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

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

Carbon accretion in unthinned and thinned young-growth forest stands of the Alaskan perhumid coastal temperate rainforest.

BACKGROUND: Accounting for carbon gains and losses in young-growth forests is a key part of carbon assessments. A common silvicultural practice in young forests is thinning to increase the growth rate of residual trees. However, the effect of thinning on total stand carbon stock in these stands is uncertain. In this study we used data from 284 long-term growth and yield plots to quantify the carbon stock in unthinned and thinned young growth conifer stands in the Alaskan coastal temperate rainforest. We estimated carbon stocks and carbon accretion rates for three thinning treatments (basal area removal of 47, 60, and 73 %) and a no-thin treatment across a range of productivity classes and ages. We also accounted for the carbon content in dead trees to quantify the influence of both thinning and natural mortality in unthinned stands. RESULTS: The total tree carbon stock in naturally-regenerating unthinned young-growth forests estimated as the asymptote of the accretion curve was 484 (±26) Mg C ha-1 for live and dead trees and 398 (±20) Mg C ha-1 for live trees only. The total tree carbon stock was reduced by 16, 26, and 39 % at stand age 40 y across the increasing range of basal area removal. Modeled linear carbon accretion rates of stands 40 years after treatment were not markedly different with increasing intensity of basal area removal from reference stand values of 4.45 Mg C ha-1 year-1to treatment stand values of 5.01, 4.83, and 4.68 Mg C ha-1 year-1 respectively. However, the carbon stock reduction in thinned stands compared to the stock of carbon in the unthinned plots was maintained over the entire 100 year period of observation. CONCLUSIONS: Thinning treatments in regenerating forest stands reduce forest carbon stocks, while carbon accretion rates recovered and were similar to unthinned stands. However, that the reduction of carbon stocks in thinned stands persisted for a century indicate that the unthinned treatment option is the optimal choice for short-term carbon sequestration. Other ecologically beneficial results of thinning may override the loss of carbon due to treatment. Our model estimates can be used to calculate regional carbon losses, alleviating uncertainty in calculating the carbon cost of the treatments

Emerging climate-driven disturbance processes: Widespread mortality associated with snow-to-rain transitions across 10° of latitude and half the range of a climate-threatened conifer

Climate change is causing rapid changes to forest disturbance regimes worldwide. While the consequences of climate change for existing disturbance processes, like fires, are relatively well studied, emerging drivers of disturbance such as snow loss and subsequent mortality are much less documented. As the climate warms, a transition from winter snow to rain in high latitudes will cause significant changes in environmental conditions such as soil temperatures, historically buffered by snow cover. The Pacific coast of North America is an excellent test case, as mean winter temperatures are currently at the snow–rain threshold and have been warming for approximately 100 years post-Little Ice Age. Increased mortality in a widespread tree species in the region has been linked to warmer winters and snow loss. Here, we present the first high-resolution range map of this climate-sensitive species, Callitropsis nootkatensis (yellow-cedar), and document the magnitude and location of observed mortality across Canada and the United States. Snow cover loss related mortality spans approximately 10° latitude (half the native range of the species) and 7% of the overall species range and appears linked to this snow–rain transition across its range. Mortality is commonly >70% of basal area in affected areas, and more common where mean winter temperatures is at or above the snow–rain threshold (>0 °C mean winter temperature). Approximately 50% of areas with a currently suitable climate for the species (< 2 °C) are expected to warm beyond that threshold by the late 21st century. Regardless of climate change scenario, little of the range which is expected to remain suitable in the future (e.g., a climatic refugia) is in currently protected landscapes (<1–9%). These results are the first documentation of this type of emerging climate disturbance and highlight the difficulties of anticipating novel disturbance processes when planning for conservation and management.Ye

New directions in building a scientific social network: Experiences in the Supercourse project and application to Central Asia.

Introduction: Networking leaders in the field of public health and medicine is very important for improving health locally and globally, especially in times of disaster. Methods: Fishing can best be defined as using an internet search engine to find the name and email address of the person or organization that is being sought. Results: With over 500 hours of work, the group compiled a list of nearly 2,000 email addresses of Ministers of Health, deans of the 1,800 medical schools and schools of public health, and heads of medical and public health societies

Incompatibility reactions and nuclear condition of three Phellinus species

Phellinus arctostaphyli (Long) Niemela, P. igniarius (L. ex Fr.) Quel., and P. tremulae (Bond.) Bond. et Boriss., heartrotting hymenomycetes in the family Hymenochaetaceae (Aphyllophorales), all conform to a multi-allelic heterothallic mating system. Both compatible and incompatible reactions result from pairings of homokaryons from the same basidiocarp. Homokaryons isolated from different basidiocarps, but the same species, are fully compatible. Cultural characteristics are not useful in distinguishing between homokaryons and heterokaryons. However, heterokaryons exhibit significantly faster growth rate in culture than homokaryons. Antagonistic responses between paired homokaryotic isolates serve as an indicator of sexual incompatibility; sexually compatible pairs acquire the faster growth rate of heterokaryons. Antagonistic characteristics similar in appearance to sexual incompatibility occur between paired heterokaryotic isolates displaying vegetative incompatibility. These three species are similar in the variation of the nuclear condition throughout their life cycles. Basidiospores are produced with one nucleus, but are ordinarily binucleate prior to germination. Both homokaryons and heterokaryons have a variable number of unpaired nuclei between septa. The dikaryophase is delayed until basidiocarp formation, when the dikaryon can be found in young basidia and mycelium underlying basidia. Incompatible reactions in hybridization attempts support the segregation of these three closely related species

Communication in Young Children with Fragile X Syndrome: A Qualitative Study of Mothers’ Perspectives

Purpose: The purposes of the study were to provide descriptive and qualitative information about communication in young children with fragile X syndrome (FXS) and about how families react to and accommodate communication differences in their children. Method: In-depth interviews were conducted with 55 mothers of young children with FXS. Interviewers asked mothers to describe their children’s communication, strategies they used to help promote their children’s communication, communication-related frustrations, their expectations for their children and the roles that they perceive for themselves. Results: Over half the children were nonverbal and learning to communicate with augmentative or alternative communication (AAC). Mothers reported using strategies that were developmentally appropriate and recommended by early childhood experts, such as reading and talking to their children. Many mothers identified challenges faced in helping their child to communicate, and some cited difficulty obtaining speech-language services as a challenge. Mothers identified their roles as caregiver, teacher, therapist and advocate. Conclusions: The perspectives offered by mothers are valuable because they indicate how children with FXS communicate in natural contexts. Information about mothers’ expectations and roles may help clinicians to be sensitive to variables that will impact working with young children and their families.NIH P30 HD003110-38S1NIH P30 HD0252