Trends in wintertime climate in the northeastern United States: 1965–2005

Humans experience climate variability and climate change primarily through changes in weather at local and regional scales. One of the most effective means to track these changes is through detailed analysis of meteorological data. In this work, monthly and seasonal trends in recent winter climate of the northeastern United States (NE-US) are documented. Snow cover and snowfall are important components of the region\u27s hydrological systems, ecosystems, infrastructure, travel safety, and winter tourism and recreation. Temperature, snowfall, and snow depth data were collected from the merged United States Historical Climate Network (USHCN) and National Climatic Data Center Cooperative Network (COOP) data set for the months of December through March, 1965–2005. Monthly and seasonal time series of snow-covered days (snow depth \u3e2.54 cm) are constructed from daily snow depth data. Spatial coherence analysis is used to address data quality issues with daily snowfall and snow depth data, and to remove stations with nonclimatic influences from the regional analysis. Monthly and seasonal trends in mean, minimum, and maximum temperature, total snowfall, and snow-covered days are evaluated over the period 1965–2005, a period during which global temperature records and regional indicators exhibit a shift to warmer climate conditions. NE-US regional winter mean, minimum, and maximum temperatures are all increasing at a rate ranging from 0.42° to 0.46°C/decade with the greatest warming in all three variables occurring in the coldest months of winter (January and February). The regional average reduction in number of snow-covered days in winter (−8.9 d/decade) is also greatest during the months of January and February. Further analysis with additional regional climate modeling is required to better investigate the causal link between the increases in temperature and reduction in snow cover during the coldest winter months of January and February. In addition, regionally averaged winter snowfall has decreased by about 4.6 cm/decade, with the greatest decreases in snowfall occurring in December and February. These results have important implications for the impacts of regional climate change on the northeastern United States hydrology, natural ecosystems, and economy

A simple model for predicting snow albedo decay using observations from the Community Collaborative Rain, Hail, and Snow-Albedo (CoCoRAHS-Albedo) Network

The albedo of seasonal snow cover plays an important role in the global climate system due to its influence on Earth’s radiation budget and energy balance. Volunteer CoCoRaHS-Albedo observers collected 3,249 individual daily albedo, snow depth, and density measurements using standardized techniques at dozens of sites across New Hampshire, USA over four winter seasons. The data show that albedo increases rapidly with snow depth up to ~ 0.14 m. Multiple linear regression models using snowpack age, snow depth or density, and air temperature provide reasonable approximations of surface snow albedo during times of albedo decay. However, the linear models also reveal systematic biases that highlight an important non-linearity in snow albedo decay. Modeled albedo values are reasonably accurate within the range of 0.6 to 0.9, but exhibit a tendency to over-estimate lower albedo values and under-estimate higher albedo values. We hypothesize that rapid reduction in high albedo fresh snow results from a decrease in snow specific surface area, while during melt-events the presence of liquid water in the snowpack accelerates metamorphism and grain growth. We conclude that the CoCoRaHS-Albedo volunteer observer network provides useful snow albedo, depth, and density measurements and serves as an effective model for future measurement campaigns

Climate Change in the Piscataqua/Great Bay Region: Past, Present, and Future

Earth ’s climate changes. It always has and always will. However, an extensive body of scientific evidence indicates that human activities are now a significant force driving change in the Earth’s climate system. This report describes how the climate of the Piscataqua/Great Bay region of coastal New Hampshire in the United States has changed over the past century and how the future climate of the region will be affected by human activities that are warming the planet. Overall, the region has been getting warmer and wetter over the last century, and the rate of change has increased over the last four decades. To generate future climate projections for the region, simulated temperature and precipitation from four general circulation models were fitted to local, long-term weather observations. Unknowns regarding future fossil fuel consumption were accounted for by using two future emissions scenarios. As greenhouse gases continue to accumulate in the atmosphere, temperatures will rise, extreme heat days are projected to occur more often and will be hotter, extreme cold temperatures are projected to occur less often, and cold days will be warmer.. Annual average precipitation is projected to increase 12 to 17% by end-of-century and the region can expect to see more extreme precipitation events in the future. Tidal gauge data indicates relative sea level at Portsmouth has risen 0.7 inches per decade over the past eight decades. Projected sea level rise of 1.7 to 6.3 feet will result in higher storm surges and more frequent flooding in coastal New Hampshire

Climate Change in Northern New Hampshire: Past, Present and Future

EARTH’S CLIMATE CHANGES. It always has and always will. However, an extensive and growing body of scientific evidence indicates that human activities—including the burning of fossil fuel (coal, oil, and natural gas) for energy, clearing of forested lands for agriculture, and raising livestock—are now the primary force driving change in the Earth’s climate system. This report describes how the climate of northern New Hampshire has changed over the past century and how the future climate of the region will be affected by a warmer planet due to human activities

Climate Change in Southern New Hampshire: Past, Present and Future

EARTH’S CLIMATE CHANGES. It always has and always will. However, an extensive and growing body of scientific evidence indicates that human activities—including the burning of fossil fuel (coal, oil, and natural gas) for energy, clearing of forested lands for agriculture, and raising livestock—are now the primary force driving change in the Earth’s climate system. This report describes how the climate of southern New Hampshire has changed over the past century and how the future climate of the region will be affected by a warmer planet due to human activities

Stability of television viewing and electronic game/computer use in a prospective cohort study of Australian children: relationship with body mass index

BackgroundWhile much cross-sectional data is available, there have been few longitudinal investigations of patterns of electronic media use in children. Further, the possibility of a bi-directional relationship between electronic media use and body mass index in children has not been considered. This study aimed to describe longitudinal patterns of television viewing and electronic game/computer use, and investigate relationships with body mass index (BMI).MethodsThis prospective cohort study was conducted in elementary schools in Victoria, Australia. 1278 children aged 5&ndash;10 years at baseline and 8&ndash;13 years at follow-up had their BMI calculated, from measured height and weight, and transformed to z-scores based on US 2000 growth data. Weight status (non-overweight, overweight and obese) was based on international BMI cut-off points. Weekly television viewing and electronic game/computer use were reported by parents, these were summed to generate total weekly screen time. Children were classified as meeting electronic media use guidelines if their total screen time was &le;14 hrs/wk.ResultsElectronic media use increased over the course of the study; 40% met guidelines at baseline but only 18% three years later. Television viewing and electronic game/computer use tracked moderately and total screen time was positively associated with adiposity cross-sectionally. While weaker relationships with adiposity were observed longitudinally, baseline z-BMI and weight status were positively associated with follow-up screen time and baseline screen time was positively associated with z-BMI and weight status at follow-up. Children who did not meet guidelines at baseline had significantly higher z-BMI and were more likely to be classified as overweight/obese at follow-up.ConclusionElectronic media use in Australian elementary school children is high, increases with age and tracks over time. There appears to be a bi-directional association suggesting that interventions targeting reductions in either screen time or adiposity may have a positive effect on both screen time and adiposity.<br /

Climate Change In The Casco Bay Watershed: Past, Present, And Future

This report describes how the climate of Casco Bay watershed in Maine has changed over the past century and how the future climate of the region is likely to be affected by human emissions of heat-trapping greenhouse gases that are warming the planet. Overall, the region has been getting warmer and wetter over the last century, and these trends have increased over the last four decades. To generate future projections for Portland, Farmington, and Lewiston, simulated temperature and precipitation from four climate models were fitted to local, long-term weather observations. Unknowns regarding fossil fuel consumption were accounted for by using two future scenarios. The scenarios describe climate in terms of temperature and precipitation for three future periods: the near-term, 2010-2039, mid-century, 2040-2069, and end-of-century, 2070-2099. All changes are relative to a historical baseline, 1970-1999. Some future changes are inevitable, so smart choices must be made to ensure our society and our environment will be able to adapt to coming change. But with prompt action, many of the most extreme consequences of climate change could be avoided or their worst impacts reduced

Evaluating the climate effects of mid-1800s deforestation in New England, USA, using a Weather, Research, and Forecasting (WRF) Model Multi-Physics Ensemble

The New England region of the northeastern United States has a land use history characterized by forest clearing for agriculture and other uses during European colonization and subsequent reforestation following widespread farm abandonment. Despite these broad changes, the potential influence on local and regional climate has received relatively little attention. This study investigated wintertime (December through March) climate impacts of reforestation in New England using a high-resolution (4 km) multiphysics ensemble of the Weather Research and Forecasting Model. In general, the conversion from mid-1800s cropland/grassland to forest led to warming, but results were sensitive to physics parameterizations. The 2-m maximum temperature (T2max) was most sensitive to choice of land surface model, 2-m minimum temperature (T2min) was sensitive to radiation scheme, and all ensemble members simulated precipitation poorly. Reforestation experiments suggest that conversion of mid-1800s cropland/grassland to present-day forest warmed T2max +0.5 to +3 K, with weaker warming during a warm, dry winter compared to a cold, snowy winter. Warmer T2max over forests was primarily the result of increased absorbed shortwave radiation and increased sensible heat flux compared to cropland/grassland. At night, T2min warmed +0.2 to +1.5 K where deciduous broadleaf forest replaced cropland/grassland, a result of decreased ground heat flux. By contrast, T2min of evergreen needleleaf forest cooled –0.5 to –2.1 K, primarily owing to increased ground heat flux and decreased sensible heat flux

Climate Change in the Casco Bay Watershed: Past, Present, and Future

This report describes how the climate of Casco Bay watershed in Maine has changed over the past century and how the future climate of the region is likely to be affected by human emissions of heat-trapping greenhouse gases that are warming the planet. Overall, the region has been getting warmer and wetter over the last century, and these trends have increased over the last four decades. To generate future projections for Portland, Farmington, and Lewiston, simulated temperature and precipitation from four climate models were fitted to local, long-term weather observations. Unknowns regarding fossil fuel consumption were accounted for by using two future scenarios. The scenarios describe climate in terms of temperature and precipitation for three future periods: the near-term, 2010-2039, mid-century, 2040-2069, and end-of-century, 2070-2099. All changes are relative to a historical baseline, 1970-1999. Some future changes are inevitable, so smart choices must be made to ensure our society and our environment will be able to adapt to coming change. But with prompt action, many of the most extreme consequences of climate change could be avoided or their worst impacts reduced