Electric power from offshore wind via synoptic-scale interconnection.

World wind power resources are abundant, but their utilization could be limited because wind fluctuates rather than providing steady power. We hypothesize that wind power output could be stabilized if wind generators were located in a meteorologically designed configuration and electrically connected. Based on 5 yr of wind data from 11 meteorological stations, distributed over a 2,500 km extent along the U.S. East Coast, power output for each hour at each site is calculated. Each individual wind power generation site exhibits the expected power ups and downs. But when we simulate a power line connecting them, called here the Atlantic Transmission Grid, the output from the entire set of generators rarely reaches either low or full power, and power changes slowly. Notably, during the 5-yr study period, the amount of power shifted up and down but never stopped. This finding is explained by examining in detail the high and low output periods, using reanalysis data to show the weather phenomena responsible for steady production and for the occasional periods of low power. We conclude with suggested institutions appropriate to create and manage the power system analyzed here.

Submerse: Visualizing Storm Surge Flooding Simulations in Immersive Display Ecologies.

We present Submerse, an end-to-end framework for visualizing flooding scenarios on large and immersive display ecologies. Specifically, we reconstruct a surface mesh from input flood simulation data and generate a to-scale 3D virtual scene by incorporating geographical data such as terrain, textures, buildings, and additional scene objects. To optimize computation and memory performance for large simulation datasets, we discretize the data on an adaptive grid using dynamic quadtrees and support level-of-detail based rendering. Moreover, to provide a perception of flooding direction for a time instance, we animate the surface mesh by synthesizing water waves. As interaction is key for effective decision-making and analysis, we introduce two novel techniques for flood visualization in immersive systems: (1) an automatic scene-navigation method using optimal camera viewpoints generated for marked points-of-interest based on the display layout, and (2) an AR-based focus+context technique using an aux display system. Submerse is developed in collaboration between computer scientists and atmospheric scientists. We evaluate the effectiveness of our system and application by conducting workshops with emergency managers, domain experts, and concerned stakeholders in the Stony Brook Reality Deck, an immersive gigapixel facility, to visualize a superstorm flooding scenario in New York City.

Comparisons of Modeled and Observed Reflectivities and Fall Speeds for Snowfall of Varied Riming Degrees during Winter Storms on Long Island, New York.

Derived radar reflectivities and fall speeds for four Weather Research and Forecasting (WRF) Model bulk microphysical parameterizations (BMPs) run at 1.33-km grid spacing are compared with ground-based, vertically pointing Ku-band radar, scanning S-band radar, and in situ measurements at Stony Brook, New York. Simulations were partitioned into periods of observed riming degree as determined manually using a stereo microscope and camera during nine winter storms. Simulations were examined to determine whether the selected BMPs captured the effects of varying riming intensities, provided a reasonable match to the vertical structure of radar reflectivity or fall speed, and whether they produced reasonable surface fall speed distributions. Schemes assuming nonspherical mass-diameter relationships yielded reflectivity distributions closer to observed values. All four schemes examined in this study provided a better match to the observed, vertical structure of reflectivity during moderate riming than light riming periods. The comparison of observed and simulated snowfall speeds had mixed results. One BMP produced episodes of excessive cloud water at times, resulting in fall speeds that were too large. However, most schemes had frequent periods of little or no cloud water during moderate riming periods and thus underpredicted the snowfall speeds at lower levels. Short, 1-4-h periods with relatively steady snow conditions were used to compare BMP and observed size and fall speed distributions. These limited data suggest the examined BMPs underpredict fall speeds of cold-type snow habits and underrepresent aggregates larger than 4-mm diameter.

A Review of Historical and Future Changes of Extratropical Cyclones and Associated Impacts Along the US East Coast.

This paper reviews the historical and potential future trends of extratropical cyclones (ECs) along the United States (US) East Coast and western Atlantic, as well as potential changes in coastal flooding, heavy precipitation, and damaging winds. Most models project a steady decrease in the number of ECs for the US East Coast and western Atlantic region by the middle to later twenty-first century, while there is an increase in more intense (<980 hPa) cyclones and heavy precipitation; however, there is also been large interdecadal and interannual variability. Potential biases may exist in the models because of difficulty capturing: (a) the Atlantic storm track sensitivity to the Gulf Stream SST gradient, (b) latent heating within these storms, and (c) dynamical interactions at jet level. More work is needed to determine future changes in hybrid storms (e.g., Sandy 2012) and diagnostics to better understand the future cyclone changes in the models.

Atmospheric fluxes of (7)Be and (210)Pb on monthly time-scales and during rainfall events at Stony Brook, New York (USA).

The particle-reactive radionuclides (7)Be and (210)Pb have been employed extensively as tracers and chronometers for a variety of aquatic and terrestrial processes. Both radionuclides are delivered to the Earth's surface from the atmosphere, and in order to use them effectively as natural tracers, an understanding of variations in atmospheric fluxes of these radionuclides due to latitudinal differences and storm events is required. The monthly atmospheric fluxes of (7)Be and (210)Pb, measured from April-2008 to December-2009 at Stony Brook, NY, ranged from 67 to 385 Bq m(-2) and 6.7 to 16.7 Bq m(-2), respectively. Composite annual atmospheric fluxes over the sampling period were 3110 ± 1200 Bq m(-2) y(-1) for (7)Be and 146 ± 50 Bq m(-2) y(-1) for (210)Pb and were similar to geographically comparable sites. The monthly atmospheric fluxes of (7)Be and (210)Pb were significantly correlated with rainfall. The (7)Be/(210)Pb ratio in the monthly samples varied seasonally, with values of ∼10-11 during the winter months and ∼20-28 during the spring - fall. The pattern of seasonal variation in (7)Be fluxes and (7)Be/(210)Pb ratios is most consistent with that observed in surface air at continental sites in which more frequent deep convective storms occur during the summer and therefore result in an increased transport of (7)Be from the upper troposphere to the Earth's surface. An additional factor may be that the winds at Stony Brook were dominantly from the northwest during the winter of 2009 and so were characterized by low (7)Be/(210)Pb ratios while in the spring, winds from the southwest brought marine air with higher (7)Be/(210)Pb ratios to the sampling site. Fluxes of (7)Be and (210)Pb also were measured over two long (16-24 h) and two short (∼1 h) intense periods of rainfall in June and July 2009. Fluxes of (7)Be and (210)Pb continued throughout the short events, but the two radionuclides showed different patterns during the long events. While the entirety of the (210)Pb flux accumulated during the first ∼1 h, (7)Be continued to be accumulated over the course of both long events. The (7)Be/(210)Pb ratio ranged from 20 to ∼300 during the events and, in general, was considerably greater than the ratios measured in the monthly samples. Radar image snapshots taken during the events show cloud heights of 7-10.5 km, and the (7)Be/(210)Pb ratios measured in the precipitation are consistent with previous model estimates of (7)Be/(210)Pb ratios in aerosols at altitudes of 5-10 km (latitude 40°N). The data suggest that (210)Pb can be effectively stripped from the lower troposphere early in a rainfall event, but intense convective mixing and scavenging of (7)Be from the upper troposphere results in a continuous flux of (7)Be and elevated (7)Be/(210)Pb ratios as the event progresses.