9, 3, and 1 km centered in the Santa Barbara Channel, the project investigates the modification of the atmospheric flows in presence of complex coastal topography in the Southern California Bight. In particular, the focus is on modeling the inhomogeneous fields of the winds, wind stress, and wind stress curl and their impact on the upwelling of the coastal waters. The numerical modeling results provided a basis for understanding the generation of the upwelling-favorable wind stress curl in the Santa Barbara Channel as well as the wind stress and wind stress curl gradients induced by the topographic effect of the islands. In addition, the study revealed significant gradients and sequence of minimum and maximum regions of the wind stress curl along the West Coast.

Development and validation of a predictive model to assess the impact of coastal operations on urban scale air quality
P.I.: A. Gertler, D. Koracin (co PI)
Duration: April 02 - April 05
Agency: Department of Defense - Strategic Environmental Research and Development Program (SERDP)

The main goal of the project is to develop improved observational and predictive capabilities to assess the impact of air pollutants emitted as a result of DoD facilities and operations on local and regional air quality. This need is motivated by the fact that many DoD facilities are located in environments such as complex coastal zones. Operations producing additional pollutant emissions are often conducted in these locations and the release of pollutants from DoD facilities and operations can contribute to increased levels of air pollution in nearby local and more distant regional environments. In order to assess the potential influence of DoD facilities and operations on air quality and, if necessary, implement effective pollutant abatement strategies, there is a need to develop and validate predictive models to estimate the impact of DoD related emissions in complex environments such as coastal regions.
To achieve the stated objective, we propose the development and validation of a prognostic modeling system to assess the impact of DoD facilities and operations conducted in complex coastal environments on mesoscale and regional air quality. As part of the proposed study, we will evaluate, assess and estimate pollutant emissions factors from on-shore and off-shore activities, develop a predictive model using state-of-the art meteorological, transport, and chemical modules, employ detailed meteorological data from current DoD coastal operations to drive the meteorological and transport modules of the model, evaluate the uncertainty in the model predictions, and verify the model predictions using real-world data. Given the experience and capabilities of the proposed research team in the development of transport and meteorological models for complex environments such as coastal regions, the advancement of atmospheric chemistry models, emission factor development and assessment, and the validation of air quality models using real-world data, we believe this study will successfully yield a prognostic modeling system capable of assessing the impact of emissions from DoD facilities and operations.

Modeling the effect of mountainous terrain on stratospheric/tropospheric exchange, atmospheric chemistry, deposition and water quality
P.I.: W. Stockwell, co PIs: V. Grubisic, D. Koracin, J. Lewis, G. Dana
Duration: Nov 01 - Nov 04
Agency: NASA EPSCoR

The main objective of the study is to integrate regional airflow, atmospheric chemistry, and hydrology models into a comprehensive framework in order to enhance our ability to analyze and forecast meteorology and atmospheric chemistry in mountainous regions and predict the impacts of these processes on the hydrology and chemistry of land surface systems. The state of Nevada in the western US provides an ideal testbed for this model integration. High mountains, including the Sierra Nevada, introduce significant perturbations in regional and global airflow that can reach very high levels in the atmosphere. Such strong modification of regional airflow influences long-range transport of pollutant. Atmospheric deposition of air pollutants, in turn, is a prominent component of non-point source pollution in watersheds, accounting for more than 50% of the pollution entering waters in the US.
Numerical models will be used to (1) simulate airflow over Nevada's complex terrain; (2) determine how mountain wind fields affect the concentration of ozone, aerosol particles, and other air pollutants over Nevada and across the western US; and (3) determine how air pollutants affect hydrological systems in alpine regions. Integration will be achieved through advance selection of models and data sets, use of simulated data as input for the other models, and comprehensive analysis of all simulated results. Model validation will be accomplished through a combination of aircraft in situ measurements, NASA remote sensing data (in collaboration with NASA investigators), and ground-based data collected under various national programs.

Atmospheric numerical simulations in support of ocean modeling during the NSF Bodega Bay field program
P.I.: D. Koracin
Duration: April 01 - April 04 (extended)
Agency: Scripps Institution of Oceanography, San Diego, California

The proposed activities are an integral part of the NSF COOP Project "The Role of Wind-driven Transport in Shelf Productivity". This is a collaborative effort among several University of California campuses (San Francisco, San Diego, and Davis), Scripps Institution of Oceanography, DRI, and recently Oregon State University and University of California, Los Angeles. The main goal of the project is to study the three-dimensional wind-driven circulation of water concurrently with size-structured distributions of phytoplankton and zooplankton species. The study focuses on the key physical and biological processes that control primary production, zooplankton population responses, and offshore transport of plankton and nutrients over the strongly wind-driven shelf and slope off Bodega Bay, CA. Some of the reasons that the shelf is selected include the occurrence of strong summer winds along the US West Coast, significant wind stress and wind stress curl, and frequent offshore flows that influence ocean dynamics in the bay. Since our main objective is to investigate the effects of the winds, wind stress, and wind stress curl on ocean dynamics on a small spatial scale, it is essential to this project to provide high-resolution fields of these parameters for the period of the field program. We are currently conducting three-month long, high-resolution MM5 simulations with the highest resolution of 1 km on the innermost domain centered in Bodega Bay. The major task is to determine the strength and duration of the upwelling and ocean relaxation periods as a function of distance from the coastline that is relevant to nutrient transport. Our atmospheric modeling results will be input for the ocean modeling following our previous work on coupling the atmospheric and ocean models.

Boundary layer marine stratus: Diurnal variability in microphysics
P.I.: S. Chai (PI), M. Wetzel (co PI), D. Koracin (co PI), M. Szumowski (former PI)
Duration: April 01 - March 04 (extended)
Agency: Department of Defense - DEPSCoR - Office of Naval Research
Marine Meteorology and Atmospheric Effects

Aircraft observations, satellite remote sensing techniques, and model simulations on cloud- and meso-scales will be used to improve predictability of diurnal variations in the microstructure of marine boundary layer stratus and stratocumulus clouds (MBS). We hypothesize that the microphysical structure and evolution of MBS varies diurnally due to the absence of solar radiation and enhanced longwave radiative cloud-top cooling at night. Daytime satellite retrievals of liquid water path (LWP) and effective radius (Re) using visible, near-infrared and thermal channels will be extended to nighttime retrieval techniques exclusively using the near-infrared and thermal channels. We seek to enhance the predictive capability of mesoscale forecast models such as COAMPS by (1) tuning the existing bulk microphysical schemes, and (2) modifying the existing parameterizations to better capture the transfer of cloud water to drizzle water in MBS clouds. Important strides in improving the current microphysical schemes can be made by comparing larger scale model simulations with fine-resolution, cloud-resolving model simulations including explicit (binned) warm rain microphysics, and in situ aircraft observations. We propose to utilize both nighttime and daytime observations to investigate the role of several variables in changing the microstructure of MBS, leading to destabilization and formation of drizzle. This research will enhance the predictability of low level cloudiness and drizzle in marine and coastal areas that are of great significance in Navy operations as well as in commercial aviation.

Multispectral remote sensing and COAMPS model analysis methods for marine cloud structure, entrainment processes and refractivity effects
P.I.: M. Wetzel (PI), S. Chai (co PI), D. Koracin (co PI)
Duration: April 01 - March 04 (extended)
Agency: Department of Defense - Office of Naval Research
Marine Meteorology and Atmospheric Effects

Research is proposed to improve short-term forecasting by the use of satellite-retrieved microphysical parameters in combination with COAMPS model simulations of cloud structure. Results of recent case studies for stratus along the Oregon coast have demonstrated new satellite remote sensing methods for cloud droplet effective radius and liquid water path, and these methods provide a spatial and temporal continuity that is not available from other sources. Datasets obtained from the COSAT '99 field program will be further developed for COAMPS model utilization and verification, including diagnostic analysis of specific conditions of the marine boundary layer such as entrainment and atmospheric refractivity.