1,436 research outputs found
Integrating climate change impacts to improve understanding of coastal climate change: heavy rains, strong winds, and high seas in coastal Hawaii, Alaska and the Pacific Northwest
Coastal storms, and the strong winds, heavy rains, and high seas that accompany them pose a serious threat to the
lives and livelihoods of the peoples of the Pacific basin, from the tropics to the high latitudes. To reduce their
vulnerability to the economic, social, and environmental risks associated with these phenomena (and correspondingly enhance their resiliency), decision-makers in coastal communities require timely access to accurate information that affords them an opportunity to plan and respond accordingly. This includes information about the potential for coastal flooding, inundation and erosion at time scales ranging from hours to years, as well as the longterm climatological context of this information.
The Pacific Storms Climatology Project (PSCP) was formed in 2006 with the intent of improving scientific understanding of patterns and trends of storm frequency and intensity - “storminess”- and related impacts of these extreme events. The project is currently developing a suite of integrated information products that can be used by emergency managers, mitigation planners, government agencies and decision-makers in key sectors, including: water and natural resource management, agriculture and fisheries, transportation and communication, and recreation and tourism.
The PSCP is exploring how the climate-related processes that govern extreme storm events are expressed within and
between three primary thematic areas: heavy rains, strong winds, and high seas. To address these thematic areas,
PSCP has focused on developing analyses of historical climate records collected throughout the Pacific region, and
the integration of these climatological analyses with near-real time observations to put recent weather and climate events into a longer-term perspective.(PDF contains 4 pages
The development and use of novel iridium complexes as catalysts for ortho-directed hydrogen isotope exchange reactions
The preparation and application of groups of new iridium complexes are described. In particular, iridium complexes possessing phosphine ligands and a bulky N-heterocyclic carbene have been shown to be robust and readily handled species and have been applied in a range of directed hydrogen-deuterium and -tritium exchange processes and, in particular, with drug-like substrates or within ADMET-related studies. Overall, these new iridium(I) complexes are shown to be highly active catalysts and display catalytic activity far in excess of the industry standard, Crabtree's catalyst, with excellent levels of labelling being achieved over short reaction times and at low metal complex loadings, whilst tolerating a wide range of functional moieties. Furthermore and again in contrast to systems employing Crabtree's catalyst, the low catalyst loadings and short reaction times made possible by these emerging iridium carbene comple have delivered tritiated products with very good levels of labelling and without any appreciable by-product waste production
Flight software development for the isothermal dendritic growth experiment
The Isothermal Dendritic Growth Experiment (IDGE) is a microgravity materials science experiment scheduled to fly in the cargo bay of the shuttle on the United States Microgravity Payload (USMP) carrier. The experiment will be operated by real-time control software which will not only monitor and control onboard experiment hardware, but will also communicate, via downlink data and uplink commands, with the Payload Operations Control Center (POCC) at NASA George C. Marshall Space Flight Center (MSFC). The software development approach being used to implement this system began with software functional requirements specification. This was accomplished using the Yourdon/DeMarco methodology as supplemented by the Ward/Mellor real-time extensions. The requirements specification in combination with software prototyping was then used to generate a detailed design consisting of structure charts, module prologues, and Program Design Language (PDL) specifications. This detailed design will next be used to code the software, followed finally by testing against the functional requirements. The result will be a modular real-time control software system with traceability through every phase of the development process
Investigating changes in global tropical cyclone storm frequency and intensity
Understanding fluctuations in tropical cyclone activity along United States shores and abroad becomes increasingly
important as coastal managers and planners seek to save lives, mitigate damage, and plan for resilience in the face of changing storminess and sea-level rise. Tropical cyclone activity has long been of concern to coastal areas as they
bring strong winds, heavy rains, and high seas. Given projections of a warming climate, current estimates suggest
that not only will tropical cyclones increase in frequency, but also in intensity (maximum sustained winds and
minimum central pressures). An understanding of what has happened historically is an important step in identifying
potential future changes in tropical cyclone frequency and intensity.
The ability to detect such changes depends on a consistent and reliable global tropical cyclone dataset. Until recently
no central repository for historical tropical cyclone data existed. To fill this need, the International Best Track
Archive for Climate Stewardship (IBTrACS) dataset was developed to collect all known global historical tropical
cyclone data into a single source for dissemination. With this dataset, a global examination of changes in tropical
cyclone frequency and intensity can be performed. Caveats apply to any historical tropical cyclone analysis
however, as the data contributed to the IBTrACS archive from various tropical cyclone warning centers is still
replete with biases that may stem from operational changes, inhomogeneous monitoring programs, and time
discontinuities. A detailed discussion of the difficulties in detecting trends using tropical cyclone data can be found
in Landsea et al. 2006.
The following sections use the IBTrACS dataset to show the global spatial variability of tropical cyclone frequency
and intensity. Analyses will show where the strongest storms typically occur, the regions with the highest number
of tropical cyclones per decade, and the locations of highest average maximum wind speeds. (PDF contains 3 pages
Recommended from our members
Effects of natural soiling and weathering on cool roof energy savings for dormitory buildings in Chinese cities with hot summers
Roofs with high-reflectance (solar reflectance) coating, commonly known as cool roofs, can stay cool in the sun, thereby reducing building energy consumption and mitigating the urban heat island. However, chemical-physical degradation and biological growth can decrease their solar reflectance and the ability to save energy. In this study, the solar spectral reflectance of 12 different roofing products with an initial albedo of 0.56–0.90 was measured before exposure and once every three months over 32 months. Specimens were exposed on the roofs of dormitory buildings in Xiamen and Chengdu, each major urban areas with hot summers. The albedos of high and medium-lightness coatings stabilized in the ranges 0.45–0.62 and 0.36–0.59 in both cities, respectively. This study yielded albedo loss exceeded those reported in the latest Chinese standard by 0.08–0.15. Finally, DesignBuilder (EnergyPlus) simulations estimate that a new cool roof with albedo 0.78 on a six-story dormitory building will yield annual site energy savings (heating and cooling) for the top floor, which are 8.01 kWh/m2 (24.2%) and 9.12 kWh/m2 (26.3%) per unit floor area in Xiamen and Chengdu, respectively; while an aged cool roof with albedo 0.45 and 0.56 will yield the annual savings by 5.12 kWh/m2 (15.4%) and 2.47 kWh/m2 (10.5%) in these two cities
What is coastal climate?
Historical definitions of what determines whether one lives in a coastal area or not have varied over time. According to Culliton (1998), a “coastal county” is defined as a county with at least 15% of its total land area located within a nation’s coastal watershed. This emphasizes the land areas within which water flows into the ocean or Great Lakes, but may be better suited for ecosystems or water quality research (Crowell et al. 2007). Some Federal Emergency Management Agency (FEMA) documents suggest that “coastal” includes shoreline-adjacent coastal counties, and perhaps even counties impacted by flooding from coastal storms. An accurate definition of “coastal” is critical in this regard since FEMA uses such definitions to revise and modernize their Flood Insurance Rate Maps (Crowell et al. 2007). A recent map published by the National Oceanic and Atmospheric Administration’s (NOAA) Coastal Services Center for the Coastal Change Analysis Program shows that the “coastal” boundary covers the entire state of New York and Michigan, while nearly all of South Carolina is
considered “coastal.”
The definition of “coastal” one chooses can have major implications, including a simple count of coastal population
and the influence of local or state coastal policies. There is, however, one aspect of defining what is “coastal” that
has often been overlooked; using atmospheric long-term climate variables to define the inland extent of the coastal
zone. This definition, which incorporates temperature, precipitation, wind speed, and relative humidity, is
furthermore scalable and globally applicable - even in the face of shifting shorelines. A robust definition using
common climate variables should condense the large broad definition often associated with “coastal” such that
completely landlocked locations would no longer be considered “coastal.” Moreover, the resulting definition,
“coastal climate” or “climatology of the coast”, will help coastal resource managers make better-informed decisions
on a wide range of climatologically-influenced issues. The following sections outline the methodology employed to
derive some new maps of coastal boundaries in the United States. (PDF contains 3 pages
Studying the Nature of Dark Energy with Galaxy Clusters
We report on the status of our effort to constrain the nature of dark energy
through the evolution of the cluster mass function. Chandra temperature
profiles for 31 clusters from a local cluster sample are shown. The X-ray
appearance of the proto supermassive binary black hole at the center of the
cluster Abell 400 is described. Preliminary weak lensing results obtained with
Megacam@MMT for a redshift z=0.5 cluster from a distant cluster sample are
given.Comment: 5 pages, to appear in: Aschenbach, B., Burwitz, V., Hasinger, G.,
Leibundgut, B. (eds.), Relativistic Astrophysics and Cosmology - Einstein's
Legacy. ESO Astrophysics Symposia, Springer Verlag, Berlin, German
Reduced basis method for computational lithography
A bottleneck for computational lithography and optical metrology are long
computational times for near field simulations. For design, optimization, and
inverse scatterometry usually the same basic layout has to be simulated
multiple times for different values of geometrical parameters. The reduced
basis method allows to split up the solution process of a parameterized model
into an expensive offline and a cheap online part. After constructing the
reduced basis offline, the reduced model can be solved online very fast in the
order of seconds or below. Error estimators assure the reliability of the
reduced basis solution and are used for self adaptive construction of the
reduced system. We explain the idea of reduced basis and use the finite element
solver JCMsuite constructing the reduced basis system. We present a 3D
optimization application from optical proximity correction (OPC).Comment: BACUS Photomask Technology 200
- …