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Sample records for food availability snow

  1. Neighborhood fast food availability and fast food consumption.

    PubMed

    Oexle, Nathalie; Barnes, Timothy L; Blake, Christine E; Bell, Bethany A; Liese, Angela D

    2015-09-01

    Recent nutritional and public health research has focused on how the availability of various types of food in a person's immediate area or neighborhood influences his or her food choices and eating habits. It has been theorized that people living in areas with a wealth of unhealthy fast-food options may show higher levels of fast-food consumption, a factor that often coincides with being overweight or obese. However, measuring food availability in a particular area is difficult to achieve consistently: there may be differences in the strict physical locations of food options as compared to how individuals perceive their personal food availability, and various studies may use either one or both of these measures. The aim of this study was to evaluate the association between weekly fast-food consumption and both a person's perceived availability of fast-food and an objective measure of fast-food presence - Geographic Information Systems (GIS) - within that person's neighborhood. A randomly selected population-based sample of eight counties in South Carolina was used to conduct a cross-sectional telephone survey assessing self-report fast-food consumption and perceived availability of fast food. GIS was used to determine the actual number of fast-food outlets within each participant's neighborhood. Using multinomial logistic regression analyses, we found that neither perceived availability nor GIS-based presence of fast-food was significantly associated with weekly fast-food consumption. Our findings indicate that availability might not be the dominant factor influencing fast-food consumption. We recommend using subjective availability measures and considering individual characteristics that could influence both perceived availability of fast food and its impact on fast-food consumption. If replicated, our findings suggest that interventions aimed at reducing fast-food consumption by limiting neighborhood fast-food availability might not be completely effective. PMID

  2. Food production & availability - Essential prerequisites for sustainable food security

    PubMed Central

    Swaminathan, M.S.; Bhavani, R.V.

    2013-01-01

    Food and nutrition security are intimately interconnected, since only a food based approach can help in overcoming malnutrition in an economically and socially sustainable manner. Food production provides the base for food security as it is a key determinant of food availability. This paper deals with different aspects of ensuring high productivity and production without associated ecological harm for ensuring adequate food availability. By mainstreaming ecological considerations in technology development and dissemination, we can enter an era of evergreen revolution and sustainable food and nutrition security. Public policy support is crucial for enabling this. PMID:24135188

  3. Potential impacts of a warming climate on water availability in snow-dominated regions.

    PubMed

    Barnett, T P; Adam, J C; Lettenmaier, D P

    2005-11-17

    All currently available climate models predict a near-surface warming trend under the influence of rising levels of greenhouse gases in the atmosphere. In addition to the direct effects on climate--for example, on the frequency of heatwaves--this increase in surface temperatures has important consequences for the hydrological cycle, particularly in regions where water supply is currently dominated by melting snow or ice. In a warmer world, less winter precipitation falls as snow and the melting of winter snow occurs earlier in spring. Even without any changes in precipitation intensity, both of these effects lead to a shift in peak river runoff to winter and early spring, away from summer and autumn when demand is highest. Where storage capacities are not sufficient, much of the winter runoff will immediately be lost to the oceans. With more than one-sixth of the Earth's population relying on glaciers and seasonal snow packs for their water supply, the consequences of these hydrological changes for future water availability--predicted with high confidence and already diagnosed in some regions--are likely to be severe. PMID:16292301

  4. Use of supplemental food by breeding Ross's Geese and Lesser Snow Geese: Evidence for variable anorexia

    USGS Publications Warehouse

    Gloutney, M.L.; Alisauskas, R.T.; Hobson, K.A.; Afton, A.D.

    1999-01-01

    Recent research suggests that foods eaten during laying and incubation play a greater role in supplying energy and nutrients to arctic-nesting geese than previously believed. We conducted food-supplementation experiments with Ross's Geese (Chen rossii) and Lesser Snow Geese (C. caerulescens) geese to evaluate: (1) if supplemental food was consumed by laying and incubating geese, (2) how food consumption influenced mass dynamics of somatic tissues of breeding geese, (3) if patterns of mass loss were consistent with fasting adaptations, and (4) whether energetic constraints would cause smaller Ross's Geese to consume more food relative to their body size than would larger Snow Geese. Quantity of supplemental food eaten by both species during laying and incubation was highly variable among individuals. Consumption of supplemental food during laying resulted in differences in overall body composition between control and treatment females. Treatment female Ross's Geese completed laying at a higher mass and with more abdominal fat than controls, whereas treatment female Snow Geese completed laying with heavier breast muscles and hearts. Overall body composition did not differ between control and treatment geese (both sexes and species) at the end of incubation, but treatment geese had heavier hearts than control geese. This suggests that treatment females did not rely to the same extent on metabolic adaptations associated with anorexia to meet energetic costs of incubation as did controls. Stable-nitrogen isotope analysis revealed patterns of protein maintenance during incubation consistent with metabolic adaptations to prolonged fasting. Our prediction that energetic constraints would cause smaller Ross's Geese to consume more food relative to their size than would Snow Geese was not supported. Mass-specific food consumption by Ross's Geese was 30% lower than that of Snow Geese during laying and 48% higher during incubation.

  5. Food availability/convenience and obesity.

    PubMed

    Gordon-Larsen, Penny

    2014-11-01

    Neighborhood environments have received considerable attention in recent local, state, and national obesity prevention initiatives, with a particular focus on food deserts, or areas with poor access to healthy foods. Yet, there are inconsistencies in the evidence base, suggesting a nuanced association between neighborhood environment, food availability, diet behaviors, and obesity. There is heterogeneity in associations between environmental exposures and health outcomes across race/ethnicity, gender, region, and urbanicity, which results in complexity in the interpretation of findings. There are several limitations in the literature, including a predominance of cross-sectional studies, reliance on commercial business listings, lack of attention to the process by which diet resources are established and expanded within neighborhoods and the potential for individuals to selectively migrate to locate near such facilities, a predominant focus on residential neighborhoods, and lack of information about the decision-making process underlying purchasing patterns. More research is needed to address the complexity of individual-level residential decision making as well as the purposeful placement of food environment resources across social and geographic space using longitudinal data and complex statistical approaches. In addition, improvements in data quality and depth related to food access and availability are needed, including behavioral data on purchase patterns and interactions with the food environment, and greater attention to heterogeneity across subpopulations. As policy changes to the food environment move forward, it is critical that there is rigorous and scientific evaluation of environmental changes and their impact on individual-level diet choices and behaviors, and their further influence on body weight. PMID:25398746

  6. Food Availability/Convenience and Obesity12345

    PubMed Central

    Gordon-Larsen, Penny

    2014-01-01

    Neighborhood environments have received considerable attention in recent local, state, and national obesity prevention initiatives, with a particular focus on food deserts, or areas with poor access to healthy foods. Yet, there are inconsistencies in the evidence base, suggesting a nuanced association between neighborhood environment, food availability, diet behaviors, and obesity. There is heterogeneity in associations between environmental exposures and health outcomes across race/ethnicity, gender, region, and urbanicity, which results in complexity in the interpretation of findings. There are several limitations in the literature, including a predominance of cross-sectional studies, reliance on commercial business listings, lack of attention to the process by which diet resources are established and expanded within neighborhoods and the potential for individuals to selectively migrate to locate near such facilities, a predominant focus on residential neighborhoods, and lack of information about the decision-making process underlying purchasing patterns. More research is needed to address the complexity of individual-level residential decision making as well as the purposeful placement of food environment resources across social and geographic space using longitudinal data and complex statistical approaches. In addition, improvements in data quality and depth related to food access and availability are needed, including behavioral data on purchase patterns and interactions with the food environment, and greater attention to heterogeneity across subpopulations. As policy changes to the food environment move forward, it is critical that there is rigorous and scientific evaluation of environmental changes and their impact on individual-level diet choices and behaviors, and their further influence on body weight. PMID:25398746

  7. Processed foods available in the Pacific Islands

    PubMed Central

    2013-01-01

    Background There is an increasing reliance on processed foods globally, yet food composition tables include minimal information on their nutrient content. The Pacific Islands share common trade links and are heavily reliant on imported foods. The objective was to develop a dataset for the Pacific Islands on nutrient composition of processed foods sold and their sources. Methods Information on the food labels, including country of origin, nutrient content and promotional claims were recorded into a standardised dataset. Data were cleaned, converted to per 100 g data as needed and then checked for anomalies and recording errors. Setting: Five representative countries were selected for data collection, based on their trading patterns: Fiji, Guam, Nauru, New Caledonia, and Samoa. Data were collected in the capitals, in larger stores which import their own foods. Subjects: Processed foods in stores. Results The data from 6041 foods and drinks were recorded. Fifty four countries of origin were identified, with the main provider of food for each Pacific Island country being that with which it was most strongly linked politically. Nutrient data were not provided for 6% of the foods, imported from various countries. Inaccurate labels were found on 132 products. Over one-quarter of the foods included some nutrient or health-related claims. Conclusions The globalisation of the food supply is having considerable impacts on diets in the Pacific Islands. While nutrient labels can be informative for consumers looking for healthier options, difficulties still exist with poor labelling and interpretation can be challenging. PMID:24160249

  8. 100 Years of Glacier Photographs: Available Online at the National Snow and Ice Data Center

    NASA Astrophysics Data System (ADS)

    Ballagh, L. M.; Wolfe, J.; Wang, I.; Casey, A.; Fetterer, F.

    2004-12-01

    Historic glacier photographs can be used to study fluctuations in glacier extent over time in response to climate change. Researchers can also use the photographs to approximate changes in glacier terminus location and mass balance. The "Glacier Photograph Collection" at the National Snow and Ice Data Center (NSIDC) contains approximately 5,000 photographs, including both aerial and terrestrial images. NSIDC received funding from the NOAA Climate Database Modernization Program (CDMP) to digitize a portion of the photographs and make an Online Glacier Photograph Database available. The CDMP's primary objective is to preserve climate data and facilitate access to the data. Although digitizing images is expensive, long-term data preservation is a major benefit. When historic photographs are stored on film, images can easily be scratched or damaged. Scanning the images and having them online makes browsing images easier for users. At present, there are 1,313 glacier photographs available online. Additional photos and metadata are being added. The Online Glacier Photograph Database will date from 1883 to 1995, totaling nearly 3,000 photographs available as high resolution TIFF images and lower resolution reference images and thumbnails by the end of 2004. Maintaining accurate metadata records for each photograph is very important. The database is searchable by various fields, including photographer name, photograph date, glacier name, glacier coordinates, state/province, and keyword.

  9. Ecosystem water availability in juniper versus sagebrush snow-dominated rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Western Juniper (J. occidentalis Hook.) now dominates over 3.6 million ha of rangeland in the Intermountain Western US. Critical ecological relationships among snow distribution, water budgets, plant community transitions, and habitat requirements for wildlife, such as sage grouse, remain poorly und...

  10. Ecosystem water availability in juniper versus sagebrush snow-domintaed rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Western Juniper (J. occidentalis Hook.) now dominates over 3.6 million ha of rangeland in the Intermountain Western US. Critical ecological relationships among snow distribution, water budgets, plant community transitions, and habitat requirements for wildlife, such as sage grouse, remain poorly und...

  11. [A comparison of parrot food commercially available in The Netherlands].

    PubMed

    Robben, J H; Lumeij, J T

    1989-01-01

    The composition of a number of parrot foods commercially available in the Netherlands was put to the test for the (partly hypothetical) needs of the larger psittacine birds such as African Grey parrots, Amazon parrots, macaws and cockatoos. These studies showed that the majority of the foods is multideficient. When the deficient foods are supplied to parrots without any additions, this will give rise to the appearance of disease. However, some of the products recently put on the market (Bogena and Kasper Fauna Food) comply better with the requirements of a 'complete parrot food'. As regards public enlightenment, food producers, petshops, consumer organisations and veterinarians are obviously responsible. PMID:2913689

  12. Retail Food Availability, Obesity, and Cigarette Smoking in Rural Communities

    ERIC Educational Resources Information Center

    Hosler, Akiko S.

    2009-01-01

    Context: Disparities in the availability of nutritionally important foods and their influence on health have been studied in US urban communities. Purpose: To assess the availability of selected retail foods and cigarettes, and explore ecologic relationships of the availability with obesity and smoking in rural communities. Methods: Inventories of…

  13. The value of data availability versus model complexity to estimate snow, glacier and rain water in mountain streams

    NASA Astrophysics Data System (ADS)

    Finger, David; Vis, Marc; Seibert, Jan

    2014-05-01

    various observational datasets in order to constrain model parameters and compute realistic discharge estimations. Finally, we postulate based on the comparison of model performance of HBV-light and the physically based, fully distributed model that the availability and use of different datasets to calibrate hydrological models might be more important than model complexity in regard to realistic predictions of runoff composition. REFERENCES: Finger, D., A. Hugentobler, M. Huss, A. Voinesco, H.R. Wernli, D. Fischer, E. Weber, P-Y. Jeannin, M. Kauzlaric, A. Wirz, T. Vennemann, F. Hüsler, B. Schädler, and R. Weingartner (2013). Identification of glacial melt water runoff in a karstic environment and its implication for present and future water availability. Hydrol. Earth Syst. Sci. Discuss. 10, 1-45, doi: 10.5194/hessd-10-1-2013. Finger, D., Heinrich, G., Gobiet, A., and Bauder, A.: Projections of future water resources and their uncertainty in a glacierized catchment in the Swiss Alps and the subsequent effects on hydropower production during the 21st century, Water Resources Research, 48, doi: 10.1029/2011wr010733, W02521, 2012. Finger, D., Pellicciotti, F., Konz, M., Rimkus, S., and Burlando, P.: The value of glacier mass balance, satellite snow cover images, and hourly discharge for improving the performance of a physically based distributed hydrological model, Water Resources Research, 47, doi: W07519, 10.1029/2010wr009824, 2011. Huss, M.: Present and future contribution of glacier storage change to runoff from macroscale drainage basins in Europe, Water Resources Research, 47, doi: W07511, 10.1029/2010wr010299, 2011. Seibert, J., and Vis, M. J. P.: Teaching hydrological modeling with a user-friendly catchment-runoff-model software package, Hydrol. Earth Syst. Sci., 16, 3315-3325, doi: 10.5194/hess-16-3315-2012, 2012.

  14. #AskBerkeleyLab: Cost and Availability of Healthy Food

    SciTech Connect

    Buluswar, Shashi

    2014-10-22

    Shashi Buluswar, Executive Director at the LBNL Institute for Globally Transformative Technologies, answers a question from Ashley on why healthy food costs so much and is not available in low-income neighborhoods.

  15. 77 FR 471 - Emergency Food Assistance Program; Availability of Foods for Fiscal Year 2012

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-05

    ...This notice announces the surplus and purchased foods that the Department expects to make available for donation to States for use in providing nutrition assistance to the needy under The Emergency Food Assistance Program (TEFAP) in Fiscal Year (FY) 2012. The foods made available under this notice must, at the discretion of the State, be distributed to eligible recipient agencies for use in......

  16. Food availability and foraging near human developments by black bears

    USGS Publications Warehouse

    Merkle, Jerod A.; Robinson, Hugh S.; Krausman, Paul R.; Alaback, Paul B.

    2013-01-01

    Understanding the relationship between foraging ecology and the presence of human-dominated landscapes is important, particularly for American black bears (Ursus americanus), which sometimes move between wildlands and urban areas to forage. The food-related factors influencing this movement have not been explored, but can be important for understanding the benefits and costs to black bear foraging behavior and the fundamental origins of bear conflicts. We tested whether the scarcity of wildland foods or the availability of urban foods can explain when black bears forage near houses, examined the extent to which male bears use urban areas in comparison to females, and identified the most important food items influencing bear movement into urban areas. We monitored 16 collared black bears in and around Missoula, Montana, during 2009 and 2010, while quantifying the rate of change in green vegetation and the availability of 5 native berry-producing species outside the urban area, the rate of change in green vegetation, and the availability of apples and garbage inside the urban area. We used parametric time-to-event models in which an event was a bear location collected within 100 m of a house. We also visited feeding sites located near houses and quantified food items bears had eaten. The probability of a bear being located near a house was 1.6 times higher for males, and increased during apple season and the urban green-up. Fruit trees accounted for most of the forage items at urban feeding sites (49%), whereas wildland foods composed <10%. Black bears foraged on human foods near houses even when wildland foods were available, suggesting that the absence of wildland foods may not influence the probability of bears foraging near houses. Additionally, other attractants, in this case fruit trees, appear to be more important than the availability of garbage in influencing when bears forage near houses.

  17. Performance of the snowmelt runoff model when remotely-sensed estimates of snow covered area are not available

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Snowmelt Runoff Model (SRM) is usually run with snow cover depletion data. These daily depletion data can be derived through interpolation of periodic, remotely sensed measurements of basin snow covered area (SCA). It is also possible to run SRM successfully without snow depletion data in “no sn...

  18. From Food Insufficiency towards Trade Dependency: A Historical Analysis of Global Food Availability

    PubMed Central

    Porkka, Miina; Kummu, Matti; Siebert, Stefan; Varis, Olli

    2013-01-01

    Achieving global food security is one of the major challenges of the coming decades. In order to tackle future food security challenges we must understand the past. This study presents a historical analysis of global food availability, one of the key elements of food security. By calculating national level dietary energy supply and production for nine time steps during 1965–2005 we classify countries based on their food availability, food self-sufficiency and food trade. We also look at how diets have changed during this period with regard to supply of animal based calories. Our results show that food availability has increased substantially both in absolute and relative terms. The percentage of population living in countries with sufficient food supply (>2500 kcal/cap/d) has almost doubled from 33% in 1965 to 61% in 2005. The population living with critically low food supply (<2000 kcal/cap/d) has dropped from 52% to 3%. Largest improvements are seen in the MENA region, Latin America, China and Southeast Asia. Besides, the composition of diets has changed considerably within the study period: the world population living with high supply of animal source food (>15% of dietary energy supply) increased from 33% to over 50%. While food supply has increased globally, food self-sufficiency (domestic production>2500 kcal/cap/d) has not changed remarkably. In the beginning of the study period insufficient domestic production meant insufficient food supply, but in recent years the deficit has been increasingly compensated by rising food imports. This highlights the growing importance of food trade, either for food supply in importing countries or as a source of income for exporters. Our results provide a basis for understanding past global food system dynamics which, in turn, can benefit research on future food security. PMID:24367545

  19. Reactive lysine content in commercially available pet foods.

    PubMed

    van Rooijen, Charlotte; Bosch, Guido; van der Poel, Antonius F B; Wierenga, Peter A; Alexander, Lucille; Hendriks, Wouter H

    2014-01-01

    The Maillard reaction can occur during processing of pet foods. During this reaction, the ε-amino group of lysine reacts with reducing sugars to become unavailable for metabolism. The aim of the present study was to determine the reactive lysine (RL; the remaining available lysine) to total lysine (TL) ratio of commercial pet foods and to evaluate whether RL levels meet minimal lysine requirements (MLR). Sixty-seven extruded, canned and pelleted commercially available dog and cat foods for growth and maintenance were analysed for proximate nutrient composition, TL and RL. RL was expressed on a metabolisable energy basis and compared with the MLR for maintenance and growth. In dog foods, average RL:TL ratios were 0·87 (se 0·02) for extruded, 0·97 (se 0·02) for canned and 0·85 (se 0·01) for pelleted foods, with the lowest ratio of 0·77 in an extruded diet for growing dogs. In extruded and canned cat foods, the average ratio was 0·91 (se 0·02) and 0·90 (se 0·03), respectively, with the lowest ratio being 0·67 in an extruded diet for growing cats. Variation in the RL:TL ratio between and within processing type indicate that ingredients rather than processing might be the key factor influencing RL content in pet foods. Eight dry foods for growing dogs had RL contents between 96 and 138 % of MLR, indicating that RL has to be between 62 and 104 % digestible to meet the MLR. Considering the variability in RL digestibility, these foods could be at risk of not meeting the MLR for growing dogs. Ingredients and pet foods should be characterised with respect to the RL content and digestibility, to avoid limitations in the lysine supply to growing dogs. PMID:26101604

  20. Epinephrine autoinjector availability among children with food allergy.

    PubMed

    DeMuth, Karen A; Fitzpatrick, Anne M

    2011-01-01

    Epinephrine is the treatment of choice for anaphylaxis. Delay in administration of epinephrine is a known risk factor for food allergy reaction-related mortality; however, individuals with food allergy may not have epinephrine readily available. This study was designed to determine the percent of food-allergic children that have an epinephrine autoinjector readily available and factors associated with epinephrine autoinjector carriage rates. Parents completed a questionnaire on food allergy and food allergy preparedness. Staff recorded whether an epinephrine autoinjector and medical alert bracelet was immediately available in clinic. Parental responses from 63 food-allergic children were included. Fifty-nine percent (37/63) had an epinephrine autoinjector present in the clinic, and 79% (50/63) reported receiving training in epinephrine autoinjector use. There was no correlation between epinephrine autoinjector presence in the clinic and parental report of having an epinephrine autoinjector available at all times (phi = 0.21). Epinephrine autoinjector training was associated with increased odds of having an epinephrine autoinjector immediately available (adjusted odds ratio, 8.74 [1.69, 45.04]). Fewer school aged children (≥5 years old) reportedly had their epinephrine autoinjector with them when eating lunch (25% [8/32] versus 42% [13/31]; p = 0.002) or snacks (28% [9/32] versus 37% [13/31]; p = 0.005) when compared with those <5 years old. Many children do not have their epinephrine autoinjectors readily available despite parental report. Epinephrine autoinjector training improved the odds of having an epinephrine autoinjector readily available. Continued patient education on the importance of having an epinephrine autoinjector easily accessible, especially when eating, is important. PMID:21781405

  1. Improved food availability for food security in Asia-Pacific region.

    PubMed

    Yang, Ray-Yu; Hanson, Peter M

    2009-01-01

    Food security requires that all people can access sufficient food for a healthy life. Enough food is produced to feed the global population, but more than 1.02 billion people are malnourished. Malnutrition and chronic food insecurity are widespread in some countries of the Asia-Pacific region; as much as 20 to 60 percent of the region's population lacks sufficient food to meet their minimum energy requirement. Food security greatly depends on food availability, although this alone is not sufficient to secure satisfactory nutritional status. Food security at the national level requires an effective framework of food, health, and economic systems coupled with awareness and consideration of environmental conditions. To improve food availability and security in the short term, lower income countries should focus on increasing productivity in the food system to generate higher incomes for workers on-farm and off-farm in the food chain. Over the long term, sustainable and small-scale farming based on ecologically viable systems should be the emphasis for agricultural development. Nutrition and health sectors should help promote food-based approaches that lead to diversification of crops, balanced diets, and ultimately better health. PMID:19965357

  2. Dining Dovekies Demand, "When, Where and What's for Dinner?" The Impact of Seasonal Changes in Snow Melt and the Development of the Arctic Marine Food Web on Seabirds.

    NASA Astrophysics Data System (ADS)

    Karnovsky, N. J.; Harding, A.; Welcker, J.; Brown, Z. W.; Kitaysky, A.; Kwasniewski, S.; Walkusz, W.; Gremillet, D.

    2011-12-01

    The Atlantic sector of the Arctic is undergoing widespread climate change with increases in air and sea temperatures which impact the timing of ice retreat, snow melt and the development of the marine food web. Dovekies (Alle alle) are small seabirds that migrate to the Atlantic Sector of the Arctic to feed in ice free waters that have abundant lipid-rich zooplankton. In the Greenland Sea, the dovekies are largely dependent on the advection of Calanus copepods into the area. We hypothesized that dovekies breeding adjacent to water masses which bring smaller, less energy-rich prey into the region (Calanus finmarchicus), work harder to find food and have higher stress levels. We tested this hypothesis by attaching time-depth recorders to provisioning dovekies at three colonies adjacent to different water masses (the West Spistbergen Current, the East Greenland Current, and the Sorkapp Current). We determined the length of time dovekies at different colonies spent at-sea collecting food for themselves and their chicks. We measured circulating corticosteroid hormone levels in their blood to assess stress levels. We collected chick meals to determine the energetic content of prey fed chicks at the different colonies. We found that dovekies are sensitive to the quality of prey available to them. Dovekies exposed to less profitable prey made longer foraging trips and worked harder while at-sea to collect prey for themselves and their chicks. Furthermore, over the past 50 years, dovekies breeding along the western shores of Spitsbergen have initiated breeding earlier in spring as their nest sites have become snow-free at earlier dates. We evaluate the impact of earlier breeding and the timing of the development of the marine food web within different currents which advect and/or support Calanus copepods into the Greenland Sea. Future possible declines in dovekies may impact terrestrial food webs which are highly influenced by the annual input of nitrogen rich guano on the

  3. Profits, Commercial Food Supplier Involvement, and School Vending Machine Snack Food Availability: Implications for Implementing the New Competitive Foods Rule

    ERIC Educational Resources Information Center

    Terry-McElrath, Yvonne M.; Hood, Nancy E.; Colabianchi, Natalie; O'Malley, Patrick M.; Johnston, Lloyd D.

    2014-01-01

    Background: The 2013-2014 school year involved preparation for implementing the new US Department of Agriculture (USDA) competitive foods nutrition standards. An awareness of associations between commercial supplier involvement, food vending practices, and food vending item availability may assist schools in preparing for the new standards.…

  4. Does the availability of snack foods in supermarkets vary internationally?

    PubMed Central

    2013-01-01

    Background Cross-country differences in dietary behaviours and obesity rates have been previously reported. Consumption of energy-dense snack foods and soft drinks are implicated as contributing to weight gain, however little is known about how the availability of these items within supermarkets varies internationally. This study assessed variations in the display of snack foods and soft drinks within a sample of supermarkets across eight countries. Methods Within-store audits were used to evaluate and compare the availability of potato chips (crisps), chocolate, confectionery and soft drinks. Displays measured included shelf length and the proportion of checkouts and end-of-aisle displays containing these products. Audits were conducted in a convenience sample of 170 supermarkets across eight developed nations (Australia, Canada, Denmark, Netherlands, New Zealand, Sweden, United Kingdom (UK), and United States of America (US)). Results The mean total aisle length of snack foods (adjusted for store size) was greatest in supermarkets from the UK (56.4 m) and lowest in New Zealand (21.7 m). When assessed by individual item, the greatest aisle length devoted to chips, chocolate and confectionery was found in UK supermarkets while the greatest aisle length dedicated to soft drinks was in Australian supermarkets. Only stores from the Netherlands (41%) had less than 70% of checkouts featuring displays of snack foods or soft drinks. Conclusion Whilst between-country variations were observed, overall results indicate high levels of snack food and soft drinks displays within supermarkets across the eight countries. Exposure to snack foods is largely unavoidable within supermarkets, increasing the likelihood of purchases and particularly those made impulsively. PMID:23672409

  5. Seston Dynamics and Food Availability on Mussel and Cockle Beds

    NASA Astrophysics Data System (ADS)

    Smaal, A. C.; Haas, H. A.

    1997-08-01

    To provide a better understanding of seston dynamics in relation to food supply to the benthos, a series of 13-h tidal cycle sampling programmes was executed in the Oosterschelde estuary (The Netherlands). Samples were taken near the surface and near the bottom on two subtidal mussel cultivation plots and on two intertidal cockle beds. Long-term annual variablity of seston concentrations was lower than coefficients of variance of the short-term tidal cycle seston data at the intertidal stations, and higher than at the subtidal stations. Near-bottom relative to surface concentrations were highest for suspended particulate matter (SPM), followed by particulate organic carbon (POC), and chlorophyll. There was no food depletion near the bottom but food quality was lower, presumably due to re-suspension of sediment, including low-quality biodeposits. Chlorophyll concentrations were lower in ebb than flood water at all stations, which was ascribed to feeding activity of the bivalves. At the subtidal stations, SPM and POC concentrations were also lower during low water, owing to sedimentation. There was a positive correlation at the intertidal stations of seston quantity with wind speed and wave action. At a wave length exceeding twice the water depth, re-suspension of low quality bottom material was observed and seston quality decreased. It was concluded that food availability for benthic suspension feeders was lower than suggested by routine monitoring data. At the intertidal stations, food quality was further reduced during periods of increased wind velocities and wave action. The low near-bottom food quality can partly be considered as an effect of the feeding activity of the benthic suspension feeders.

  6. Long-term trends in food availability, food prices, and obesity in Samoa

    PubMed Central

    Seiden, Andrew; Hawley, Nicola; Schulz, Dirk; Raifman, Sarah; McGarvey, Stephen T

    2012-01-01

    Objectives To describe long term food availability and prices from 1961 to 2007 and BMI trends from 1980–2010 in Samoa, and to contextualize these trends within political, economic, cultural, behavioral, and climatic influences. Methods National level data on food availability and pricing were obtained from the open access database FAO (http://faostat.fao.org). Data for Samoa were collected from annual food balance sheets available for the period 1961 to 2007. Mean BMI for Samoan men and women ages 35–44 years of age is reported from four different time periods, 1979–82, 1991, 2003, and 2010. Results Total energy availability increased substantially, by 47%, with more than 900 extra calories available per capita per day in 2007 than in 1961. Many of these extra calories are supplied by dietary fat, the availability of which rose by a proportionally greater amount, 73%. Availability of both meat and vegetable oils rose substantially. Poultry meat increased the most proportionally, from 10 to 117 kcal per capita per day. Coconut products, fruit and starchy root crops – all locally grown – showed little to no increase over this time. As import prices for poultry and mutton increased their availability decreased, but the availability of vegetable oils rose despite a rise in their price. Mean BMI for men and women ages 35–44 years rose 18% rise from 1980–2010. Conclusions These long-term trends in food availability and prices, and the temporal pattern of BMI provide national level data for understanding the process of the nutrition transition in Samoa. Further work on consumer food prices, diet, food security and health is needed to further contextualize the transformation of the local food system in Samoa. PMID:22371334

  7. Food availability is expressed through physiological stress indicators in nestling white ibis: A food supplementation experiment

    USGS Publications Warehouse

    Herring, G.; Cook, Mark I.; Gawlik, D.E.; Call, Erynn M.

    2011-01-01

    Physiological responses to environmental stress such as adrenocortical hormones and cellular stress proteins have recently emerged as potentially powerful tools for investigating physiological effects of avian food limitation. However, little is known about the physiological stress responses of free-living nestling birds to environmental variation in food availability. We experimentally tested how hydrologically mediated changes in food availability affect the physiological stress responses of juvenile white ibises Eudocimus albus in a fluctuating wetland. We provided supplementary food to free-living nestlings during 2years with contrasting hydrologic and food availability conditions, and used plasma (PCORT) and faecal (FCORT) corticosterone and heat shock proteins (HSP60 and HSP70) from first-hatched (A-nestlings) and second-hatched (B-nestlings) to detect relatively short- to long-term responses to food limitation. Nestling physiological stress responses were relatively low in all treatments during the year with optimal food availability, but PCORT, FCORT and HSP60 levels increased during the poor food year. FCORT and HSP60 responses were clearly due to nutritional condition as elevated concentrations were evident primarily in control nestlings. Significant year by hatch order interactions for both FCORT and HSP60 revealed that these increases were largely incurred by B-nestlings. FCORT and HSP60 responses were also well developed early in neonatal development and remained elevated for the duration of the experiment suggesting a chronic stress response. PCORT and HSP70 were less informative stress responses. The nutritionally mediated increases in FCORT and HSP60 provide compelling evidence that white ibis nestlings can be physiologically affected by environmental food levels. FCORT and HSP60 are effective indicators of nutritional mediated stress for nestling white ibises and potentially for other species prone to capture or handling stress. ?? 2010 The Authors

  8. Interactions between oxygen homeostasis, food availability, and hydrogen sulfide signaling

    PubMed Central

    Iranon, Nicole N.; Miller, Dana L.

    2012-01-01

    The ability to sense and respond to stressful conditions is essential to maintain organismal homeostasis. It has long been recognized that stress response factors that improve survival in changing conditions can also influence longevity. In this review, we discuss different strategies used by animals in response to decreased O2 (hypoxia) to maintain O2 homeostasis, and consider interactions between hypoxia responses, nutritional status, and H2S signaling. O2 is an essential environmental nutrient for almost all metazoans as it plays a fundamental role in development and cellular metabolism. However, the physiological response(s) to hypoxia depend greatly on the amount of O2 available. Animals must sense declining O2 availability to coordinate fundamental metabolic and signaling pathways. It is not surprising that factors involved in the response to hypoxia are also involved in responding to other key environmental signals, particularly food availability. Recent studies in mammals have also shown that the small gaseous signaling molecule hydrogen sulfide (H2S) protects against cellular damage and death in hypoxia. These results suggest that H2S signaling also integrates with hypoxia response(s). Many of the signaling pathways that mediate the effects of hypoxia, food deprivation, and H2S signaling have also been implicated in the control of lifespan. Understanding how these pathways are coordinated therefore has the potential to reveal new cellular and organismal homeostatic mechanisms that contribute to longevity assurance in animals. PMID:23233860

  9. 21 CFR 20.120 - Records available in Food and Drug Administration Public Reading Rooms.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Records available in Food and Drug Administration Public Reading Rooms. 20.120 Section 20.120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF....120 Records available in Food and Drug Administration Public Reading Rooms. (a) The Food and...

  10. 21 CFR 20.120 - Records available in Food and Drug Administration Public Reading Rooms.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Records available in Food and Drug Administration Public Reading Rooms. 20.120 Section 20.120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PUBLIC INFORMATION Availability of Specific Categories of Records § 20.120 Records available in Food and...

  11. Molecular diversity of bacteria in commercially available "Spirulina" food supplements.

    PubMed

    Vardaka, Elisabeth; Kormas, Konstantinos A; Katsiapi, Matina; Genitsaris, Savvas; Moustaka-Gouni, Maria

    2016-01-01

    The cyanobacterium Arthrospira is among the most well-known food supplements worldwide known as "Spirulina." While it is a widely recognized health-promoting natural product, there are no reports on the molecular diversity of commercially available brands of "Spirulina" supplements and the occurrence of other cyanobacterial and heterotrophic bacterial microorganisms in these products. In this study, 454-pyrosequencing analysis of the total bacterial occurrence in 31 brands of "Spirulina" dietary supplements from the Greek market was applied for the first time. In all samples, operational taxonomic units (OTUs) of Arthrospira platensis were the predominant cyanobacteria. Some products contained additional cyanobacterial OTUs including a few known potentially toxic taxa. Moreover, 469 OTUs were detected in all 31 products collectively, with most of them being related to the Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria and Verrucomicrobia. All samples included heterotrophic bacterial OTUs, ranging from 9-157 per product. Among the most common OTUs were ones closely related to taxa known for causing health issues (i.e., Pseudomonas, Flavobacterium, Vibrio, Aeromonas, Clostridium, Bacillus, Fusobacterium, Enterococcus). The observed high cyanobacterial and heterotrophic bacterial OTUs richness in the final product is a point for further research on the growth and processing of Arthrospira biomass for commercial purposes. PMID:26819852

  12. Potential Impacts of Food Production on Freshwater Availability

    NASA Astrophysics Data System (ADS)

    Yano, Shinjiro; Hanasaki, Naota; Itsubo, Norihiro; Kim, Hyungjun; Oki, Taikan

    2014-05-01

    The sustainability of freshwater use is often evaluated based on the total volume of water consumption or withdrawal. However, the renewable freshwater resource and potential impacts of water depletion differ with location and water source. In addition, most estimates of the environmental impacts of water use have focused on depletion from a single-source perspective without separating geographically different water sources. Therefore, comprehensive potential impacts from multiple water sources remain unclear. In this study, we quantified the potential impacts of the global food production on freshwater availability (water availability footprint), applying the Water Availability Factor (fwa). Each water source including rainfall, surface water, and groundwater had individual fwa, which is calculated based on the geophysical hydrological cycle, to reflect the differences among renewable freshwater resources by place and source. The fwa for each water source was estimated based on land area or time period required to obtain the reference volume of freshwater. The reference volume was regarded as 1 m3 of rainfall over an area of 1.0 m2 (1,000 mm/year), based on the global mean annual precipitation. This concept is consistent with the Ecological Footprint (EF), which measures how much biologically productive land area is required to provide the resources consumed. The EF concept is measured in global hectares, a standardized unit equal to one hectare with global average bioproductivity. We found that the current agriculture consumes freshwater resources at 1.3 times the rapid rate than sustainable water use. This rate can also indicate environmental water scarcity. Among environmentally water-scarce countries, well-financed countries tend to import cereal products as virtual water to compensate for their domestic water resources. Among water-abundant countries, well-financed countries tend to export cereal products by exploiting their freshwater availability. The fwa

  13. Stress hormones link food availability and population processes in seabirds

    USGS Publications Warehouse

    Kitaysky, A.S.; Piatt, J.F.; Wingfield, J.C.

    2007-01-01

    Catastrophic population declines in marine top predators in the northern Pacific have been hypothesized to result from nutritional stress affecting reproduction and survival of individuals. However, empirical evidence for food-related stress in wild animals is frequently lacking or inconclusive. We used a field endocrinology approach to measure stress, identify its causes, and examine a link between stress and population processes in the common murre Uria aalge. We tested the empirical relationship between variations in the stress hormone corticosterone (CORT) and food abundance, reproduction, and persistence of individuals at declining and increasing colonies in Cook Inlet, Alaska, from 1996 to 2001. We found that CORT secretion in murres is independent of colony, reproductive stage effects, and gender of individuals, but is directly negatively correlated with abundance of their food. Baseline CORT reflected current food abundance, whereas acute stress-induced CORT reflected food abundance in the previous month. As food supply diminished, increased CORT secretion predicted a decrease in reproductive performance. At a declining colony, increased baseline levels of CORT during reproduction predicted disappearance of individuals from the population. Persistence of individuals in a growing colony was independent of CORT during reproduction. The obtained results support the hypothesis that nutritional stress during reproduction affects reproduction and survival in seabirds. This study provides the first unequivocal evidence for CORT secretion as a mechanistic link between fluctuations in food abundance and population processes in seabirds. ?? Inter-Research 2007.

  14. 21 CFR 1.243 - Is food registration information available to the public?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Is food registration information available to the public? 1.243 Section 1.243 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL GENERAL ENFORCEMENT REGULATIONS Registration of Food Facilities Additional Provisions §...

  15. Simulation of water available for runoff in clearcut forest openings during rain-on-snow events in the western Cascade Range of Oregon and Washington

    USGS Publications Warehouse

    van Heeswijk, Marijke; Kimball, J.S.; Marks, Danny

    1996-01-01

    Rain-on-snow events are common on mountain slopes within the transient-snow zone of the Pacific Northwest. These events make more water available for runoff than does precipitation alone by melting the snowpack and by adding a small amount of condensate to the snowpack. In forest openings (such as those resulting from clearcut logging), the amount of snow that accumulates and the turbulent- energy input to the snowpack are greater than below forest stands. Both factors are believed to contribute to a greater amount of water available for runoff during rain-on-snow events in forest openings than forest stands. Because increased water available for runoff may lead to increased downstream flooding and erosion, knowledge of the amount of snowmelt that can occur during rain on snow and the processes that control snowmelt in forest openings is useful when making land-use decisions. Snow accumulation and melt were simulated for clearcut conditions only, using an enery- balance approach that accounts for the most important energy and mass exchanges between a snowpack and its environment. Meteorological measurements provided the input for the simulations. Snow accumulation and melt were not simulated in forest stands because interception of precipitation processes are too complex to simulate with a numerical model without making simplifying assumptions. Such a model, however, would need to be extensively tested against representative observations, which were not available for this study. Snowmelt simulated during three rain-on-snow events (measured in a previous study in a clearcut in the transient-snow zone of the H.J. Andrews Experimental Forest in Oregon) demonstrated that melt generation is most sensitive to turbulent- energy exchanges between the air and the snowpack surface. As a result, the most important climate variable that controls snowmelt is wind speed. Air temperature, however, is a significant variable also. The wind speeds were light, with a maximum of 3

  16. 75 FR 17145 - Food Additives; Bisphenol A; Availability

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-05

    ... Bisphenol A (BPA) and soliciting public comments on the four documents prepared by FDA's Center for Food... BPA, on which an interim update was recently provided. (See http://www.fda.gov/NewsEvents/PublicHealth... considered by FDA as it continues its safety assessment of BPA. This action will enable FDA to...

  17. To eat or not to eat: Effects of food availability on reward system activity during food picture viewing.

    PubMed

    Blechert, Jens; Klackl, Johannes; Miedl, Stephan F; Wilhelm, Frank H

    2016-04-01

    Neuroimaging studies have started to explore the role of food characteristics (e.g., calorie-content) and psychological factors (e.g., restrained eating, craving) for the human appetitive system, motivated by the significant health implications of food-choice, overeating and overweight/obesity. However, one key aspect of modern food environments, food availability, especially of high energy foods, has not been adequately modeled in experimental research. Food that is immediately available for consumption could elicit stronger reward system activity and associated cognitive control than food that is not currently available for consumption and this could vary as a function of energy density. To examine this question, 32 healthy participants (16 women) underwent functional magnetic resonance imaging while passively viewing available foods - i.e. foods that could be eaten during and after the experiment - and unavailable foods of either high or low-caloric density in a 2 × 2 design. Available compared to unavailable foods elicited higher palatability ratings as well as stronger neural activation in the orbitofrontal cortex (OFC), amygdala, and left caudate nucleus as well as in the anterior cingulate cortex (ACC) - and thus structures implicated in reward and appetitive motivation as well as cognitive control, respectively. Availability effects in the caudate were mainly attributable to the high calorie condition (availability × calorie density interaction). These neuroimaging results support the contention that foods are particularly rewarding when immediately available and particularly so when high in caloric density. Thus, our results are consistent with health promoting interventions utilizing a nudging approach, i.e. aiming at decreasing accessibility of high calorie and increasing accessibility of low calorie foods in daily life. Results also imply that controlling/manipulating food availability may be an important methodological aspect in neuroscientific

  18. BOREAS HYD-3 Snow Measurements

    NASA Technical Reports Server (NTRS)

    Hardy, Janet P.; Hall, Forrest G. (Editor); Knapp, David E. (Editor); Davis, Robert E.; Smith, David E. (Technical Monitor)

    2000-01-01

    The Boreal Ecosystem-Atmosphere Study (BOREAS) Hydrology (HYD)-3 team collected several data sets related to the hydrology of forested areas. This data set contains measurements of snow depth, snow density in three cm intervals, an integrated snow pack density and snow water equivalent (SWE), and snow pack physical properties from snow pit evaluation taken in 1994 and 1996. The data were collected from several sites in both the southern study area (SSA) and the northern study area (NSA). A variety of standard tools were used to measure the snow pack properties, including a meter stick (snow depth), a 100 cc snow density cutter, a dial stem thermometer, and the Canadian snow sampler as used by HYD-4 to obtain a snow pack-integrated measure of SWE. This study was undertaken to predict spatial distributions of snow properties important to the hydrology, remote sensing signatures, and the transmissivity of gases through the snow. The data are available in tabular ASCII files. The snow measurement data are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The data files are available on a CD-ROM (see document number 20010000884).

  19. Assessing gull abundance and food availability in urban parking lots

    USGS Publications Warehouse

    Clark, Daniel E.; Whitney, Jillian J.; MacKenzie, Kenneth G.; Koenen, Kiana K. G.; DeStefano, Stephen

    2015-01-01

    Feeding birds is a common activity throughout the world; yet, little is known about the extent of feeding gulls in urban areas. We monitored 8 parking lots in central Massachusetts, USA, during the fall and winter of 2011 to 2013 in 4 monitoring sessions to document the number of gulls present, the frequency of human–gull feeding interactions, and the effectiveness of signage and direct interaction in reducing human-provisioned food. Parking lots were divided between “education” and “no-education” lots. In education lots, we erected signs about problems caused when people feed birds and also asked people to stop feeding birds. We did not erect signs or ask people to stop feeding birds at no-education lots. We spent >1,200 hours in parking lots (range = 136 to 200 hours per parking lot), and gulls were counted every 20 minutes. We conducted >4,000 counts, and ring-billed gulls (Lorus delawarensis) accounted for 98% of all gulls. Our educational efforts were minimally effective. There were fewer feedings (P = 0.01) in education lots during one of the monitoring sessions but significantly more gulls (P = 0.008) in education lots during 2 monitoring sessions. While there was a marginal decrease (P = 0.055) in the number of feedings after no-education lots were transformed into education lots, there was no difference in gull numbers in these lots (P = 0.16). Education appears to have some influence in reducing the number of people feeding gulls, but our efforts were not able to reduce the number of human feeders or the amount of food enough to influence the number of gulls using parking lots.

  20. Availability of healthier options in traditional and nontraditional rural fast-food outlets

    PubMed Central

    Creel, Jennifer S; Sharkey, Joseph R; McIntosh, Alex; Anding, Jenna; Huber, J Charles

    2008-01-01

    Background Food prepared away from home has become increasingly popular to U.S. families, and may contribute to obesity. Sales have been dominated by fast food outlets, where meals are purchased for dining away from home or in the home. Although national chain affiliated fast-food outlets are considered the main source for fast food, fast foods are increasingly available in convenience stores and supermarkets/grocery stores. In rural areas, these nontraditional fast-food outlets may provide most of the opportunities for procurement of fast foods. Methods Using all traditional and nontraditio nal fast-food outlets identified in six counties in rural Texas, the type and number of regular and healthiermenu options were surveyed using on-site observation in all food venues that were primarily fast food, supermarket/grocery store, and convenience store and compared with 2005 Dietary Guidelines. Results Traditional fast-food outlets represented 84 (41%) of the 205 opportunities for procurement of fast food; 109 (53.2%) were convenience stores and 12 (5.8%) supermarkets/grocery stores. Although a s imilar variety of regular breakfast and lunch/dinner entrées were available in traditional fast-food outlets and convenience stores, the variety of healthier breakfast and lunch/dinner entrées was significantly greater in fast food outlets. Compared with convenience stores, supermarkets/grocery stores provided a greater variety of regular and healthier entrées and lunch/dinner side dishes. Conclusion Convenience stores and supermarkets/grocery stores more than double the potential access to fast foods in this rural area than traditional fast-food outlets alone; however, traditional fast food outlets offer greater opportunity for healthier fast food options than convenience stores. A complete picture of fast food environment and the availability of healthier fast food options are essential to understand environmental influences on diet and health outcomes, and identify

  1. Using multiple household food inventories to measure food availability in the home over 30 days: a pilot study

    PubMed Central

    2010-01-01

    Background The consumption of foods, especially by children, may be determined by the types of foods that are available in the home. Because most studies use a single point of data collection to determine the types of foods in the home, which can miss the change in availability when resources are not available, the primary objective of this study was to determine the extent to which the weekly availability of household food items changed over one month by 1) developing the methodology for the direct observation of the presence and amount of food items in the home; 2) conducting five in-home household food inventories over a thirty-day period in a small convenience sample; and 3) determining the frequency that food items were present in the participating households. Methods After the development and pre-testing of the 251-item home observation guide that used direct observation to determine the presence and amount of food items in the home (refrigerator, freezer, pantry, elsewhere), two trained researchers recruited a convenience sample of 9 households (44.4% minority); administered a baseline questionnaire (personal info, shopping habits, food resources, and food security); and conducted 5 in-home assessments (7-day interval) over a 30-day period. Each in-home assessment included food-related activities since the last assessment, and an observational survey of types and amounts of foods present. Results Complete data were collected from all 9 women (32.8 y ± 6.0; 3 married; 4 ± 1.6 adults/children in household; 4 received food assistance; and 6 had very low food security) and their households. Weekly grocery purchases (place, amount, and purpose) varied from once (n = 1) to every week (n = 5); 4 used fast food 2-3 times/wk for 4 weeks. The weekly presence and amounts of fresh and processed fruits and vegetables and dairy varied. Conclusions The feasibility of conducting multiple in-home assessments was confirmed with 100% retention of participants through 5 in

  2. Appalachia Snow

    Atmospheric Science Data Center

    2014-05-15

    ... on December 4 and 5, 2002, also brought the season's first snow to parts of the south and southern Appalachia. The extent of snow cover over central Kentucky, eastern Tennessee, western North Carolina and ...

  3. Measuring food availability and accessibility among adolescents: Moving beyond the neighbourhood boundary.

    PubMed

    Shearer, Cindy; Rainham, Daniel; Blanchard, Chris; Dummer, Trevor; Lyons, Renee; Kirk, Sara

    2015-05-01

    Geographic methods have provided insight about food location availability and accessibility in understanding neighbourhood variations in health. However, quantifying exposure to food locations within a pre-defined range of an individual's residence ignores locations outside of the residential neighbourhood encountered in daily life. Global positioning system (GPS) data enables exploration of multiple contextual influences on health. This study defines place in relation to behaviour, employing GPS data to 1) describe adolescent food environments within and outside of the residential buffer, 2) quantify actual food location visits, and 3) explore associations between availability and accessibility of food locations and dietary intake. Adolescents (N = 380; ages 12-16), wore GPS loggers for up to seven days. Availability and accessibility of food locations were defined by counts and distances to food locations within a 15-min walk (1 km) of home, as well as within 50 m of an adolescent's GPS track. We compared the proportion of food locations within the residential buffer to the proportion outside but within the GPS buffer. These proportions were compared to counts and distances to food locations actually visited. We explored associations between food location availability and accessibility with dietary intake variables. Food location availability and accessibility was greater and visits occurred more commonly outside of the residential buffer than within it. Food location availability and accessibility was greater for urban than suburban and rural adolescents. There were no associations between home-based measures of availability and accessibility and dietary intake and only one for GPS-based measures, with greater distance to convenience stores associated with greater fruit and vegetable consumption. This study provides important descriptive information about adolescent exposure to food locations. Findings confirm that traditional home-based approaches

  4. Convenience stores are the key food environment influence on nutrients available from household food supplies in Texas Border Colonias

    PubMed Central

    2013-01-01

    Background Few studies have focused on the relationship between the retail food environment and household food supplies. This study examines spatial access to retail food stores, food shopping habits, and nutrients available in household food supplies among 50 Mexican-origin families residing in Texas border colonias. Methods The design was cross-sectional; data were collected in the home March to June 2010 by promotora-researchers. Ground-truthed methods enumerated traditional (supercenters, supermarkets, grocery stores), convenience (convenience stores and food marts), and non-traditional (dollar stores, discount stores) retail food stores. Spatial access was computed using the network distance from each participant’s residence to each food store. Data included survey data and two household food inventories (HFI) of the presence and amount of food items in the home. The Spanish language interviewer-administered survey included demographics, transportation access, food purchasing, food and nutrition assistance program participation, and the 18-item Core Food Security Module. Nutrition Data Systems for Research (NDS-R) was used to calculate HFI nutrients. Adult equivalent adjustment constants (AE), based on age and gender calorie needs, were calculated based on the age- and gender composition of each household and used to adjust HFI nutrients for household composition. Data were analyzed using bivariate analysis and linear regression models to determine the association of independent variables with the availability of each AE-adjusted nutrient. Results Regression models showed that households in which the child independently purchased food from a convenience store at least once a week had foods and beverages with increased amounts of total energy, total fat, and saturated fat. A greater distance to the nearest convenience store was associated with reduced amounts of total energy, vitamin D, total sugar, added sugar, total fat, and saturated fat. Participation in

  5. Food Insecurity is Related to Home Availability of Fruit, 100% Fruit Juice, and Vegetables

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Household food security is defined as access to enough food at all times for active, healthy living. Low food security may influence consumption because those households may lack sufficient resources to purchase more healthful items like fruit and vegetables. Because home availability is related to ...

  6. Availability of Non-Nutritious Foods in Alberta Schools. Research Bulletin 77-1.

    ERIC Educational Resources Information Center

    Alberta Dept. of Education, Edmonton.

    School authorities in a total of 68 Alberta school jurisdictions (representing 82 percent of the student population of the province) responded to a request for details about the availability in schools of nonnutritious foods--defined as food that contains minimal nutrients in proportion to number of calories. Foods that are commonly consumed at…

  7. City Level of Income and Urbanization and Availability of Food Stores and Food Service Places in China

    PubMed Central

    Liao, Chunxiao; Tan, Yayun; Wu, Chaoqun; Wang, Shengfeng; Yu, Canqing; Cao, Weihua; Gao, Wenjing; Lv, Jun; Li, Liming

    2016-01-01

    Objective The contribution of unhealthy dietary patterns to the epidemic of obesity has been well recognized. Differences in availability of foods may have an important influence on individual eating behaviors and health disparities. This study examined the availability of food stores and food service places by city characteristics on city level of income and urbanization. Methods The cross-sectional survey was comprised of two parts: (1) an on-site observation to measure availability of food stores and food service places in 12 cities of China; (2) an in-store survey to determine the presence of fresh/frozen vegetables or fruits in all food stores. Trained investigators walked all the streets/roads within study tracts to identify all the food outlets. An observational survey questionnaire was used in all food stores to determine the presence of fresh/frozen vegetables or fruits. Urbanization index was determined for each city using a principal components factor analysis. City level of income and urbanization and numbers of each type of food stores and food service places were examined using negative binomial regression models. Results Large-sized supermarkets and specialty retailers had higher number of fresh/frozen vegetables or fruits sold compared to small/medium-sized markets. High-income versus low-income, high urbanized versus low urbanized areas had significantly more large-sized supermarkets and fewer small/medium-sized markets. In terms of restaurants, high urbanized cities had more western fast food restaurants and no statistically significant difference in the relative availability of any type of restaurants was found between high- and low-income areas. Conclusions The findings suggested food environment disparities did exist in different cities of China. PMID:26938866

  8. Using a Household Food Inventory to Assess the Availability of Traditional Vegetables among Resettled African Refugees.

    PubMed

    Gichunge, Catherine; Somerset, Shawn; Harris, Neil

    2016-01-01

    A cross-sectional sequential explanatory mixed methods study was conducted among household food preparers to examine the association between home availability and consumption of traditional vegetables among resettled African refugees living in Queensland, Australia. Home availability of traditional African vegetables was associated with age, having a vegetable garden, employment status, and having a supermarket in the local neighborhood. Food preparers from homes with low vegetable availability were less likely to consume the recommended number of vegetable servings. Barriers faced in the food environment included language, lack of availability of traditional vegetables and lack of transport. All of these aspects contributed to the study findings that both individual and food environment characteristics may play a role in access to and availability of food and vegetable consumption of resettled refugees. Consumption of traditional foods among the resettled refugees continues post resettlement. PMID:26797623

  9. Using a Household Food Inventory to Assess the Availability of Traditional Vegetables among Resettled African Refugees

    PubMed Central

    Gichunge, Catherine; Somerset, Shawn; Harris, Neil

    2016-01-01

    A cross-sectional sequential explanatory mixed methods study was conducted among household food preparers to examine the association between home availability and consumption of traditional vegetables among resettled African refugees living in Queensland, Australia. Home availability of traditional African vegetables was associated with age, having a vegetable garden, employment status, and having a supermarket in the local neighborhood. Food preparers from homes with low vegetable availability were less likely to consume the recommended number of vegetable servings. Barriers faced in the food environment included language, lack of availability of traditional vegetables and lack of transport. All of these aspects contributed to the study findings that both individual and food environment characteristics may play a role in access to and availability of food and vegetable consumption of resettled refugees. Consumption of traditional foods among the resettled refugees continues post resettlement. PMID:26797623

  10. Agriculture and food availability -- remote sensing of agriculture for food security monitoring in the developing world

    USGS Publications Warehouse

    Budde, Michael E.; Rowland, James; Funk, Christopher C.

    2010-01-01

    For one-sixth of the world’s population - roughly 1 billion children, women and men - growing, buying or receiving adequate, affordable food to eat is a daily uncertainty. The World Monetary Fund reports that food prices worldwide increased 43 percent in 2007-2008, and unpredictable growing conditions make subsistence farming, on which many depend, a risky business. Scientists with the U.S. Geological Survey (USGS) are part of a network of both private and government institutions that monitor food security in many of the poorest nations in the world.

  11. Small Food Stores and Availability of Nutritious Foods: A Comparison of Database and In-Store Measures, Northern California, 2009

    PubMed Central

    Laraia, Barbara; Kelly, Maggi; Adler, Nancy; Yen, Irene H.

    2012-01-01

    Introduction Small food stores are prevalent in urban neighborhoods, but the availability of nutritious food at such stores is not well known. The objective of this study was to determine whether data from 3 sources would yield a single, homogenous, healthful food store category that can be used to accurately characterize community nutrition environments for public health research. Methods We conducted in-store surveys in 2009 on store type and the availability of nutritious food in a sample of nonchain food stores (n = 102) in 6 predominantly urban counties in Northern California (Alameda, Contra Costa, Marin, Sacramento, San Francisco, and Santa Clara). We compared survey results with commercial database information and neighborhood sociodemographic data by using independent sample t tests and classification and regression trees. Results Sampled small food stores yielded a heterogeneous group of stores in terms of store type and nutritious food options. Most stores were identified as convenience (54%) or specialty stores (22%); others were small grocery stores (19%) and large grocery stores (5%). Convenience and specialty stores were smaller and carried fewer nutritious and fresh food items. The availability of nutritious food and produce was better in stores in neighborhoods that had a higher percentage of white residents and a lower population density but did not differ significantly by neighborhood income. Conclusion Commercial databases alone may not adequately categorize small food stores and the availability of nutritious foods. Alternative measures are needed to more accurately inform research and policies that seek to address disparities in diet-related health conditions. PMID:22789445

  12. NOAA's National Snow Analyses

    NASA Astrophysics Data System (ADS)

    Carroll, T. R.; Cline, D. W.; Olheiser, C. M.; Rost, A. A.; Nilsson, A. O.; Fall, G. M.; Li, L.; Bovitz, C. T.

    2005-12-01

    NOAA's National Operational Hydrologic Remote Sensing Center (NOHRSC) routinely ingests all of the electronically available, real-time, ground-based, snow data; airborne snow water equivalent data; satellite areal extent of snow cover information; and numerical weather prediction (NWP) model forcings for the coterminous U.S. The NWP model forcings are physically downscaled from their native 13 km2 spatial resolution to a 1 km2 resolution for the CONUS. The downscaled NWP forcings drive an energy-and-mass-balance snow accumulation and ablation model at a 1 km2 spatial resolution and at a 1 hour temporal resolution for the country. The ground-based, airborne, and satellite snow observations are assimilated into the snow model's simulated state variables using a Newtonian nudging technique. The principle advantages of the assimilation technique are: (1) approximate balance is maintained in the snow model, (2) physical processes are easily accommodated in the model, and (3) asynoptic data are incorporated at the appropriate times. The snow model is reinitialized with the assimilated snow observations to generate a variety of snow products that combine to form NOAA's NOHRSC National Snow Analyses (NSA). The NOHRSC NSA incorporate all of the available information necessary and available to produce a "best estimate" of real-time snow cover conditions at 1 km2 spatial resolution and 1 hour temporal resolution for the country. The NOHRSC NSA consist of a variety of daily, operational, products that characterize real-time snowpack conditions including: snow water equivalent, snow depth, surface and internal snowpack temperatures, surface and blowing snow sublimation, and snowmelt for the CONUS. The products are generated and distributed in a variety of formats including: interactive maps, time-series, alphanumeric products (e.g., mean areal snow water equivalent on a hydrologic basin-by-basin basis), text and map discussions, map animations, and quantitative gridded products

  13. Food venue choice, consumer food environment, but not food venue availability within daily travel patterns are associated with dietary intake among adults, Lexington Kentucky 2011

    PubMed Central

    2013-01-01

    Objective The retail food environment may be one important determinant of dietary intake. However, limited research focuses on individuals’ food shopping behavior and activity within the retail food environment. This study’s aims were to determine the association between six various dietary indicators and 1) food venue availability; 2) food venue choice and frequency; and 3) availability of healthy food within food venue. Methods In Fall, 2011, a cross-sectional survey was conducted among adults (n=121) age 18 years and over in Lexington, Kentucky. Participants wore a global position system (GPS) data logger for 3-days (2 weekdays and 1 weekend day) to track their daily activity space, which was used to assess food activity space. They completed a survey to assess demographics, food shopping behaviors, and dietary outcomes. Food store audits were conducted using the Nutrition Environment Measurement Survey-Store Rudd (NEMS-S) in stores where respondents reported purchasing food (n=22). Multivariate logistic regression was used to examine associations between six dietary variables with food venue availability within activity space; food venue choice; frequency of shopping; and availability of food within food venue. Results 1) Food venue availability within activity space – no significant associations. 2) Food Venue Choice – Shopping at farmers’ markets or specialty grocery stores reported higher odds of consuming fruits and vegetables (OR 1.60 95% CI [1.21, 2.79]). Frequency of shopping - Shopping at a farmers’ markets and specialty stores at least once a week reported higher odds of consumption of fruits and vegetables (OR 1.55 95% CI [1.08, 2.23]). Yet, shopping frequently at a super market had higher odds of consuming sugar-sweetened beverages (OR 1.39 95% CI [1.03, 1.86]). 3) Availability of food within store – those who shop in supermarkets with high availability of healthy food has lower odds of consuming sugar-sweetened beverages (OR 0.65 95

  14. Baltimore City Stores Increased The Availability Of Healthy Food After WIC Policy Change.

    PubMed

    Cobb, Laura K; Anderson, Cheryl A M; Appel, Lawrence; Jones-Smith, Jessica; Bilal, Usama; Gittelsohn, Joel; Franco, Manuel

    2015-11-01

    As part of a 2009 revision to the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) program, the Department of Agriculture required WIC-authorized stores to stock additional varieties of healthy food. The long-term effects of this policy on access to healthy food are unknown. Using surveys conducted in 118 Baltimore City, Maryland, food stores in 2006 and 2012, we examined associations of the change in healthy food availability with store type, neighborhood demographics, and the 2009 WIC policy change. Overall, healthy food availability improved significantly between 2006 and 2012, with the greatest increases in corner stores and in census tracts with more than 60 percent black residents. On an 11-point scale measuring availability of fruit (3 points), vegetables (4 points), bread (2 points), and milk (2 points), the WIC policy change was associated with a 0.72-point increase in WIC-relevant healthy food availability, while joining WIC was associated with a 0.99-point increase. Stores that carry a limited variety of food items may be more receptive to stocking healthier food than previously thought, particularly within neighborhoods with a majority of black residents. Policies targeting healthy food availability have the potential to increase availability and decrease health disparities. PMID:26526242

  15. Functional responses to food diversity: the effect of seed availability on the feeding of facultative granivores

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The relative importance and availability of different foods to animals is critical in determining how they function within food webs. We examined how the diverse communities of carabid beetles and crickets in a perennial hayfield respond to seed availability numerically and in their feeding behavior...

  16. Snow Art

    ERIC Educational Resources Information Center

    Kraus, Nicole

    2012-01-01

    It was nearing the end of a very long, rough winter with a lot of snow and too little time to play outside. The snow had formed small hills and valleys over the bushes and this was at the perfect height for the students to paint. In this article, the author describes how her transitional first-grade students created snow art paintings. (Contains 1…

  17. 75 FR 78674 - Emergency Food Assistance Program; Availability of Foods for Fiscal Year 2011

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-16

    ... in FY 2010 are being delivered to States in FY 2011. These foods include potatoes, cran-apple juice, apple juice, cranberry sauce, dried cranberries, dried cherries, strawberries, applesauce, wild..., blackeye beans, garbanzo beans, great northern beans, light red kidney beans, lentils, lima beans,...

  18. The role of local food availability in explaining obesity risk among young school-aged children.

    PubMed

    Lee, Helen

    2012-04-01

    In recent years, research and public policy attention has increasingly focused on understanding whether modifiable aspects of the local food environment - the types and composition of food outlets families have proximate access to - are drivers of and potential solutions to the problem of childhood obesity in the United States. Given that much of the earlier published research has documented greater concentrations of fast-food outlets alongside limited access to large grocery stores in neighborhoods with higher shares of racial/ethnic minority groups and residents living in poverty, differences in retail food contexts may indeed exacerbate notable child obesity disparities along socioeconomic and racial/ethnic lines. This paper examines whether the lack of access to more healthy food retailers and/or the greater availability of "unhealthy" food purveyors in residential neighborhoods explains children's risk of excessive weight gain, and whether differential food availability explains obesity disparities. I do so by analyzing a national survey of U.S. children followed over elementary school (Early Childhood Longitudinal Study - Kindergarten Cohort) who are linked to detailed, longitudinal food availability measures from a comprehensive business establishment database (the National Establishment Time Series). I find that children who live in residentially poor and minority neighborhoods are indeed more likely to have greater access to fast-food outlets and convenience stores. However, these neighborhoods also have greater access to other food establishments that have not been linked to increased obesity risk, including large-scale grocery stores. When examined in a multi-level modeling framework, differential exposure to food outlets does not independently explain weight gain over time in this sample of elementary school-aged children. Variation in residential food outlet availability also does not explain socioeconomic and racial/ethnic differences. It may thus be

  19. Effects of food origin and availability on sea urchin condition and feeding behaviour

    NASA Astrophysics Data System (ADS)

    Livore, Juan P.; Connell, Sean D.

    2012-02-01

    The origin of food is recognised to be an important trait for sedentary consumers that have little control over the source of their food. Elevated herbivory in sea urchins is often linked to poor gonad condition as provoked by reduced food availability, but there is little recognition of the possibility that the origin of food may contribute to their poor condition and elevated feeding. This study assesses the possibility that variation in food availability and origin may together affect urchin condition and feeding rates such that they account for more intensive grazing (by Heliocidaris erythrogramma) on sheltered than exposed coasts (South Australia). We experimentally tested the hypothesis that reduced food availability from sheltered coasts would result in poor gonad condition and greater feeding rate; whilst enhanced food availability from exposed coasts would result in better condition and reduced feeding rates. We found that reduced food had negative effects on condition and positive effects on feeding rates independently of coastal source. Greater food availability did not equate to better condition, rather it was the delivery of more food from exposed than sheltered coasts that translated into the better gonad condition and lower feeding rates. These results suggest that plant origin and availability could help explain the greater impacts of these urchins on sheltered coasts. Whilst other factors such as water energy and sea urchin density may contribute to variation in herbivory our results suggest that origin of food may also play a role in sea urchin condition and behaviour. Understanding how such traits link to large scale features of the environment may improve models that account for variation in strength of consumer effects across landscapes.

  20. Gluten detection in foods available in the United States - a market survey.

    PubMed

    Sharma, Girdhari M; Pereira, Marion; Williams, Kristina M

    2015-02-15

    Many gluten-free (GF) food choices are now available in supermarkets. However, the unintentional presence of gluten in these foods poses a serious health risk to wheat-allergic and celiac patients. Different GF labelled foods (275) and non-GF labelled foods, without wheat/rye/barley on the ingredient label (186), were analysed for gluten content by two different enzyme linked immunosorbent assay (ELISA) kits. Considering the gluten threshold of 20ppm, GF labelled foods had 98.9% GF labelling compliance with 1.1% (3 out of 275) of foods being mislabelled/misbranded. Among the non-GF labelled foods, 19.4% (36 out of 186) of foods had >20ppm of gluten, as measured by at least one ELISA kit, of which 19 foods had >100ppm of gluten. The presence of oats in non-GF labelled foods was strongly correlated with a positive ELISA result. Gluten was also found in a significant number of foods with gluten/wheat-related advisory warnings. PMID:25236206

  1. Inventory versus Checklist Approach to Assess Middle School a la Carte Food Availability

    ERIC Educational Resources Information Center

    Hearst, Mary O.; Lytle, Leslie A.; Pasch, Keryn E.; Heitzler, Carrie D.

    2009-01-01

    Background: The purpose of this research is to evaluate 2 methods of assessing foods available on school a la carte lines for schools' ability to assess the proportion of foods that are healthful options. Methods: This observational study used data collected at 38 middle schools, October 2006-May 2007. An inventory method was used to collect…

  2. Developmental plasticity of growth and digestive efficiency in dependence of early-life food availability

    PubMed Central

    Kotrschal, Alexander; Szidat, Sönke; Taborsky, Barbara

    2014-01-01

    Nutrition is a potent mediator of developmental plasticity. If food is scarce, developing organisms may invest into growth to outgrow size-dependent mortality (short-term benefit) and/or into an efficient digestion system (long-term benefit). We investigated this potential trade-off, by determining the influence of food availability on juvenile body and organ growth, and on adult digestive efficiency in the cichlid fish Simochromis pleurospilus. We reared two groups of fish at constant high or low food rations, and we switched four other groups between these two rations at an early and late juvenile period. We measured juvenile growth and organ sizes at different developmental stages and determined adult digestive efficiency. Fish kept at constant, high rations grew considerably faster than low-food fish. Nevertheless, S. pleurospilus partly buffered the negative effects of low food availability by developing heavier digestive organs, and they were therefore more efficient in digesting their food as adults. Results of fish exposed to a ration switch during either the early or late juvenile period suggest (i) that the ability to show compensatory growth after early exposure to low food availability persists during the juvenile period, (ii) that digestive efficiency is influenced by varying juvenile food availability during the late juvenile phase and (iii) that the efficiency of the adult digestive system is correlated with the growth rate during a narrow time window of juvenile period. PMID:25866430

  3. 21 CFR 20.120 - Records available in Food and Drug Administration Public Reading Rooms.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Public Reading Rooms. 20.120 Section 20.120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PUBLIC INFORMATION Availability of Specific Categories of Records § 20... opinions, as well as orders, made in the adjudication of cases; (2) Statements of policy and...

  4. 21 CFR 20.120 - Records available in Food and Drug Administration Public Reading Rooms.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Public Reading Rooms. 20.120 Section 20.120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PUBLIC INFORMATION Availability of Specific Categories of Records § 20... opinions, as well as orders, made in the adjudication of cases; (2) Statements of policy and...

  5. 21 CFR 20.120 - Records available in Food and Drug Administration Public Reading Rooms.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Public Reading Rooms. 20.120 Section 20.120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PUBLIC INFORMATION Availability of Specific Categories of Records § 20... opinions, as well as orders, made in the adjudication of cases; (2) Statements of policy and...

  6. The availability of snack food displays that may trigger impulse purchases in Melbourne supermarkets

    PubMed Central

    2012-01-01

    Background Supermarkets play a major role in influencing the food purchasing behaviours of most households. Snack food exposures within these stores may contribute to higher levels of consumption and ultimately to increasing levels of obesity, particularly within socioeconomically disadvantaged neighbourhoods. We aimed to examine the availability of snack food displays at checkouts, end-of-aisle displays and island displays in major supermarket chains in the least and most socioeconomically disadvantaged neighbourhoods of Melbourne. Methods Within-store audits of 35 Melbourne supermarkets. Supermarkets were sampled from the least and most socioeconomically disadvantaged suburbs within 30 km of the Melbourne CBD. We measured the availability of crisps, chocolate, confectionery, and soft drinks (diet and regular) at the checkouts, in end-of-aisle displays, and in island bin displays. Results Snack food displays were most prominent at checkouts with only five stores not having snack foods at 100% of their checkouts. Snack foods were also present at a number of end-of-aisle displays (at both the front (median 38%) and back (median 33%) of store), and in island bin displays (median number of island displays: 7; median total circumference of island displays: 19.4 metres). Chocolate items were the most common snack food item on display. There was no difference in the availability of these snack food displays by neighbourhood disadvantage. Conclusions As a result of the high availability of snack food displays, exposure to snack foods is almost unavoidable in Melbourne supermarkets, regardless of levels of neighbourhood socioeconomic disadvantage. Results of this study could promote awareness of the prominence of unhealthy food items in chain-brand supermarkets outlets. PMID:22420759

  7. Disparities of food availability and affordability within convenience stores in Bexar County, Texas.

    PubMed

    Smith, Matthew Lee; Sunil, T S; Salazar, Camerino I; Rafique, Sadaf; Ory, Marcia G

    2013-01-01

    The American Diabetes Association (ADA) recommends healthful food choices; however, some geographic areas are limited in the types of foods they offer. Little is known about the role of convenience stores as viable channels to provide healthier foods in our "grab and go" society. The purposes of this study were to (1) identify foods offered within convenience stores located in two Bexar County, Texas, ZIP Codes and (2) compare the availability and cost of ADA-recommended foods including beverages, produce, grains, and oils/fats. Data were analyzed from 28 convenience store audits performed in two sociodemographically diverse ZIP Codes in Bexar County, Texas. Chi-squared tests were used to compare food availability, and t-tests were used to compare food cost in convenience stores between ZIP Codes. A significantly larger proportion of convenience stores in more affluent areas offered bananas (χ (2) = 4.17, P = 0.003), whole grain bread (χ (2) = 8.33, P = 0.004), and baked potato chips (χ (2) = 13.68, P < 0.001). On average, the price of diet cola (t = -2.12, P = 0.044) and certain produce items (e.g., bananas, oranges, tomatoes, broccoli, and cucumber) was significantly higher within convenience stores in more affluent areas. Convenience stores can play an important role to positively shape a community's food environment by stocking healthier foods at affordable prices. PMID:23935645

  8. Monitoring food and nutrient availability in a nationally representative sample of Bolivian households.

    PubMed

    Pérez-Cueto, F J Armando; Naska, Androniki; Monterrey, Javier; Almanza-Lopez, Magaly; Trichopoulou, Antonia; Kolsteren, Patrick

    2006-03-01

    The study objective was to estimate food and nutrient availability in Bolivian households using data from the nationally representative under the Programme for the household surveys undertaken yearly from 1999 to 2002 Improvement of Surveys and the Measurement of Living Conditions in Latin America and the Caribbean (MECOVI). In the present study, we analysed data from four repeated, cross-sectional surveys and applied European Data Food Networking (DAFNE) methodology for post-harmonising the data. Raw data of 19 483 households in Bolivia (3035 in 1999, 4857 in 2000, 5845 in 2001 and 5746 in 2002) were retrieved from the databases of the national household surveys. Results showed that the Bolivian diet is characterised by higher availability of foods of plant origin (cereals, fruits, potatoes and vegetables). Meat, milk and their products follow in the dietary preferences of Bolivians. Disparities in food availability within the country were also observed. Rural households systematically recorded lower amounts of food available, in comparison with the urban ones. Households of higher social status recorded higher availability values for all food groups, except for potatoes and cereals. Findings suggest that Bolivian households of lower socio-economic status prefer energy-dense and cheaper food sources. We concluded the dietary and socio-demographic data collected in the MECOVI household surveys could serve nutrition surveillance purposes. In addition, the application of DAFNE methodology for post-harmonising the data allows both national and international comparisons. PMID:16512943

  9. SPATIAL AND DIEL AVAILABILITY OF FLYING INSECTS AS POTENTIAL DUCKLING FOOD IN PRAIRIE WETLANDS.

    EPA Science Inventory

    The study examined spatial and diel availibility of flying insects that are a critical food resource to young duckings. Insects were sampled in three native prairie wetlands on the Woodworth Study Area of south-central North Dakota.

  10. Competitive foods in schools: Availability and purchasing in predominately rural small and large high schools

    PubMed Central

    Nollen, Nicole L.; Befort, Christie; Davis, Ann McGrath; Snow, Tricia; Mahnken, Jonathan; Hou, Qingjiang; Story, Mary; Ahluwalia, Jasjit S.

    2013-01-01

    OBJECTIVES Schools have an important role to play in obesity prevention, but little is known about the food environment in small, predominately rural schools. The primary purpose of this study was to compare the availability and student purchasing of foods sold outside of the reimbursable meals program through a la carte (ALC) or vending (i.e., competitive foods) in small (n = 7) and large (n = 6) Kansas high schools. METHODS A cross-sectional observational study design was used to capture the number of ALC and vending items available and purchased, and the fat and caloric content of all available and purchased items on a single school day between January and May 2005. RESULTS Small schools had significantly fewer vending machines than large schools [median=3.0 (range=2.0–5.0) versus 6.5 (range=4.0–8.0), p<0.01]. Vending and ALC items at small schools contained a median of 2.3 fewer fat grams per item (p≤0.05), while vending products contained a median of 25.0 fewer calories per item (p≤0.05) than at large schools. Significantly less fat (median= −15.4 grams/student) and fewer calories (median= −306.8 kcal/student) were purchased per student from all competitive food sources and from ALC (median= −12.9 fat grams and −323.3 kcal/student) by students in small schools compared to students in large schools (p≤0.05). CONCLUSIONS The findings, which highlight less availability and lower energy content from competitive foods at small compared to large schools, have implications for understanding how small schools support their food service programs with limited dependence on competitive foods and the impact that food and nutrition professionals can have on the school environment by providing more oversight into the nutritional quality of foods available. PMID:19394472

  11. Healthful food availability in stores and restaurants--American Samoa, 2014.

    PubMed

    Lee-Kwan, Seung Hee; Kumar, Gayathri; Ayscue, Patrick; Santos, Marjorie; McGuire, Lisa C; Blanck, Heidi M; Nua, Motusa Tuileama

    2015-03-20

    American Samoa, one of the U.S.-affiliated Pacific Islands, has documented the highest prevalence of adults with obesity (75%) in the world. The nutritionally poor food and beverage environment of food retail venues has been suspected to be a contributing factor, although an evaluation of these venues in American Samoa has not been conducted. In January 2014, American Samoa established an Obesity Task Force to develop policies and strategies to combat obesity. To inform the efforts of the task force, the American Samoa Department of Health and CDC conducted a baseline assessment of the availability, pricing, and promotion of healthful foods at retail food venues. Previously validated food environment assessment tools were modified to incorporate American Samoa foods and administered in a geographically representative sample of 70 stores (nine grocery stores and 61 convenience stores) and 20 restaurants. In convenience stores, healthful items were not found as available as less healthful counterparts, and some healthful items were more expensive than their less healthful counterparts. For restaurants, 70% offered at least one healthful entrée, whereas only 30% had healthful side dishes, such as vegetables. Actions to promote healthy eating, such as providing calorie information, were rare among restaurants. Improving availability, affordability, and the promotion of healthful foods in American Samoa stores and restaurants could support healthy eating among American Samoa residents. PMID:25789743

  12. Influence of food availability on the spatial distribution of juvenile fish within soft sediment nursery habitats

    NASA Astrophysics Data System (ADS)

    Tableau, A.; Brind'Amour, A.; Woillez, M.; Le Bris, H.

    2016-05-01

    Soft sediments in coastal shallow waters constitute nursery habitats for juveniles of several flatfishes. The quality of a nursery is defined by its capacity to optimize the growth and the survival of juvenile fish. The influence of biotic factors, such as food availability, is poorly studied at the scale of a nursery ground. Whether food availability limits juvenile survival is still uncertain. A spatial approach is used to understand the influence of food availability on the distribution of juvenile fish of various benthic and demersal species in the Bay of Vilaine (France), a productive nursery ground. We quantified the spatial overlap between benthic macro-invertebrates and their predators (juvenile fish) to assess if the latter were spatially covering the most productive areas of the Bay. Three scenarios describing the shapes of the predator-prey spatial relationship were tested to quantify the strength of the relationship and consequently the importance of food availability in determining fish distribution. Our results underline that both food availability and fish densities vary greatly over the nursery ground. When considering small organisational levels (e.g., a single fish species), the predator-prey spatial relationship was not clear, likely because of additional environmental effects not identified here; but at larger organisational level (the whole juvenile fish community), a strong overlap between the fish predators and their prey was identified. The evidence that fish concentrate in sectors with high food availability suggests that either food is the limiting factor in that nursery or/and fish display behavioural responses by optimising their energetic expenditures associated with foraging. Further investigations are needed to test the two hypotheses and to assess the impact of benthic and demersal juvenile fish in the food web of coastal nurseries.

  13. Effects of substrate differences on water availability for Arctic lichens during the snow-free summers in the High Arctic glacier foreland

    NASA Astrophysics Data System (ADS)

    Inoue, Takeshi; Kudoh, Sakae; Uchida, Masaki; Tanabe, Yukiko; Inoue, Masakane; Kanda, Hiroshi

    2014-12-01

    We used observational and experimental analyses to investigate the photosynthetic activity and water relationships of five lichen species attached to different substrates in a glacier foreland in the High Arctic, Ny-Ålesund, Svalbard (79°N) during the snow-free season in 2009 and 2010. After the rains ceased, lichens and their attached substrates quickly dried, whereas photosynthetic activity in the lichens decreased gradually. The in situ photosynthetic activity was estimated based on the relative electron transportation rate (rETR) in four fruticose lichens: Cetrariella delisei, Flavocetraria nivalis, Cladonia arbuscula ssp. mitis, and Cladonia pleurota. The rETR approached zero around noon, although the crustose lichen Ochrolechia frigida grown on biological soil crust (BSC) could acquire water from the BSC and retain its WC to perform positive photosynthesis. The light-rETR relationship curves of the five well-watered lichens were characterized into two types: shade-adapted with photoinhibition for the fruticose lichens, and light-adapted with no photoinhibition for O. frigida. The maximum rETR was expected to occur when they could acquire water from the surrounding air or from substrates during the desiccation period. Our results suggest that different species of Arctic lichens have different water availabilities due to their substrates and/or morphological characteristics, which affect their photosynthetic active periods during the summer.

  14. MODIS Snow-Cover Products

    NASA Technical Reports Server (NTRS)

    Hall, Dorothy K.; Riggs, George A.; Salomonson, Vinvent V.; DiGirolamo, Nicolo; Bayr, Klaus J.; Houser, Paul (Technical Monitor)

    2001-01-01

    On December 18, 1999, the Terra satellite was launched with a complement of five instruments including the Moderate Resolution Imaging Spectroradiometer (MODIS). Many geophysical products are derived from MODIS data including global snow-cover products. These products have been available through the National Snow and Ice Data Center (NSIDC) Distributed Active Archive Center (DAAC) since September 13, 2000. MODIS snow-cover products represent potential improvement to the currently available operation products mainly because the MODIS products are global and 500-m resolution, and have the capability to separate most snow and clouds. Also the snow-mapping algorithms are automated which means that a consistent data set is generated for long-term climates studies that require snow-cover information. Extensive quality assurance (QA) information is stored with the product. The snow product suite starts with a 500-m resolution swath snow-cover map which is gridded to the Integerized Sinusoidal Grid to produce daily and eight-day composite tile products. The sequence then proceeds to a climate-modeling grid product at 5-km spatial resolution, with both daily and eight-day composite products. A case study from March 6, 2000, involving MODIS data and field and aircraft measurements, is presented. Near-term enhancements include daily snow albedo and fractional snow cover.

  15. Reliability of a store observation tool in measuring availability of alcohol and selected foods.

    PubMed

    Cohen, Deborah A; Schoeff, Diane; Farley, Thomas A; Bluthenthal, Ricky; Scribner, Richard; Overton, Adrian

    2007-11-01

    Alcohol and food items can compromise or contribute to health, depending on the quantity and frequency with which they are consumed. How much people consume may be influenced by product availability and promotion in local retail stores. We developed and tested an observational tool to objectively measure in-store availability and promotion of alcoholic beverages and selected food items that have an impact on health. Trained observers visited 51 alcohol outlets in Los Angeles and southeastern Louisiana. Using a standardized instrument, two independent observations were conducted documenting the type of outlet, the availability and shelf space for alcoholic beverages and selected food items, the purchase price of standard brands, the placement of beer and malt liquor, and the amount of in-store alcohol advertising. Reliability of the instrument was excellent for measures of item availability, shelf space, and placement of malt liquor. Reliability was lower for alcohol advertising, beer placement, and items that measured the "least price" of apples and oranges. The average kappa was 0.87 for categorical items and the average intraclass correlation coefficient was 0.83 for continuous items. Overall, systematic observation of the availability and promotion of alcoholic beverages and food items was feasible, acceptable, and reliable. Measurement tools such as the one we evaluated should be useful in studies of the impact of availability of food and beverages on consumption and on health outcomes. PMID:17763963

  16. Flexibility in metabolic rate confers a growth advantage under changing food availability

    PubMed Central

    Auer, Sonya K; Salin, Karine; Rudolf, Agata M; Anderson, Graeme J; Metcalfe, Neil B; Ardia, Daniel

    2015-01-01

    Phenotypic flexibility in physiological, morphological and behavioural traits can allow organisms to cope with environmental challenges. Given recent climate change and the degree of habitat modification currently experienced by many organisms, it is therefore critical to quantify the degree of phenotypic variation present within populations, individual capacities to change and what their consequences are for fitness. Flexibility in standard metabolic rate (SMR) may be particularly important since SMR reflects the minimal energetic cost of living and is one of the primary traits underlying organismal performance. SMR can increase or decrease in response to food availability, but the consequences of these changes for growth rates and other fitness components are not well known. We examined individual variation in metabolic flexibility in response to changing food levels and its consequences for somatic growth in juvenile brown trout (Salmo trutta). SMR increased when individuals were switched to a high food ration and decreased when they were switched to a low food regime. These shifts in SMR, in turn, were linked with individual differences in somatic growth; those individuals that increased their SMR more in response to elevated food levels grew fastest, while growth at the low food level was fastest in those individuals that depressed their SMR most. Flexibility in energy metabolism is therefore a key mechanism to maximize growth rates under the challenges imposed by variability in food availability and is likely to be an important determinant of species’ resilience in the face of global change. PMID:25939669

  17. Flexibility in metabolic rate confers a growth advantage under changing food availability.

    PubMed

    Auer, Sonya K; Salin, Karine; Rudolf, Agata M; Anderson, Graeme J; Metcalfe, Neil B

    2015-09-01

    1. Phenotypic flexibility in physiological, morphological and behavioural traits can allow organisms to cope with environmental challenges. Given recent climate change and the degree of habitat modification currently experienced by many organisms, it is therefore critical to quantify the degree of phenotypic variation present within populations, individual capacities to change and what their consequences are for fitness. 2. Flexibility in standard metabolic rate (SMR) may be particularly important since SMR reflects the minimal energetic cost of living and is one of the primary traits underlying organismal performance. SMR can increase or decrease in response to food availability, but the consequences of these changes for growth rates and other fitness components are not well known. 3. We examined individual variation in metabolic flexibility in response to changing food levels and its consequences for somatic growth in juvenile brown trout (Salmo trutta). 4. SMR increased when individuals were switched to a high food ration and decreased when they were switched to a low food regime. These shifts in SMR, in turn, were linked with individual differences in somatic growth; those individuals that increased their SMR more in response to elevated food levels grew fastest, while growth at the low food level was fastest in those individuals that depressed their SMR most. 5. Flexibility in energy metabolism is therefore a key mechanism to maximize growth rates under the challenges imposed by variability in food availability and is likely to be an important determinant of species' resilience in the face of global change. PMID:25939669

  18. Availability and accessibility of healthier options and nutrition information at New Zealand fast food restaurants.

    PubMed

    Chand, Ashmita; Eyles, Helen; Ni Mhurchu, Cliona

    2012-02-01

    The aim of this study was to assess the availability of healthier options and nutrition information at major New Zealand fast food chains. A cross-sectional survey was undertaken at 24 fast food stores (two from each of 12 major chains) using on-site visits, telephone calls, and website searches. Of available products, only 234/1126 (21%) were healthier options. Healthier options were generally cheaper and lower in energy, total fat, saturated fat, sugar, and sodium per serve than their regular counterparts. Regular options were commonly high in sugar or sodium per serve (mean sugar content of beverages=56 g (11 teaspoons) and sodium content of burgers and pasta=1095 mg and 1172 mg, respectively). Nutrition information was available at 11/12 (92%) restaurant chains (range=0% at Tank Juice to 99% at Domino's Pizza). However, <1% of this information was available at the point-of-purchase. Therefore, there is huge potential for improving nutrition in the New Zealand fast food restaurant setting. Implications of these findings for policy and food industry include: consideration of mandatory menu labelling, increasing the percentage of healthier options available, and improving the nutrient content of regular options at New Zealand fast food restaurants. PMID:22019449

  19. MODIS Snow and Ice Production

    NASA Technical Reports Server (NTRS)

    Hall, Dorthoy K.; Hoser, Paul (Technical Monitor)

    2002-01-01

    Daily, global snow cover maps, and sea ice cover and sea ice surface temperature (IST) maps are derived from NASA's Moderate Resolution Imaging Spectroradiometer (MODIS), are available at no cost through the National Snow and Ice Data Center (NSIDC). Included on this CD-ROM are samples of the MODIS snow and ice products. In addition, an animation, done by the Scientific Visualization studio at Goddard Space Flight Center, is also included.

  20. Influence of food availability on demography and local population dynamics in a long-lived seabird.

    PubMed Central

    Oro, Daniel; Cam, Emmanuelle; Pradel, Roger; Martínez-Abraín, Alejandro

    2004-01-01

    Few studies have addressed the effects of food availability as a proximate factor affecting local adult survival in long-lived organisms and their consequences at local population dynamics. We used capture-recapture analysis of resightings of 10 birth cohorts of ringed Audouin's gulls, Larus audouinii, to estimate adult survival and dispersal (both emigration and immigration). For the first time, permanent emigration (the transient effect in capture-recapture analysis) was modelled for the whole population and not only for the newly marked birds. Gulls exploit to a large extent fishes discarded from trawlers, and a trawling moratorium established since 1991 has decreased food supply for the colony. This was used as a natural experiment of food availability to assess its effects on adult survival and emigration. These and other demographic parameters were used in a projection modelling to assess the probabilities of extinction of the colony under two scenarios of lower and higher food availability. Food availability (together with the age of individuals) influenced emigration probabilities, but not adult survival, which was estimated at 0.91 (s.e. = 0.02). When food was in shorter supply during the chick-rearing period, emigration was very high (ca. 65%) for younger breeders, although this rate decreased sharply with age. Probabilities of extinction were very high when food availability was low, and when environmental stochasticity was introduced, and only stochastic immigration from the outside seemed to prevent extinction. The results highlight the importance of dispersal processes in the population dynamics of long-lived organisms. PMID:15101698

  1. Demand-feeding rhythm in rainbow trout and European catfish. Synchronisation by photoperiod and food availability.

    PubMed

    Bolliet, V; Aranda, A; Boujard, T

    2001-07-01

    The effect of light-dark (LD) cycle and food availability was tested on the demand-feeding rhythm of single and groups of rainbow trout and European catfish. Under LD and free food access, most trout and catfish displayed, respectively, a diurnal and a nocturnal pattern of demand-feeding activity, whereas a few fish or groups of fish switched from diurnalism to nocturnalism or vice versa. In both species held under constant lighting conditions and a restricted feeding (RF) cycle (RF 20:4), the demand-feeding rhythm rapidly synchronised to food availability. The demand-feeding rhythm was under endogenous control and, in rainbow trout, periodogram analysis suggested the existence of two oscillators, one synchronised by photoperiod (LEO) and the other by food (FEO). When submitted to both LD and RF cycles, LD was, at least in the rainbow trout, the dominant zeitgeber synchronising the demand-feeding rhythm. In catfish, food availability rapidly synchronised demand-feeding rhythm. Finally, in both species, the synchronisation of single fish to LD or feed availability appeared slower than that of groups of fish, supporting the idea that social organisation affects the circadian activity in fish. PMID:11495668

  2. Food availability affects the maternal transfer of androgens and antibodies into eggs of a colonial seabird

    USGS Publications Warehouse

    Gasparini, J.; Boulinier, T.; Gill, V.A.; Gil, D.; Hatch, Shyla A.; Roulin, A.

    2007-01-01

    Mothers can improve the quality of their offspring by increasing the level of certain components in their eggs. To examine whether or not mothers increase deposition of such components in eggs as a function of food availability, we food-supplemented black-legged kittiwake females (Rissa tridactyla) before and during egg laying and compared deposition of androgens and antibodies into eggs of first and experimentally induced replacement clutches. Food-supplemented females transferred lower amounts of androgens and antibodies into eggs of induced replacement clutches than did non-food-supplemented mothers, whereas first clutches presented no differences between treatments. Our results suggest that when females are in lower condition, they transfer more androgens and antibodies into eggs to facilitate chick development despite potential long-term costs for juveniles. Females in prime condition may avoid these potential long-term costs because they can provide their chicks with more and higher quality resources. ?? 2007 The Authors.

  3. Development and acceptability testing of ready-to-use supplementary food made from locally available food ingredients in Bangladesh

    PubMed Central

    2014-01-01

    Background Inadequate energy and micronutrient intake during childhood is a major public health problem in developing countries. Ready-to-use supplementary food (RUSF) made of locally available food ingredients can improve micronutrient status and growth of children. The objective of this study was to develop RUSF using locally available food ingredients and test their acceptability. Methods A checklist was prepared of food ingredients available and commonly consumed in Bangladesh that have the potential of being used for preparing RUSF. Linear programming was used to determine possible combinations of ingredients and micronutrient premix. To test the acceptability of the RUSF compared to Pushti packet (a cereal based food-supplement) in terms of amount taken by children, a clinical trial was conducted among 90 children aged 6–18 months in a slum of Dhaka city. The mothers were also asked to rate the color, flavor, mouth-feel, and overall liking of the RUSF by using a 7-point Hedonic Scale (1 = dislike extremely, 7 = like extremely). Results Two RUSFs were developed, one based on rice-lentil and the other on chickpea. The total energy obtained from 50 g of rice-lentil, chickpea-based RUSF and Pushti packet were 264, 267 and 188 kcal respectively. Children were offered 50 g of RUSF and they consumed (mean ± SD) 23.8 ± 14 g rice-lentil RUSF, 28.4 ± 15 g chickpea based RUSF. Pushti packet was also offered 50 g but mothers were allowed to add water, and children consumed 17.1 ± 14 g. Mean feeding time for two RUSFs and Pushti packet was 20.9 minutes. Although the two RUSFs did not differ in the amount consumed, there was a significant difference in consumption between chickpea-based RUSF and Pushti packet (p = 0.012). Using the Hedonic Scale the two RUSFs were more liked by mothers compared to Pushti packet. Conclusions Recipes of RUSF were developed using locally available food ingredients. The study results suggest that rice

  4. Competing pressures on populations: long-term dynamics of food availability, food quality, disease, stress and animal abundance

    PubMed Central

    Chapman, Colin A.; Schoof, Valérie A. M.; Bonnell, Tyler R.; Gogarten, Jan F.; Calmé, Sophie

    2015-01-01

    Despite strong links between sociality and fitness that ultimately affect the size of animal populations, the particular social and ecological factors that lead to endangerment are not well understood. Here, we synthesize approximately 25 years of data and present new analyses that highlight dynamics in forest composition, food availability, the nutritional quality of food, disease, physiological stress and population size of endangered folivorous red colobus monkeys (Procolobus rufomitratus). There is a decline in the quality of leaves 15 and 30 years following two previous studies in an undisturbed area of forest. The consumption of a low-quality diet in one month was associated with higher glucocorticoid levels in the subsequent month and stress levels in groups living in degraded forest fragments where diet was poor was more than twice those in forest groups. In contrast, forest composition has changed and when red colobus food availability was weighted by the protein-to-fibre ratio, which we have shown positively predicts folivore biomass, there was an increase in the availability of high-quality trees. Despite these changing social and ecological factors, the abundance of red colobus has remained stable, possibly through a combination of increasing group size and behavioural flexibility. PMID:25870398

  5. Competing pressures on populations: long-term dynamics of food availability, food quality, disease, stress and animal abundance.

    PubMed

    Chapman, Colin A; Schoof, Valérie A M; Bonnell, Tyler R; Gogarten, Jan F; Calmé, Sophie

    2015-05-26

    Despite strong links between sociality and fitness that ultimately affect the size of animal populations, the particular social and ecological factors that lead to endangerment are not well understood. Here, we synthesize approximately 25 years of data and present new analyses that highlight dynamics in forest composition, food availability, the nutritional quality of food, disease, physiological stress and population size of endangered folivorous red colobus monkeys (Procolobus rufomitratus). There is a decline in the quality of leaves 15 and 30 years following two previous studies in an undisturbed area of forest. The consumption of a low-quality diet in one month was associated with higher glucocorticoid levels in the subsequent month and stress levels in groups living in degraded forest fragments where diet was poor was more than twice those in forest groups. In contrast, forest composition has changed and when red colobus food availability was weighted by the protein-to-fibre ratio, which we have shown positively predicts folivore biomass, there was an increase in the availability of high-quality trees. Despite these changing social and ecological factors, the abundance of red colobus has remained stable, possibly through a combination of increasing group size and behavioural flexibility. PMID:25870398

  6. MODIS Snow-Cover Products

    NASA Technical Reports Server (NTRS)

    Hall, Dorothy K.; Riggs, George A.; Salomonson, Vincent V.; DiGirolamo, Nicole E.; Bayr, Klaus J.; Houser, Paul R. (Technical Monitor)

    2002-01-01

    On December 18, 1999, the Terra satellite was launched with a complement of five instruments including the Moderate Resolution Imaging Spectroradiometer (MODIS). Many geophysical products are derived from MODIS data including global snow-cover products. MODIS snow and ice products have been available through the National Snow and Ice Data Center (NSIDC) Distributed Active Archive Center (DAAC) since September 13, 2000. MODIS snow-cover products represent potential improvement to or enhancement of the currently-available operational products mainly because the MODIS products are global and 500-m resolution, and have the capability to separate most snow and clouds. Also the snow-mapping algorithms are automated which means that a consistent data set may be generated for long-term climate studies that require snow-cover information. Extensive quality assurance (QA) information is stored with the products. The MODIS snow product suite begins with a 500-m resolution, 2330-km swath snow-cover map which is then gridded to an integerized sinusoidal grid to produce daily and 8-day composite tile products. The sequence proceeds to a climate-modeling grid (CMG) product at about 5.6-km spatial resolution, with both daily and 8-day composite products. Each pixel of the CMG contains fraction of snow cover from 40 - 100%. Measured errors of commission in the CMG are low, for example, on the continent of Australia in the spring, they vary from 0.02 - 0.10%. Near-term enhancements include daily snow albedo and fractional snow cover. A case study from March 6, 2000, involving MODIS data and field and aircraft measurements, is presented to show some early validation work.

  7. Feeding ecology, food availability and ranging patterns of wild hamadryas baboons at Filoha.

    PubMed

    Schreier, Amy L

    2010-01-01

    Most hamadryas baboons rely on Acacia species for subsistence in their semidesert habitats. Unlike other hamadryas sites, palm forests at Filoha in Awash National Park, Ethiopia, provide the baboons with a preferred food resource close to a commonly used sleeping site. The baboons are expected to feed on doum palm trees when fruit is available, and this resource use should play a role in ranging patterns. This paper describes the feeding ecology, food availability and ranging patterns of a band of wild hamadryas baboons at Filoha from March 2005 to February 2006. Data on feeding and ranging behavior derive from band scans during all-day follows of baboons, and data on food availability derive from monthly phenological monitoring of frequently consumed food species. The baboons fed predominantly on palms when fruit was available, and preferred the flowers of Acacia senegal to its leaves. There was no relationship between daily path length and the proportion of palm fruit in the baboons' diet, but changes in the availability of fruit across the Filoha region appear to mirror the baboons' shifting use of its home range. The large band sizes at Filoha may obscure the effects doum palm fruit might have on ranging patterns. PMID:20714160

  8. Short-term effects of hurricane disturbance on food availability for migrant songbirds during autumn stopover

    USGS Publications Warehouse

    Dobbs, R.C.; Barrow, W.C., Jr.; Jeske, C.W.; Dimiceli, J.; Michot, T.C.; Beck, J.W.

    2009-01-01

    Understanding the consequences of hurricanes on the food resources available to neotropical-nearctic migrant songbirds may provide important insight into the effects of hurricanes on migratory populations. During autumn migration 2006 we investigated the foraging ecology of two species of insectivorous migrants, Blue-gray Gnatcatcher (Polioptila caerulea) and Yellow Warbler (Dendroica petechia), and the availability of their foraging substrates and arthropod food resources in two coastal forests in western Louisiana, which were impacted to different degrees by Hurricane Rita in autumn 2005. Both migrant species attacked prey on bark substrates significantly more frequently, and on live foliage less frequently, in severely damaged forest than in lightly damaged forest (??2 tests, P < 0.05). However, both species attacked prey on bark less than expected given its availability (i.e., migrants avoided bark), and attacked prey on live foliage more than expected given its availability (i.e., migrants selected live foliage), in severely damaged forest (??2 tests, P < 0.03). Branch-clipping revealed that arthropod biomass on live hackberry (Celtis laevigata) and sweet acacia (Acacia farnesiana) branches was significantly higher in severely damaged forest than in lightly damaged forest (Mann-Whitney test, P < 0.01). However, because live foliage was significantly less available in severely damaged forest, overall food availability for migrants was lower in severely damaged forest than in lightly damaged forest. Migrant use of, and arthropod biomass on, bark and live-foliage substrates were thus dependent on the availability of those substrates, which differed between sites as a result of hurricane-related habitat disturbance. These results demonstrate that severe hurricane disturbance reduces food availability for insectivorous songbirds during migratory stopover by reducing the availability of preferred foraging substrates. ?? 2009 The Society of Wetland Scientists.

  9. Limiting resources in sessile systems: food enhances diversity and growth of suspension feeders despite available space.

    PubMed

    Svensson, Robin J; Marshall, Dustin J

    2015-03-01

    Much of our understanding of competition comes trom onservations in sessue systems, such as rainforests and marine invertebrate communities. In terrestrial systems, sessile species often compete for multiple limiting resources (i.e., space, light, and nutrients), but in marine systems, space is viewed as the primary or sole limiting resource. Competition theory, on the other hand, suggests that competition for a single limiting resource is unlikely to maintain high species diversity, but manipulative tests of competition for other resources in marine benthic systems are exceedingly rare. Here, we manipulate the availability of food for a classic system, marine sessile invertebrate communities, and investigate the effects on species diversity, abundance, and composition during early succession as well as on the growth of bryozoan populations in the field. We found the number of species to be greater, available space to be lower, and the community composition to be different in assemblages subjected to increased food availability compared to controls. Similarly, laboratory-settled bryozoans deployed into the field grew more in the presence of enhanced food. Our results suggest that food can act as a limiting resource, affecting both diversity and abundance, even when bare space is still available in hard-substratum communities. Consequently, broadening the view of resource limitation beyond solely space may increase our understanding and predictability of marine sessile systems. PMID:26236877

  10. Feeding Strategies of Brown Howler Monkeys in Response to Variations in Food Availability

    PubMed Central

    Chaves, Óscar M.; Bicca-Marques, Júlio César

    2016-01-01

    Primates display varying degrees of behavioral flexibility that allow them to adjust their diet to temporal changes in food availability. This trait might be critical for the survival of folivorous-frugivorous species inhabiting small forest fragments, where the availability of food resources tends to be lower than in large fragments and continuous forests. However, the scarcity of studies addressing this issue hampers our understanding of the adaptive behaviors that favor the survival of these primates in low-quality habitats. We conducted a 36-mo study testing the hypothesis that brown howler monkeys (Alouatta guariba clamitans) are able to adjust their diet in response to local and seasonal changes in resource availability. We compared the diet of six free-ranging groups inhabiting three small (<10 ha) and three large (>90 ha) Atlantic forest fragments in southern Brazil and estimated the temporal availability of their top food species (i.e., those species that together contribute ≥80% of total feeding records). We found that brown howlers exploited similarly rich diets in small (45, 54, and 57 plant species) and large (48, 51, and 56 species) fragments. However, intermonth diet similarity was higher for groups in small fragments, where howlers also fed on plant items from nine alien species. Fruits and leaves were the most consumed plant items in both small (42% and 49% of feeding records, respectively) and large (51% and 41%, respectively) fragments. The consumption of young leaves was higher in small than in large fragments, whereas the consumption of other plant items did not show a pattern related to fragment size. Regarding the contribution of growth forms as food sources, only the exploitation of palms showed a pattern related to fragment size. Palms contributed more to the diet of groups inhabiting large fragments. The availability of seasonal food items–ripe fruits and young leaves–influenced their consumption in both habitat types. Therefore

  11. Feeding Strategies of Brown Howler Monkeys in Response to Variations in Food Availability.

    PubMed

    Chaves, Óscar M; Bicca-Marques, Júlio César

    2016-01-01

    Primates display varying degrees of behavioral flexibility that allow them to adjust their diet to temporal changes in food availability. This trait might be critical for the survival of folivorous-frugivorous species inhabiting small forest fragments, where the availability of food resources tends to be lower than in large fragments and continuous forests. However, the scarcity of studies addressing this issue hampers our understanding of the adaptive behaviors that favor the survival of these primates in low-quality habitats. We conducted a 36-mo study testing the hypothesis that brown howler monkeys (Alouatta guariba clamitans) are able to adjust their diet in response to local and seasonal changes in resource availability. We compared the diet of six free-ranging groups inhabiting three small (<10 ha) and three large (>90 ha) Atlantic forest fragments in southern Brazil and estimated the temporal availability of their top food species (i.e., those species that together contribute ≥80% of total feeding records). We found that brown howlers exploited similarly rich diets in small (45, 54, and 57 plant species) and large (48, 51, and 56 species) fragments. However, intermonth diet similarity was higher for groups in small fragments, where howlers also fed on plant items from nine alien species. Fruits and leaves were the most consumed plant items in both small (42% and 49% of feeding records, respectively) and large (51% and 41%, respectively) fragments. The consumption of young leaves was higher in small than in large fragments, whereas the consumption of other plant items did not show a pattern related to fragment size. Regarding the contribution of growth forms as food sources, only the exploitation of palms showed a pattern related to fragment size. Palms contributed more to the diet of groups inhabiting large fragments. The availability of seasonal food items-ripe fruits and young leaves-influenced their consumption in both habitat types. Therefore, brown

  12. Monitoring the availability of healthy and unhealthy foods and non-alcoholic beverages in community and consumer retail food environments globally.

    PubMed

    Ni Mhurchu, C; Vandevijvere, S; Waterlander, W; Thornton, L E; Kelly, B; Cameron, A J; Snowdon, W; Swinburn, B

    2013-10-01

    Retail food environments are increasingly considered influential in determining dietary behaviours and health outcomes. We reviewed the available evidence on associations between community (type, availability and accessibility of food outlets) and consumer (product availability, prices, promotions and nutritional quality within stores) food environments and dietary outcomes in order to develop an evidence-based framework for monitoring the availability of healthy and unhealthy foods and non-alcoholic beverages in retail food environments. Current evidence is suggestive of an association between community and consumer food environments and dietary outcomes; however, substantial heterogeneity in study designs, methods and measurement tools makes it difficult to draw firm conclusions. The use of standardized tools to monitor local food environments within and across countries may help to validate this relationship. We propose a step-wise framework to monitor and benchmark community and consumer retail food environments that can be used to assess density of healthy and unhealthy food outlets; measure proximity of healthy and unhealthy food outlets to homes/schools; evaluate availability of healthy and unhealthy foods in-store; compare food environments over time and between regions and countries; evaluate compliance with local policies, guidelines or voluntary codes of practice; and determine the impact of changes to retail food environments on health outcomes, such as obesity. PMID:24074215

  13. Commercially Available Rapid Methods for Detection of Selected Food-borne Pathogens.

    PubMed

    Valderrama, Wladir B; Dudley, Edward G; Doores, Stephanie; Cutter, Catherine N

    2016-07-01

    Generally, the enumeration and isolation of food-borne pathogens is performed using culture-dependent methods. These methods are sensitive, inexpensive, and provide both qualitative and quantitative assessment of the microorganisms present in a sample, but these are time-consuming. For this reason, researchers are developing new techniques that allow detection of food pathogens in shorter period of time. This review identifies commercially available methods for rapid detection and quantification of Listeria monocytogenes, Salmonella spp., Staphylococcus aureus, and Shiga toxin-producing Escherichia coli in food samples. Three categories are discussed: immunologically based methods, nucleic acid-based assays, and biosensors. This review describes the basic mechanism and capabilities of each method, discusses the difficulties of choosing the most convenient method, and provides an overview of the future challenges for the technology for rapid detection of microorganisms. PMID:25749054

  14. Convenience stores surrounding urban schools: an assessment of healthy food availability, advertising, and product placement.

    PubMed

    Gebauer, Hilary; Laska, Melissa Nelson

    2011-08-01

    Adolescent obesity is a national public health problem, particularly among urban populations. Recent evidence has linked neighborhood food environments to health and nutrition status, with easier access to convenience stores being associated with increased risk for obesity. Little is known about the availability of healthy purchasing options within small, urban food stores, or the extent to which these factors are relevant to youth. The objective of this research was to characterize various features of the food environment within small convenience stores located nearby urban junior high and high schools. In-store audits were conducted in 63 stores located within 800 m of 36 urban Minnesota public secondary schools. Results indicated that a limited number of healthier beverages (i.e., water and 100% fruit juice) and snack options (i.e., nuts and pretzels) were available at most stores (≥85%). However, a wide range of healthy snack options were typically not available, with many specific items stocked in less than half of stores (e.g., low-fat yogurt in 27% of stores and low-fat granola bars in 43%). Overall, 51% of stores had fresh fruit and 49% had fresh vegetables. Few stores carried a range of healthier snack alternatives in single-serving packages. All stores had less healthful impulse purchase items available (e.g., candy) while only 46% carried healthier impulse items (e.g., fruit). Most stores (97%) had food/beverage advertising. Overall, convenience stores located in close proximity to secondary schools represent an important and understudied component of the youth food environment. PMID:21491151

  15. A model for the development of Aedes (Stegomyia) aegypti as a function of the available food.

    PubMed

    Romeo Aznar, Victoria; De Majo, María Sol; Fischer, Sylvia; Francisco, Diego; Natiello, Mario A; Solari, Hernán G

    2015-01-21

    We discuss the preimaginal development of the mosquito Aedes aegypti from the point of view of the statistics of developmental times and the final body-size of the pupae and adults. We begin the discussion studying existing models in relation to published data for the mosquito. The data suggest a developmental process that is described by exponentially distributed random times. The existing data show as well that the idea of cohorts emerging synchronously is verified only in optimal situations created at the laboratory but it is not verified in field experiments. We propose a model in which immature individuals progress in successive stages, all of them with exponentially distributed times, according to two different rates (one food-dependent and the other food-independent). This phenomenological model, coupled with a general model for growing, can explain the existing observations and new results produced in this work. The emerging picture is that the development of the larvae proceeds through a sequence of steps. Some of the steps depend on the available food. While food is in abundance, all steps can be thought as having equal duration, but when food is scarce, those steps that depend on food take considerably longer times. For insufficient levels of food, increase in larval mortality sets in. As a consequence of the smaller rates, the average pupation time increases and the cohort disperses in time. Dispersion, as measured by standard deviation, becomes a quadratic function of the average time indicating that cohort dispersion responds to the same causes than delays in pupation and adult emergence. During the whole developmental process the larva grows monotonically, initially at an exponential rate but later at decreasing rates, approaching a final body-size. Growth is stopped by maturation when it is already slow. As a consequence of this process, there is a slight bias favoring small individuals: Small individuals are born before larger individuals, although

  16. Home food availability mediates associations between mothers' nutrition knowledge and child diet.

    PubMed

    Campbell, Karen J; Abbott, Gavin; Spence, Alison C; Crawford, David A; McNaughton, Sarah A; Ball, Kylie

    2013-12-01

    Evidence suggests that mothers' nutrition knowledge and home food availability (HFA) are directly and independently associated with children's food intakes. In this study we test the hypothesis that HFA mediates the association between maternal nutrition knowledge and child diet. In this cross-sectional study of Australian women living in socioeconomically disadvantaged neighbourhoods in Melbourne, Australia, mothers with dependent children (aged 5-12 years) provided data on their child's diet, HFA, nutrition knowledge and a range of sociodemographic characteristics. To test our hypothesis we assessed associations between nutrition knowledge and HFA, and between HFA and child food intake (adjusting for nutrition knowledge and child age). In all instances significant associations were found. HFA was found to mediate relationships between mother's nutrition knowledge and children's intake of fruit, vegetables, salty foods and soft drink. Our analyses showed that HFA was a mediator of the associations between maternal nutrition knowledge and child's diet in this population. This supports a focus on nutrition education that expands mothers' understanding of what foods to buy, prepare and serve. Further exploration of these associations will provide a stronger evidence base upon which to inform 'best bets' for parent-focussed nutrition promotion seeking to promote children's healthy eating. PMID:23891673

  17. Autumn diet of lesser snow geese staging in northeastern Alaska

    USGS Publications Warehouse

    Brackney, Alan W.; Hupp, J.W.

    1993-01-01

    The coastal plain of the Arctic National Wildlife Refuge (ANWR) is used by lesser snow geese (Chen caerulescens caerulescens) in autumn for premigratory staging. To better understand the potential impacts of human disturbance on snow geese, we investigated species composition of, and temporal and age-related variation in, their diet during staging. Depending on age and time of collection, between 35.2 and 94.1% of the diet (aggregate percent wet mass, n = 75) consisted of 2 species of plants; underground stems of tall cotton-grass (Eriophorum angustifolium), and aerial shoots of northern scouring rush (Equisetum variegatum). The diet varied between August and September (P = 0.0089), morning and afternoon (P < 0.0001), but not between age classes (P = 0.066). Throughout staging, snow geese consumed more tall cotton-grass during the afternoon than during the morning (P < 0.05). Tall cotton-grass was a larger component of the afternoon diet in September than in August (P < 0.05). In September, snow geese consumed more northern scouring rush in the mornings than in the afternoon (P < 0.05). Nighttime freezing, interspecific differences in nutritional quality, and plant senescence likely constrained the diet of snow geese to a small number of food items. Because alternative foods may not be available, human disturbance should be minimized in areas that provide these forage species.

  18. Food availability controls seasonal cycle of growth in Macoma balthica (L.) in San Francisco Bay, California

    USGS Publications Warehouse

    Thompson, J.K.; Nichols, F.H.

    1988-01-01

    A 2-yr field study of growth in the bivalve Macoma balthica (L.) at four locations in San Francisco Bay, California, U.S., showed that the timing and rate of growth (increase in shell length) were related to food supply. This clam feeds on both planktonic and benthic microalgae, depending on availability. Growth was apparently food-limited during some months, during one year more than the other, and at some locations more than others. Tissue-weight changes were also related to food availability. The heaviest animals were found in that year and at those locations with the highest chl a concentrations. Tissue-weight gains usually coincided with increased shell-growth rate or with reproductive development, although some large animals showed weight gain independent of both of these factors during periods with mid-range chl a levels. Weight losses coincided with spawning or periods of low growth rate, except at one station where, during a period when most animals were reproductively ripe, food concentrations were high, and shell growth was rapid, animals lost weight. This study failed to show a relation between salinity and the timing or rate of change of either shell length or tissue weight. The mild temperatures (10-23 ??C water temperature) of the area studied resulted in no growth inhibition due to low temperature, but there was some indication that the high air temperatures found in these intertidal areas limited growth rates. ?? 1988.

  19. Food availability determines the response to pond desiccation in anuran tadpoles.

    PubMed

    Enriquez-Urzelai, Urtzi; San Sebastián, Olatz; Garriga, Núria; Llorente, Gustavo A

    2013-09-01

    Food availability and pond desiccation are two of the most studied factors that condition amphibian metamorphosis. It is well known that, when food is abundant, organisms undergo metamorphosis early and when they are relatively large. The capability of anurans to accelerate their developmental rate in response to desiccation is also common knowledge. These two variables must act together in nature, since we know that, as a pond dries, the per capita resources decrease. We conduct an experiment to evaluate the effects of desiccation and food availability separately and in combination in tadpoles of the painted frog (Discoglossus pictus). We demonstrate that food deprivation leads to slow growth rates, which delay metamorphosis and produce smaller size and weight. The capability to accelerate metamorphosis when facing a drying pond is also confirmed, but, nevertheless, with factor interaction (when the pool is drying and resources are scarce) the capacity to respond to desiccation is lost. In addition, slow drying rates are shown to be stressful situations, but not enough to provoke a shortening of the larval period; in fact, the larval period becomes longer. We also demonstrate that the interaction of these factors changes the allometric relationship of different parts of the hind limb, which has implications for the biomechanics of jumping. Due to low mortality rates and an adequate response to both environmental factors, we expect D. pictus to have a great invasive potential in its new Mediterranean distribution area, where lots of temporary and ephemeral ponds are present. PMID:23344427

  20. Accessibility Over Availability: Associations Between the School Food Environment and Student Fruit and Green Vegetable Consumption

    PubMed Central

    O'Malley, Patrick M.; Johnston, Lloyd D.

    2014-01-01

    Abstract Background: No national studies have examined associations between (1) school food availability and accessibility and (2) secondary student fruit and vegetable (FV) consumption. This article uses 5 years of nationally representative data from secondary school students to examine associations between the school food environment and student fruit and green vegetable consumption. Methods: From 2008 to 2012, cross-sectional, nationally representative data from US middle and high school students were collected annually on self-reported fruit and green vegetable consumption. Each year, data from administrators at each relevant school were collected on food item availability (any venue) and accessibility (total number of school sources). Data were obtained from 10,254 eighth-grade students in 317 schools and 18,898 tenth- and 12th-grade students in 518 schools. Associations were estimated by multi-level models controlling for student- and school-level characteristics. Results: Availability showed minimal association with student consumption. Candy/regular-fat snack accessibility was associated negatively with middle school fruit consumption. Salad bar availability and accessibility were positively associated with middle school green vegetable consumption; FV accessibility was associated positively with high school fruit and green vegetable consumption. Significant associations were consistent across student racial/ethnic and socioeconomic groups. Conclusions: Forthcoming USDA nutrition standards for school foods and beverages sold outside of reimbursable meal programs should result in the removal of school candy/regular-fat snacks. In deciding which items to make available under the new standards, schools should consider increasing the number of FV sources—including salad bars—thereby potentially increasing student FV consumption. PMID:24872011

  1. Intraspecific competition and high food availability are associated with insular gigantism in a lizard

    NASA Astrophysics Data System (ADS)

    Pafilis, Panayiotis; Meiri, Shai; Foufopoulos, Johannes; Valakos, Efstratios

    2009-09-01

    Resource availability, competition, and predation commonly drive body size evolution. We assess the impact of high food availability and the consequent increased intraspecific competition, as expressed by tail injuries and cannibalism, on body size in Skyros wall lizards ( Podarcis gaigeae). Lizard populations on islets surrounding Skyros (Aegean Sea) all have fewer predators and competitors than on Skyros but differ in the numbers of nesting seabirds. We predicted the following: (1) the presence of breeding seabirds (providing nutrients) will increase lizard population densities; (2) dense lizard populations will experience stronger intraspecific competition; and (3) such aggression, will be associated with larger average body size. We found a positive correlation between seabird and lizard densities. Cannibalism and tail injuries were considerably higher in dense populations. Increases in cannibalism and tail loss were associated with large body sizes. Adult cannibalism on juveniles may select for rapid growth, fuelled by high food abundance, setting thus the stage for the evolution of gigantism.

  2. SnowClim: Snow climate monitoring for Europe

    NASA Astrophysics Data System (ADS)

    Bissolli, P.; Maier, U.

    2009-09-01

    Snow cover, particularly its depth and its frequency, is a very essential climate element. It influences the earth's surface radiation budget considerably due to its reflectivity properties and also it has large impact on economy and daily life (e.g. traffic, tourism). Although a lot of research and many national activities of snow monitoring have been done, there are very few products describing an integrated snow monitoring for whole Europe. In the light of a foreseen future Regional Climate Centre on Climate Monitoring (RCC-CM), the German Meteorological Service (Deutscher Wetterdienst, DWD) has established some first operational snow climate monitoring activities for the WMO Region VI (Europe and the Middle East). First selected key elements are the number of snowdays with a snow cover > 1 cm, the mean and the maximum snow depth per month. Results are presented in form of monthly and climatological maps, tables and diagrams of time series starting in 1981. Data presently are taken from observations at synoptical stations, received by the Global Telecommunication System. A first quality control based on threshold tests has been developed. The snow climate monitoring products are currently under further development. New evaluations will be carried out also on a daily data basis, additional satellite data, and also the quality control procedure will be extended. Some operational SnowClim products are available on the DWD web site: www.dwd.de/snowclim

  3. Assessing the applicability of currently available methods for attributing foodborne disease to sources, including food and food commodities.

    PubMed

    Pires, Sara M

    2013-03-01

    A variety of approaches to attribute foodborne diseases to specific sources are available, including hazard occurrence analysis, epidemiological methods, intervention studies, and expert elicitations. The usefulness of each method to attribute disease caused by a foodborne hazard depends on the public health question being addressed, on the data requirements, on advantages and limitations of the method, and on the data availability of the country or region in question. Previous articles have described available methods for source attribution, but have focused only on foodborne microbiological hazards. These articles have described strengths and weaknesses of each method, but no guidance on how to choose the most appropriate tool to address different public health questions has thus far been provided. We reviewed available source attribution methods; assessed their applicability to attribute illness caused by enteric, parasitic, and chemical foodborne hazards to the responsible sources; and renamed some of the approaches. The main objective was to make recommendations on the most appropriate method(s) to attribute human disease caused by different foodborne hazards. We concluded that the proportion of disease that can be attributed to specific foods items or transmission routes may be estimated for the majority of the evaluated hazards by applying one or more of the source attribution methods assessed. It was also recognized that the use of source attribution methods may be limited to specific countries, reflecting the data availability. PMID:23489045

  4. Food availability affects the strength of mutualistic host-microbiota interactions in Daphnia magna.

    PubMed

    Callens, Martijn; Macke, Emilie; Muylaert, Koenraad; Bossier, Peter; Lievens, Bart; Waud, Michael; Decaestecker, Ellen

    2016-04-01

    The symbiotic gut microbial community is generally known to have a strong impact on the fitness of its host. Nevertheless, it is less clear how the impact of symbiotic interactions on the hosts' fitness varies according to environmental circumstances such as changes in the diet. This study aims to get a better understanding of host-microbiota interactions under different levels of food availability. We conducted experiments with the invertebrate, experimental model organism Daphnia magna and compared growth, survival and reproduction of conventionalized symbiotic Daphnia with germ-free individuals given varying quantities of food. Our experiments revealed that the relative importance of the microbiota for the hosts' fitness varied according to dietary conditions. The presence of the microbiota had strong positive effects on Daphnia when food was sufficient or abundant, but had weaker effects under food limitation. Our results indicate that the microbiota can be a potentially important factor in determining host responses to changes in dietary conditions. Characterization of the host-associated microbiota further showed that Aeromonas sp. was the most prevalent taxon in the digestive tract of Daphnia. PMID:26405832

  5. Effects of food availability on serum insulin and lipid concentrations in free-ranging baboons.

    PubMed

    Kemnitz, Joseph W; Sapolsky, Robert M; Altmann, Jeanne; Muruthi, Philip; Mott, Glen E; Stefanick, Marcia L

    2002-05-01

    The relationship between food availability and metabolic physiology was studied in groups of free-ranging baboons (Papio spp.) living in the Amboseli National Park and the Masai Mara National Reserve of Kenya. Three groups subsisted entirely on natural forage, while two other groups lived near tourist facilities and often consumed food wastes from these lodges. The refuse provided a very accessible food source with relatively high caloric density. Consumption of the refuse was associated with reduced locomotion. Sexually mature individuals from all five groups were sedated surreptitiously in the early morning and blood samples were collected. Compared to animals foraging exclusively in the wild, animals that supplemented their diet with the refuse items had two- to threefold elevations in serum insulin concentrations, as well as increased total cholesterol (C), HDL-C, and VLDL+LDL-C levels. No sex differences in physiological measures were observed except in body mass. Elevated serum insulin, and cholesterol and lipoprotein concentrations influence the development of cardiovascular disease and have been shown to be subject to dietary manipulation and exercise under controlled conditions. The present results suggest potentially deleterious effects of a highly accessible, calorically dense food source, and associated reduction of physical activity for baboons living in an otherwise natural environment. PMID:11977122

  6. Dynamics of food availability, body condition and physiological stress response in breeding Black-legged Kittiwakes

    USGS Publications Warehouse

    Kitaysky, A.S.; Wingfield, J.C.; Piatt, J.F.

    1999-01-01

    1. The seasonal dynamics of body condition (BC), circulating corticosterone levels (baseline, BL) and the adrenocortical response to acute stress (SR) were examined in long-lived Black-legged Kittiwakes, Rissa tridactyla, breeding at Duck (food-poor colony) and Gull (food-rich colony) Islands in lower Cook Inlet, Alaska. It was tested whether the dynamics of corticosterone levels reflect a seasonal change in bird physiological condition due to reproduction and/or variation in foraging conditions. 2. BC declined seasonally, and the decline was more pronounced in birds at the food-poor colony. BL and SR levels of corticosterone rose steadily through the reproductive season, and BL levels were significantly higher in birds on Duck island compared with those on Gull Island. During the egg-laying and chick-rearing stages, birds had lower SR on Duck Island than on Gull Island. 3. The results suggest that, in addition to a seasonal change in bird physiology during reproduction, local ecological factors such as food availability affect circulating levels of corticosterone and adrenal response to acute stress.

  7. Availability, preference, and consumption of indigenous forest foods in the Eastern Arc Mountains, Tanzania.

    PubMed

    Msuya, Tuli S; Kideghesho, Jafari R; Mosha, Theobald C E

    2010-01-01

    We investigated the availability, preference, and consumption of indigenous forest foods in Uluguru North (UNM) and West Usambara Mountains (WUM) of Tanzania. Data collection techniques involved focus group discussion, structured questionnaires, and botanical identification. Results revealed (1) there were 114 indigenous forest food plant species representing 57 families used by communities living adjacent to the two mountains; (2) sixty-seven species supplied edible fruits, nuts and seeds: 24 and 14 species came from WUM and UNM, respectively, while 29 came from both study areas; (3) of the 57 identified vegetable species, 22 were found in WUM only, 13 in UNM only, and 12 in both areas; (4) there were three species of edible mushrooms and five species of roots and tubers; (5) unlike the indigenous roots and tubers, the preference and consumption of indigenous vegetables, nuts, and seeds/oils was higher than exotic species in both study areas; and (6) UNM had more indigenous fruits compared to WUM, although preference and consumption was higher in WUM. We recommend increased research attention on forest foods to quantify their contribution to household food security and ensure their sustainability. PMID:21883080

  8. NASA’s Sense of Snow: the Airborne Snow Observatory

    NASA Video Gallery

    Water is a critical resource in the western U.S. NASA’s Airborne Snow Observatory is giving California water agencies the first complete measurements of the water available in the Sierra snowpack ...

  9. Snow-Cover Variability in North America in the 2000-2001 Winter as Determined from MODIS Snow Products

    NASA Technical Reports Server (NTRS)

    Hall, Dorothy K.; Salomonson, Vincent V.; Riggs, George A.; Chien, Janet Y. L.; Houser, Paul R. (Technical Monitor)

    2001-01-01

    Moderate Resolution Imaging Spectroradiometer (MODIS) snow-cover maps have been available since September 13, 2000. These products, at 500 m spatial resolution, are available through the National Snow and Ice Data Center Distributed Active Archive Center in Boulder, Colorado. By the 2001-02 winter, 5 km climate-modeling grid (CMG) products will be available for presentation of global views of snow cover and for use in climate models. All MODIS snow-cover products are produced from automated algorithms that map snow in an objective manner. In this paper, we describe the MODIS snow products, and show snow maps from the fall of 2000 in North America.

  10. Snow-Cover Variability in North America in the 2000-2001 Winter as Determined from MODIS Snow Products

    NASA Technical Reports Server (NTRS)

    Hall, Dorothy K.; Salomonson, Vincent V.; Riggs, George A.; Chien, Y. L.; Houser, Paul R. (Technical Monitor)

    2001-01-01

    Moderate Resolution Imaging Spectroradiometer (MODIS) snow-cover maps have been available since September 13, 2000. These products, at 500-m spatial resolution, are available through the National Snow and Ice Data Center Distributed Active Archive Center in Boulder, Colorado. By the 2001-02 winter, 5-km climate-modeling grid (CMG) products will be available for presentation of global views of snow cover and for use in climate models. All MODIS snow-cover products are produced from automated algorithms that map snow in an objective manner. In this paper, we describe the MODIS snow products, and show snow maps from the fall of 2000 in North America.

  11. Amygdalin content of seeds, kernels and food products commercially-available in the UK.

    PubMed

    Bolarinwa, Islamiyat F; Orfila, Caroline; Morgan, Michael R A

    2014-01-01

    Cyanogenic glycosides are a large group of secondary metabolites that are widely distributed in the plant kingdom, including many plants that are commonly consumed by humans. The diverse chemical nature of cyanogenic glycosides means that extraction and analysis of individual compounds can be difficult. In addition, degradation can be rapid under appropriate conditions. Amygdalin is one of the cyanogenic glycosides found, for example, in apples, apricots and almonds. We have developed and applied a high performance liquid chromatographic procedure for amygdalin quantification to investigate extraction efficiency and to determine levels in a range of commercially-available foods for the first time. Our results show that seed from Rosaceae species contained relatively high amounts (range 0.1-17.5 mg g(-1)) of amygdalin compared to seed from non-Rosaceae species (range 0.01-0.2 mg g(-1)). The amygdalin content of processed food products was very low. PMID:24444917

  12. Food availability promotes rapid recovery from thermal stress in a scleractinian coral

    NASA Astrophysics Data System (ADS)

    Connolly, S. R.; Lopez-Yglesias, M. A.; Anthony, K. R. N.

    2012-12-01

    Bleaching in corals due to environmental stress represents a loss of energy intake often leading to an increase in mortality risk. Successful coral recovery from severe bleaching events may depend on the rate of replenishment of algal symbiont populations following the period of thermal stress, the supply of an alternative food source, or both. Here, we explore the role of food availability in promoting the survival and recovery of a common coral ( Acropora intermedia) following acute experimentally induced thermal stress. Fed corals were provided with live rotifers daily, to maintain densities of zooplankton in tanks that are typical of coral reefs. After a 6-week acclimation phase, heated corals were subjected to a +4 °C thermal anomaly for a 7-day period (bleaching phase) then temperatures were returned to normal for a further 2 weeks (recovery phase). Results demonstrated that heated corals had higher survival when they were provided with heterotrophic food. Fed corals experienced reduced loss of chlorophyll a, relative to unfed corals. During the recovery phase, both fed and unfed corals recovered within a few days; however, fed corals recovered to pre-bleaching phase levels of chlorophyll a, whereas unfed corals stabilized approximately one-third below this level. Protein levels of fed corals declined markedly during the bleaching phase, but recovered all of their losses by the end of the recovery phase. In contrast, unfed corals had low protein levels that were maintained throughout the experiment. To the extent that these results are representative of corals' responses to thermal anomalies in nature, the findings imply that availability of particulate food matter has the potential to increase corals' capacity to survive thermally induced bleaching and to ameliorate its sub-lethal effects. They also support the hypothesis that different rates of heterotrophy are an important determinant of variation in resilience to thermal stress among reef environments.

  13. Food Service and Foods and Beverages Available at School: Results from the School Health Policies and Programs Study 2000.

    ERIC Educational Resources Information Center

    Wechsler, Howell; Brener, Nancy D.; Kuester, Sarah; Miller, Clare

    2001-01-01

    Presents School Health Policies and Programs Study 2000 findings about state- and district-level policies and practices regarding various school food service issues, e.g., organization and staffing, food service and child nutrition requirements and recommendations, menu planning and food preparation, and collaboration. Also addressed are food…

  14. Availability and price of food products with and without trans fatty acids in food stores around elementary schools in low- and medium-income neighborhoods.

    PubMed

    Silveira, Bruna Maria; Kliemann, Nathalie; Silva, Daniele Pagliarini; Colussi, Cláudia Flemming; Proença, Rossana Pacheco da Costa

    2013-01-01

    The purpose of this exploratory, descriptive, and cross-sectional study was to investigate the relationship between the price and availability of food products with and without trans fatty acids in food stores near elementary schools located in low- and medium-income neighborhoods of a Brazilian city. The supply of products containing trans fatty acids was higher in both regions, and these products were also cheaper. It is noteworthy that this availability may influence food choices and, consequently, the health status of children and adolescents, since this population is more likely to buy less-healthy foods when these are more available, accessible, and financially attractive. PMID:23282191

  15. Linking food availability, body growth and survival in the black-legged kittiwake Rissa tridactyla

    NASA Astrophysics Data System (ADS)

    Vincenzi, Simone; Mangel, Marc

    2013-10-01

    Population dynamics of black-legged kittiwakes Rissa tridactyla in Bering Sea colonies are likely to increasingly experience climate-induced changes in the physical environment. Since adult kittiwakes are central place foragers with high energy requirements, increased variability of forage patch dynamics, as predicted for polar regions, may influence both quantity and quality of food available and consequently alter the population dynamics of kittiwake colonies. Here, we describe, conceptualize, and model the effects of environment and energy resources on kittiwake growth, fledging age (from 35 to 50 days) and survival from hatching up to first breeding (post-hatching productivity). For our life-history model, we use a von Bertalanffy growth function for body growth in mass. We model nestling mortality as a function of somatic growth, in order to account for oxidative damage and trade-offs in the allocation of resources, and energy available, since low food availability increases the risk of chicks' starvation and predation risk. In the case of a good environment (i.e., high food availability), the best strategy (i.e., highest post-hatching productivity) is to grow fast (about 18.6 g d-1) and to spend a moderately long time in the nest (up to 45 days), while in the case of a poor environment the best strategy is to grow fast (about 18 g d-1) and leave the nest soon (35-40 days). Different ages at first breeding do not change the optimal strategies. We discuss the implications of optimal growth strategy in terms of evolution of life histories in kittiwakes and how our work, coupled with models of post-breeding survival and reproductive dynamics, could lead to the development of a full life-history model and the exploration of future evolutionary trajectories for traits like body growth and age at first breeding.

  16. Utilizing Multiple Datasets for Snow Cover Mapping

    NASA Technical Reports Server (NTRS)

    Tait, Andrew B.; Hall, Dorothy K.; Foster, James L.; Armstrong, Richard L.

    1999-01-01

    Snow-cover maps generated from surface data are based on direct measurements, however they are prone to interpolation errors where climate stations are sparsely distributed. Snow cover is clearly discernable using satellite-attained optical data because of the high albedo of snow, yet the surface is often obscured by cloud cover. Passive microwave (PM) data is unaffected by clouds, however, the snow-cover signature is significantly affected by melting snow and the microwaves may be transparent to thin snow (less than 3cm). Both optical and microwave sensors have problems discerning snow beneath forest canopies. This paper describes a method that combines ground and satellite data to produce a Multiple-Dataset Snow-Cover Product (MDSCP). Comparisons with current snow-cover products show that the MDSCP draws together the advantages of each of its component products while minimizing their potential errors. Improved estimates of the snow-covered area are derived through the addition of two snow-cover classes ("thin or patchy" and "high elevation" snow cover) and from the analysis of the climate station data within each class. The compatibility of this method for use with Moderate Resolution Imaging Spectroradiometer (MODIS) data, which will be available in 2000, is also discussed. With the assimilation of these data, the resolution of the MDSCP would be improved both spatially and temporally and the analysis would become completely automated.

  17. ESA SnowLab project

    NASA Astrophysics Data System (ADS)

    Wiesmann, Andreas; Caduff, Rafael; Frey, Othmar; Werner, Charles

    2016-04-01

    Retrieval of the snow water equivalaent (SWE) from passive microwave observations dates back over three decades to initial studies made using the first operational radiometers in space. However, coarse spatial resolution (25 km) is an acknowledged limitation for the application of passive microwave measurements. The natural variability of snow cover itself is also notable; properties such as stratigraphy and snow microstructure change both spatially and over time, affecting the microwave signature. To overcome this deficit, the satellite mission COld REgions Hydrology High-resolution Observatory (CoReH2O) was proposed to the European Space Agency (ESA) in 2005 in response to the call for Earth Explorer 7 candidate missions. CoReH2O was a dual frequency (X- and Ku-band) SAR mission aimed to provide maps of SWE over land and snow accumulation on glaciers at a spatial resolution of 200 to 500 meters with an unprecedented accuracy. Within the frame of preparatory studies for CoReH2O Phase A, ESA undertook several research initiatives from 2009 to 2013 to study the mission concept and capabilities of the proposed sensor. These studies provided a wealth of information on emission and backscattering signatures of natural snow cover, which can be exploited to study new potential mission concepts for retrieval of snow cover properties and other elements of the cryosphere. Currently data related to multi-frequency, multi-polarisation, multitemporal of active and passive microwave measurements are still not available. In addition, new methods related to e.g. tomography are currently under development and need to be tested with real data. Also, the potential of interferometric and polarimetric measurements of the snow cover and its possible impact for novel mission/retrieval concepts must be assessed. . The objective of the SnowLab activity is to fill this gap and complement these datasets from earlier campaigns by acquiring a comprehensive multi-frequency, multi

  18. Food availability affects onset of reproduction in a long-lived seabird

    PubMed Central

    Vincenzi, Simone; Hatch, Scott; Mangel, Marc; Kitaysky, Alexander

    2013-01-01

    Life-history theory predicts that suboptimal developmental conditions may lead to faster life histories (younger age at recruitment and higher reproductive investment), but experimental testing of this prediction is still scarce in long-lived species. We report the effects of an experimental manipulation of food availability during early development and at recruitment on the onset of reproduction and reproductive performance (productivity at first breeding) in a long-lived seabird, the black-legged kittiwake Rissa tridactyla, breeding on Middleton Island, Alaska. Birds were born and raised in nests with supplemented food (‘fed’) or unsupplemented control nests (‘unfed’), and later recruited into either fed or unfed nests. Fed chicks grew faster than unfed chicks, and males grew faster than females. Birds were more likely to reproduce at younger ages when recruiting into fed nests. Faster growth during development tended to increase age at recruitment in all individuals. Social rank of individuals also affected age at recruitment: B-chicks recruited earlier than A-chicks and singletons recruited later than A- and B-chicks. Productivity increased with the age at recruitment and growth rate as chick, but much of the variability remained unexplained. We conclude that results of this study at least partially support predictions of life-history theory: younger age at first breeding for kittiwakes that experienced suboptimal natal conditions, as well as greater productivity of early recruiting kittiwakes that grew in control nests compared with those that grew in food-supplemented nests. PMID:23576791

  19. Unusually high food availability in Kaikoura Canyon linked to distinct deep-sea nematode community

    NASA Astrophysics Data System (ADS)

    Leduc, D.; Rowden, A. A.; Nodder, S. D.; Berkenbusch, K.; Probert, P. K.; Hadfield, M. G.

    2014-06-01

    Kaikoura Canyon, on the eastern New Zealand continental margin, is the most productive, non-chemosynthetic deep-sea habitat described to date, with megafaunal biomass 100-fold higher than those of other deep-sea habitats. The present study, which focused on free-living nematodes, provides the first comparison of faunal community structure and diversity between Kaikoura Canyon and nearby open slope habitats. Results show substantially higher food availability in the canyon relative to open slope sediments, which probably reflects greater levels of primary productivity above the canyon, coupled with downwelling and/or topographically-induced channelling, which serves to concentrate surface-derived organic matter along the canyon axis. This high food availability appears to be responsible for the elevated nematode biomass in Kaikoura Canyon, with values exceeding all published nematode biomass data from canyons elsewhere. There was also markedly lower local species diversity of nematodes inside the canyon relative to the open slope habitat, as well as a distinct community structure. The canyon community was dominated by species, such as Sabateria pulchra, which were absent from the open slope and are typically associated with highly eutrophic and/or disturbed environments. The presence of these taxa, as well as the low observed diversity, is likely to reflect the high food availability, and potentially the high levels of physically and biologically induced disturbance within the canyon. Kaikoura Canyon is a relatively small habitat characterised by different environmental conditions that makes a disproportionate contribution to deep-sea diversity in the region, despite its low species richness.

  20. Reproductive seasonality in female goats adapted to a subtropical environment persists independently of food availability.

    PubMed

    Duarte, G; Flores, J A; Malpaux, B; Delgadillo, J A

    2008-11-01

    The aim of this study was to determine whether the seasonal change in food availability provides a predictive cue that synchronizes the breeding season in goats adapted to the subtropical conditions of Northern Mexico. Groups of multiparous intact (n=7) and ovariectomized does bearing a subcutaneous implant constantly releasing estradiol-l7 beta (OVX+E; n=12) were allocated in two pens and received a constant amount of feed. Another group of OVX+E does (n=10) was incorporated into a flock raised under natural grazing conditions with seasonal fluctuations in food availability. Blood samples were taken twice weekly. Ovulation of intact goats was inferred from plasma progesterone levels. In OVX+E does plasma levels of LH were measured. Intact does displayed seasonal variations in ovulation and the breeding season lasted from September to February. OVX+E goats displayed large seasonal variations in LH secretion regardless of whether they were fed constantly indoors or kept under natural grazing conditions (P<0.0001). The mean date of increase in LH secretion varied between years (P<0.0001) but did not differ between groups (naturally grazed: August 13+/-10 days; constantly fed: August 26+/-10 days). In contrast, the seasonal decline in LH secretion differed between groups: it was consistently delayed in constantly fed animals compared to those feeding naturally (naturally grazed: January 28+/-4 days; constantly fed: February 24+/-6 days, group effect, P<0.01). These results show that local female goats from subtropical Mexico display large reproductive seasonality independently of food availability. PMID:18790595

  1. Iodisation of Salt in Slovenia: Increased Availability of Non-Iodised Salt in the Food Supply

    PubMed Central

    Žmitek, Katja; Pravst, Igor

    2016-01-01

    Salt iodisation is considered a key public health measure for assuring adequate iodine intake in iodine-deficient countries. In Slovenia, the iodisation of all salt was made mandatory in 1953. A considerable regulatory change came in 2003 with the mandatory iodisation of rock and evaporated salt only. In addition, joining the European Union’s free single market in 2004 enabled the import of non-iodised salt. The objective of this study was to investigate the extent of salt iodising in the food supply. We examined both the availability and sale of (non-)iodised salt. Average sales-weighted iodine levels in salt were calculated using the results of a national monitoring of salt quality. Data on the availability and sales of salts were collected in major food retailers in 2014. Iodised salt represented 59.2% of the salt samples, and 95.9% of salt sales, with an average (sales-weighted) level of 24.2 mg KI/kg of salt. The average sales-weighted KI level in non-iodised salts was 3.5 mg KI/kg. We may conclude that the sales-weighted average iodine levels in iodised salt are in line with the regulatory requirements. However, the regulatory changes and the EU single market have considerably affected the availability of non-iodised salt. While sales of non-iodised salt are still low, non-iodised salt represented 33.7% of the salts in our sample. This indicates the existence of a niche market which could pose a risk of inadequate iodine intake in those who deliberately decide to consume non-iodised salt only. Policymakers need to provide efficient salt iodisation intervention to assure sufficient iodine supply in the future. The reported sales-weighting approach enables cost-efficient monitoring of the iodisation of salt in the food supply. PMID:27438852

  2. Effects of variable sequences of food availability on interval time-place learning by pigeons.

    PubMed

    García-Gallardo, Daniel; Carpio, Claudio

    2016-09-01

    The effects of within session variability of the sequences of food availability in a 16 period Time Place Learning (TPL) task on the performance of pigeons were assessed. Two groups of birds were exposed to two conditions. For group 1 (N=3), the first condition consisted of a TPL task in which food could be obtained according to a Random Interval (RI) 25s schedule of reinforcement in one of four feeders, the correct feeder changed every 3min. The same sequence was repeated four times within every training session (Fixed Sequence). The second condition was exactly the same as the first one with the exception that the sequence in which the correct feeder changed was randomized, yielding a total of four randomized sequences of food availability each session (Variable Sequence). An Open Hopper Test (OHT) was conducted at the end of each condition. Birds in group 2 (N=3) experienced the same conditions but in the reverse order. Results showed high percent correct responses for both group of birds under both conditions. However, birds were able to time the availability period's duration only under the Fixed Sequence condition, as shown by anticipation, anticipation of depletion and persistence of visiting patterns on the OHT. The implications of these results to Gallistels (1990) tripartite time-place-event memory code model are discussed, pointing out that these results are in line with previous findings about the important role that spatial parameters of a TPL task can play, for accurate timing was precluded when a variable sequence was employed. PMID:27425658

  3. City snow's physicochemical property affects snow disposal

    NASA Astrophysics Data System (ADS)

    Dovbysh, V. O.; Sharukha, A. V.; Evtin, P. V.; Vershinina, S. V.

    2015-10-01

    At the present day the industrial cities run into severe problem: fallen snow in a city it's a concentrator of pollutants and their quantity is constantly increasing by technology development. Pollution of snow increases because of emission of gases to the atmosphere by cars and factories. Large accumulation of polluted snow engenders many vexed ecological problems. That's why we need a new, non-polluting, scientifically based method of snow disposal. This paper investigates polluted snow's physicochemical property effects on snow melting. A distinctive feature of the ion accelerators with self-magnetically insulated diode is that there.

  4. Effects of food availability on growth and reproduction of the deep-sea pedunculate barnacle Heteralepas canci

    NASA Astrophysics Data System (ADS)

    Yasuda, Natsumi; Miyamoto, Norio; Fujiwara, Yoshihiro; Yamamoto, Tomoko; Yusa, Yoichi

    2016-02-01

    Sessile animals living on continental shelves or slopes may adjust their growth and reproduction according to temporally and spatially variable food availability, but little information is available on these animals to date. We collected the pedunculate barnacle Heteralepas canci on a continental slope at a depth of 229 m off Cape Nomamisaki in southern Japan. We developed a rearing method for the barnacles and studied their growth and reproduction at different food levels in the laboratory. A total of 136 individual H. canci were fed with Artemia salina larvae and brewer's yeast at three different food levels for 100 days. Both the growth and the ovary development were delayed when food availability was low, whereas the survival rate was lower at the high food level. In addition, an individual survived under complete starvation for 167 days. We concluded that H. canci has plastic life history traits that are adaptive for variable food availability.

  5. Drivers of household food availability in sub-Saharan Africa based on big data from small farms.

    PubMed

    Frelat, Romain; Lopez-Ridaura, Santiago; Giller, Ken E; Herrero, Mario; Douxchamps, Sabine; Andersson Djurfeldt, Agnes; Erenstein, Olaf; Henderson, Ben; Kassie, Menale; Paul, Birthe K; Rigolot, Cyrille; Ritzema, Randall S; Rodriguez, Daniel; van Asten, Piet J A; van Wijk, Mark T

    2016-01-12

    We calculated a simple indicator of food availability using data from 93 sites in 17 countries across contrasted agroecologies in sub-Saharan Africa (>13,000 farm households) and analyzed the drivers of variations in food availability. Crop production was the major source of energy, contributing 60% of food availability. The off-farm income contribution to food availability ranged from 12% for households without enough food available (18% of the total sample) to 27% for the 58% of households with sufficient food available. Using only three explanatory variables (household size, number of livestock, and land area), we were able to predict correctly the agricultural determined status of food availability for 72% of the households, but the relationships were strongly influenced by the degree of market access. Our analyses suggest that targeting poverty through improving market access and off-farm opportunities is a better strategy to increase food security than focusing on agricultural production and closing yield gaps. This calls for multisectoral policy harmonization, incentives, and diversification of employment sources rather than a singular focus on agricultural development. Recognizing and understanding diversity among smallholder farm households in sub-Saharan Africa is key for the design of policies that aim to improve food security. PMID:26712016

  6. Drivers of household food availability in sub-Saharan Africa based on big data from small farms

    PubMed Central

    Frelat, Romain; Lopez-Ridaura, Santiago; Herrero, Mario; Douxchamps, Sabine; Djurfeldt, Agnes Andersson; Erenstein, Olaf; Henderson, Ben; Kassie, Menale; Paul, Birthe K.; Rigolot, Cyrille; Ritzema, Randall S.; Rodriguez, Daniel; van Asten, Piet J. A.; van Wijk, Mark T.

    2016-01-01

    We calculated a simple indicator of food availability using data from 93 sites in 17 countries across contrasted agroecologies in sub-Saharan Africa (>13,000 farm households) and analyzed the drivers of variations in food availability. Crop production was the major source of energy, contributing 60% of food availability. The off-farm income contribution to food availability ranged from 12% for households without enough food available (18% of the total sample) to 27% for the 58% of households with sufficient food available. Using only three explanatory variables (household size, number of livestock, and land area), we were able to predict correctly the agricultural determined status of food availability for 72% of the households, but the relationships were strongly influenced by the degree of market access. Our analyses suggest that targeting poverty through improving market access and off-farm opportunities is a better strategy to increase food security than focusing on agricultural production and closing yield gaps. This calls for multisectoral policy harmonization, incentives, and diversification of employment sources rather than a singular focus on agricultural development. Recognizing and understanding diversity among smallholder farm households in sub-Saharan Africa is key for the design of policies that aim to improve food security. PMID:26712016

  7. Evaluating snow density models for integration in operational snow water resources monitoring

    NASA Astrophysics Data System (ADS)

    Jonas, T.; Magnusson, J.

    2012-12-01

    In the Alps, the distribution of seasonal snow is highly complex in time and space. Being able to monitor snow water resources is crucial for lake and reservoir management as well as for forecasting of snow-melt related spring floods. In Switzerland, while networks for periodic SWE measurements exist, they do not resolve the variability of snow at spatial and temporal scales as required by the national snow water resources monitoring program. However, there are hundreds of stations that provide daily snow depth information. Including these stations into SWE monitoring schemes requires the use of snow density models. In this study we first look at several model approaches to predict SWE under different scenarios regarding data availability: single snow depth reading, daily snow depth, daily snow and temperature data, etc. The model assessment is based on a large archive of snow pit data measured in the Swiss Alps over several decades. In a second step, we apply the above models to integrate daily snow depth readings in a data assimilation scheme to provide SWE distribution at medium to large scale. Finally, we compare the results of the data assimilation scheme intended for larger scale applications against field data from a 50 km2 test catchment that resolves the natural variability of snow depth and density at a smaller scale. This comparison reveals interesting differences in average density and depth from both data sets, suggesting that including a basic representation of small-scale variability may enhance larger-scale model approaches.

  8. MODIS Snow and Sea Ice Products

    NASA Technical Reports Server (NTRS)

    Hall, Dorothy K.; Riggs, George A.; Salomonson, Vincent V.

    2004-01-01

    In this chapter, we describe the suite of Earth Observing System (EOS) Moderate-Resolution Imaging Spectroradiometer (MODIS) Terra and Aqua snow and sea ice products. Global, daily products, developed at Goddard Space Flight Center, are archived and distributed through the National Snow and Ice Data Center at various resolutions and on different grids useful for different communities Snow products include binary snow cover, snow albedo, and in the near future, fraction of snow in a 5OO-m pixel. Sea ice products include ice extent determined with two different algorithms, and sea ice surface temperature. The algorithms used to develop these products are described. Both the snow and sea ice products, available since February 24,2000, are useful for modelers. Validation of the products is also discussed.

  9. Effect of food availability and leptin on the physiology and hypothalamic gene expression of the golden spiny mouse: a desert rodent that does not hoard food.

    PubMed

    Gutman, Roee; Hacmon-Keren, Ronit; Choshniak, Itzhak; Kronfeld-Schor, Noga

    2008-12-01

    Food availability and quality in desert habitats are spatially and temporally unpredictable, and animals face periods of food shortage. The golden spiny mouse (Acomys russatus) is an omnivorous desert rodent that does not hoard food, requiring it to withstand such periods by physiological means alone. In response to food restriction, plasma leptin concentrations, core body temperature, and energy expenditure of the spiny mouse decrease significantly after 24 h, and most spiny mice are able to maintain their body mass to approximately 85% of ad libitum for a prolonged period of time. Both 1-day food deprivation and long-term food restriction had a significant effect on body mass and plasma leptin concentrations, which decreased significantly with a high correlation, as well as on the orexigenic agouti-related protein, which increased significantly as a result of the 24-h food deprivation; and on neuropeptide Y (NPY), in which the increase was more pronounced under long-term food restriction. Food restriction and food deprivation had no effect, however, on the anorexigenic pro-opiomelanocortin and cocaine and amphetamine-related transcript. Leptin administration to food-restricted spiny mice did not affect food intake or the rate of decrease in body mass, indicating that it cannot overcome the drive to eat when food is scarce. However, it did result in a significant decrease in NPY levels, and the spiny mice spent less time at low body temperatures compared with PBS-treated golden spiny mice. These results show that in food-restricted golden spiny mice, leptin affects thermogenesis, but not food consumption, and suggest that the thermoregulatory effects of leptin are mediated by NPY. PMID:18843093

  10. Storing snow for the next winter: Two case studies on the application of snow farming.

    NASA Astrophysics Data System (ADS)

    Grünewald, Thomas; Wolfsperger, Fabian

    2016-04-01

    Snow farming is the conservation of snow during the warm half-year. This means that large piles of snow are formed in spring in order to be conserved over the summer season. Well-insulating materials such as chipped wood are added as surface cover to reduce melting. The aim of snow farming is to provide a "snow guaranty" for autumn or early winter - this means that a specific amount of snow will definitively be available, independent of the weather conditions. The conserved snow can then be used as basis for the preparation of winter sports grounds such as cross-country tracks or ski runs. This helps in the organization of early winter season sport events such as World Cup races or to provide appropriate training conditions for athletes. We present a study on two snow farming projects, one in Davos (Switzerland) and one in the Martell valley of South Tyrol. At both places snow farming has been used for several years. For the summer season 2015, we monitored both snow piles in order to assess the amount of snow conserved. High resolution terrestrial laser scanning was performed to measure snow volumes of the piles at the beginning and at the end of the summer period. Results showed that only 20% to 30 % of the snow mass was lost due to ablation. This mass loss was surprisingly low considering the extremely warm and dry summer. In order to identify the most relevant drivers of snow melt we also present simulations with the sophisticated snow cover models SNOWPACK and Alpine3D. The simulations are driven by meteorological input data recorded in the vicinity of the piles and enable a detailed analysis of the relevant processes controlling the energy balance. The models can be applied to optimize settings for snow farming and to examine the suitability of new locations, configurations or cover material for future snow farming projects.

  11. [MATCHE: Management Approach to Teaching Consumer and Homemaking Education.] Economically Depressed Areas Strand: Foods and Nutrition. Module III-C-1: Food Availability in Economically Depressed Areas.

    ERIC Educational Resources Information Center

    California State Univ., Fresno. Dept. of Home Economics.

    This competency-based preservice home economics teacher education module on food availability in economically depressed areas (EDA) is the first in a set of three modules on foods and nutrition in economically depressed areas. (This set is part of a larger set of sixty-seven modules on the Management Approach to Teaching Consumer and Homemaking…

  12. In kittiwakes food availability partially explains the seasonal decline in humoral immunocompetence

    USGS Publications Warehouse

    Gasparini, J.; Roulin, A.; Gill, V.A.; Hatch, Shyla A.; Boulinier, T.

    2006-01-01

    1. The immune system plays an important role in fitness, and interindividual variation in immunocompetence is due to several factors including food supply. 2. Seasonal variation in food resources may therefore explain why immunocompetence in bird nestlings usually declines throughout the breeding season, with chicks born early in the season receiving more food than chicks born later, and thereby possibly developing a more potent immune system. Although there are studies supporting this hypothesis, none has been experimental. 3. We performed an experiment in the kittiwake Rissa tridactyla by manipulating the food supply of pairs that were left to produce a first brood, and of pairs that were induced to produce a late replacement brood. 4. If food supply mediates, at least partially, seasonal variations in chick immunocompetence, non-food-supplemented chicks would show a stronger seasonal decline in immunocompetence than food-supplemented chicks. 5. Food supplementation improved humoral immunocompetence (the production of immunoglobulins Y), but not T-cell immunocompetence (phytohaemagglutinin, PHA response). T-cell immunocompetence of food-supplemented and non-food- supplemented chicks decreased through the season but to a similar extent, whereas the humoral immunocompetence of non-food-supplemented chicks decreased more strongly than that of food-supplemented chicks. 6. Our results suggest that the seasonal decline in humoral immunocompetence can be explained, at least partly, by variations in food supply throughout the breeding season. ?? 2006 British Ecological Society.

  13. 78 FR 68852 - Draft Guidance for Industry on Acrylamide in Foods; Availability

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-15

    ..., modifying processing practices, and choosing ingredients, so as to reduce acrylamide in potato-based foods (such as fries, sliced potato chips, and fabricated potato chips) and cereal-based foods (such as... service operations on preparation of potato-based and cereal-based foods. II. Paperwork Reduction Act...

  14. Evaluating the Impact of a Connecticut Program to Reduce Availability of Unhealthy Competitive Food in Schools

    ERIC Educational Resources Information Center

    Long, Michael W.; Henderson, Kathryn E.; Schwartz, Marlene B.

    2010-01-01

    Background: This article seeks to inform state and local school food policies by evaluating the impact of Connecticut's Healthy Food Certification (HFC), a program which provides monetary incentives to school districts that choose to implement state nutrition standards for all foods sold to students outside reimbursable school meals. Methods: Food…

  15. Yeah!!! A Snow Day!

    ERIC Educational Resources Information Center

    Cone, Theresa Purcell; Cone, Stephen L.

    2006-01-01

    As children see the first snowflake fall from the sky, they are filled with anticipation of playing in the snow. The snowy environment presents a wonderful opportunity for presenting interdisciplinary activities that connect snow play, snow formation, and snow stories with manipulative activities, gymnastic balances, and dance sequences. In this…

  16. Snow economics and the NOHRSC Snow Information System (SNOW-INFO) for the United States

    NASA Astrophysics Data System (ADS)

    Carroll, T.; Cline, D.; Berkowitz, E.; Savage, D.

    2003-04-01

    .7 trillion (16%) of the Nation's GDP related to the water contained in seasonal snowpacks, reliable snow information is critical to the management of the U.S. economy. In addition to helping improve river and flood forecasts and water supply forecasts, NOHRSC snow information has the potential also to support better decision making and improved efficiency in manufacturing, mining, agriculture, and thermo- and hydroelectric power generation. A 0.1% improvement in revenue resulting from reliable snow information results in an economic benefit to the Nation of 1.7 billion each year (in 2002 dollars). In an effort to provide snow information to support hydrologic forecasting operations in the NWS as well as to enhance the national economy, the NOHRSC has developed and implemented a Snow Information System (SNOW-INFO) that generates and distributes a variety of snow cover products in a variety of formats for the coterminous U.S. SNOW-INFO provides several new products that include: modeled snowpack characteristics such as snow ripeness, melt rates, mean snowpack temperature, and sublimation losses in a variety of alphanumeric, gridded, map, and time-series representations. SNOW-INFO products and data sets are available in near real-time to end-users from the NOHRSC web site (www.nohrsc.nws.gov) and FTP. A variety of SNOW-INFO products and maps from the 2003 snow season depicting simulated and assimilated snow model state variables for the coterminous U.S. are presented.

  17. 76 FR 66073 - Guidance for Industry on What You Need to Know About Administrative Detention of Foods; Availability

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-25

    ... HUMAN SERVICES Food and Drug Administration Guidance for Industry on What You Need to Know About.... SUMMARY: The Food and Drug Administration (FDA) is announcing the availability of a guidance for industry... part 1, subpart K (21 CFR part 1, subpart K), (76 FR 25538), that pertain to the criteria for...

  18. Operational snow mapping with simplified data assimilation using the seNorge snow model

    NASA Astrophysics Data System (ADS)

    Saloranta, Tuomo M.

    2016-07-01

    Frequently updated maps of snow conditions are useful for many applications, e.g., for avalanche and flood forecasting services, hydropower energy situation analysis, as well as for the general public. Numerical snow models are often applied in snow map production for operational hydrological services. However, inaccuracies in the simulated snow maps due to model uncertainties and the lack of suitable data assimilation techniques to correct them in near-real time may often reduce the usefulness of the snow maps in operational use. In this paper the revised seNorge snow model (v.1.1.1) for snow mapping is described, and a simplified data assimilation procedure is introduced to correct detected snow model biases in near real-time. The data assimilation procedure is theoretically based on the Bayesian updating paradigm and is meant to be pragmatic with modest computational and input data requirements. Moreover, it is flexible and can utilize both point-based snow depth and satellite-based areal snow-covered area observations, which are generally the most common data-sources of snow observations. The model and analysis codes as well as the "R" statistical software are freely available. All these features should help to lower the challenges and hurdles hampering the application of data-assimilation techniques in operational hydrological modeling. The steps of the data assimilation procedure (evaluation, sensitivity analysis, optimization) and their contribution to significantly increased accuracy of the snow maps are demonstrated with a case from eastern Norway in winter 2013/2014.

  19. Snow particle speeds in drifting snow

    NASA Astrophysics Data System (ADS)

    Nishimura, Kouichi; Yokoyama, Chika; Ito, Yoichi; Nemoto, Masaki; Naaim-Bouvet, Florence; Bellot, Hervé; Fujita, Koji

    2014-08-01

    Knowledge of snow particle speeds is necessary for deepening our understanding of the internal structures of drifting snow. In this study, we utilized a snow particle counter (SPC) developed to observe snow particle size distributions and snow mass flux. Using high-frequency signals from the SPC transducer, we obtained the sizes of individual particles and their durations in the sampling area. Measurements were first conducted in the field, with more precise measurements being obtained in a boundary layer established in a cold wind tunnel. The obtained results were compared with the results of a numerical analysis. Data on snow particle speeds, vertical velocity profiles, and their dependence on wind speed obtained in the field and in the wind tunnel experiments were in good agreement: both snow particle speed and wind speed increased with height, and the former was always 1 to 2 m s-1 less than the latter below a height of 1 m. Thus, we succeeded in obtaining snow particle speeds in drifting snow, as well as revealing the dependence of particle speed on both grain size and wind speed. The results were verified by similar trends observed using random flight simulations. However, the difference between the particle speed and the wind speed in the simulations was much greater than that observed under real conditions. Snow transport by wind is an aeolian process. Thus, the findings presented here should be also applicable to other geophysical processes relating to the aeolian transport of particles, such as blown sand and soil.

  20. Using direct observations on multiple occasions to measure household food availability among low-income Mexicano residents in Texas colonias

    PubMed Central

    2010-01-01

    Background It has been recognized that the availability of foods in the home are important to nutritional health, and may influence the dietary behavior of children, adolescents, and adults. It is therefore important to understand food choices in the context of the household setting. Considering their importance, the measurement of household food resources becomes critical. Because most studies use a single point of data collection to determine the types of foods that are present in the home, which can miss the change in availability within a month and when resources are not available, the primary objective of this pilot study was to examine the feasibility and value of conducting weekly in-home assessments of household food resources over the course of one month among low-income Mexicano families in Texas colonias. Methods We conducted five in-home household food inventories over a thirty-day period in a small convenience sample; determined the frequency that food items were present in the participating households; and compared a one-time measurement with multiple measurements. After the development and pre-testing of the 252-item culturally and linguistically- appropriate household food inventory instrument that used direct observation to determine the presence and amount of food and beverage items in the home (refrigerator, freezer, pantry, elsewhere), two trained promotoras recruited a convenience sample of 6 households; administered a baseline questionnaire (personal info, shopping habits, and food security); conducted 5 in-home assessments (7-day interval) over a 30-day period; and documented grocery shopping and other food-related activities within the previous week of each in-home assessment. All data were collected in Spanish. Descriptive statistics were calculated for mean and frequency of sample characteristics, food-related activities, food security, and the presence of individual food items. Due to the small sample size of the pilot data, the Friedman

  1. Effect of food availability on the growth and thermal physiology of juvenile Dungeness crabs (Metacarcinus magister)

    PubMed Central

    McLean, Katherine M.; Todgham, Anne E.

    2015-01-01

    Juvenile Dungeness crabs spend ~1 year in the San Francisco Estuary, where they undergo considerable growth before returning to the coastal ocean. Previous studies suggest that competition, food scarcity and avoidance of conspecifics may cause some juvenile Dungeness crabs in the San Francisco Estuary to become food limited. Food limitation may force these crabs to forage in higher temperature intertidal environments in the estuary, exposing them to stressful conditions in order to sustain growth and, potentially, necessitating physiological trade-offs in energy allocation between growth and stress tolerance. To investigate the effects of food limitation on aerobic metabolism and physiological performance of crabs, we assessed growth, moulting frequency, metabolic rate, citrate synthase and malate dehydrogenase enzyme activity and cardiac performance, as an index of temperature sensitivity and upper temperature tolerance. Summer- and winter-caught crabs were acclimated to either a high- or a low-food ration for 5 weeks. Overall, our results demonstrated that while food limitation had a negative effect on growth of juvenile Dungeness crabs in both the summer and the winter feeding trials, crabs in the low-food group maintained both metabolic rate at ambient San Francisco Estuary temperatures (15°C; summer trial only) and upper temperature tolerance as determined by failure of cardiac function when compared with crabs in the high-food group (summer and winter trials). Therefore, the ability to maintain stress tolerance when food is limited appears to come as a physiological trade-off to growth. Food-limited crabs were unable to increase their metabolic rate to the same level as that achieved by well-fed crabs; therefore, if exposure to elevated temperatures persists and requires more energy than can be met by crabs in their food-limited state, physiological performance may be compromised. PMID:27293698

  2. Scattering optics of snow.

    PubMed

    Kokhanovsky, Alexander A; Zege, Eleonora P

    2004-03-01

    Permanent snow and ice cover great portions of the Arctic and the Antarctic. It appears in winter months in northern parts of America, Asia, and Europe. Therefore snow is an important component of the hydrological cycle. Also, it is a main regulator of the seasonal variation of the planetary albedo. This seasonal change in albedo is determined largely by the snow cover. However, the presence of pollutants and the microstructure of snow (e.g., the size and shape of grains, which depend also on temperature and on the age of the snow) are also of importance in the variation of the snow's spectral albedo. The snow's spectral albedo and its bidirectional reflectance are studied theoretically. The albedo also determines the spectral absorptance of snow, which is of importance, e.g., in studies of the heating regime in snow. We investigate the influence of the nonspherical shape of grains and of close-packed effects on snow's reflectance in the visible and the near-infrared regions of the electromagnetic spectrum. The rate of the spectral transition from highly reflective snow in the visible to almost totally absorbing black snow in the infrared is governed largely by the snow's grain sizes and by the load of pollutants. Therefore both the characteristics of snow and its concentration of impurities can be monitored on a global scale by use of spectrometers and radiometers placed on orbiting satellites. PMID:15015542

  3. Molecular diversity of bacteria in commercially available “Spirulina” food supplements

    PubMed Central

    Kormas, Konstantinos A.; Katsiapi, Matina; Genitsaris, Savvas; Moustaka-Gouni, Maria

    2016-01-01

    The cyanobacterium Arthrospira is among the most well-known food supplements worldwide known as “Spirulina.” While it is a widely recognized health-promoting natural product, there are no reports on the molecular diversity of commercially available brands of “Spirulina” supplements and the occurrence of other cyanobacterial and heterotrophic bacterial microorganisms in these products. In this study, 454-pyrosequencing analysis of the total bacterial occurrence in 31 brands of “Spirulina” dietary supplements from the Greek market was applied for the first time. In all samples, operational taxonomic units (OTUs) of Arthrospira platensis were the predominant cyanobacteria. Some products contained additional cyanobacterial OTUs including a few known potentially toxic taxa. Moreover, 469 OTUs were detected in all 31 products collectively, with most of them being related to the Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria and Verrucomicrobia. All samples included heterotrophic bacterial OTUs, ranging from 9–157 per product. Among the most common OTUs were ones closely related to taxa known for causing health issues (i.e., Pseudomonas, Flavobacterium, Vibrio, Aeromonas, Clostridium, Bacillus, Fusobacterium, Enterococcus). The observed high cyanobacterial and heterotrophic bacterial OTUs richness in the final product is a point for further research on the growth and processing of Arthrospira biomass for commercial purposes. PMID:26819852

  4. Advertised quality, caste and food availability influence the survival cost of juvenile hormone in paper wasps.

    PubMed

    Tibbetts, Elizabeth A; Banan, Maral

    2010-11-22

    Life-history trade-offs are often hormonally mediated. Here, we provide a comparative perspective on the endocrine basis of life-history trade-offs by examining the invertebrate hormone juvenile hormone (JH). JH is often associated with benefits, including increased dominance and reproductive success. We tested whether JH reduced survival of Polistes dominulus wasps and whether this survival cost was influenced by factors such as advertised quality, food availability, caste and body size. Overall, JH reduced individual survival. Among fed and unfed queens, JH reduced survival in a dose-dependent manner. Among workers, JH had a stronger effect on survival of fed workers than unfed workers. Unfed workers died quickly and body size was the best predictor of survival. Surprisingly, queens and workers treated with JH survived longer when they had signals advertising high quality than when they had signals advertising low quality. The relationship between advertised quality and ability to withstand high levels of JH suggests that there are differential physiological costs associated with ornament elaboration that could play a role in maintaining signal accuracy over evolutionary time. Overall, the convergence of endocrine-mediated costs across diverse systems suggests that endocrine-mediated trade-offs may be an adaptive way to optimize resource allocation rather than a non-adaptive constraint specific to a particular hormone. PMID:20534614

  5. Are corticosterone levels a good indicator of food availability and reproductive performance in a kittiwake colony?

    USGS Publications Warehouse

    Lanctot, Richard B.; Hatch, Shyla A.; Gill, V.A.; Eens, M.

    2003-01-01

    We evaluated the use of corticosterone to gauge forage availability and predict reproductive performance in black-legged kittiwakes (Rissa tridactyla) breeding in Alaska during 1999 and 2000. We modeled the relationship between baseline levels of corticosterone and a suite of individual and temporal characteristics of the sampled birds. We also provided supplemental food to a sample of pairs and compared their corticosterone levels with that of pairs that were not fed. Corticosterone levels were a good predictor of forage availability in some situations, although inconsistencies between corticosterone levels and reproductive performance of fed and unfed kittiwakes suggested that this was not always the case. In general, higher corticosterone levels were found in birds that lacked breeding experience and in birds sampled shortly after arriving from their wintering grounds. All parameters investigated, however, explained only a small proportion of the variance in corticosterone levels. We also investigated whether corticosterone, supplemental feeding, year of the study, breeding experience, body weight, and sex of a bird were able to predict laying, hatching, and fledging success in kittiwakes. Here, breeding experience, year of the study, and body weight were the best predictors of a bird's performance. Corticosterone level and supplemental feeding were good predictors of kittiwake reproductive performance in some cases. For example, corticosterone levels of birds sampled during the arrival stage reliably predicted laying success, but were less reliable at predicting hatching and fledging success. Counts of active nests with eggs or chicks may be more reliable estimates of the actual productivity of the colony. Supplemental feeding had strong effects on kittiwake productivity when natural forage was poor, but had little effect when natural forage was plentiful. ?? 2003 Elsevier Science (USA). All rights reserved.

  6. Effects of antinutritional factors on protein digestibility and amino acid availability in foods.

    PubMed

    Gilani, G Sarwar; Cockell, Kevin A; Sepehr, Estatira

    2005-01-01

    Digestibility of protein in traditional diets from developing countries such as India, Guatemala, and Brazil is considerably lower compared to that of protein in typical North American diets (54-78 versus 88-94%). The presence of less digestible protein fractions, high levels of insoluble fiber, and high concentrations of antinutritional factors in the diets of developing countries, which are based on less refined cereals and grain legumes as major sources of protein, are responsible for poor digestibility of protein. The effects of the presence of some of the important antinutritional factors on protein and amino digestibilities of food and feed products are reviewed in this chapter. Food and feed products may contain a number of antinutritional factors that may adversely affect protein digestibility and amino acid availability. Antinutritional factors may occur naturally, such as glucosinolates in mustard and rapeseed protein products, trypsin inhibitors and hemagglutinins in legumes, tannins in legumes and cereals, phytates in cereals and oilseeds, and gossypol in cottonseed protein products. Antinutritional factors may also be formed during heat/alkaline processing of protein products, yielding Maillard compounds, oxidized forms of sulfur amino acids, D-amino acids, and lysinoalanine (LAL, an unnatural amino acid derivative). The presence of high levels of dietary trypsin inhibitors from soybeans, kidney beans, or other grain legumes can cause substantial reductions in protein and amino acid digestibilities (up to 50%) in rats and pigs. Similarly, the presence of high levels of tannins in cereals, such as sorghum, and grain legumes, such as fababean (Vicia faba L.), can result in significantly reduced protein and amino acid digestibilities (up to 23%) in rats, poultry, and pigs. Studies involving phytase supplementation of production rations for swine or poultry have provided indirect evidence that normally encountered levels of phytates in cereals and legumes

  7. The Impact of Increased Food Availability on Reproduction in a Long-Distance Migratory Songbird: Implications for Environmental Change?

    PubMed Central

    Seward, Adam M.; Beale, Colin M.; Gilbert, Lucy; Jones, T. Hefin; Thomas, Robert J.

    2014-01-01

    Many populations of migratory songbirds are declining or shifting in distribution. This is likely due to environmental changes that alter factors such as food availability that may have an impact on survival and/or breeding success. We tested the impact of experimentally supplemented food on the breeding success over three years of northern wheatears (Oenanthe oenanthe), a species in decline over much of Europe. The number of offspring fledged over the season was higher for food-supplemented birds than for control birds. The mechanisms for this effect were that food supplementation advanced breeding date, which, together with increased resources, allowed further breeding attempts. While food supplementation did not increase the clutch size, hatching success or number of chicks fledged per breeding attempt, it did increase chick size in one year of the study. The increased breeding success was greater for males than females; males could attempt to rear simultaneous broods with multiple females as well as attempting second broods, whereas females could only increase their breeding effort via second broods. Multiple brooding is rare in the study population, but this study demonstrates the potential for changes in food availability to affect wheatear breeding productivity, primarily via phenotypic flexibility in the number of breeding attempts. Our results have implications for our understanding of how wheatears may respond to natural changes in food availability due to climate changes or changes in habitat management. PMID:25333485

  8. The reflectance characteristics of snow covered surfaces

    NASA Technical Reports Server (NTRS)

    Batten, E. S.

    1979-01-01

    Data analysis techniques were developed to most efficiently use available satellite measurements to determine and understand components of the surface energy budget for ice and snow-covered areas. The emphasis is placed on identifying the important components of the heat budget related to snow surfaces, specifically the albedo and the energy consumed in the melting process. Ice and snow charts are prepared by NOAA from satellite observations which map areas into three relative reflectivity zones. Field measurements are analyzed of the reflectivity of an open snow field to assist in the interpretation of the NOAA reflectivity zones.

  9. Larval food plants of Australian Larentiinae (Lepidoptera: Geometridae) - a review of available data

    PubMed Central

    2016-01-01

    Abstract Background In Australia, the subfamily Larentiinae (Lepidoptera: Geometridae) comprises over 45 genera with about 270 species described so far. However, life histories of the Australian larentiine moths have barely been studied. New information The current paper presents a list of larval food plants of 51 Australian larentiine species based on literature references, data from specimen labels and own observations. Some Australian habitats are shown. Possible relationships among the taxa based on food preference of the larvae are discussed. Additionally, a list of Australasian larentiine species from the genera occurring in Australia and their food plants is presented. PMID:27099558

  10. Modeling the spatial variability of snow instability with the snow cover model SNOWPACK

    NASA Astrophysics Data System (ADS)

    Richter, Bettina; Reuter, Benjamin; Gaume, Johan; Fierz, Charles; Bavay, Mathias; van Herwijnen, Alec; Schweizer, Jürg

    2016-04-01

    Snow stratigraphy - key information for avalanche forecasting - can be obtained using numerical snow cover models driven by meteorological data. Simulations are typically performed for the locations of automatic weather station or for virtual slopes of varying aspect. However, it is unclear to which extent these simulations can represent the snowpack properties in the surrounding terrain, in particular snow instability, which is known to vary in space. To address this issue, we implemented two newly developed snow instability criteria in SNOWPACK relating to failure initiation and crack propagation, two fundamental processes for dry-snow slab avalanche release. Snow cover simulations were performed for the Steintälli field site above Davos (Eastern Swiss Alps), where snowpack data from several field campaigns are available. In each campaign, about 150 vertical snow penetration resistance profiles were sampled with the snow micro-penetrometer (SMP). For each profile, SMP and SNOWPACK- based instability criteria were compared. In addition, we carried out SNOWPACK simulations for multiple aspects and slope angles, allowing to obtain statistical distributions of the snow instability at the basin scale. Comparing the modeled to the observed distributions of snow instability suggests that it is feasible to obtain an adequate spatial representation of snow instability without high resolution distributed modeling. Hence, for the purpose of regional avalanche forecasting, simulations for a selection of virtual slopes seems sufficient to assess the influence of basic terrain features such as aspect and elevation.

  11. Group-Living Herbivores Weigh Up Food Availability and Dominance Status when Making Patch-Joining Decisions

    PubMed Central

    Stears, Keenan; Kerley, Graham I. H.; Shrader, Adrian M.

    2014-01-01

    Two key factors that influence the foraging behaviour of group-living herbivores are food availability and individual dominance status. Yet, how the combination of these factors influences the patch-joining decisions of individuals foraging within groups has scarcely been explored. To address this, we focused on the patch-joining decisions of group-living domestic goats (Capra hircus). When individuals were tested against the top four ranked goats of the herd, we found that at patches with low food availability they avoided these dominant patch-holders and only joined subordinates (i.e. costs outweighed benefits). However, as the amount of food increased, the avoidance of the top ranked individuals declined. Specifically, goats shifted and joined the patch of an individual one dominance rank higher than the previous dominant patch holder when the initial quantity of food in the new patch was twice that of the lower ranking individual’s patch (i.e. benefits outweighed costs). In contrast, when individuals chose between patches held by dominant goats, other than the top four ranked goats, and subordinate individuals, we found that they equally joined the dominant and subordinate patch-holders. This joining was irrespective of the dominance gap, absolute rank of the dominant patch-holder, sex or food availability (i.e. benefits outweighed costs). Ultimately, our results highlight that herbivores weigh up the costs and benefits of both food availability and patch-holder dominance status when making patch-joining decisions. Furthermore, as the initial quantity of food increases, food availability becomes more important than dominance with regard to influencing patch-joining decisions. PMID:25271889

  12. Black bear habitat use in relation to food availability in the Interior Highlands of Arkansas

    USGS Publications Warehouse

    Clark, Joseph D.; Clapp, Daniel L.; Smith, Kimberly G.; Ederington, Belinda

    1994-01-01

    A black bear (Ursus americanus) food value index (FVI) was developed and calculated for forest cover type classifications on Ozark Mountain (White Rock) and Ouachita Mountain (Dry Creek) study areas in western Arkansas. FVIs are estimates of bear food production capabilities of the major forest cover types and were calculated using percent cover, mean fruit production scorings, and the dietary percentage of each major plant food species as variables. Goodness-of-fit analyses were used to determine use of forest cover types by 23 radio-collared female bears. Habitat selection by forest cover type was not detected on White Rock but was detected on Dry Creek. Use of habitats on Dry Creek appeared to be related to food production with the exception of regeneration areas, which were used less than expected but had a high FVI ranking. In general, pine cover types had low FVI rankings and were used less than expected by bears. Forest management implications are discussed. 

  13. Neighborhood socioeconomic characteristics and differences in the availability of healthy food stores and restaurants in Sao Paulo, Brazil

    PubMed Central

    Duran, Ana Clara; Diez Roux, Ana V; do Rosario DO Latorre, Maria; Jaime, Patricia C

    2013-01-01

    Differential access to healthy foods has been hypothesized to contribute to health disparities, but evidence from low and middle-income countries is still scarce. This study examines whether the access of healthy foods varies across store types and neighborhoods of different socioeconomic statuses (SES) in a large Brazilian city. A cross-sectional study was conducted in 2010–2011 across 52 census tracts. Healthy food access was measured by a comprehensive in-store data collection, summarized into two indexes developed for retail food stores (HFSI) and restaurants (HMRI). Descriptive analyses and multilevel models were used to examine associations of store type and neighborhood SES with healthy food access. Fast food restaurants were more likely to be located in low SES neighborhoods whereas supermarkets and full service restaurants were more likely to be found in higher SES neighborhoods. Multilevel analyses showed that both store type and neighborhood SES were independently associated with in-store food measures. We found differences in the availability of healthy food stores and restaurants in Sao Paulo city favoring middle and high SES neighborhoods. PMID:23747923

  14. When to initiate torpor use? Food availability times the transition to winter phenotype in a tropical heterotherm.

    PubMed

    Vuarin, Pauline; Dammhahn, Melanie; Kappeler, Peter M; Henry, Pierre-Yves

    2015-09-01

    Timing of winter phenotype expression determines individual chances of survival until the next reproductive season. Environmental cues triggering this seasonal phenotypic transition have rarely been investigated, although they play a central role in the compensation of climatic fluctuations via plastic phenotypic adjustments. Initiation of winter daily torpor use-a widespread energy-saving phenotype-could be primarily timed according to anticipatory seasonal cues (anticipatory cues hypothesis), or flexibly fine-tuned according to actual energy availability (food shortage hypothesis). We conducted a food supplementation experiment on wild heterothermic primates (grey mouse lemurs, Microcebus murinus) at the transition to the food-limited dry season, i.e. the austral winter. As expected under the food shortage hypothesis, food-supplemented individuals postponed the seasonal transition to normal torpor use by 1-2 month(s), spent four times less torpid, and exhibited minimal skin temperature 6 °C higher than control animals. This study provides the first in situ experimental evidence that food availability, rather than abiotic cues, times the launching of torpor use. Fine-tuning of the timing of seasonal phenotypic transitions according to actual food shortage should provide heterotherms with a flexible adaptive mechanism to survive unexpected environmental fluctuations. PMID:25953115

  15. Mental imagery interventions reduce subsequent food intake only when self-regulatory resources are available

    PubMed Central

    Missbach, Benjamin; Florack, Arnd; Weissmann, Lukas; König, Jürgen

    2014-01-01

    Research has shown that imagining food consumption leads to food-specific habituation effects. In the present research, we replicated these effects and further examined whether the depletion of self-regulatory resources would reduce the habituation effects of imagined food consumption. Since self-regulatory resources have been shown to reduce habituation effects during the perception of emotional stimuli, we expected a reduction in habituation effects from imagined food consumption when self-regulatory resources were depleted. In Study 1, we replicated habituation effects as a response to imagining gummy bear consumption with a high (36) and medium number (18) of repetitions in a camouflaged taste test. Participants imagining gummy bear intake showed decreased food intake compared with participants who imagined putting a coin into a laundry machine. The number of repetitions did not significantly moderate the observed habituation effect. In Study 2, we investigated whether self-regulatory depletion would impede habituation effects evoked by the imagination of walnut consumption. Participants in a depleted state did not show a reduction in food intake after imagining walnut intake compared with participants in a non-depleted state. We discuss directions for future research and processes that might underlie the observed moderating effect of self-regulatory resources. PMID:25506337

  16. The Winter Environment: Snow

    ERIC Educational Resources Information Center

    Murphy, James E.

    1974-01-01

    Discusses the structure and formation of snow crystals, outlines the history of snow removal, and describes techniques that can be used by students for studying snowflakes and relating their structure to the conditions under which they were formed. (JR)

  17. Camping in the Snow.

    ERIC Educational Resources Information Center

    Brown, Constance

    1979-01-01

    Describes the experience of winter snow camping. Provides suggestions for shelter, snow kitchens, fires and stoves, cooking, latrines, sleeping warm, dehydration prevention, and clothing. Illustrated with full color photographs. (MA)

  18. Monitoring global snow cover

    NASA Technical Reports Server (NTRS)

    Armstrong, Richard; Hardman, Molly

    1991-01-01

    A snow model that supports the daily, operational analysis of global snow depth and age has been developed. It provides improved spatial interpolation of surface reports by incorporating digital elevation data, and by the application of regionalized variables (kriging) through the use of a global snow depth climatology. Where surface observations are inadequate, the model applies satellite remote sensing. Techniques for extrapolation into data-void mountain areas and a procedure to compute snow melt are also contained in the model.

  19. Remote sensing of snow

    NASA Technical Reports Server (NTRS)

    Foster, J. L.; Hall, D. K.; Chang, A. T. C.

    1987-01-01

    The snow parameters affecting sensor responses at different wavelengths are discussed. The effects of snow depth and background radiation on gamma ray sensors and of crystal size, contaminants, snow depth, liquid water, and surface roughness on visible and near-infrared sensors are considered. The influence of temperature, crystal size, and liquid water on thermal infrared sensors and of liquid water, crystal size, water equivalent depth, stratification, snow surface roughness, density, temperature, and soil condition on microwave sensors are addressed.

  20. Measuring food availability and access in African-American communities: implications for intervention and policy.

    PubMed

    Odoms-Young, Angela M; Zenk, Shannon; Mason, Maryann

    2009-04-01

    Obesity is a major public health concern in the U.S. As compared to whites, minority populations are disproportionately at risk, with the highest prevalence rates of overweight and obesity occurring among African American women. Although researchers and policymakers argue that environmental approaches have the greatest potential to reverse the rising prevalence of obesity, critical gaps remain in our understanding of the complex mechanisms that underlie the associations between neighborhood food environments and weight status. A major challenge has been the need for reliable and valid measures to assess aspects of the neighborhood food environment that encourage or inhibit healthful eating behaviors and weight management. Investigators have made considerable gains in the development of tools and approaches to measure neighborhood food environments overall, but few studies focus on the specific challenges and issues associated with characterizing neighborhood food environments in communities of color. This paper highlights important considerations for measuring food environments in African-American neighborhoods and their implications for developing programmatic and policy solutions to reduce racial disparities in overweight. PMID:19285205

  1. Timed food availability affects circadian behavior but not the neuropeptide Y expression in Indian weaverbirds exposed to atypical light environment.

    PubMed

    Singh, Devraj; Trivedi, Neerja; Malik, Shalie; Rani, Sangeeta; Kumar, Vinod

    2016-07-01

    We tested the hypothesis whether daily food availability period would restore rhythmicity in individuals with disrupted circadian behavior with no effect on appetite regulation. Particularly, we investigated the effects of timed food availability on activity behavior, and Fos and neuropeptide Y expressions in Indian weaverbirds (Ploceus philippinus) under atypical light conditions. Initially, weaverbirds in 3 groups of 7-8 each were entrained to 7L:17D (25: <0.3lx) with food ad libitum. Thereafter, food availability was restricted for 7h such that it overlapped with the light period. After a week, 7L:17D was replaced with 3.5L: 3.5D (T7, group 1), 3.5L: 20.5D (T24, group 2) or constant dim light, LLdim (<0.3lx, group 3) for 5weeks. Food cycles synchronized the circadian activity behavior, albeit with group differences, but did not affect body mass, blood glucose levels or testis size. Further, Fos, not NPY mRNA or peptide, expression measured at ZT2 and ZT14 (ZT0=time of food given) showed significant group differences in the hippocampus, dorsomedial hypothalamus and infundibular nuclear complex. Another identical experiment examined after-effects of the 3 light conditions on persistence of the circadian rhythms. Weaverbirds exposed for 4weeks to identical food but different light conditions, as above, were released into the free-running condition of food ad libitum and LLdim. Circadian rhythms were decayed in birds previously exposed to T7 LD cycle. Overall, these results show that timed meal restores rhythmicity in individuals with circadian rhythm disruptions without involving neuropeptide Y, the key appetite regulatory molecule. PMID:27085910

  2. Snow Bank Detectives

    ERIC Educational Resources Information Center

    Olson, Eric A.; Rule, Audrey C.; Dehm, Janet

    2005-01-01

    In the city where the authors live, located on the shore of Lake Ontario, children have ample opportunity to interact with snow. Water vapor rising from the relatively warm lake surface produces tremendous "lake effect" snowfalls when frigid winter winds blow. Snow piles along roadways after each passing storm, creating impressive snow banks. When…

  3. Macroeconomic adjustment, food availability and nutrition status in Nigeria. A look at the 1990s.

    PubMed

    Igbedioh, S O

    1990-12-01

    Faced with balance of payment problems, declining commodity prices, and a corresponding reduction in foreign exchange earnings, Nigeria implemented a structural adjustment program in 1986. This step was taken in response to encouragement from the International Monetary Fund and the World Bank, and was aimed to accomplish the following: find the true value of the official currency; overcome public sector inefficiency through improved public expenditure and parastatal rationalization; reschedule medium- and long-term debt to relieve debt burden; and encourage net foreign capital inflow while limiting foreign loans. Implementing and adhering to these macroeconomic adjustment policies has brought unprecedented inflation, lower real earnings, and increased malnutrition among lower income sectors of the population. The poor have suffered diminishing access to nutritious foods. Conscribed access to food and compromised nutritional status will most likely persist into the 1990s unless corrective policies are adopted. Appropriate policy would aim to increase the poor's access to food and limit population growth. PMID:12285940

  4. Refrigeration and Food Safety

    MedlinePlus

    ... Types of Bacteria in Refrigerated Foods Safe Refrigerator Temperature Safe Handling of Foods for Refrigerating Placement of ... or packed in snow. He realized the cold temperatures would keep game for times when food was ...

  5. EFFECTS OF FOOD AVAILABILITY ON LIPID CLASS COMPOSITION AND C AND N ACCUMULATION IN HEPATOPANCREATIC, OVARIAN AND EMBRYONIC TISSUES OF THE GRASS SHRIMP PALAEMONETES PUGIO: A LABORATORY STUDY

    EPA Science Inventory

    In a laboratory experiment, limited food availability caused severe mortality and reduced growth of adult female grass shrimp Palaemonetes pugio. However, reproduction, measured by % gravid females and clutch size, was unaffected by food availability. It appears that female shrim...

  6. Sharing, Trading, Stealing: Exploring the Role of Peers in Shaping Foods Available at Lunchtime

    ERIC Educational Resources Information Center

    Sutter, Carolyn; Nishina, Adrienne; Scherr, Rachel E.; Zidenberg-Cherr, Sheri; Ontai, Lenna L.

    2016-01-01

    Childhood obesity continues to be a major concern in the United States, warranting a comprehensive approach. However, the majority of research studies continue to neglect the influence of peers on dietary behaviors. The present descriptive study aimed to provide information about the ways peers directly shape dietary choices via food exchanges…

  7. Snow depth on Arctic and Antarctic sea ice derived from autonomous (Snow Buoy) measurements

    NASA Astrophysics Data System (ADS)

    Nicolaus, Marcel; Arndt, Stefanie; Hendricks, Stefan; Heygster, Georg; Huntemann, Marcus; Katlein, Christian; Langevin, Danielle; Rossmann, Leonard; Schwegmann, Sandra

    2016-04-01

    The snow cover on sea ice received more and more attention in recent sea ice studies and model simulations, because its physical properties dominate many sea ice and upper ocean processes. In particular; the temporal and spatial distribution of snow depth is of crucial importance for the energy and mass budgets of sea ice, as well as for the interaction with the atmosphere and the oceanic freshwater budget. Snow depth is also a crucial parameter for sea ice thickness retrieval algorithms from satellite altimetry data. Recent time series of Arctic sea ice volume only use monthly snow depth climatology, which cannot take into account annual changes of the snow depth and its properties. For Antarctic sea ice, no such climatology is available. With a few exceptions, snow depth on sea ice is determined from manual in-situ measurements with very limited coverage of space and time. Hence the need for more consistent observational data sets of snow depth on sea ice is frequently highlighted. Here, we present time series measurements of snow depths on Antarctic and Arctic sea ice, recorded by an innovative and affordable platform. This Snow Buoy is optimized to autonomously monitor the evolution of snow depth on sea ice and will allow new insights into its seasonality. In addition, the instruments report air temperature and atmospheric pressure directly into different international networks, e.g. the Global Telecommunication System (GTS) and the International Arctic Buoy Programme (IABP). We introduce the Snow Buoy concept together with technical specifications and results on data quality, reliability, and performance of the units. We highlight the findings from four buoys, which simultaneously drifted through the Weddell Sea for more than 1.5 years, revealing unique information on characteristic regional and seasonal differences. Finally, results from seven snow buoys co-deployed on Arctic sea ice throughout the winter season 2015/16 suggest the great importance of local

  8. Food availability affects Osmia pumila (Hymenoptera: Megachilidae) foraging, reproduction, and brood parasitism.

    PubMed

    Goodell, Karen

    2003-03-01

    Food limitation can reduce reproductive success directly, as well as indirectly, if foraging imposes a risk of predation or parasitism. The solitary bee Osmia pumila suffers brood parasitism by the cleptoparasitic wasp Sapyga centrata, which enters the host nest to oviposit while the female bee is away. I studied foraging and reproduction of O. pumila nesting within cages stocked with rich or sparse floral resources, and the presence or absence of S. centrata to test (1) the response of nesting female O. pumila to food shortages, (2) the response of nesting female O. pumila to the presence of parasites, and (3) whether brood produced under scarce resources are more likely to be parasitized by S. centrata. The rate of brood cell production was significantly lower in cages with sparse floral resources, although females in sparse cages did not produce significantly fewer brood cells overall. Sapyga centrata did not influence the rate of brood cell production, but females exposed to the cleptoparasites had marginally significantly lower reproductive output. Nests in parasite cages had significantly fewer brood cells than those in parasite free cages. The mean duration of foraging bouts made by female O. pumila in sparse cages was not significantly longer than that in rich cages. O. pumila spent less time in the nest between pollen and nectar foraging bouts in sparse cages with S. centrata than those in other cages suggesting that these individuals made more frequent food foraging trips. Despite the weak effects of parasites and bloom density on foraging behavior, O. pumila brood cells experienced a 5-fold higher probability of parasitism by S. centrata in cages with sparse bloom than in those with rich bloom [corrected]. These results support the hypothesis that indirect effects of food scarcity increase O. pumila susceptibility to brood parasitism, although the exact mechanism is not entirely clear yet. PMID:12647124

  9. Influence of Seasonal Food Availability on the Dynamics of Seabird Feeding Flocks at a Coastal Upwelling Area.

    PubMed

    Anguita, Cristóbal; Simeone, Alejandro

    2015-01-01

    The formation of multi-species feeding flocks (MSFFs) through visual recruitment is considered an important strategy for obtaining food in seabirds and its functionality has been ascribed to enhanced foraging efficiency. Its use has been demonstrated in much of the world's oceans and includes numerous species. However, there is scant information on the temporal stability of the composition and abundance of MSFFs as well as the effect of seasonal food availability on their dynamics. Between July 2006 and September 2014, we conducted monthly at-sea seabird counts at Valparaiso Bay (32°56' to 33°01'S, 71°36' to 71°46'W) within the area of influence of the Humboldt Current in central Chile. This area is characterized by a marked seasonality in primary and secondary production associated with upwelling, mainly during austral spring-summer. Based on studies that provide evidence that flocking is most frequent when food is both scarce and patchy, we hypothesized that seabird MSFF attributes (i.e. frequency of occurrence, abundance and composition) will be modified according to the seasonal availability of food. Using generalized linear models (GLMs), our results show that the contrasting seasonality in food availability of the study area (using chlorophyll-a concentration as a proxy) had no significant influence on MSFF attributes, sparsely explaining their variations (P>0.05). Rather than seasonal food availability, the observed pattern for MSFF attributes at Valparaiso Bay suggests a substantial influence of reproductive and migratory (boreal and austral migrants) habits of birds that modulates MSFF dynamics consistently throughout the whole year in this highly variable and patchy environment. We highlight the importance of visual recruitment as a mechanism by which migratory and resident birds interact. This would allow them to reduce resource unpredictability, which in turn has a major impact on structuring seabird's MSFF dynamics. PMID:26125630

  10. Influence of Seasonal Food Availability on the Dynamics of Seabird Feeding Flocks at a Coastal Upwelling Area

    PubMed Central

    Anguita, Cristóbal; Simeone, Alejandro

    2015-01-01

    The formation of multi-species feeding flocks (MSFFs) through visual recruitment is considered an important strategy for obtaining food in seabirds and its functionality has been ascribed to enhanced foraging efficiency. Its use has been demonstrated in much of the world's oceans and includes numerous species. However, there is scant information on the temporal stability of the composition and abundance of MSFFs as well as the effect of seasonal food availability on their dynamics. Between July 2006 and September 2014, we conducted monthly at-sea seabird counts at Valparaiso Bay (32°56′ to 33°01′S, 71°36′ to 71°46′W) within the area of influence of the Humboldt Current in central Chile. This area is characterized by a marked seasonality in primary and secondary production associated with upwelling, mainly during austral spring-summer. Based on studies that provide evidence that flocking is most frequent when food is both scarce and patchy, we hypothesized that seabird MSFF attributes (i.e. frequency of occurrence, abundance and composition) will be modified according to the seasonal availability of food. Using generalized linear models (GLMs), our results show that the contrasting seasonality in food availability of the study area (using chlorophyll-a concentration as a proxy) had no significant influence on MSFF attributes, sparsely explaining their variations (P>0.05). Rather than seasonal food availability, the observed pattern for MSFF attributes at Valparaiso Bay suggests a substantial influence of reproductive and migratory (boreal and austral migrants) habits of birds that modulates MSFF dynamics consistently throughout the whole year in this highly variable and patchy environment. We highlight the importance of visual recruitment as a mechanism by which migratory and resident birds interact. This would allow them to reduce resource unpredictability, which in turn has a major impact on structuring seabird’s MSFF dynamics. PMID:26125630

  11. Evaluating the impact of climate policies on regional food availability and accessibility using an Integrated Assessment Model

    NASA Astrophysics Data System (ADS)

    Gilmore, E.; Cui, Y. R.; Waldhoff, S.

    2015-12-01

    Beyond 2015, eradicating hunger will remain a critical part of the global development agenda through the Sustainable Development Goals (SDG). Efforts to limit climate change through both mitigation of greenhouse gas emissions and land use policies may interact with food availability and accessibility in complex and unanticipated ways. Here, we develop projections of regional food accessibility to 2050 under the alternative futures outlined by the Shared Socioeconomic Pathways (SSPs) and under different climate policy targets and structures. We use the Global Change Assessment Model (GCAM), an integrated assessment model (IAM), for our projections. We calculate food access as the weighted average of consumption of five staples and the portion of income spend on those commodities and extend the GCAM calculated universal global producer price to regional consumer prices drawing on historical relationships of these prices. Along the SSPs, food access depends largely on expectations of increases in population and economic status. Under a more optimistic scenario, the pressures on food access from increasing demand and rising prices can be counterbalanced by faster economic development. Stringent climate policies that increase commodity prices, however, may hinder vulnerable regions, namely Sub-Saharan Africa, from achieving greater food accessibility.

  12. Multiple excitatory and inhibitory neural signals converge to fine-tune Caenorhabditis elegans feeding to food availability.

    PubMed

    Dallière, Nicolas; Bhatla, Nikhil; Luedtke, Zara; Ma, Dengke K; Woolman, Jonathan; Walker, Robert J; Holden-Dye, Lindy; O'Connor, Vincent

    2016-02-01

    How an animal matches feeding to food availability is a key question for energy homeostasis. We addressed this in the nematode Caenorhabditis elegans, which couples feeding to the presence of its food (bacteria) by regulating pharyngeal activity (pumping). We scored pumping in the presence of food and over an extended time course of food deprivation in wild-type and mutant worms to determine the neural substrates of adaptive behavior. Removal of food initially suppressed pumping but after 2 h this was accompanied by intermittent periods of high activity. We show pumping is fine-tuned by context-specific neural mechanisms and highlight a key role for inhibitory glutamatergic and excitatory cholinergic/peptidergic drives in the absence of food. Additionally, the synaptic protein UNC-31 [calcium-activated protein for secretion (CAPS)] acts through an inhibitory pathway not explained by previously identified contributions of UNC-31/CAPS to neuropeptide or glutamate transmission. Pumping was unaffected by laser ablation of connectivity between the pharyngeal and central nervous system indicating signals are either humoral or intrinsic to the enteric system. This framework in which control is mediated through finely tuned excitatory and inhibitory drives resonates with mammalian hypothalamic control of feeding and suggests that fundamental regulation of this basic animal behavior may be conserved through evolution from nematode to human. PMID:26514165

  13. Cyanogenic glycosides in plant-based foods available in New Zealand.

    PubMed

    Cressey, Peter; Saunders, Darren; Goodman, Janet

    2013-01-01

    Cyanogenic glycosides occur in a wide range of plant species. The potential toxicity of cyanogenic glycosides arises from enzymatic degradation to produce hydrogen cyanide, which may result in acute cyanide poisoning and has also been implicated in the aetiology of several chronic diseases. One hundred retail foods were sampled and analysed for the presence of total hydrocyanic acid using an acid hydrolysis-isonicotinic/barbituric acid colourimetric method. Food samples included cassava, bamboo shoots, almonds and almond products, pome fruit products, flaxseed/linseed, stone fruit products, lima beans, and various seeds and miscellaneous products, including taro leaves, passion fruit, spinach and canned stuffed vine leaves. The concentrations of total hydrocyanic acid (the hydrocyanic acid equivalents of all cyanogenic compounds) found were consistent with or lower than concentrations reported in the scientific literature. Linseed/flaxseed contained the highest concentrations of total hydrocyanic acid of any of the analysed foods (91-178 mg kg(-1)). Linseed-containing breads were found to contain total hydrocyanic acid at concentrations expected from their linseed content, indicating little impact of processing on the total hydrocyanic acid content. Simulation modelling was used to assess the risk due to the total hydrocyanic acid in fruit juice and linseed-containing bread.  PMID:23984870

  14. Food web structure and seasonality of slope megafauna in the NW Mediterranean elucidated by stable isotopes: Relationship with available food sources

    NASA Astrophysics Data System (ADS)

    Papiol, V.; Cartes, J. E.; Fanelli, E.; Rumolo, P.

    2013-03-01

    Boundary Layer (BBL). δ15N enrichment was detected in periods of water column stratification, particularly amongst benthic feeder fishes. Megafauna relied on a single source of nutrition after peaks in surface production, presumably marine snow. Conversely, a larger array of food sources, probably from advection, sustained the community in periods of water column stratification. Benthic feeder δ13C values of both taxa were positively correlated with fluorescence measured 5 m above the seabed and negatively correlated with total organic carbon in the sediments, both being food sources for deposit feeding macroinfauna. Macroplankton feeder δ13C values were linked to environmental variables related to vertical transport from surface production, i.e. lipids and chlorophyll and their degradation products, likely due to their stronger reliance on sinking phytodetritus through consumption of planktonic prey.

  15. Fast food price, diet behavior, and cardiometabolic health: Differential associations by neighborhood SES and neighborhood fast food restaurant availability in the CARDIA study.

    PubMed

    Rummo, Pasquale E; Meyer, Katie A; Green Howard, Annie; Shikany, James M; Guilkey, David K; Gordon-Larsen, Penny

    2015-09-01

    Little research has addressed whether neighborhood context influences associations between fast food price, diet, and cardiometabolic health. We investigated these associations using 25 years of Coronary Artery Risk Development in Young Adults (CARDIA) study data (n=4,469, observations=21,134). We found a negative association between fast food price and consumption, with stronger inverse associations in more (vs. less) deprived neighborhoods [3rd tertile: β=-0.68 (95% CI: (-0.85, -0.51); 1st tertile: β=-0.22 (95% CI: -0.42, -0.02); p-interaction-0.002], and a similar association for BMI [3rd tertile: β=-1.34 (95% CI: -1.54, -1.14); 1st tertile: β=-0.45 (95% CI: -0.66, -0.25); p-interaction<0.001], but not insulin resistance [3rd tertile: β=-0.07 (95% CI: -0.24, 0.09); 1st tertile: β=0.09 (95% CI: -0.08, 0.26); p-interaction=0.40]. We observed no modification of fast food price by fast food availability. Future research on obesity disparities should consider potential differences in the association between fast food prices and health outcomes across neighborhood socioeconomic levels. PMID:26319447

  16. Price, promotion, and availability of nutrition information: a descriptive study of a popular fast food chain in New York City.

    PubMed

    Basch, Corey Hannah; Ethan, Danna; Rajan, Sonali

    2013-11-01

    Legislation in NYC requires chain restaurants to post calorie information on menu boards in an effort to help consumers make more informed decisions about food and beverage items they are purchasing. While this is a step in the right direction in light of the current obesity epidemic, there are other issues that warrant attention in a fast food setting, namely the pricing of healthy food options, promotional strategies, and access to comprehensive nutrition information. This study focused on a popular fast-food chain in NYC. The study's aims were threefold: (1) to determine the cost differential between the healthiest meal item on the chain's general menu and meal items available specifically on a reduced cost menu for one dollar (US$1.00); (2) to identify and describe the promotions advertised in the windows of these restaurants, as well as the nutrition content of promoted items; and (3) to ascertain availability of comprehensive nutrition information to consumers within the restaurants. We found the healthiest meal item to be significantly higher in price than less nutritious meal items available for $1.00 (t=146.9, p<.001), with the mean cost differential equal to $4.33 (95% CI: $4.27, $4.39). Window promotions generally advertised less healthful menu items, which may aid in priming customers to purchase these versus more healthful options. Comprehensive nutrition information beyond calorie counts was not readily accessible prior to purchasing. In addition to improving access to comprehensive nutrition information, advertising more of and lowering the prices of nutritious options may encourage consumers to purchase healthier foods in a fast food setting. Additional research in this area is needed in other geographic locations and restaurant chains.  PMID:24171876

  17. Price, Promotion, and Availability of Nutrition Information: A Descriptive Study of a Popular Fast Food Chain in New York City

    PubMed Central

    Basch, Corey Hannah; Ethan, Danna; Rajan, Sonali

    2013-01-01

    Legislation in NYC requires chain restaurants to post calorie information on menu boards in an effort to help consumers make more informed decisions about food and beverage items they are purchasing. While this is a step in the right direction in light of the current obesity epidemic, there are other issues that warrant attention in a fast food setting, namely the pricing of healthy food options, promotional strategies, and access to comprehensive nutrition information. This study focused on a popular fast-food chain in NYC. The study’s aims were threefold: (1) to determine the cost differential between the healthiest meal item on the chain’s general menu and meal items available specifically on a reduced cost menu for one dollar (US$1.00); (2) to identify and describe the promotions advertised in the windows of these restaurants, as well as the nutrition content of promoted items; and (3) to ascertain availability of comprehensive nutrition information to consumers within the restaurants. We found the healthiest meal item to be significantly higher in price than less nutritious meal items available for $1.00 (t = 146.9, p < .001), with the mean cost differential equal to $4.33 (95% CI $4.27, $4.39). Window promotions generally advertised less healthful menu items, which may aid in priming customers to purchase these versus more healthful options. Comprehensive nutrition information beyond calorie counts was not readily accessible prior to purchasing. In addition to improving access to comprehensive nutrition information, advertising more of and lowering the prices of nutritious options may encourage consumers to purchase healthier foods in a fast food setting. Additional research in this area is needed in other geographic locations and restaurant chains. PMID:24171876

  18. The content of high-intensity sweeteners in different categories of foods available on the Polish market.

    PubMed

    Zygler, Agata; Wasik, Andrzej; Kot-Wasik, Agata; Namieśnik, Jacek

    2012-01-01

    The objective of this study was to measure the concentrations of nine high-intensity sweeteners (acesulfame-K, aspartame, alitame, cyclamate, dulcin, neohesperidin DC, neotame, saccharin and sucralose) in different categories of food available on the Polish market. Over 170 samples of different brands of beverages, yoghurts, fruit preparations, vegetable preserves and fish products were analysed using an analytical procedure based on SPE and LC/MS. The results indicated that foodstuffs under the study generally comply with European Union legislation in terms of sweetener content. However, a few cases of food product mislabelling were detected, i.e. the use of cyclamate for non-approved applications. PMID:22827164

  19. Nonexercise muscle tension and behavioral fidgeting are positively correlated with food availability/palatability and body weight in rats.

    PubMed

    Heinrichs, Stephen C

    2003-07-01

    While certain measures of energy expenditure such as respiratory quotient and thermogenesis are readily quantifiable using existing animal models, the mechanism for and measurement of energy expenditure via nonexercise activity have not been thoroughly characterized. This low intensity form of physical exertion, associated with involuntary fidgeting and postural changes in man, was quantified in the present studies using passive measurement of muscle tension in rats. In particular, long-term weight loss and gain were induced using diet yoking and feeding of preferred foods in order to assess corresponding changes in locomotor activity and radiotelemetered measures of muscle tension, temperature and global activity. Hind limb muscle tension, but not body temperature, was increased 30-60% by enhancing the availability or palatability of food relative to the decreased muscle tension resulting from limited food availability. Enhancing food availability or palatability also produced a relative 5-15% increase in the amount of telemetered global activity. Importantly, neither diet yoking nor provision of a highly preferred diet altered a precise measure of behavioral locomotor activity. These results suggest that muscle tension and activity-in-place are positively correlated with weight change in the present studies and that these mechanisms of energy expenditure are mobilized by environmental changes in diet composition and meal pattern. PMID:12834791

  20. Using snowboards and lysimeters to constrain snow model choices in a rain-snow transitional environment

    NASA Astrophysics Data System (ADS)

    Wayand, N. E.; Massmann, A.; Clark, M. P.; Lundquist, J. D.

    2015-12-01

    Physically based models of the hydrological cycle are critical for testing our understanding of the natural world and enabling forecasting of extreme events. Previous intercomparison studies (i.e. SNOWMIP I & II, PILPS) of existing snow models that vary in complexity have been hampered by multiple differences in model structure. Recent efforts to encompass multiple model hypothesizes into a single framework (i.e. the Structure for Understanding Multiple Modeling Alternatives [SUMMA] model), have provided the tools necessary for a more rigorous validation of process representation. However, there exist few snow observatories that measure sufficient physical states and fluxes to fully constrain the possible combinations within these multiple model frameworks. In practice, observations of bulk snow states, such as the snow water equivalent (SWE) or snow depth, are most commonly available. The downfall of calibrating a snow model using such single bulk variables can lead to parameter equanimity and compensatory errors, which ultimately impacts the skill of a model as a predictive tool. This study provides two examples of diagnosing modeled snow processes through novel error source identification. Simulations were performed at a recently upgraded (Oct. 2012) snow study site located at Snoqualmie Pass (917 m), in the Washington Cascades, USA. We focused on two physical processes, new snow accumulation and snowpack outflow during mid-winter rain-on-snow events, for their importance towards controlling runoff and flooding in this rain-snow transitional basin. Main results were: 1) modifying the snow model structure to match what was actually observed (i.e. a snow board), allowed the attribution of daily errors in model new snow accumulation to either partitioning, new snow density, or compaction. 2) Observed snow pit temperature profiles from infrared cameras and manual thermometers found that cold biases in the model snowpack temperature prior to rain-on-snow events could

  1. Microwave emissions from snow

    NASA Technical Reports Server (NTRS)

    Chang, A. T. C.

    1984-01-01

    The radiation emitted from dry and wet snowpack in the microwave region (1 to 100 GHz) is discussed and related to ground observations. Results from theoretical model calculations match the brightness temperatures obtained by truck mounted, airborne and spaceborne microwave sensor systems. Snow wetness and internal layer structure complicate the snow parameter retrieval algorithm. Further understanding of electromagnetic interaction with snowpack may eventually provide a technique to probe the internal snow properties

  2. Sensitivity of Passive Microwave Snow Depth Retrievals to Weather Effects and Snow Evolution

    NASA Technical Reports Server (NTRS)

    Markus, Thorsten; Powell, Dylan C.; Wang, James R.

    2006-01-01

    Snow fall and snow accumulation are key climate parameters due to the snow's high albedo, its thermal insulation, and its importance to the global water cycle. Satellite passive microwave radiometers currently provide the only means for the retrieval of snow depth and/or snow water equivalent (SWE) over land as well as over sea ice from space. All algorithms make use of the frequency-dependent amount of scattering of snow over a high-emissivity surface. Specifically, the difference between 37- and 19-GHz brightness temperatures is used to determine the depth of the snow or the SWE. With the availability of the Advanced Microwave Scanning Radiometer (AMSR-E) on the National Aeronautics and Space Administration's Earth Observing System Aqua satellite (launched in May 2002), a wider range of frequencies can be utilized. In this study we investigate, using model simulations, how snow depth retrievals are affected by the evolution of the physical properties of the snow (mainly grain size growth and densification), how they are affected by variations in atmospheric conditions and, finally, how the additional channels may help to reduce errors in passive microwave snow retrievals. The sensitivity of snow depth retrievals to atmospheric water vapor is confirmed through the comparison with precipitable water retrievals from the National Oceanic and Atmospheric Administration's Advanced Microwave Sounding Unit (AMSU-B). The results suggest that a combination of the 10-, 19-, 37-, and 89-GHz channels may significantly improve retrieval accuracy. Additionally, the development of a multisensor algorithm utilizing AMSR-E and AMSU-B data may help to obtain weather-corrected snow retrievals.

  3. Home Food Availability, Parental Dietary Intake, and Familial Eating Habits Influence the Diet Quality of Urban Hispanic Children

    PubMed Central

    Adams, Alexandra K.; Carrel, Aaron L.; LaRowe, Tara L.; Schoeller, Dale A.

    2014-01-01

    Abstract Background: The home food environment influences children's eating behaviors and potentially affects overall diet quality. The aim of the present study was to evaluate the relationship between the home food environment and Hispanic children's diet quality. Methods: Hispanic children, 10–14 years of age (n=187), and their parents participated in this cross-sectional study. The Healthy Eating Index (HEI) was used to determine diet quality based on reported dietary intake obtained through a food frequency questionnaire administered to the children. Parents self-reported home food availability, familial eating habits, and their own habitual diet through a home environment survey. Results: The children's HEI total score was 59.4±8.8. Reported diets did not adhere to the dietary recommendations for total vegetables, greens and beans, whole grains, seafood and plant proteins, fatty acids, refined grains, sodium, solid fats, and added sugars. None of the participants had “good” scores (HEI, >80), 86% had scores that “need improvement” (HEI, 51–80), and 14% had “poor” scores (HEI, <50). Children with lower HEI scores had sugar-sweetened beverages available at home and participated in family meals while watching television more frequently, when compared with children with higher HEI scores. Conclusions: Home food availability, parental diet, and familial eating habits seem to play an important role in the diet quality of children. Interventions targeting family education on healthful dietary habits at home could have a positive impact on children's diet quality and overall health. PMID:25259675

  4. Data sets for snow cover monitoring and modelling from the National Snow and Ice Data Center

    NASA Astrophysics Data System (ADS)

    Holm, M.; Daniels, K.; Scott, D.; McLean, B.; Weaver, R.

    2003-04-01

    A wide range of snow cover monitoring and modelling data sets are pending or are currently available from the National Snow and Ice Data Center (NSIDC). In-situ observations support validation experiments that enhance the accuracy of remote sensing data. In addition, remote sensing data are available in near-real time, providing coarse-resolution snow monitoring capability. Time series data beginning in 1966 are valuable for modelling efforts. NSIDC holdings include SMMR and SSM/I snow cover data, MODIS snow cover extent products, in-situ and satellite data collected for NASA's recent Cold Land Processes Experiment, and soon-to-be-released ASMR-E passive microwave products. The AMSR-E and MODIS sensors are part of NASA's Earth Observing System flying on the Terra and Aqua satellites Characteristics of these NSIDC-held data sets, appropriateness of products for specific applications, and data set access and availability will be presented.

  5. 76 FR 45221 - Notice of Funding Availability: Inviting Applications for the Food for Progress Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-28

    ... Progress (FFPr) program. The total resources available are estimated at about $160 million. The FFPr... estimated number of beneficiaries? (e) Is the number of beneficiaries realistic for the proposed...

  6. "Let It Snow, Let It Snow, Let It Snow!"

    ERIC Educational Resources Information Center

    Pangbourne, Laura

    2010-01-01

    Winter in the UK has, in recent years, brought a significant amount of snow and cold weather. This was the case while the author was a trainee teacher on placement at a rural primary school in Dartmoor early in 2010. The day started promisingly with the class looking at the weather forecast on the interactive whiteboard and having a short…

  7. Food availability and offspring sex in a monogamous seabird: insights from an experimental approach

    USGS Publications Warehouse

    Merkling, Thomas; Leclaire, Sarah; Danchin, Etienne; Lhuillier, Emeline; Wagner, Richard H.; White, Joël; Hatch, Scott A.; Blanchard, Pierrick

    2012-01-01

    Sex allocation theory predicts that parents should favor offspring of the sex that provides the greatest fitness return. Despite growing evidence suggesting that vertebrates are able to overcome the constraint of chromosomal sex determination, the general pattern remains equivocal, indicating a need for experimental investigations. We used an experimental feeding design to study sex allocation during 3 years in black-legged kittiwakes (Rissa tridactyla). Intense male–male competition for securing a breeding site is common in this species in which males are heavier and larger than females. Hence, we hypothesized that parents producing fledglings in better than average condition, as supplementarily fed pairs do, would increase their fitness return by producing sons. Conversely, producing daughters would be a better tactic for Unfed parents. Hence, we predicted that Fed parents produce more sons than Unfed parents. This prediction is particularly expected if sexual dimorphism arises as early as during chick rearing, suggesting strong selective pressures for optimal male development. Our results showed that 1) males were heavier and larger than females prior to fledging and that 2) Fed parents produced relatively more male hatchlings than Unfed parents. We interpret this result in terms of a Trivers–Willard-type process. Furthermore, our data revealed that Unfed parents significantly overproduced female hatchlings, whereas offspring sex ratio was balanced among Fed parents. Because the 3 reproductive seasons we considered were particularly poor food years, Unfed parents may have overproduced daughters to avoid the apparent higher reproductive costs of raising sons.

  8. Demand for food on fixed-ratio schedules as a function of the quality of concurrently available reinforcement1

    PubMed Central

    Lea, S. E. G.; Roper, T. J.

    1977-01-01

    Six rats lever pressed for food on concurrent fixed-ratio schedules, in a two-compartment chamber. In one compartment, mixed diet pellets were delivered on fixed-ratio schedules of 1, 6, 11, and 16; in the other, either no food was delivered, or sucrose or mixed diet pellets were delivered on fixed-ratio 8. The number of pellets obtained in the first compartment declined as a function of fixed-ratio size in that compartment in all three conditions, but the decline was greatest overall with mixed diet pellets concurrently available in the other compartment, and least with no food concurrently available. The result is discussed in terms of economic demand theory, and is consistent with the prediction that elasticity of demand for a commodity (defined in operant terms as the ratio of the proportionate change in number of reinforcements per session to the proportionate change in fixed-ratio size) is greater the more substitutable for that commodity are any concurrently available commodities. PMID:16811999

  9. A Distributed Snow Evolution Modeling System (SnowModel)

    NASA Astrophysics Data System (ADS)

    Liston, G. E.; Elder, K.

    2004-12-01

    A spatially distributed snow-evolution modeling system (SnowModel) has been specifically designed to be applicable over a wide range of snow landscapes, climates, and conditions. To reach this goal, SnowModel is composed of four sub-models: MicroMet defines the meteorological forcing conditions, EnBal calculates surface energy exchanges, SnowMass simulates snow depth and water-equivalent evolution, and SnowTran-3D accounts for snow redistribution by wind. While other distributed snow models exist, SnowModel is unique in that it includes a well-tested blowing-snow sub-model (SnowTran-3D) for application in windy arctic, alpine, and prairie environments where snowdrifts are common. These environments comprise 68% of the seasonally snow-covered Northern Hemisphere land surface. SnowModel also accounts for snow processes occurring in forested environments (e.g., canopy interception related processes). SnowModel is designed to simulate snow-related physical processes occurring at spatial scales of 5-m and greater, and temporal scales of 1-hour and greater. These include: accumulation from precipitation; wind redistribution and sublimation; loading, unloading, and sublimation within forest canopies; snow-density evolution; and snowpack ripening and melt. To enhance its wide applicability, SnowModel includes the physical calculations required to simulate snow evolution within each of the global snow classes defined by Sturm et al. (1995), e.g., tundra, taiga, alpine, prairie, maritime, and ephemeral snow covers. The three, 25-km by 25-km, Cold Land Processes Experiment (CLPX) mesoscale study areas (MSAs: Fraser, North Park, and Rabbit Ears) are used as SnowModel simulation examples to highlight model strengths, weaknesses, and features in forested, semi-forested, alpine, and shrubland environments.

  10. Availability of food resources, distribution of invasive species, and conservation of a Hawaiian bird along a gradient of elevation

    USGS Publications Warehouse

    Banko, P.C.; Oboyski, P.T.; Slotterback, J.W.; Dougill, Steve J.; Goltz, Dan M.; Johnson, L.; Laut, M.E.; Murray, T.C.

    2002-01-01

    Aim: We evaluated how an elevation gradient affects: (1) the availability of food required by a specialist seed-eater, Loxioides bailleui Oustalet (Drepanidinae), or pallia, and hence the distribution of this endangered Hawaiian bird, and (2) the distribution of alien threats to Loxioides populations, their primary foods, and their dry-forest habitat, and hence strategies for their conservation. Location: We worked throughout the subalpine forest that encircles Mauna Kea Volcano, Hawai'i Island, but we focused our studies mainly on the western slope between 2000 and 3000 m elevation, where the gradient of elevation was greatest and palila were most abundant. Methods: We determined phenology and productivity patterns of the endemic dry-forest tree species, Sophora chrysophylla (Salisb.) Seem. (Fabaceae), or ma??mane, which provides Loxioides with most of their food, and another common endemic tree, Myoporum sandwicense A. Gray (Myoporaceae), or naio, which provides some resources, along a 786-m elevation gradient at monthly intervals for 10 years (Sophora only). We also determined the availability each month of moth larvae (Lepidoptera) for that were important in the diet of nestling and adult palila. In addition, we documented the incidence of parasitism on moth larvae by several wasp (Hymenoptera) and fly (Diptera) species, and we determined the distribution of predatory wasps and ants (Hymenoptera), which potentially threaten insect prey of birds. Percentage cover of alien grass species that pose fire threats in palila habitat and other weeds were assessed during one survey. Small mammal abundance and distribution were determined by trapping during three (rodent) or five (carnivore) surveys. Results: Sophora flower and seed (pod) availability varied predictably along the elevation gradient, with about 4 months separating peaks in reproduction at high and low elevations. This, together with highly variable production of flowers and pods within elevation strata

  11. BOREAS HYD-4 Standard Snow Course Data

    NASA Technical Reports Server (NTRS)

    Metcalfe, John R.; Goodison, Barry E.; Walker, Anne; Hall, Forrest G. (Editor); Knapp, David E. (Editor); Smith, David E. (Technical Monitor)

    2000-01-01

    The Boreal Ecosystem-Atmosphere Study (BOREAS) Hydrology (HYD)-4 work was focused on collecting data during the winter focused field campaign (FFC-W) to improve the understanding of winter processes within the boreal forest. Knowledge of snow cover and its variability in the boreal forest is fundamental if BOREAS is to achieve its goals of understanding the processes and states involved in the exchange of energy and water. The development and validation of remote sensing algorithms will provide the means to extend the knowledge of these processes and states from the local to the regional scale. A specific thrust of the research is the development and validation of snow cover algorithms from airborne passive microwave measurements. Snow surveys were conducted at special snow courses throughout the 1993/94, 1994/95, 1995/96, and 1996/97 winter seasons. These snow courses were located in different boreal forest land cover types (i.e., old aspen, old black spruce, young jack pine, forest clearing, etc.) to document snow cover variations throughout the season as a function of different land cover. Measurements of snow depth, density, and water equivalent were acquired on or near the first and fifteenth of each month during the snow cover season. The data are provided in tabular ASCII files. The HYD-4 standard snow course data are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The data files are available on a CD-ROM (see document number 20010000884).

  12. Loropetalum chinense 'Snow Panda'

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new Loropetalum chinense, ‘Snow Panda’, developed at the U.S. National Arboretum is described. ‘Snow Panda’ (NA75507, PI660659) originated from seeds collected near Yan Chi He, Hubei, China in 1994 by the North America-China Plant Exploration Consortium (NACPEC). Several seedlings from this trip w...

  13. "Snowing" Core in Earth?

    NASA Astrophysics Data System (ADS)

    Li, J.; Chen, B.; Cormier, V.; Gao, L.; Gubbins, D.; Kharlamova, S. A.; He, K.; Yang, H.

    2008-12-01

    As a planet cools, an initially molten core gradually solidifies. Solidification occurs at shallow depths in the form of "snow", if the liquidus temperature gradient of the core composition is smaller than the adiabatic temperature gradient in the core. Experimental data on the melting behavior of iron-sulfur binary system suggest that the cores of Mercury and Ganymede are probably snowing at the present time. The Martian core is predicted to snow in the future, provided that the sulfur content falls into the range of 10 to 14 weight percent. Is the Earth's core snowing? If so, what are the surface manifestations? If the Earth's core snowed in the past, how did it affect the formation of the solid inner core and the geodynamo? Here, we evaluate the likelihood and consequences of a snowing core throughout the Earth's history, on the basis of mineral physics data describing the melting behavior, equation-of-state, and thermodynamic properties of iron-rich alloys at high pressures. We discuss if snowing in the present-day Earth can reproduce the shallow gradients of compressional wave velocity above the inner-core boundary, and whether or not snowing in the early Earth may reconcile the apparent young age of the solid inner core with a long-lived geodynamo.

  14. GulfSnow Peach

    Technology Transfer Automated Retrieval System (TEKTRAN)

    GulfSnow peach is jointly released for grower trial by the U.S. Department of Agriculture, Agricultural Research Service (Byron, GA), Georgia Agricultural Experiment Station and Florida Agricultural Experiment Station. GulfSnow was previously tested as AP06-09W and originated from a cross of AP98-3...

  15. Do Food Availability and Microclimate Determine Bird Use of Forest Canopy Gaps?

    SciTech Connect

    CHAMPLIN, TRACEY BERNICE

    2007-07-01

    We investigated the influence of arthropod availability and microclimate on avian use of forest canopy gaps in 2002 and 2003. We used mist netting and observation of foraging effort (attack rates) to determine the influence of arthropod abundance on avian habitat use of three sizes (0.13, 0.26, and 0.50 ha) of 2- to 3-year-old group-selection timber harvest openings during four periods (spring migration, breeding, post-breeding, and fall migration).

  16. Impacts of Change in Irrigation Water Availability on Food Production in the Yellow River Basin under Climate Change

    NASA Astrophysics Data System (ADS)

    Yin, Y. Y.; Tang, Q.

    2014-12-01

    Approximately 9 percent of China's population and 17 percent of its agricultural area are settled in the Yellow River Basins. Irrigation, which plays an important role in agricultural production, occupies the largest share of human consumptive water use in the basin. Given increasing water demands, the basin faces acute water scarcity. Previous studies have suggested that decrease in irrigation water availability under climate change might have an overall adverse impact on the food production of the basin. The timing and area that would face severe water stress are yet to be identified. We used a land surface hydrological model forced with the bias-corrected climatic variables from 5 climate models under 4 Representative Concentration Pathways (RCPs) to estimate total water availability in the sub-basins of the Yellow River basin. The future socioeconomic conditions, the Shared Socioeconomic Pathways (SSPs), were used to estimate the water requirement in the nonagricultural water use sectors. The irrigation water availability was estimated from the total water availability and nonagricultural water use, and the irrigation water demands were estimated based on the current irrigation project efficiencies. The timing and area of irrigation water shortage were shown and the implication of change in irrigation water availability on food production was assessed. The results show that the sub-basins with high population density and gross domestic product (GDP) are likely to confront severe water stress and reduction in food production earlier because irrigation water was to be appropriated by the rapid increase in nonagricultural water use sectors. The study stresses the need for adaptive management of water to balance agriculture and nonagricultural demands in northern China.

  17. Responses of squirrel monkeys to seasonal changes in food availability in an eastern Amazonian forest.

    PubMed

    Stone, Anita I

    2007-02-01

    Tropical forests are characterized by marked temporal and spatial variation in productivity, and many primates face foraging problems associated with seasonal shifts in fruit availability. In this study, I examined seasonal changes in diet and foraging behaviors of two groups of squirrel monkeys (Saimiri sciureus), studied for 12 months in Eastern Brazilian Amazonia, an area characterized by seasonal rainfall. Squirrel monkeys were primarily insectivorous (79% of feeding and foraging time), with fruit consumption highest during the rainy season. Although monkeys fed from 68 plant species, fruit of Attalea maripa palms accounted for 28% of annual fruit-feeding records. Dietary shifts in the dry season were correlated with a decline in ripe A. maripa fruits. Despite pronounced seasonal variation in rainfall and fruit abundance, foraging efficiency, travel time, and distance traveled remained stable between seasons. Instead, squirrel monkeys at this Eastern Amazonian site primarily dealt with the seasonal decline in fruit by showing dietary flexibility. Consumption of insects, flowers, and exudates increased during the dry season. In particular, their foraging behavior at this time strongly resembled that of tamarins (Saguinus sp.) and consisted of heavy use of seed-pod exudates and specialized foraging on large-bodied orthopterans near the forest floor. Comparisons with squirrel monkeys at other locations indicate that, across their geographic range, Saimiri use a variety of behavioral tactics during reduced periods of fruit availability. PMID:17154390

  18. Validation of the Snow Submodel of the Biosphere-Atmosphere Transfer Scheme with Russian Snow Cover and Meteorological Observational Data.

    NASA Astrophysics Data System (ADS)

    Yang, Zong-Liang; Dickinson, Robert E.; Robock, Alan; Vinnikov, K. Ya.

    1997-02-01

    Snow cover is one of the most important variables affecting agriculture, hydrology, and climate, but detailed measurements are not widely available. Therefore, the effectiveness and validity of snow schemes in general circulation models have been difficult to assess. Using long-term snow cover data from the former Soviet Union, this paper focuses on the validation of the snow submodel in the Biosphere-Atmosphere Transfer Scheme (BATS) using 6 years of data (1978-83) at six stations. Fundamental uncertainties in the datasets limit the accuracy of our assessment of the model's performance.In the absence of a wind correction for the gauge-measured precipitation and with the standard rain-snow transition criterion (2.2°C), the model gives reasonable simulations of snow water equivalent and surface temperature for all of the six stations and the six winters examined. In particular, the time of accumulation and the end of ablation and the alteration due to aging are well captured. With some simple modifications of the code, the model can also reproduce snow depth, snow cover fraction, and surface albedo. In view of the scheme's simplicity and efficiency, these results are encouraging.However, if a wind correction is applied to the gauge-measured precipitation, the model shows increased root-mean-square errors in snow water equivalent for all six stations except Tulun. Perhaps, the better agreement without wind correction means that the snow has blown beyond the area of snow measurement, as might be accounted for only by a detailed regional snow-wind distribution model.This study underlines four aspects that warrant special attention: (i) estimation of the downward longwave radiation, (ii) separation of the aging processes for snowpack density and snow surface albedo, (iii) parameterization of snow cover fraction, and (iv) choice of critical temperature for rain-snow transition.

  19. Albedo reduction by dirty snow: measurements and implications

    NASA Astrophysics Data System (ADS)

    Zender, C. S.; Gallet, J.; Domine, F.; Picard, G.

    2008-12-01

    Industrial and biomass burning emissions of black carbon (BC) from low- and mid-latitudes dominate the radiative forcing by absorbing impurities trapped in snow and ice at mid- and high- northern latitudes. Correct model representation of albedo reduction by BC-contaminated snow is crucial because our GCM simulations show that dirty snow can explain about 30% of the observed 20th century Arctic warming. Until now, measurements of actual snow darkening by BC have been attempted only in the field, under non- reproducible conditions, and limited to the environmental BC concentration. We have conducted the first measurements of the direct effect of BC-contamination on snow albedo by in a controlled environment. We doped natural snow with a commercially available BC-analogue and measured the resulting albedo change at visible and near-infrared wavelengths. Snow albedo was measured in a (portable) integrating sphere system. Snow grain size is estimated from the near-infrared albedo. Snow density, temperature, and BC properties were known a priori. The albedo measurement reproducibility is about 1% for natural snow. Our measurements agree with model predictions that BC concentrations from 250 ppbm to 200 ppmm darken snow albedo by 1--70%. Our results lend confidence to the current model representations of surface darkening in the cryosphere. Applying these methods to impurity records in polar ice cores yields surface radiative forcing estimates that can be extrapolated to regional scales.

  20. Low-fat milk and high-fiber bread availability in food stores in urban and rural communities.

    PubMed

    Hosler, Akiko S; Varadarajulu, Deepa; Ronsani, Adrienne E; Fredrick, Bonnie L; Fisher, Brian D

    2006-01-01

    As part of the Albany Prevention Research Center's Core Project to understand environmental influences on a healthy lifestyle, all food stores in downtown Albany (N=79) and rural Columbia and Greene counties (N=177) in New York State were visited and surveyed for their availability of low-fat milk and high-fiber bread. Stores in the rural community were significantly (P < .01) more likely to stock low-fat milk (71%) and high-fiber bread (55%) than stores in Albany (40% and 33%, respectively). The rural community also had a significantly higher population ratio of "healthy milk & bread (M&B) stores" (carrying both items) than Albany (7.6 vs 3.9 per 10,000 residents). Urban healthy M&B stores were more likely to be a convenience store and accept food stamps, whereas rural healthy M&B stores were more likely to be a gas station store and offer off-street parking. Multiple logistic regression analysis found that healthy M&B stores were inversely associated with proportions of ethnic/racial minorities in the census block group (CBG). More than 80 percent of minorities in Albany resided in a CBG without a healthy M&B store. Urban residents in predominantly minority neighborhoods were most likely to encounter environmental barriers to obtain healthy staple food, and intervention should be tailored to aid this population. PMID:17041304

  1. Body mass of prefledging Emperor Geese Chen canagica: Large-scale effects of interspecific densities and food availability

    USGS Publications Warehouse

    Lake, B.C.; Schmutz, J.A.; Lindberg, M.S.; Ely, C.R.; Eldridge, W.D.; Broerman, F.J.

    2008-01-01

    We studied body mass of prefledging Emperor Geese Chen canagica at three locations across the Yukon-Kuskokwim Delta, Alaska, during 1990-2004 to investigate whether large-scale variation in body mass was related to interspecific competition for food. From 1990 to 2004, densities of Cackling Geese Branta hutchinsii minima more than doubled and were c. 2-5?? greater than densities of Emperor Geese, which were relatively constant over time. Body mass of prefledging Emperor Geese was strongly related (negatively) to interspecific densities of geese (combined density of Cackling and Emperor Geese) and positively related to measures of food availability (grazing lawn extent and net above-ground primary productivity (NAPP)). Grazing by geese resulted in consumption of ??? 90% of the NAPP that occurred in grazing lawns during the brood-rearing period, suggesting that density-dependent interspecific competition was from exploitation of common food resources. Efforts to increase the population size of Emperor Geese would benefit from considering competitive interactions among goose species and with forage plants. ?? 2008 The Authors.

  2. Improved Snow Mapping Accuracy with Revised MODIS Snow Algorithm

    NASA Technical Reports Server (NTRS)

    Riggs, George; Hall, Dorothy K.

    2012-01-01

    The MODIS snow cover products have been used in over 225 published studies. From those reports, and our ongoing analysis, we have learned about the accuracy and errors in the snow products. Revisions have been made in the algorithms to improve the accuracy of snow cover detection in Collection 6 (C6), the next processing/reprocessing of the MODIS data archive planned to start in September 2012. Our objective in the C6 revision of the MODIS snow-cover algorithms and products is to maximize the capability to detect snow cover while minimizing snow detection errors of commission and omission. While the basic snow detection algorithm will not change, new screens will be applied to alleviate snow detection commission and omission errors, and only the fractional snow cover (FSC) will be output (the binary snow cover area (SCA) map will no longer be included).

  3. Comparison of commercially available kits with standard methods for the detection of coliforms and Escherichia coli in foods.

    PubMed Central

    Venkateswaran, K; Murakoshi, A; Satake, M

    1996-01-01

    Three commercially available kits that were supplemented with substrates for enzyme reactions were evaluated to determine their abilities to detect coliforms and fecal coliforms in foods. Japanese and U.S. Food and Drug Administration standard methods, as well as two agar plate methods, were compared with the three commercial kits. A total of 50 food samples from various retailers were examined. The levels of detection of coliforms were high with the commercial kits (78 to 98%) compared with the levels of detection with the standard methods (80 to 83%) and the agar plate methods (56 to 83%). Among the kits tested, the Colilert kit had highest level of recovery of coliforms (98%), and the level of recovery of Escherichia coli as determined by beta-glucuronidase activity with the Colilert kit (83%) was comparable to the level of recovery obtained by the U.S. Food and Drug Administration method (87%). Isolation of E. coli on the basis of the beta-glucuronidase enzyme reaction was found to be good. Levine's eosine methylene blue agar, which has been widely used in various laboratories to isolate E. coli was compared with 4-methylumbelliferyl-beta-D-glucuronide (MUG)-supplemented agar for isolation of E. coli. Only 47% of the E. coli was detected when eosine methylene blue agar was used; however, when violet red bile (VRB)-MUG agar was used, the E. coli detection rate was twice as high. Of the 200 E. coli strains isolated, only 2 were found to be MUG negative, and the gene responsible for beta-glucuronidase activity (uidA gene) was detected by the PCR method in these 2 strains. Of the 90 false-positive strains isolated that exhibited various E. coli characteristic features, only 2 non-E.coli strains hydrolyzed MUG and produced fluorescent substrate in VRB-MUG agar. However, the PCR did not amplify uidA gene products in these VRB-MUG fluorescence-positive strains. PMID:8779561

  4. Adaptation of Locally Available Portion Sizes for Food Frequency Questionnaires in Nutritional Epidemiological Studies: How Much Difference does it Make?

    PubMed Central

    Gupta, Neha; Verma, Sonika; Singh, Abhishek; Tandon, Nikhil; Puri, Seema; Arora, Narendra Kumar

    2016-01-01

    Introduction: There is need for employing strategies to minimize measurement errors while administering semi-quantitative FFQ. The current study was planned to adapt and standardize locally available portion sizes for semi-quantitative FFQ to improve its validity and document the process of standardization of portion sizes. Methodology: The study was conducted in 9 villages of the INCLEN-SOMAARTH DDESS (Demographic, Development and Environmental Surveillance Site), Palwal district, Haryana, India. The subjects in these nine villages are part of a cohort study to assess the interaction between societal and household factors with food intake and physical activity of children. Systematic utensil survey was undertaken in 3 randomly chosen households per village i.e. 27 households and the portion sizes were derived from a total of 74 serving utensils. The derived sizes were classified as small (240 ml), medium (320 ml) and large (600 ml). The semi-quantitative FFQ with locally derived portion sizes was then administered to 63 children in 6-12 year age group. Results: The volume of food measured by the reference portion sizes generally being employed in the national surveys, would have been underestimated the food consumed by the child by 55-60% as compared to what was being consumed by the children in the study area. The correlation between food intake assessed by 24-hr recall method and FFQ using derived (local) portion sizes was better as compared to that obtained with the semi-quantitative FFQ done with reference portions. Conclusion: In conclusion, local portion size adaptation of FFQ for semi-quantification is useful to mitigate measurement errors associated with this technique. PMID:27385878

  5. "Proximal Sensing" capabilities for snow cover monitoring

    NASA Astrophysics Data System (ADS)

    Valt, Mauro; Salvatori, Rosamaria; Plini, Paolo; Salzano, Roberto; Giusti, Marco; Montagnoli, Mauro; Sigismondi, Daniele; Cagnati, Anselmo

    2013-04-01

    The seasonal snow cover represents one of the most important land cover class in relation to environmental studies in mountain areas, especially considering its variation during time. Snow cover and its extension play a relevant role for the studies on the atmospheric dynamics and the evolution of climate. It is also important for the analysis and management of water resources and for the management of touristic activities in mountain areas. Recently, webcam images collected at daily or even hourly intervals are being used as tools to observe the snow covered areas; those images, properly processed, can be considered a very important environmental data source. Images captured by digital cameras become a useful tool at local scale providing images even when the cloud coverage makes impossible the observation by satellite sensors. When suitably processed these images can be used for scientific purposes, having a good resolution (at least 800x600x16 million colours) and a very good sampling frequency (hourly images taken through the whole year). Once stored in databases, those images represent therefore an important source of information for the study of recent climatic changes, to evaluate the available water resources and to analyse the daily surface evolution of the snow cover. The Snow-noSnow software has been specifically designed to automatically detect the extension of snow cover collected from webcam images with a very limited human intervention. The software was tested on images collected on Alps (ARPAV webcam network) and on Apennine in a pilot station properly equipped for this project by CNR-IIA. The results obtained through the use of Snow-noSnow are comparable to the one achieved by photo-interpretation and could be considered as better as the ones obtained using the image segmentation routine implemented into image processing commercial softwares. Additionally, Snow-noSnow operates in a semi-automatic way and has a reduced processing time. The analysis

  6. Assessment of Northern Hemisphere Snow Water Equivalent Datasets in ESA SnowPEx project

    NASA Astrophysics Data System (ADS)

    Luojus, Kari; Pulliainen, Jouni; Cohen, Juval; Ikonen, Jaakko; Derksen, Chris; Mudryk, Lawrence; Nagler, Thomas; Bojkov, Bojan

    2016-04-01

    Reliable information on snow cover across the Northern Hemisphere and Arctic and sub-Arctic regions is needed for climate monitoring, for understanding the Arctic climate system, and for the evaluation of the role of snow cover and its feedback in climate models. In addition to being of significant interest for climatological investigations, reliable information on snow cover is of high value for the purpose of hydrological forecasting and numerical weather prediction. Terrestrial snow covers up to 50 million km² of the Northern Hemisphere in winter and is characterized by high spatial and temporal variability. Therefore satellite observations provide the best means for timely and complete observations of the global snow cover. There are a number of independent SWE products available that describe the snow conditions on multi-decadal and global scales. Some products are derived using satellite-based information while others rely on meteorological observations and modelling. What is common to practically all the existing hemispheric SWE products, is that their retrieval performance on hemispherical and multi-decadal scales are not accurately known. The purpose of the ESA funded SnowPEx project is to obtain a quantitative understanding of the uncertainty in satellite- as well as model-based SWE products through an internationally coordinated and consistent evaluation exercise. The currently available Northern Hemisphere wide satellite-based SWE datasets which were assessed include 1) the GlobSnow SWE, 2) the NASA Standard SWE, 3) NASA prototype and 4) NSIDC-SSM/I SWE products. The model-based datasets include: 5) the Global Land Data Assimilation System Version 2 (GLDAS-2) product 6) the European Centre for Medium-Range Forecasts Interim Land Reanalysis (ERA-I-Land) which uses a simple snow scheme 7) the Modern Era Retrospective Analysis for Research and Applications (MERRA) which uses an intermediate complexity snow scheme; and 8) SWE from the Crocus snow scheme, a

  7. Make Your Own Snow Day!

    ERIC Educational Resources Information Center

    Robeck, Edward

    2011-01-01

    Children love snow days, even when they come during the warmest weather. In this lesson the snow isn't falling outside, it's in the classroom--thanks to "Snowflake Bentley" (Briggs Martin 1998) and several models of snowflakes. A lesson on snow demonstrates several principles of practice for using models in elementary science. Focusing on snow was…

  8. ESA Globsnow - Hemispherical Snow Extent and Snow Water Equivalent Records for Climate Research Purposes

    NASA Astrophysics Data System (ADS)

    Luojus, K.; Pulliainen, J. T.; Takala, M.; Lemmetyinen, J.; Derksen, C.; Bojkov, B. R.

    2011-12-01

    The efforts of the European Space Agency (ESA) Data User Element (DUE) funded GlobSnow project has resulted in two new global records of snow parameters intended for climate research purposes. The datasets contains satellite-retrieved information on snow extent (SE) and snow water equivalent (SWE) extending 15 and 30 years respectively. The dataset on snow extent is based on optical data of Envisat AATSR and ERS-2 ATSR-2 sensors covering Northern Hemisphere between years 1995 to 2010. The record on snow water equivalent is based on satellite-based radiometer measurements (SMMR, SSM/I and AMSR-E) combined with ground-based weather station data, starting from 1979 and extending to present day. The GlobSnow SWE product is the first satellite-based dataset of snow water equivalent information on a daily basis at a hemispherical scale for 30+ years. In addition to the SE and SWE time-series, an operational near-real time (NRT) snow information service has been implemented. The current data, including the prototype products and the used validation data are available for all interested parties through the GlobSnow www-pages (http://www.globsnow.info). Extensive algorithm evaluation efforts were carried out for the candidate SWE and SE algorithms using ground truth data gathered from Canada, Scandinavia, Russia and the Alps. The acquired evaluation results enabled the selection of the final algorithms to be utilized for the GlobSnow products. The SWE product is derived using an assimilation algorithm by FMI and the SE product is a combination of NR and SYKE developed algorithms utilizing optical data. Both algorithms showed enhanced estimation characteristics when compared with currently available existing products. Prototype SE and SWE products were released for user evaluation during November 2009 covering the years 2003-2008 for SWE and 2004-2006 for SE. The final SWE product covers the Northern Hemisphere, spanning 1979 - 2010. The SE product covers the Northern

  9. Habitat manipulation of Exposed Riverine Sediments (ERS) how does microhabitat, microclimate and food availability influence beetle distributions?

    NASA Astrophysics Data System (ADS)

    Henshall, S. E.; Sadler, J. P.; Hannah, D. M.

    2009-04-01

    Exposed riverine sediments (ERS) are frequently inundated areas of relatively un-vegetated, fluvially deposited sediment (sand, silt, gravel and pebble). These habitats provide an important interface allowing the interaction of aquatic and terrestrial habitats and species. ERS are highly valuable for many rare and specialist invertebrates particularly beetles. Within an area of ERS, beetle species richness tends to be highest along the water's edge. This higher species richness may be linked to: (1) the availability of food items in the form of emerging and stranded aquatic invertebrates and (2) favourable physical microhabitat conditions in terms of temperature and moisture. This paper explores the role of microclimate and food availability by creating areas of ‘water's edge' habitat in the centre of a gravel bar. Typically these areas are drier, reach higher temperatures and devoid of emerging aquatic invertebrate prey. Four 2m x 2m experimental plots were created: one wet plot, one wet- fed plot, one dry-fed plot and one dry plot (control). These plots were each replicated on three separate areas of ERS. Sixty colour marked ERS specialist ground beetles (Bembidion atrocaeruleum) were released into each plot to monitor beetle persistence and movement on and between plots. The plots were maintained wet using a capillary pump system, and fed with dried blood worms for 30 days. Sediment temperature (0.05 m depth) was measured at 15 minute intervals and spot measurements of surface temperature were taken daily. A hand search was carried out on 25% of each plot after 7, 14, 21 and 30 days. Significant temperature differences were observed between the wet and dry sediment and air temperature. The wet plots on average were 1.8oC cooler than the dry plots and had a reduced temperature range. Both wet and dry sediments remained significantly warmer than air temperature. The wet and wet-fed plots yielded significantly greater numbers of beetles and marked beetles than

  10. North American Land Data Assimiliation (NLDAS) Data: 30 Years of Hourly Gridded Precipitation, Surface Meteorology and Fluxes, Soil Moisture, Runoff, and Snow Cover Available at the NASA Goddard GES DISC

    NASA Astrophysics Data System (ADS)

    Mocko, D. M.; Cosgrove, B.; Xia, Y.; Ek, M. B.; Mitchell, K.; Fang, H.; Vollmer, B.; Teng, W. L.; Lei, G.; Wood, E. F.; Luo, L.; Sheffield, J.; Lettenmaier, D. P.; Livneh, B.; Alonge, C. J.; Meng, C. J.; Wei, H.; Koren, V.; Schaake, J. C.; Mo, K. C.; Robock, A.

    2009-12-01

    The North American Land Data Assimilation System (NLDAS) has produced 30-years (1979 to present in near real-time) of hourly 1/8th-degree surface meteorology and hydrology datasets over CONUS and parts of Canada and Mexico. The NLDAS project has many government and university partners involved in producing and using these datasets, many funded under the Climate Prediction Program of the Americas (CPPA). NLDAS combines observations from many different sources (rain gauges, radar, satellite, model reanalysis) to generate a surface forcing dataset, which is used to drive several different land-surface models. Hourly datasets of gridded precipitation, surface meteorology and surface fluxes, soil moisture at multiple depths, surface runoff and baseflow, and snow cover are produced and available to users. This presentation will describe NLDAS forcing and land-surface model output datasets, and provide an example or two of the many applications of NLDAS data already in use. One such application is the NLDAS Drought Monitor, which updates in near real-time using several different drought indices. All 30-plus years of hourly data are now available at the NASA Goddard Earth Science Data and Information Services Center (GES DISC). Users can access the data by searching and downloading via anonymous ftp or Mirador. Mirador, a Spanish word for a window offering an extensive view, uses keywords to find data quickly in a Google-like interface. The NLDAS data are also provided via a GrADS Data Server (GDS). GDS users can access the data and perform subsetting and analysis operations online. More advanced tools will be provided in later releases, such as spatial and parameter subsetting, data format transformation, and an online visualization and analysis tool (Giovanni). Giovanni is a Web-based application developed by the GES DISC that provides a simple and intuitive way to visualize, analyze, and access vast amounts of Earth science remote sensing data without having to download

  11. 76 FR 13598 - Notice of Funding Availability: Inviting Applications for McGovern-Dole International Food for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-14

    ... International Food for Education and Child Nutrition Program's Micronutrient-Fortified Food Aid Products Pilot... Agricultural Service (FAS) announces it is inviting proposals for the McGovern-Dole International Food for Education and Child Nutrition (McGovern-Dole) Program Micronutrient- Fortified Food Aid Products...

  12. Metabolic Physiology of the Invasive Clam, Potamocorbula amurensis: The Interactive Role of Temperature, Salinity, and Food Availability

    PubMed Central

    Miller, Nathan A.; Chen, Xi; Stillman, Jonathon H.

    2014-01-01

    In biological systems energy serves as the ultimate commodity, often determining species distributions, abundances, and interactions including the potential impact of invasive species on native communities. The Asian clam Potamocorbula amurensis invaded the San Francisco Estuary (SFE) in 1986 and is implicated in the decline of native fish species through resource competition. Using a combined laboratory/field study we examined how energy expenditure in this clam is influenced by salinity, temperature and food availability. Measures of metabolism were made at whole organism (metabolic rate) and biochemical (pyruvate kinase (PK) and citrate synthase (CS) enzyme activities) levels. We found in the field, over the course of a year, the ratio of PK to CS was typically 1.0 suggesting that aerobic and fermentative metabolism were roughly equivalent, except for particular periods characterized by low salinity, higher temperatures, and intermediate food availabilities. In a 30-day laboratory acclimation experiment, however, neither metabolic rate nor PK:CS ratio was consistently influenced by the same variables, though the potential for fermentative pathways did predominate. We conclude that in field collected animals, the addition of biochemical measures of energetic state provide little additional information to the previously measured whole organism metabolic rate. In addition, much of the variation in the laboratory remained unexplained and additional variables, including reproductive stage or body condition may influence laboratory-based results. Further study of adult clams must consider the role of organismal condition, especially reproductive state, in comparisons of laboratory experiments and field observations. PMID:24599347

  13. Metabolic physiology of the invasive clam, Potamocorbula amurensis: the interactive role of temperature, salinity, and food availability.

    PubMed

    Miller, Nathan A; Chen, Xi; Stillman, Jonathon H

    2014-01-01

    In biological systems energy serves as the ultimate commodity, often determining species distributions, abundances, and interactions including the potential impact of invasive species on native communities. The Asian clam Potamocorbula amurensis invaded the San Francisco Estuary (SFE) in 1986 and is implicated in the decline of native fish species through resource competition. Using a combined laboratory/field study we examined how energy expenditure in this clam is influenced by salinity, temperature and food availability. Measures of metabolism were made at whole organism (metabolic rate) and biochemical (pyruvate kinase (PK) and citrate synthase (CS) enzyme activities) levels. We found in the field, over the course of a year, the ratio of PK to CS was typically 1.0 suggesting that aerobic and fermentative metabolism were roughly equivalent, except for particular periods characterized by low salinity, higher temperatures, and intermediate food availabilities. In a 30-day laboratory acclimation experiment, however, neither metabolic rate nor PK:CS ratio was consistently influenced by the same variables, though the potential for fermentative pathways did predominate. We conclude that in field collected animals, the addition of biochemical measures of energetic state provide little additional information to the previously measured whole organism metabolic rate. In addition, much of the variation in the laboratory remained unexplained and additional variables, including reproductive stage or body condition may influence laboratory-based results. Further study of adult clams must consider the role of organismal condition, especially reproductive state, in comparisons of laboratory experiments and field observations. PMID:24599347

  14. Theoretical life history responses of juvenile Oncorhynchus mykiss to changes in food availability using a dynamic state-dependent approach

    USGS Publications Warehouse

    Romine, Jason G.; Benjamin, Joseph R.; Perry, Russell W.; Casal, Lynne; Connolly, Patrick J.; Sauter, Sally S.

    2013-01-01

    Marine subsidies can play an important role in the growth, survival, and migratory behavior of rearing juvenile salmonids. Availability of high-energy, marine-derived food sources during critical decision windows may influence the timing of emigration or the decision to forego emigration completely and remain in the freshwater environment. Increasing growth and growth rate during these decision windows may result in an altered juvenile population structure, which will ultimately affect the adult population age-structure. We used a state dependent model to understand how the juvenile Oncorhynchus mykiss population structure may respond to increased availability of salmon eggs in their diet during critical decision windows. Our models predicted an increase in smolt production until coho salmon eggs comprised more than 50 percent of juvenile O. mykiss diet at the peak of the spawning run. At higher-than intermediate levels of egg consumption, smolt production decreased owing to increasing numbers of fish adopting a resident life-history strategy. Additionally, greater growth rates decreased the number of age-3 smolts and increased the number of age-2 smolts. Increased growth rates with higher egg consumption also decreased the age at which fish adopted the resident pathway. Our models suggest that the introduction of a high-energy food source during critical periods of the year could be sufficient to increase smolt production.

  15. The frequency of hippocampal theta rhythm is modulated on a circadian period and is entrained by food availability

    PubMed Central

    Munn, Robert G. K.; Tyree, Susan M.; McNaughton, Neil; Bilkey, David K.

    2015-01-01

    The hippocampal formation plays a critical role in the generation of episodic memory. While the encoding of the spatial and contextual components of memory have been extensively studied, how the hippocampus encodes temporal information, especially at long time intervals, is less well understood. The activity of place cells in hippocampus has previously been shown to be modulated at a circadian time-scale, entrained by a behavioral stimulus, but not entrained by light. The experimental procedures used in the previous study of this phenomenon, however, necessarily conflated two alternative entraining stimuli, the exposure to the recording environment and the availability of food, making it impossible to distinguish between these possibilities. Here we demonstrate that the frequency of theta-band hippocampal EEG varies with a circadian period in freely moving animals and that this periodicity mirrors changes in the firing rate of hippocampal neurons. Theta activity serves, therefore, as a proxy of circadian-modulated hippocampal neuronal activity. We then demonstrate that the frequency of hippocampal theta driven by stimulation of the reticular formation also varies with a circadian period. Because this effect can be observed without having to feed the animal to encourage movement we were able to identify what stimulus entrains the circadian oscillation. We show that with reticular-activated recordings started at various times of the day the frequency of theta varies quasi-sinusoidally with a 25 h period and phase-aligned when referenced to the animal’s regular feeding time, but not the recording start time. Furthermore, we show that theta frequency consistently varied with a circadian period when the data obtained from repeated recordings started at various times of the day were referenced to the start of food availability in the recording chamber. This pattern did not occur when data were referenced to the start of the recording session or to the actual time of

  16. Long-term changes in food availability mediate the effects of temperature on growth, development and survival in striped marsh frog larvae: implications for captive breeding programmes

    PubMed Central

    Courtney Jones, Stephanie K.; Munn, Adam J.; Penman, Trent D.; Byrne, Phillip G.

    2015-01-01

    Food availability and temperature are known to trigger phenotypic change, but the interactive effects between these factors are only beginning to be considered. The aim of this study was to examine the independent and interactive effects of long-term stochastic food availability and water temperature on larval survivorship, growth and development of the striped marsh frog, Limnodynastes peronii. Larval L. peronii were reared in conditions of either constant or stochastic food availability and in water at three different temperatures (18, 22 and 26°C), and effects on survival, growth and development were quantified. Over the experimental period, larval growth rate was highest and survivorship lowest at the warmest temperature. However, changes in food availability mediated the effects of temperature, with slower larval growth and higher survivorship in stochastic food availability treatments. Tadpoles in the stochastic food availability treatments did not reach metamorphosis during the experimental period, suggesting that developmental stasis may have been induced by food restriction. Overall, these results demonstrate that changes in food availability alter the effects of water temperature on survival, growth and development. From an applied perspective, understanding how environmental factors interact to cause phenotypic change may assist with amphibian conservation by improving the number of tadpoles generated in captive breeding programmes. PMID:27293714

  17. Longitudinal Trends in Tobacco Availability, Tobacco Advertising, and Ownership Changes of Food Stores, Albany, New York, 2003–2015

    PubMed Central

    Done, Douglas H.; Michaels, Isaac H.; Guarasi, Diana C.; Kammer, Jamie R.

    2016-01-01

    Introduction Frequency of visiting convenience and corner grocery stores that sell tobacco is positively associated with the odds of ever smoking and the risk of smoking initiation among youth. We assessed 12-year trends of tobacco availability, tobacco advertising, and ownership changes in various food stores in Albany, New York. Methods Eligible stores were identified by multiple government lists and community canvassing in 2003 (n = 107), 2009 (n = 117), 2012 (n = 135), and 2015 (n = 137). Tobacco availability (all years) and advertising (2009, 2012, and 2015) were directly measured; electronic cigarettes (e-cigarettes) were included in 2015. Results Percentage of stores selling tobacco peaked at 83.8% in 2009 and declined to 74.5% in 2015 (P for trend = .11). E-cigarettes were sold by 63.7% of tobacco retailers. The largest decline in tobacco availability came from convenience stores that went out of business (n = 11), followed by pharmacies that dropped tobacco sales (n = 4). The gain of tobacco availability mostly came from new convenience stores (n = 24) and new dollar stores (n = 8). Significant declining trends (P < .01) were found in tobacco availability and any tobacco advertising in pharmacies and in low (<3 feet) tobacco advertising in convenience stores and stores overall. Only one-third of stores that sold tobacco in 2003 continued to sell tobacco with the same owner in 2015. Conclusion The observed subtle declines in tobacco availability and advertising were explained in part by local tobacco control efforts, the pharmacy industry’s self-regulation of tobacco sales, and an increase in the state’s tobacco retailer registration fee. Nonetheless, overall tobacco availability remained high (>16 retailers per 10,000 population) in this community. The high store ownership turnover rate suggests that a moratorium of new tobacco retailer registrations would be an integral part of a multi-prong policy strategy to reduce tobacco availability and

  18. Effects of Light, Food Availability and Temperature Stress on the Function of Photosystem II and Photosystem I of Coral Symbionts

    PubMed Central

    Hoogenboom, Mia O.; Campbell, Douglas A.; Beraud, Eric; DeZeeuw, Katrina; Ferrier-Pagès, Christine

    2012-01-01

    Background Reef corals are heterotrophic coelenterates that achieve high productivity through their photosynthetic dinoflagellate symbionts. Excessive seawater temperature destabilises this symbiosis and causes corals to “bleach,” lowering their photosynthetic capacity. Bleaching poses a serious threat to the persistence of coral reefs on a global scale. Despite expanding research on the causes of bleaching, the mechanisms remain a subject of debate. Methodology/Principal Findings This study determined how light and food availability modulate the effects of temperature stress on photosynthesis in two reef coral species. We quantified the activities of Photosystem II, Photosystem I and whole chain electron transport under combinations of normal and stressful growth temperatures, moderate and high light levels and the presence or absence of feeding of the coral hosts. Our results show that PS1 function is comparatively robust against temperature stress in both species, whereas PS2 and whole chain electron transport are susceptible to temperature stress. In the symbiotic dinoflagellates of Stylophora pistillata the contents of chlorophyll and major photosynthetic complexes were primarily affected by food availability. In Turbinaria reniformis growth temperature was the dominant influence on the contents of the photosynthetic complexes. In both species feeding the host significantly protected photosynthetic function from high temperature stress. Conclusions/Significance Our findings support the photoinhibition model of coral bleaching and demonstrate that PS1 is not a major site for thermal damage during bleaching events. Feeding mitigates bleaching in two scleractinian corals, so that reef responses to temperature stresses will likely be influenced by the coinciding availabilities of prey for the host. PMID:22253915

  19. The Availability of Competitive Foods and Beverages to Middle School Students in Appalachian Virginia Before Implementation of the 2014 Smart Snacks in School Standards

    PubMed Central

    Kraak, Vivica; Serrano, Elena

    2015-01-01

    The study objective was to examine the nutritional quality of competitive foods and beverages (foods and beverages from vending machines and à la carte foods) available to rural middle school students, before implementation of the US Department of Agriculture’s Smart Snacks in School standards in July 2014. In spring 2014, we audited vending machines and à la carte cafeteria foods and beverages in 8 rural Appalachian middle schools in Virginia. Few schools had vending machines. Few à la carte and vending machine foods met Smart Snacks in School standards (36.6%); however, most beverages did (78.2%). The major challenges to meeting standards were fat and sodium content of foods. Most competitive foods (63.4%) did not meet new standards, and rural schools with limited resources will likely require assistance to fully comply. PMID:26378899

  20. Assessment of the Particulate Food Supply Available for Mussel ( Mytilus spp.) Farming in a Semi-enclosed, Northern Inlet

    NASA Astrophysics Data System (ADS)

    Penney, R. W.; McKenzie, C. H.; Mills, T. J.

    2001-07-01

    Temporal variability in the quantity, organic content, and phytoplankton composition of the particulate food supply available to a cultured mussel population was assessed for a 3-year period in a small inlet of Notre Dame Bay, Newfoundland, Canada. The study site had a restricted flushing rate estimated at 1-2·75 times wk -1for a complete water exchange. The quantity of both total (TPM) and organic (POM) seston varied temporally from 0·7-23·7 mg l -1and 0·05-1·97 mg l -1respectively during the 3-year sampling period. TPM typically remained relatively high (>10 mg l -1) through the winter and spring period. Most of the seasonal variation in total seston was due to seasonal variability in the PIM component. Both PIM and POM concentrations were seasonally lowest during summer. The organic fraction of the seston (POM/TPM ratio) was seasonally low in winter and increased steadily through spring and summer to reach its maximum in the autumn. The living phytoplankton component of the seston was typically dominated, both numerically and in biomass, by a variety of diatom and autotrophic nanoflagellate species in the 2- 20-μm diameter size range. Discrete diatom population blooms occurred in the autumn of all three years and largely consisted of a single species, Skeletonema costatum. Phytoplankton:detritus ratios were significantly lower during winter. Total phytoplankton biomass levels were seasonally low during winter and summer and were associated with seasonal variation in diatom biomass. We conducted modelling simulations of relationships among seston organic food levels, their temporal variability, tidal flushing rates, cultured mussel biomass and production indices, and estimates of mussel maintenance ration requirements to predict the adequacy of northern inlets to sustain commercial-scale mussel farm development. We conclude from these simulations that small, semi-enclosed, northern inlets likely frequently experience periods when naturally occurring organic

  1. Effects of preparation and cooking of folic acid-fortified foods on the availability of folic acid in a folate depletion/repletion rat model.

    PubMed

    O'Leary, K; Sheehy, P J

    2001-09-01

    The practice of food fortification with folic acid offers the potential to increase the folate intake of the general population. To fully exploit the potential of fortification for raising folate nutriture, appropriate food vehicles need to be selected. Selection should involve determination of the availability of folic acid as affected by characteristics of the carrier food, food matrix, food preparation, and cooking. The present study investigated the effects of preparation and cooking of a range of folic acid-fortified foods on the folate status of folate-deficient rats. Fifty-six weanling male rats (Wistar strain) were fed a folate-deficient diet containing 1% succinyl sulfathiazole for 28 days. Following depletion, six rats were randomly assigned to each of eight repletion diets containing cooked or uncooked meringue mix, quick bread mix, brownie mix, or pizza base mix. The test foods were fortified with 1400 microg of folic acid/kg of food and incorporated as 19% of the repletion diets. Each of the first four groups was pair-fed a diet containing a cooked fortified food with another group fed the corresponding uncooked fortified food. After a further 28 days, plasma, liver, and kidney folate concentrations were determined by microbiological assay. Mean plasma and liver folate concentrations of rats fed diets containing cooked fortified foods were similar to those of rats fed uncooked fortified foods. Preparation and cooking did not affect the availability of folic acid from the selected cereal-based convenience foods in this rat model system, suggesting that these foods are appropriate vehicles for fortification with folic acid. PMID:11559162

  2. Integrating snow albedo from the Airborne Snow Observatory into the distributed energy balance snowmelt model iSnobal

    NASA Astrophysics Data System (ADS)

    Skiles, M.; Painter, T. H.; Marks, D. G.; Hedrick, A. R.

    2015-12-01

    Since 2013 the Airborne Snow Observatory (ASO) has been measuring spatial and temporal distribution of both snow water equivalent and snow albedo, the two most critical properties for understanding snowmelt runoff and timing, across key basins in the Western US. It is generally understood that net solar radiation (as controlled by variations in snow albedo and irradiance) provides the energy available for melt in almost all snow-covered environments. Until now, sparse measurements have restricted the ability to utilize measured net solar radiation in energy balance models, and current process simulations and model prediction of albedo evolution rely on oversimplifications of the processes. Data from ASO offers the unprecedented opportunity to utilize weekly measurements of spatially extensive spectral snow albedo to constrain and update snow albedo in a distributed snowmelt model for the first time. Here, we first investigate the sensitivity of the snow energy balance model SNOBAL to prescribed changes in snow albedo at two instrumented alpine catchments: at the point scale across 10 years at Senator Beck Basin Study Area in the San Juan Mountains, southwestern Colorado, and at the distributed scale across 25 years at Reynolds Creek Experimental Watershed, Idaho. We then compare distributed energy balance and snowmelt results across the ASO measurement record in the Tuolumne Basin in the Sierra Nevada Mountains, California, for model runs with and without integrated snow albedo from ASO.

  3. Observations of distributed snow depth and snow duration within diverse forest structures in a maritime mountain watershed

    NASA Astrophysics Data System (ADS)

    Dickerson-Lange, Susan E.; Lutz, James A.; Gersonde, Rolf; Martin, Kael A.; Forsyth, Jenna E.; Lundquist, Jessica D.

    2015-11-01

    Spatially distributed snow depth and snow duration data were collected over two to four snow seasons during water years 2011-2014 in experimental forest plots within the Cedar River Municipal Watershed, 50 km east of Seattle, Washington, USA. These 40 × 40 m forest plots, situated on the western slope of the Cascade Range, include unthinned second-growth coniferous forests, variable density thinned forests, forest gaps in which a 20 m diameter (approximately equivalent to one tree height) gap was cut in the middle of each plot, and old-growth forest. Together, this publicly available data set includes snow depth and density observations from manual snow surveys, distributed snow duration observations from ground temperature sensors and time-lapse cameras, meteorological data collected at two open locations and three forested locations, and forest canopy data from airborne light detection and ranging (LiDAR) data and hemispherical photographs. These colocated snow, meteorological, and forest data have the potential to improve understanding of forest influences on snow processes, and provide a unique model-testing data set for hydrological analyses in a forested, maritime watershed. We present empirical snow depletion curves within forests to illustrate an application of these data to improve subgrid representation of snow cover in distributed modeling.

  4. Quantifying tradeoffs between water availability, water quality, food production and bioenergy production in a Central German Catchment

    NASA Astrophysics Data System (ADS)

    Volk, M.; Lautenbach, S.; Strauch, M.; Whittaker, G. W.

    2012-04-01

    Worldwide increasing bioenergy production is on the political agenda. It is well known that bioenergy production comes at a cost - several trade-offs with food production, water quality and quantity issues, biodiversity and ecosystem services are known. However, a quantification of these trade-offs is still missing. Hence, our study presents an analysis of trade-offs between water availability, water quality, bioenergy production and production in a Central German agricultural catchment. Our analysis is based on using SWAT and a multi-objective genetic algorithm (NSGA II). The genetic algorithm is used to find Pareto optimal configurations of crop rotation schemes. The Pareto-optimality describes solutions in which an objective cannot be improved without decreasing other objectives. This allows us to quantify the costs at which several levels of increase in bioenergy production come and to derive recommendations for policy makers.

  5. 76 FR 20305 - Notice of Funding Availability: Inviting Applications for McGovern-Dole International Food for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-12

    ... International Food for Education and Child Nutrition Program's Micronutrient-Fortified Food Aid Products Pilot... the McGovern-Dole International Food for Education and Child Nutrition (McGovern-Dole) Program... . SUPPLEMENTARY INFORMATION: FAS published a notice in the Federal Register on March 14, 2011 (76 FR 13598)...

  6. Interactions between Seagrass Complexity, Hydrodynamic Flow and Biomixing Alter Food Availability for Associated Filter-Feeding Organisms

    PubMed Central

    González-Ortiz, Vanessa; Egea, Luis G.; Jiménez-Ramos, Rocio; Moreno-Marín, Francisco; Pérez-Lloréns, José L.; Bouma, Tjeed J.; Brun, Fernando G.

    2014-01-01

    Seagrass shoots interact with hydrodynamic forces and thereby a positively or negatively influence the survival of associated species. The modification of these forces indirectly alters the physical transport and flux of edible particles within seagrass meadows, which will influence the growth and survivorship of associated filter-feeding organisms. The present work contributes to gaining insight into the mechanisms controlling the availability of resources for filter feeders inhabiting seagrass canopies, both from physical (influenced by seagrass density and patchiness) and biological (regulated by filter feeder density) perspectives. A factorial experiment was conducted in a large racetrack flume, which combined changes in hydrodynamic conditions, chlorophyll a concentration in the water and food intake rate (FIR) in a model active filter-feeding organism (the cockle). Results showed that seagrass density and patchiness modified both hydrodynamic forces and availability of resources for filter feeders. Chlorophyll a water content decreased to 50% of the initial value when densities of both seagrass shoots and cockles were high. Also, filter feeder density controlled resource availability within seagrass patches, depending on its spatial position within the racetrack flume. Under high density of filter-feeding organisms, chlorophyll a levels were lower between patches. This suggests that the pumping activity of cockles (i.e. biomixing) is an emergent key factor affecting both resource availability and FIR for filter feeders in dense canopies. Applying our results to natural conditions, we suggest the existence of a direct correlation between habitat complexity (i.e. shoot density and degree of patchiness) and filter feeders density. Fragmented and low-density patches seem to offer both greater protection from hydrodynamic forces and higher resource availability. In denser patches, however, resources are allocated mostly within the canopy, which would benefit

  7. Interactions between seagrass complexity, hydrodynamic flow and biomixing alter food availability for associated filter-feeding organisms.

    PubMed

    González-Ortiz, Vanessa; Egea, Luis G; Jiménez-Ramos, Rocio; Moreno-Marín, Francisco; Pérez-Lloréns, José L; Bouma, Tjeed J; Brun, Fernando G

    2014-01-01

    Seagrass shoots interact with hydrodynamic forces and thereby a positively or negatively influence the survival of associated species. The modification of these forces indirectly alters the physical transport and flux of edible particles within seagrass meadows, which will influence the growth and survivorship of associated filter-feeding organisms. The present work contributes to gaining insight into the mechanisms controlling the availability of resources for filter feeders inhabiting seagrass canopies, both from physical (influenced by seagrass density and patchiness) and biological (regulated by filter feeder density) perspectives. A factorial experiment was conducted in a large racetrack flume, which combined changes in hydrodynamic conditions, chlorophyll a concentration in the water and food intake rate (FIR) in a model active filter-feeding organism (the cockle). Results showed that seagrass density and patchiness modified both hydrodynamic forces and availability of resources for filter feeders. Chlorophyll a water content decreased to 50% of the initial value when densities of both seagrass shoots and cockles were high. Also, filter feeder density controlled resource availability within seagrass patches, depending on its spatial position within the racetrack flume. Under high density of filter-feeding organisms, chlorophyll a levels were lower between patches. This suggests that the pumping activity of cockles (i.e. biomixing) is an emergent key factor affecting both resource availability and FIR for filter feeders in dense canopies. Applying our results to natural conditions, we suggest the existence of a direct correlation between habitat complexity (i.e. shoot density and degree of patchiness) and filter feeders density. Fragmented and low-density patches seem to offer both greater protection from hydrodynamic forces and higher resource availability. In denser patches, however, resources are allocated mostly within the canopy, which would benefit

  8. Maternal nutritional status may be stressed by seasonal fluctuations in food availability: evidence from rural women in Kenya.

    PubMed

    Kigutha, H N; van Staveren, W A; Wijnhoven, T M; Hautvast, J G

    1995-08-01

    The effect of seasonal changes in household food availability on the dietary intakes and the nutritional status of 24 lactating women from smallholder rural households in Nakuru district Kenya, were investigated over a 15-month period in 1992/93 agricultural cycle. Dietary intakes and body weights were measured on monthly basis. Significant seasonal differences were found in intakes of calcium, vitamin A, vitamin C, riboflavin, and niacin respectively (P < 0.01), as well as in the intake of protein, iron, and thiamin (P < 0.05), but not with energy and fat intake. Large interseasonal weight losses of 5.6 kg (about 9%) at the rate of 1.1 kg/month, were observed between baseline measurements and the peak of the lean months when the energy intakes were 36.7 kcal/kg/day and protein at 1.1 g/kg/day. About 50% of the lost weight (2.8 kg) were recovered during the harvest months of January and February, when energy intakes improved to 41.0 kcal/kg/day, and protein to 1.2 g/kg/day. However, further weight losses of 1.6 kg or 0.5 kg/month occurred in the immediate postharvest months between March and June. While much of the weight loss may have been due to reduced energy intake during periods of food scarcity, part of the lost weight may have been due to increased energy requirement as a result of lactation and to increased physical activities. Further investigations are recommended. PMID:7584164

  9. Impact of metal pollution, food availability, and excessive fishing on Rhabdosargus haffara stock (family: Sparidae) in Timsah lake.

    PubMed

    Mehanna, Sahar F; Abd El-Azim, Hoda; Belal, Aisha A

    2016-08-01

    The lakes' fisheries play an important role in Egyptian economy. In 1980s, they provided more than 50 % of harvested fish in Egypt but now their contribution to the Egypt fish production decreased to only 12.5 % in 2012. Lake Timsah, one of the Suez Canal lakes, faced many challenges that lead to serious changes in its water and fish quality, fish production, as well as the catch composition. The present work investigated the impact of pollution, food availability, and excessive fishing mortality on the haffara production in lake Timsah. The distribution of four heavy metals (Pb, Zn, Ni, and Fe) was detected seasonally in water and in muscles, gills, and livers of Rhabdosargus haffara, during 2012 through 2013. Fe and Zn were presented by high values in liver, while Pb and Ni in gills. Generally, the lowest concentrations of all metals were found in muscles. The recorded crustacean organisms (the main food of haffara) decreased from 12 species and 32,079 organisms⁄m(2) in 2012 to only 7 species and 7290 organisms⁄m(2) in 2013 while the amphipods completely disappeared. This serious change was due to the severe pollution in the lake. A logistic surplus production model was fitted to the catch per unit effort indices, to estimate the maximum sustainable yield and the optimum level of fishing effort. The results revealed that haffara stock at lake Timsah is overfished, and the estimated precautionary target reference points advised the reduction of fishing effort by about 30-50 %. PMID:27234823

  10. The stress hormone corticosterone in a marine top predator reflects short-term changes in food availability

    PubMed Central

    Barrett, Robert T; Erikstad, Kjell E; Sandvik, Hanno; Myksvoll, Mari; Jenni-Eiermann, Susi; Kristensen, Ditte L; Moum, Truls; Reiertsen, Tone K; Vikebø, Frode

    2015-01-01

    In many seabird studies, single annual proxies of prey abundance have been used to explain variability in breeding performance, but much more important is probably the timing of prey availability relative to the breeding season when energy demand is at a maximum. Until now, intraseasonal variation in prey availability has been difficult to quantify in seabirds. Using a state-of-the-art ocean drift model of larval cod Gadus morhua, an important constituent of the diet of common guillemots Uria aalge in the southwestern Barents Sea, we were able to show clear, short-term correlations between food availability and measurements of the stress hormone corticosterone (CORT) in parental guillemots over a 3-year period (2009–2011). The model allowed the extraction of abundance and size of cod larvae with very high spatial (4 km) and temporal resolutions (1 day) and showed that cod larvae from adjacent northern spawning grounds in Norway were always available near the guillemot breeding colony while those from more distant southerly spawning grounds were less frequent, but larger. The latter arrived in waves whose magnitude and timing, and thus overlap with the guillemot breeding season, varied between years. CORT levels in adult guillemots were lower in birds caught after a week with high frequencies of southern cod larvae. This pattern was restricted to the two years (2009 and 2010) in which southern larvae arrived before the end of the guillemot breeding season. Any such pattern was masked in 2011 by already exceptionally high numbers of cod larvae in the region throughout chick-rearing period. The findings suggest that CORT levels in breeding birds increase when the arrival of southern sizable larvae does not match the period of peak energy requirements during breeding. PMID:25859335

  11. The association of binge eating and neighbourhood fast-food restaurant availability on diet and weight status

    PubMed Central

    Ledoux, Tracey; Adamus-Leach, Heather; O’Connor, Daniel P; Mama, Scherezade; Lee, Rebecca E

    2015-01-01

    Objective Fast-food restaurants (FFR) are prevalent. Binge eating is common among overweight and obese women. For women prone to binge eating, neighbourhood FFR availability (i.e. the neighbourhood around one’s home) may promote poor diet and overweight/obesity. The present study tested the effects of binge eating and neighbourhood FFR availability on diet (fat and total energy intake) and BMI among African American and Hispanic/Latino women. Design All measures represent baseline data from the Health is Power randomized clinical trial. The numbers of FFR in participants’ neighbourhoods were counted and dichotomized (0 or ≥1 neighbourhood FFR). Participants completed measures of binge eating status and diet. Weight and height were measured and BMI calculated. 2 (binge eating status) × 2 (neighbourhood FFR availability) ANCOVA tested effects on diet and BMI while controlling for demographics. Setting Houston and Austin, TX, USA. Subjects African American and Hispanic/Latino women aged 25–60 years. Results Of the total sample (n 162), 48% had 1–15 neighbourhood FFR and 29% were binge eaters. There was an interaction effect on BMI (P=0·05). Binge eaters with ≥1 neighbourhood FFR had higher BMI than non-binge eaters or binge eaters with no neighbourhood FFR. There were no significant interactions or neighbourhood FFR main effects on total energy or fat intake (P>0·05). A main effect of binge eating showed that binge eaters consumed more total energy (P=0·005) and fat (P=0·005) than non-binge eaters. Conclusions Binge eaters represented a substantial proportion of this predominantly overweight and obese sample of African American and Hispanic/ Latino women. The association between neighbourhood FFR availability and weight status is complicated by binge eating status, which is related to diet. PMID:24476972

  12. Investigation of the available technologies and their feasibility for the conversion of food waste into fish feed in Hong Kong.

    PubMed

    Cheng, Jack Y K; Lo, Irene M C

    2016-04-01

    Food waste is the largest constituent of municipal solid waste in Hong Kong, but food waste recycling is still in its infancy. With the imminent saturation of all landfill sites by 2020, multiple technologies are needed to boost up the food waste recycling rate in Hong Kong. Conversion of food waste into animal feeds is prevalent in Japan, South Korea, and Taiwan, treating over 40 % of their recycled food waste. This direction is worth exploring in Hong Kong once concerns over food safety are resolved. Fortunately, while feeding food waste to pigs and chickens poses threats to public health, feeding it to fish is considered low risk. In order to examine the feasibility of converting food waste into fish feed in Hong Kong, this paper investigates the market demand, technical viability, feed quality, regulatory hurdles, and potential contribution. The results show that a significant amount of food waste can be recycled by converting it into fish feed due to the enormous demand from feed factories in mainland China. Two conversion technologies, heat drying and black soldier fly bioconversion, are studied extensively. Black soldier fly bioconversion is preferable because the end-product, insect powder, is anticipated to gain import approval from mainland China. The authors suggest further research efforts to speed up its application for food waste recycling in urban cities. PMID:25982983

  13. Recent research in snow hydrology

    NASA Technical Reports Server (NTRS)

    Dozier, Jeff

    1987-01-01

    Recent work on snow-pack energy exchange has involved detailed investigations on snow albedo and attempts to integrate energy-balance calculations over drainage basins. Along with a better understanding of the EM properties of snow, research in remote sensing has become more focused toward estimation of snow-pack properties. In snow metamorphism, analyses of the physical processes must now be coupled to better descriptions of the geometry of the snow microstructure. The dilution method now appears to be the best direct technique for measuring the liquid water content of snow; work on EM methods continues. Increasing attention to the chemistry of the snow pack has come with the general focus on acid precipitation in hydrology.

  14. Secrets of Snow Liveshot Recap

    NASA Video Gallery

    Research Physical Scientist and Deputy Project Scientist for GPM Gail Skofronick-Jackson answers questions about the importance of studying snow from space, the impact of not enough snow, and the f...

  15. Snow Water Equivalent estimation based on satellite observation

    NASA Astrophysics Data System (ADS)

    Macchiavello, G.; Pesce, F.; Boni, G.; Gabellani, S.

    2009-09-01

    The availability of remotely sensed images and them analysis is a powerful tool for monitoring the extension and typology of snow cover over territory where the in situ measurements are often difficult. Information on snow are fundamental for monitoring and forecasting the available water above all in regions at mid latitudes as Mediterranean where snowmelt may cause floods. The hydrological model requirements and the daily acquisitions of MODIS (Moderate Resolution Imaging Spectroradiometer), drove, in previous research activities, to the development of a method to automatically map the snow cover from multi-spectral images. But, the major hydrological parameter related to the snow pack is the Snow Water Equivalent (SWE). This represents a direct measure of stored water in the basin. Because of it, the work was focused to the daily estimation of SWE from MODIS images. But, the complexity of this aim, based only on optical data, doesn’t find any information in literature. Since, from the spectral range of MODIS data it is not possible to extract a direct relation between spectral information and the SWE. Then a new method, respectful of the physic of the snow, was defined and developed. Reminding that the snow water equivalent is the product of the three factors as snow density, snow depth and the snow covered areas, the proposed approach works separately on each of these physical behaviors. Referring to the physical characteristic of snow, the snow density is function of the snow age, then it was studied a new method to evaluate this. Where, a module for snow age simulation from albedo information was developed. It activates an age counter updated by new snow information set to estimate snow age from zero accumulation status to the end of melting season. The height of the snow pack, can be retrieved by adopting relation between vegetation and snow depth distributions. This computes snow height distribution by the relation between snow cover fraction and the

  16. Improving the snow physics of WEB-DHM and its point evaluation at the SnowMIP sites

    NASA Astrophysics Data System (ADS)

    Shrestha, M.; Wang, L.; Koike, T.; Xue, Y.; Hirabayashi, Y.

    2010-12-01

    In this study, the snow physics of a distributed biosphere hydrological model, referred to as the Water and Energy Budget based Distributed Hydrological Model (WEB-DHM) is significantly improved by incorporating the three-layer physically based energy balance snowmelt model of Simplified Simple Biosphere 3 (SSiB3) and the Biosphere-Atmosphere Transfer Scheme (BATS) albedo scheme. WEB-DHM with improved snow physics is hereafter termed WEB-DHM-S. Since the in-situ observations of spatially-distributed snow variables with high resolution are currently not available over large regions, the new distributed system (WEB-DHM-S) is at first rigorously tested with comprehensive point measurements. The stations used for evaluation comprise the four open sites of the Snow Model Intercomparison Project (SnowMIP) phase 1 with different climate characteristics (Col de Porte in France, Weissfluhjoch in Switzerland, Goose Bay in Canada and Sleepers River in USA) and one open/forest site of the SnowMIP phase 2 (Hitsujigaoka in Japan). The comparisons of the snow depth, snow water equivalent, surface temperature, snow albedo and snowmelt runoff at the SnowMIP1 sites reveal that WEB-DHM-S, in general, is capable of simulating the internal snow process better than the original WEB-DHM. Sensitivity tests (through incremental addition of model processes) are performed to illustrate the necessity of improvements over WEB-DHM and indicate that both the 3-layer snow module and the new albedo scheme are essential. The canopy effects on snow processes are studied at the Hitsujigaoka site of the SnowMIP2 showing that the snow holding capacity of the canopy plays a vital role in simulating the snow depth on ground. Through these point evaluations and sensitivity studies, WEB-DHM-S has demonstrated the potential to address basin-scale snow processes (e.g., the snowmelt runoff), since it inherits the distributed hydrological framework from the WEB-DHM (e.g., the slope-driven runoff generation

  17. Snow as Field-Teaching Medium for Earth Science.

    ERIC Educational Resources Information Center

    Custer, Stephan Gregory

    1991-01-01

    Snow is a widely available earth-science teaching medium which can be used to explore scientific concepts in the field, either directly or by analogy. Snow can be considered a mineral, sediment, sedimentary rock, or metamorphic rock. Natural processes such as crystal growth, melting, sedimentation, and metamorphism can be studied in practical time…

  18. Spatial Scale for Modelling Blowing Snow on the Canadian Prairieis

    NASA Astrophysics Data System (ADS)

    Pomeroy, J. W.; Fang, X.

    2007-12-01

    Blowing snow transports and sometimes sublimates much of the seasonal snowfall in the Prairies of western Canada. Snow redistribution is an important feature of Prairie hydrology as deep snowdrifts provide a source of meltwater to replenish ponds and generate streamflow in this dry region. The spatial distribution of snow water equivalent in the spring is therefore of great interest for Prairie hydrology. A test of the appropriate spatial scale for modelling blowing snow redistribution and sublimation was conducted at St Denis National Wildlife Area in the rolling, internally drained prairie pothole region east of Saskatoon, Saskatchewan, Canada. A LiDAR based DEM and LANDSAT based vegetation map were available for this region. A coupled complex windflow and blowing snow model was run with ~250,000 6 m x 6 m grid cells to produce spatially distributed estimates of seasonal blowing snow transport and sublimation. The calculation was then aggregated, using 7 landscape units that represented the major influences of surface roughness, topography and fetch on blowing snow transport and sublimation. Both the distributed and aggregated simulations described similar end of winter snow water equivalent with substantive redistribution of blowing snow from exposed sparsley vegetated sites across topographic drainage divides to the densely vegetated pothole wetlands. Both simulations also agreed well with snow survey observations. While the distributed calculations provide a fascinating and detailed visual image of the interaction of complex landscapes and blowing snow redistribution and sublimation, it is clear that blowing snow transport and sublimation calculations can be successfully aggregated to the spatial scale of the major landscape units in this environment.

  19. Snow and the ground temperature record of climate change

    NASA Astrophysics Data System (ADS)

    Bartlett, Marshall G.; Chapman, David S.; Harris, Robert N.

    2004-12-01

    Borehole temperature-depth profiles contain a record of surface ground temperature (SGT) changes with time and complement surface air temperature (SAT) analysis to infer climate change over multiple centuries. Ground temperatures are generally warmer than air temperatures due to solar radiation effects in the summer and the insulating effect of snow cover during the winter. The low thermal diffusivity of snow damps surface temperature variations; snow effectively acts as an insulator of the ground during the coldest part of the year. A numerical model of snow-ground thermal interactions is developed to investigate the effect of seasonal snow cover on annual ground temperatures. The model is parameterized in terms of three snow event parameters: onset time of the annual snow event, duration of the event, and depth of snow during the event. These parameters are commonly available from meteorological and remotely sensed data making the model broadly applicable. The model is validated using SAT, subsurface temperature from a depth of 10 cm, and snow depth data from the 6 years of observations at Emigrant Pass climate observatory in northwestern Utah and 217 station years of National Weather Service data from sites across North America. Measured subsurface temperature-time series are compared to changes predicted by the model. The model consistently predicts ground temperature changes that compare well with those observed. Sensitivity analysis of the model leads to a nonlinear relationship between the three snow event parameters (onset, duration, and depth of the annual snow event) and the influence snow has on mean annual SGT.

  20. Crystal growth of artificial snow

    NASA Technical Reports Server (NTRS)

    Kimura, S.; Oka, A.; Taki, M.; Kuwano, R.; Ono, H.; Nagura, R.; Narimatsu, Y.; Tanii, J.; Kamimiytat, Y.

    1984-01-01

    Snow crystals were grown onboard the space shuttle during STS-7 and STS-8 to facilitate the investigation of crystal growth under conditions of weightlessness. The experimental design and hardware are described. Space-grown snow crystals were polyhedrons looking like spheres, which were unlike snow crystals produced in experiments on Earth.

  1. A Blended Global Snow Product using Visible, Passive Microwave and Scatterometer Satellite Data

    NASA Technical Reports Server (NTRS)

    Foster, James L.; Hall, Dorothy K.; Eylander, John B.; Riggs, George A.; Nghiem, Son V.; Tedesco, Marco; Kim, Edward; Montesano, Paul M.; Kelly, Richard E. J.; Casey, Kimberly A.; Choudhury, Bhaskar

    2009-01-01

    A joint U.S. Air Force/NASA blended, global snow product that utilizes Earth Observation System (EOS) Moderate Resolution Imaging Spectroradiometer (MODIS), Advanced Microwave Scanning Radiometer for EOS (AMSR-E) and QuikSCAT (Quick Scatterometer) (QSCAT) data has been developed. Existing snow products derived from these sensors have been blended into a single, global, daily, user-friendly product by employing a newly-developed Air Force Weather Agency (AFWA)/National Aeronautics and Space Administration (NASA) Snow Algorithm (ANSA). This initial blended-snow product uses minimal modeling to expeditiously yield improved snow products, which include snow cover extent, fractional snow cover, snow water equivalent (SWE), onset of snowmelt, and identification of actively melting snow cover. The blended snow products are currently 25-km resolution. These products are validated with data from the lower Great Lakes region of the U.S., from Colorado during the Cold Lands Processes Experiment (CLPX), and from Finland. The AMSR-E product is especially useful in detecting snow through clouds; however, passive microwave data miss snow in those regions where the snow cover is thin, along the margins of the continental snowline, and on the lee side of the Rocky Mountains, for instance. In these regions, the MODIS product can map shallow snow cover under cloud-free conditions. The confidence for mapping snow cover extent is greater with the MODIS product than with the microwave product when cloud-free MODIS observations are available. Therefore, the MODIS product is used as the default for detecting snow cover. The passive microwave product is used as the default only in those areas where MODIS data are not applicable due to the presence of clouds and darkness. The AMSR-E snow product is used in association with the difference between ascending and descending satellite passes or Diurnal Amplitude Variations (DAV) to detect the onset of melt, and a QSCAT product will be used to

  2. Georectification and snow classification of webcam images: potential for complementing satellite-derrived snow maps over Switzerland

    NASA Astrophysics Data System (ADS)

    Dizerens, Céline; Hüsler, Fabia; Wunderle, Stefan

    2016-04-01

    The spatial and temporal variability of snow cover has a significant impact on climate and environment and is of great socio-economic importance for the European Alps. Satellite remote sensing data is widely used to study snow cover variability and can provide spatially comprehensive information on snow cover extent. However, cloud cover strongly impedes the surface view and hence limits the number of useful snow observations. Outdoor webcam images not only offer unique potential for complementing satellite-derived snow retrieval under cloudy conditions but could also serve as a reference for improved validation of satellite-based approaches. Thousands of webcams are currently connected to the Internet and deliver freely available images with high temporal and spatial resolutions. To exploit the untapped potential of these webcams, a semi-automatic procedure was developed to generate snow cover maps based on webcam images. We used daily webcam images of the Swiss alpine region to apply, improve, and extend existing approaches dealing with the positioning of photographs within a terrain model, appropriate georectification, and the automatic snow classification of such photographs. In this presentation, we provide an overview of the implemented procedure and demonstrate how our registration approach automatically resolves the orientation of a webcam by using a high-resolution digital elevation model and the webcam's position. This allows snow-classified pixels of webcam images to be related to their real-world coordinates. We present several examples of resulting snow cover maps, which have the same resolution as the digital elevation model and indicate whether each grid cell is snow-covered, snow-free, or not visible from webcams' positions. The procedure is expected to work under almost any weather condition and demonstrates the feasibility of using webcams for the retrieval of high-resolution snow cover information.

  3. Principles of Snow Hydrology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Snow hydrology is a specialized field of hydrology that is of particular importance for high latitudes and mountainous terrain. In many parts of the world, river and groundwater supplies for domestic, irrigation, industrial and ecosystem needs are generated from snowmelt, and an in-depth understand...

  4. Improving WEPP snow simulation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Snow simulation is essential to reliable prediction of runoff and erosion, particularly in high-latitude areas in the northern tier of states and forested watersheds at high elevations. The Water Erosion Prediction Project (WEPP) model is one of a few including a component for winter hydrology simul...

  5. 76 FR 45223 - Notice of Funding Availability: Inviting Applications for McGovern-Dole International Food for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-28

    ... International Food for Education and Child Nutrition Program Announcement Type: New. Catalog of Federal Domestic... applications for the McGovern-Dole International Food for Education and Child Nutrition program (McGovern-Dole... education and nutrition plans; and (e) Demonstrated cooperation with other USG agencies doing...

  6. Snow surface temperature, radiative forcing and snow depth as determinants of snow density

    NASA Astrophysics Data System (ADS)

    Kirchner, P. B.; Painter, T. H.; Skiles, M.; Deems, J. S.

    2014-12-01

    Watershed scale observations of snow water equivalence (SWE) are becoming increasingly important globally as the quantity and timing of snowmelt has become less predictable. In the Colorado River watershed, where dust deposition can hasten snowmelt by several weeks, the need for these observations is critical. While advances in measuring snow depth and albedo from the NASA Airborne Snow Observatory have greatly improved our ability to constrain snow depth and radiative forcing, we have yet to develop a method for remotely observing snow density, which is required for calculating SWE. We evaluate measured and modeled variables of snow- infrared surface temperature, radiative forcing and snow depth as predictors of snow density. We use 10 seasons of in situ measured snow surface temperature, cumulative modeled dust in snow radiative forcing, snow depth and manually measured snow density from locations in the Rocky Mountains of southwestern Colorado. We also use measured snow depth and SWE from the 2013 and 2014 water years, from 23-35 locations stratified by modeled downwelling short wave radiation, and evaluate them as predictors of snow density. Our analysis shows that daily mean snow surface temperature (R2 0.61, p = <0.001) and cumulative radiative forcing (R2 0.54, p = <0.001) individually have significant coefficients of determination whereas snow depth alone was not significant. Multiple regression with all three variables (R2 0.84, p = <0.001) was the best predictor of density. Furthermore, when snowpack conditions were isothermal at 0° C, the diurnal coefficient of variation, of measured hourly surface temperature, exhibited consistently high variance. In 2013 we found significant correlations between spatially distributed measurements of snow density (R2 0.33, p = <0.001) and modeled downwelling short wave radiation. However, in 2014 the correlation was very low, supporting our hypothesis that seasonal differences in dust driven radiative forcing are also

  7. Snow and ice ecosystems: not so extreme.

    PubMed

    Maccario, Lorrie; Sanguino, Laura; Vogel, Timothy M; Larose, Catherine

    2015-12-01

    Snow and ice environments cover up to 21% of the Earth's surface. They have been regarded as extreme environments because of their low temperatures, high UV irradiation, low nutrients and low water availability, and thus, their microbial activity has not been considered relevant from a global microbial ecology viewpoint. In this review, we focus on why snow and ice habitats might not be extreme from a microbiological perspective. Microorganisms interact closely with the abiotic conditions imposed by snow and ice habitats by having diverse adaptations, that include genetic resistance mechanisms, to different types of stresses in addition to inhabiting various niches where these potential stresses might be reduced. The microbial communities inhabiting snow and ice are not only abundant and taxonomically diverse, but complex in terms of their interactions. Altogether, snow and ice seem to be true ecosystems with a role in global biogeochemical cycles that has likely been underestimated. Future work should expand past resistance studies to understanding the function of these ecosystems. PMID:26408452

  8. 'Snow Queen' Animation

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This animation consists of two close-up images of 'Snow Queen,' taken several days apart, by the Robotic Arm Camera (RAC) aboard NASA's Phoenix Mars Lander.

    Snow Queen is the informal name for a patch of bright-toned material underneath the lander.

    Thruster exhaust blew away surface soil covering Snow Queen when Phoenix landed on May 25, 2008, exposing this hard layer comprising several smooth rounded cavities beneath the lander. The RAC images show how Snow Queen visibly changed between June 15, 2008, the 21st Martian day, or sol, of the mission and July 9, 2008, the 44th sol.

    Cracks as long as 10 centimeters (about four inches) appeared. One such crack is visible at the left third and the upper third of the Sol 44 image. A seven millimeter (one-third inch) pebble or clod appears just above and slightly to the right of the crack in the Sol 44 image. Cracks also appear in the lower part of the left third of the image. Other pieces noticeably shift, and some smooth texture has subtly roughened.

    The Phoenix team carefully positioned and focused RAC the same way in both images. Each image is about 60 centimeters, or about two feet, wide. The object protruding in from the top on the right half of the images is Phoenix's thermal and electrical conductivity probe.

    Snow Queen and other ice exposed by Phoenix landing and trenching operations on northern polar Mars is the first time scientists have been able to monitor Martian ice at a place where temperatures are cold enough that the ice doesn't immediately sublimate, or vaporize, away.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  9. A corner store intervention in a low-income urban community is associated with increased availability and sales of some healthy foods

    PubMed Central

    Song, Hee-Jung; Gittelsohn, Joel; Kim, Miyong; Suratkar, Sonali; Sharma, Sangita; Anliker, Jean

    2011-01-01

    Objective While corner store-based nutrition interventions have emerged as a potential strategy to increase healthy food availability in low-income communities, few evaluation studies exist. We present the results of a trial in Baltimore City to increase the availability and sales of healthier food options in local stores. Design Quasi-experimental study. Setting Corner stores owned by Korean-Americans and supermarkets located in East and West Baltimore. Subjects Seven corner stores and two supermarkets in East Baltimore received a 10-month intervention and six corner stores and two supermarkets in West Baltimore served as comparison. Results During and post-intervention, stocking of healthy foods and weekly reported sales of some promoted foods increased significantly in intervention stores compared with comparison stores. Also, intervention storeowners showed significantly higher self-efficacy for stocking some healthy foods in comparison to West Baltimore storeowners. Conclusions Findings of the study demonstrated that increases in the stocking and promotion of healthy foods can result in increased sales. Working in small corner stores may be a feasible means of improving the availability of healthy foods and their sales in a low-income urban community. PMID:19402943

  10. Importance of snow to global precipitation

    NASA Astrophysics Data System (ADS)

    Field, P. R.; Heymsfield, A. J.

    2015-11-01

    Precipitation controls the availability of drinking water and viability of the land to support agriculture. Failure to accurately predict the location, magnitude, and frequency of precipitation impacts not only numerical weather forecasting but also climate modeling. It has been proposed that most rainfall events originate from ice that has melted to form rain. Here we use remote sensing from spaceborne cloud radar to quantify that idea. A new metric is constructed to quantify the fraction of rain events at the surface that are linked to snow melting at a higher altitude. CloudSat is used to show the global variation of the importance of snow in the precipitation process. In the tropics, subtropics, midlatitude and polar regions 0.3, 0.4, 0.8, and >0.9, respectively, of all precipitation events (>1 mm/d) are linked to the production of snow in clouds.

  11. Climate sensitivity of snow regimes simulated by physically based snow models (Invited)

    NASA Astrophysics Data System (ADS)

    Pomeroy, J. W.; Fang, X.; Sabourin, A.; Ellis, C. R.

    2009-12-01

    Seasonal snow regimes consist of snowfall, snow redistribution by wind, snow interception and snowmelt. Sublimation can be an important ablation mechanism under highly ventilated conditions. All of these processes are strongly controlled by the energy inputs and energy state of the snowpack. Warmer winter temperatures have been observed and are predicted for many cold regions environments. The Cold Regions Hydrological Model (CRHM) has the capability to successfully model the major snow processes in a physically based manner. It is used here to explore the sensitivity of snow regimes in three environments to warmer winter temperatures. The windswept alpine and mountain spruce forest environments use baseline data from Marmot Creek Research Basin in the Rocky Mountains of Alberta, Canada and the prairie cropland environments use data from Bad Lake Research Basin in the semi-arid prairies of Saskatchewan, Canada. Under current conditions blowing snow in both alpine and prairie environments redistributes most snowfall from wind exposed ridge and fallow-field surfaces and deposits transported snow in drifts on lee slopes, gullies and treed or shrub areas. Sublimation losses are substantial. Melt occurs in May-June in the alpine and in March-April on the Prairie. Currently, snow interception and sublimation are major losses of seasonal snowpack in mountain forest environments due to high sublimation losses. Forest melt occurs in April-May. Warming is shown to reduce sublimation losses - its restriction of wind redistribution and interception overcomes the additional energy available for sublimation. Warming also advances the timing of snowmelt initiation to varying degrees, but its effects on the rate and duration of melt are equivocal. In certain environments melt is faster and shorter in duration as warming occurs, but in others the rate diminishes with warming and so duration is not strongly affected. These results have important implications for determining the

  12. Evaluating the Initial Impact of the Revised Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) Food Packages on Dietary Intake and Home Food Availability in African American and Hispanic Families

    PubMed Central

    Odoms-Young, Angela M.; Kong, Angela; Schiffer, Linda A.; Porter, Summer J.; Blumstein, Lara; Bess, Stephanie; Berbaum, Michael L.; Fitzgibbon, Marian L.

    2013-01-01

    OBJECTIVE The present study assessed the impact of the 2009 food packages mandated by the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) on dietary intake and home food availability in low-income African American and Hispanic parent/child dyads. DESIGN A natural experiment was conducted to assess if the revised WIC food package altered dietary intake, home food availability, weight, and various lifestyle measures immediately (6 months) following policy implementation. SETTING 12 WIC clinics in Chicago, USA. SUBJECTS 273, 2–3 year old Hispanic and African American children enrolled in WIC and their mothers RESULTS Six months after the WIC food package revisions were implemented, we observed modest changes in dietary intake. Fruit consumption increased among Hispanic mothers (mean=0.33 servings/d, p=.04), and low-fat dairy intake increased among Hispanic mothers (0.21 servings/d, p=.02), Hispanic children (0.34 servings/d, p<.001), and African American children (0.24 servings/d, p=.02). Home food availability of low fat dairy and whole grains also increased. Dietary changes, however, varied by racial/ethnic group. Changes in home food availability were not significantly correlated with changes in diet. CONCLUSIONS The WIC food package revisions are one of the first efforts to modify the nutrition guidelines that govern foods provided in a federal food and nutrition assistance program. It will be important to examine the longer term impact of these changes on dietary intake and weight status. PMID:23544992

  13. Black Carbon and Dust in Snow and Ice on Snow Dome, Mt. Olympus

    NASA Astrophysics Data System (ADS)

    Kaspari, S.; Delaney, I.; Skiles, M.; Dixon, D. A.

    2012-12-01

    Deposition of black carbon (BC) and dust on highly reflective snow and glacier ice causes darkening of the surface, resulting in greater absorption of solar energy, heating of the snow/ice, and accelerated snow and glacier melt. The deposition of BC and dust may be affecting the timing and availability of water resources in the Pacific Northwest where the majority of runoff comes from snow and glacier melt, but minimal related research has taken place in this region. A recent modeling study suggested that BC deposition is causing a decrease in spring snow water equivalent and a shift to earlier peak runoff in the spring in the Western United States. Additionally, limited observations made in the early 1980s in Washington State determined that light absorbing impurities (e.g., BC and dust) were reducing the snow albedo. Since 2009, we have collected snow and ice samples from glaciers and the seasonal snowpack from spatially distributed sites in Washington State to determine impurity content, and to assess how impurity concentrations vary in relation to emission source proximity. Here we present results from the summer 2012 fieldwork on Snow Dome, Mt. Olympus in Washington State. Mt. Olympus is located upwind from major regional sources of BC and dust, but may receive BC from ocean shipping and trans-Pacific transport of BC and dust from large Asian sources. We used a field spectrometer to measure spectral albedo on Snow Dome, and analyzed surface snow samples and shallow ice cores to characterize the spatial and temporal variability of impurity deposition. Total impurity load was determined gravimetrically. Dust concentrations are inferred from ICPMS analyses and BC concentrations are determined using a Single Particle Soot Photometer (SP2), with select samples also analyzed for BC using a Sunset EC-OC to facilitate method inter-comparison. We assess the role that absorbing impurities may play in accelerating melt at Snow Dome, and briefly compare our results to

  14. Assessment of radar-derived snow depth over Arctic sea ice

    NASA Astrophysics Data System (ADS)

    Newman, Thomas; Farrell, Sinead L.; Richter-Menge, Jacqueline; Connor, Laurence N.; Kurtz, Nathan T.; Elder, Bruce C.; McAdoo, David

    2014-12-01

    Knowledge of contemporaneous snow depth on Arctic sea ice is important both to constrain the regional climatology and to improve the accuracy of satellite altimeter estimates of sea ice thickness. We assess new data available from the NASA Operation IceBridge snow radar instrument and derive snow depth estimates across the western Arctic ice pack using a novel methodology based on wavelet techniques that define the primary reflecting surfaces within the snow pack. We assign uncertainty to the snow depth estimates based upon both the radar system parameters and sea ice topographic variability. The accuracy of the airborne snow depth estimates are examined via comparison with coincident measurements gathered in situ across a range of ice types in the Beaufort Sea. We discuss the effect of surface morphology on the derivation, and consequently the accuracy, of airborne snow depth estimates. We find that snow depths derived from the airborne snow radar using the wavelet-based technique are accurate to 1 cm over level ice. Over rougher surfaces including multiyear and ridged ice, the radar system is impacted by ice surface morphology. Across basin scales, we find the snow-radar-derived snow depth on first-year ice is at least ˜60% of the value reported in the snow climatology for the Beaufort Sea, Canada Basin, and parts of the central Arctic, since these regions were previously dominated by multiyear ice during the measurement period of the climatology. Snow on multiyear ice is more consistent with the climatology.

  15. Snow depth on Arctic sea ice derived from radar: In situ comparisons and time series analysis

    NASA Astrophysics Data System (ADS)

    Holt, Benjamin; Johnson, Michael P.; Perkovic-Martin, Dragana; Panzer, Ben

    2015-06-01

    The snow radar being flown on NASA's Operation IceBridge, ongoing aircraft campaigns to the Arctic and the Antarctic are providing unique observations of the depth of snow on the sea ice cover. In this paper, we focus on the radar-derived snow depth results from the 2009-2012 Arctic campaigns. We develop and evaluate the use of a distinct snow layer tracker to measure snow depth based on a Support Vector Machine (SVM) supervised learning algorithm. The snow radar is designed to detect both the air-snow and snow-ice interfaces using ultrawideband frequencies from 2 to 8 GHz. The quality, errors, and repeatability of the snow radar snow depth estimates are examined, based on comparisons with in situ data obtained during two separate sea ice field campaigns, the GreenArc 2009 and the CryoVEx 2011 campaigns off Greenland in the Lincoln Sea. Finally, we analyze 4 years (2009-2012) of three annually repeated sea ice flight lines obtained in early spring, located off Greenland and the Canadian Arctic. We examine the annual variations of snow depth differences between perennial and seasonal ice when available. Overall, the snow layer tracker produced consistent, accurate results for snow depths between 0.10 and ˜0.60 m. This was confirmed with comparisons with the two data sets from the in situ measurement campaigns as well as with the time series analysis, and is consistent with other published results.

  16. An Intervention to Increase Availability of Healthy Foods and Beverages in New York City Hospitals: The Healthy Hospital Food Initiative, 2010–2014

    PubMed Central

    Krepp, Erica M.; Johnson Curtis, Christine; Lederer, Ashley

    2016-01-01

    Background Hospitals serve millions of meals and snacks each year; however, hospital food is often unhealthy. Hospitals are ideal settings for modeling healthy eating, but few programs have sought to improve nutrition in all venues where food is served. Community Context The New York City Department of Health and Mental Hygiene created the Healthy Hospital Food Initiative (HHFI) to improve the healthfulness of food served in hospitals. The HHFI built on prior work implementing mandatory nutrition standards for patient meals and vending in public hospitals. Public hospitals joined the HHFI by voluntarily adopting standards for cafeterias and cafés. Private hospitals joined by implementing nutrition standards for patient meals, food and beverage vending machines, and cafeterias and cafés. Methods Hospitals were recruited from 2010 through 2014 and provided technical assistance from health department staff. Implementation in each of the 4 areas was monitored through on-site assessments and menu review. Twenty-eight hospital cafeterias and cafés were evaluated at baseline and at the end of the HHFI to assess changes. Outcome Sixteen public hospitals and 24 private hospitals joined the HHFI. Most (n = 18) private hospitals implemented standards in at least 2 areas. In cafeterias, most hospitals introduced a healthy value meal (n = 19), removed unhealthy items from the entrance and checkout (n = 18), increased whole grains to at least half of all grains served (n = 17), and reduced calories in pastries and desserts (n = 15). Interpretation Most New York City hospitals joined the HHFI and voluntarily adopted rigorous nutrition standards. Partnerships between hospitals and local government are feasible and can lead to significant improvements in hospital food environments. PMID:27281392

  17. Impacts of climate and land use change on ecosystem hydrology and net primary productivity: Linking water availability to food security in Asia

    NASA Astrophysics Data System (ADS)

    Dangal, S. R. S.; Tian, H.; Pan, S.; Zhang, B.; Yang, J.

    2015-12-01

    The nexus approach to food, water and energy security in Asia is extremely important and relevant as the region has to feed two-third of the world's population and accounts for 59% of the global water consumption. The distribution pattern of food, water and energy resources have been shaped by the legacy effect of both natural and anthropogenic disturbances and therefore are vulnerable to climate change and human activities including land use/cover change (LUCC) and land management (irrigation and nitrogen fertilization). In this study, we used the Dynamic Land Ecosystem Model (DLEM) to examine the effects of climate change, land use/cover change, and land management practices (irrigation and nitrogen fertilization) on the spatiotemporal trends and variability in water availability and its role in limiting net primary productivity (NPP) and food security in the 20th and early 21st centuries. Our specific objectives are to quantify how climate change, LUCC and other environmental changes have interactively affected carbon and water dynamics across the Asian region. In particular, we separated the Asian region into several sub-region based on the primary limiting factor - water, food and energy. We then quantified how changes in environmental factors have altered the water and food resources during the past century. We particularly focused on Net Primary Productivity (NPP) and water cycle (Evapotranspiration, discharge, and runoff) as a measure of available food and water resources, respectively while understanding the linkage between food and water resources in Asia.

  18. Evidence for an annual reproductive rhythm independent of food availability in male Creole goats in subtropical northern Mexico.

    PubMed

    Delgadillo, J A; Canedo, G A; Chemineau, P; Guillaume, D; Malpaux, B

    1999-09-01

    The aim of this study was to determine if there is a seasonal pattern of sexual activity dependent on food availability in male Creole goats in subtropical Mexico. The study was conducted in the Laguna Region in the State of Coahuila, Mexico (26 degrees N). Male Creole goats (n = 8) were kept in a shed, fed alfalfa ad libitum and given 200 g of concentrate daily throughout the study. Live weight and testicular weight were determined every 2 wk. Sexual behavior and sperm production were determined monthly. Blood samples were obtained weekly to determine testosterone plasma concentrations. All variables were subjected to sinusoidal modeling procedures and showed important seasonal variations (P < 0.0001) with different phase angles for body weight, testicular weight and testosterone plasma concentrations. The nadir of live weight occurred in November and the peak in May. The lowest testicular weight (90 g) and testosterone plasma concentrations (0.1 ng/mL) were observed in January and February, respectively, while the peaks were observed in July and August (145 g and 10 ng/mL, respectively). Ejaculation latency also varied during the study, being low between May and November (96 sec) and reaching a peak in April (183 sec). Minimum number of spermatozoa per ejaculate occurred between February and April (1.4 x 10(9) cells/ejaculate) while the maximum number was observed between May and September (2.8 x 10(9) spermatozoa/ejaculate). Progressive sperm motility was low between January and April (3.04 on average) and high between May and November (about 3.55 on average). The percentage of live spermatozoa diminished between January and April (68% in April) and then increased to values around 80% between May and November. These results lead us to conclude that male Creole goats in Northern Mexico, fed constantly throughout the year, exhibit seasonality in their reproductive activity. Intense sexual activity occurred between May and December. PMID:10734370

  19. , Testing a bioenergetics-based habitat choice model: bluegill (Lepomis macrochirus) responses to food availability and temperature

    USGS Publications Warehouse

    Wildhaber, Mark L.; Crowder, Larry B.

    2011-01-01

    Using an automated shuttlebox system, we conducted patch choice experiments with 32, 8–12 g bluegill sunfish (Lepomis macrochirus) to test a behavioral energetics hypothesis of habitat choice. When patch temperature and food levels were held constant within patches but different between patches, we expected bluegill to choose patches that maximized growth based on the bioenergetic integration of food and temperature as predicted by a bioenergetics model. Alternative hypotheses were that bluegill may choose patches based only on food (optimal foraging) or temperature (behavioral thermoregulation). The behavioral energetics hypothesis was not a good predictor of short-term (from minutes to weeks) patch choice by bluegill; the behavioral thermoregulation hypothesis was the best predictor. In the short-term, food and temperature appeared to affect patch choice hierarchically; temperature was more important, although food can alter temperature preference during feeding periods. Over a 19-d experiment, mean temperatures occupied by fish offered low rations did decline as predicted by the behavioral energetics hypothesis, but the decline was less than 1.0 °C as opposed to a possible 5 °C decline. A short-term, bioenergetic response to food and temperature may be precluded by physiological costs of acclimation not considered explicitly in the behavioral energetics hypothesis.

  20. [Effect of food availability in early ontogenesis on the rate of growth and numbers of bream Abramis brama L. (Cypriniformes, Cyprinidae) in Kursh Bay of the Baltic Sea].

    PubMed

    Naumenko, E N

    2011-01-01

    On the basis of studies of zooplankton and ichthyoplankton in the coastal zone of Kursh Bay of the Baltic Sea, zooplankton production accessible for juveniles of bream Abramis brama L. at early stages of ontogenesis, degree of removal of food resources, and food availability of juveniles of the bream that was reflected in the rate of growth were calculated. It is concluded that the removal of more than 60% of production of food zooplankton by bream juveniles leads to an increase of their mortality at early stages and a decrease in the rate of increase in the body weight. PMID:21786657

  1. NASA Airborne Snow Observatory: Measuring Spatial Distribution of Snow Water Equivalent and Snow Albedo

    NASA Astrophysics Data System (ADS)

    Joyce, M.; Painter, T. H.; Mattmann, C. A.; Ramirez, P.; Laidlaw, R.; Bormann, K. J.; Skiles, M.; Richardson, M.; Berisford, D. F.

    2015-12-01

    The two most critical properties for understanding snowmelt runoff and timing are the spatial and temporal distributions of snow water equivalent (SWE) and snow albedo. Despite their importance in controlling volume and timing of runoff, snowpack albedo and SWE are still largely unquantified in the US and not at all in most of the globe, leaving runoff models poorly constrained. NASA Jet Propulsion Laboratory, in partnership with the California Department of Water Resources, has developed the Airborne Snow Observatory (ASO), an imaging spectrometer and scanning LiDAR system, to quantify SWE and snow albedo, generate unprecedented knowledge of snow properties for cutting edge cryospheric science, and provide complete, robust inputs to water management models and systems of the future. This poster will describe the NASA Airborne Snow Observatory, its outputs and their uses and applications, along with recent advancements to the system and plans for the project's future. Specifically, we will look at how ASO uses its imaging spectrometer to quantify spectral albedo, broadband albedo, and radiative forcing by dust and black carbon in snow. Additionally, we'll see how the scanning LiDAR is used to determine snow depth against snow-free acquisitions and to quantify snow water equivalent when combined with in-situ constrained modeling of snow density.

  2. No meaningful association of neighborhood food store availability with dietary intake, body mass index, or waist circumference in young Japanese women.

    PubMed

    Murakami, Kentaro; Sasaki, Satoshi; Takahashi, Yoshiko; Uenishi, Kazuhiro

    2010-08-01

    The affordability of food is considered as an important factor influencing people's diet and hence health status. The objective of this cross-sectional study was to test the hypothesis that neighborhood food store availability is associated with some aspects of dietary intake and thus possibly with body mass index (BMI) and waist circumference in young Japanese women. Subjects were 989 female Japanese dietetic students 18 to 22 years of age. Neighborhood food store availability was defined as the number of food stores within a 0.5-mile (0.8-km) radius of residence (meat stores, fish stores, fruit and vegetable stores, confectionery stores/bakeries, rice stores, convenience stores, and supermarkets/grocery stores). Dietary intake was estimated using a validated, comprehensive self-administered diet history questionnaire. No association was seen between any measure of neighborhood food store availability and dietary intake, except for a positive association between confectionery and bread availability (based on confectionery stores/bakeries, convenience stores, and supermarkets/grocery stores) and intake of these items (P for trend = .02). Further, no association was seen for BMI or waist circumference, except for an inverse relationship between availability of convenience stores and BMI and a positive relationship between store availability for meat (meat stores and supermarkets/grocery stores) and fish (fish stores and supermarkets/grocery stores) and waist circumference. In conclusion, this study of young Japanese women found no meaningful association between neighborhood food store availability and dietary intake, BMI, or waist circumference, with the exception of a positive relationship between availability and intake for confectionery and bread. PMID:20851311

  3. 'Snow White' Trench

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This image was acquired by NASA's Phoenix Mars Lander's Surface Stereo Imager on Sol 43, the 43rd Martian day after landing (July 8, 2008). This image shows the trench informally called 'Snow White.'

    Two samples were delivered to the Wet Chemistry Laboratory, which is part of Phoenix's Microscopy, Electrochemistry, and Conductivity Analyzer (MECA). The first sample was taken from the surface area just left of the trench and informally named 'Rosy Red.' It was delivered to the Wet Chemistry Laboratory on Sol 30 (June 25, 2008). The second sample, informally named 'Sorceress,' was taken from the center of the 'Snow White' trench and delivered to the Wet Chemistry Laboratory on Sol 41 (July 6, 2008).

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  4. Snow depth and snow duration variability in Trentino (North-East Italy)

    NASA Astrophysics Data System (ADS)

    Marcolini, Giorgia; Bellin, Alberto; Disse, Markus; Chiogna, Gabriele

    2016-04-01

    Snowpack dynamics is an important indicator in assessing climate change in mountainous regions. In fact, it is strongly influenced by temperature and precipitation behavior and is the strongest single element controlling the hydrological cycle of Alpine catchments. Furthermore, related quantities, such as snow cover duration and extension, affect many aspects of life in mountainous regions, from economical activities, such as winter tourism and hydropower production, to water availability and ecosystem dynamics. Available data on snowpack are often heterogeneous and long time series, useful for climate analysis, are often obtained by merging data of different origins. This, among other factors, calls for robust homogenization techniques. We apply the Standard Normal Homogeneity Test (SNHT) to detect breakpoints in 109 timeseries of snowpack collected in Trentino (North-East Italy). After having performed the detection of anthropogenic breakpoints, we investigated the occurrence of anomalies and changes in the mean seasonal snow-depth, in the number of days with snowfall, in the snow cover duration and the correlation of these variables with the altitude of the sites. We mainly focus on the period 1950-2013, since it is the richest in terms of data availability. The analyses clearly indicate that the period 1990-2000 was critical in terms of seasonal mean snow depth and snow-cover duration, in particular for stations below 1600 m a.s.l.

  5. Niche shifts and energetic condition of songbirds in response to phenology of food-resource availability in a high-elevation sagebrush ecosystem

    USGS Publications Warehouse

    Cutting, Kyle A.; Anderson, Michelle L.; Beever, Erik; Schroff, Sean; Korb, Nathan; Klaphake, Eric; McWilliams, Scott R.

    2016-01-01

    Seasonal fluctuations in food availability can affect diets of consumers, which in turn may influence the physiological state of individuals and shape intra- and inter-specific patterns of resource use. High-elevation ecosystems often exhibit a pronounced seasonal “pulse” in productivity, although few studies document how resource use and energetic condition by avian consumers change in relation to food-resource availability in these ecosystems. We tested the hypothesis that seasonal increases (pulses) in food resources in high-elevation sagebrush ecosystems result in 2 changes after the pulse, relative to the before-pulse period: (1) reduced diet breadth of, and overlap between, 2 sympatric sparrow species; and (2) enhanced energetic condition in both species. We tracked breeding-season diets using stable isotopes and energetic condition using plasma metabolites of Brewer's Sparrows (Spizella breweri), Vesper Sparrows (Pooecetes gramineus), and their food resources during 2011, and of only Brewer's Sparrows and their food resources during 2013. We quantify diet breadth and overlap between both species, along with coincident physiological consequences of temporal changes in resource use. After invertebrate biomass increased following periods of rainfall in 2011, dietary breadth decreased by 35% in Brewer's Sparrows and by 48% in Vesper Sparrows, while dietary overlap decreased by 88%. Energetic condition of both species increased when dietary overlap was lower and diet breadth decreased, after the rapid rise of food-resource availability. However, energetic condition of Brewer's Sparrows remained constant in 2013, a year with low precipitation and lack of a strong pulse in food resources, even though the species' dietary breadth again decreased that year. Our results indicate that diet breadth and overlap in these sparrow species inhabiting sagebrush ecosystems generally varied as predicted in relation to intra- and interannual changes in food resources, and

  6. Snow-melt Runoff Simulation for Dam Reservoir in the Heavy Snow Region

    NASA Astrophysics Data System (ADS)

    Sato, Yoshinobu; Murai, Akihiro; Sumi, Tetsuya

    2014-05-01

    Increases in land surface temperature will have a significant affect on the hydrological cycle, particularly in regions where the available water resources are mainly dominated by the melting snow or ice. Thus, to clarify the impact of climate change on river discharge in cold and mountainous region is becoming one of the urgent issues for policy making and planning for the integrated river water management under the inevitable warming climate. However, in order to study climate change impacts on water resources in the heavy snow region, snow-melt runoff simulation for dam reservoir should be improved. Because, the available meteorological data for runoff simulation is quite limited, especially in a mountainous regions in Japan. In this study, we analyzed the inflow into the Okutadami Dam in the Agano River basin located in the northern mountainous region in Japan by a distributed hydrological model (Hydro-BEAM: Hydrological river Basin Environment Assessment Model). The Okutadami dam has an important role as one of the largest hydro-power generation dam in Japan. The result of our initial simulation underestimated the inflow significantly, especially in snow melting season, because of small input precipitation. We firstly modified the input precipitation by the JMA (Japan Meteorological Agency)'s climatic value 2010 (monthly 1km2 averaged mesh based precipitation dataset during the period from 1981 to 2010). Due to the modification, simulated annual mean river discharge (water balance) was improved significantly. Secondly, we modified the threshold temperature which distinguishes rainfall and snowfall improved the reproducibility slightly. Lastly, we modified the monthly discharge variation (seasonal change pattern) in snow melting period by considering the effect of heat supply by rainfall on snow surface layer. Consequently, we found that the calculated inflow to the Okutadami dam agreed well the observation. These methods will contribute to clarify the

  7. Producing Snow Extent and Snow Water Equivalent Information for Climate Research Purposes - ESA DUE Globsnow Effort

    NASA Astrophysics Data System (ADS)

    Luojus, Kari; Pulliainen, Jouni; Rott, Helmut; Nagler, Thomas; Solberg, Rune; Wiesmann, Andreas; Derksen, Chris; Metsämäki, Sari; Malnes, Eirik; Bojkov, Bojan

    2010-05-01

    The European Space Agency (ESA) Data User Element (DUE) funded GlobSnow project aims at creating a global database of snow parameters for climate research purposes. The main objective is to create a long term dataset on two essential snow parameters. The project will provide information concerning the areal extent of snow (SE) on a global scale and snow water equivalent (SWE) for the Northern Hemisphere. Both products will include the end product derived from the satellite data along with accuracy information for each snow parameter. The temporal span of the SE product will be 15 years and the span for the SWE product will be 30 years. A key improvement of the snow products, when compared with the currently available data sets, will be the inclusion of a statistically derived accuracy estimate accompanying each SE or SWE estimate (on a pixel level). In addition to the SE and SWE time-series, an operational near-real time (NRT) snow information service will be implemented. The service will provide daily snow maps for hydrological, meteorological, and climate research purposes. The snow products will be based on data acquired from optical and passive microwave-based spaceborne sensors combined with ground-based weather station observations. The work was initiated in November 2008, and is being coordinated by the Finnish Meteorological Institute (FMI). Other project partners involved are NR (Norwegian Computing Centre), ENVEO IT GmbH, GAMMA Remote Sensing AG, Finnish Environment Institute (SYKE), Environment Canada (EC) and Northern Research Institute (Norut). Extensive algorithm evaluation efforts were carried out for the candidate SWE and SE algorithms during 2009 using ground truth data gathered from Canada, Scandinavia, Russia and the Alps. The acquired evaluation results have enabled the selection of the algorithms to be utilized for the GlobSnow SE and SWE products. The SWE product is derived using the FMI Algorithm and the SE product is a combination of NR and

  8. Isothermal densification and metamorphism of new snow

    NASA Astrophysics Data System (ADS)

    Schleef, S.; Loewe, H.; Schneebeli, M.

    2012-12-01

    The interplay between overburden stress and surface energy induced growth and coarsening is relevant for the densification of snow and porous ice at all densities. The densification of new snow is amenable to high precision experiments on short time scales. To this end we investigate the coupling of densification and metamorphism of new snow via time-lapse tomography experiments in the laboratory. We compare the evolution of density, strain, and specific surface area to previous long-time metamorphism experiments of snow and creep of polycrystalline ice. Experimental conditions are tailored to the requirements of time-lapse tomography and the measurements are conducted under nearly isothermal conditions at -20°C with a duration of two days. Images were taken with temporal resolution of a few hours which reveal precise details of the microstructure evolution due to sintering and compaction. We used different crystal shapes of natural new snow and snow samples obtained by sieving crystals grown in a snowmaker in the laboratory. To simulate the effect of overburden stress due to an overlying snowpack additional weights were applied to the sample. As expected we find an influence of the densification rate on initial density and overburden stress. We calculated strain rates and identified a transient creep behavior with a similar power law for all crystal types which substantially differs from the Andrade creep of polycrystalline ice. As a main result we found that the evolution of the specific surface area is independent of the density and follows a unique decay form for all measurements of each crystal type. The accuracy of the measurements allows to obtain a decay exponent for the SSA which is the same as previously obtained from the long-time regime during isothermal metamorphism after several months. Our preliminary results for all available types of new snow suggest a correlation between the initial density and SSA. We also find snow samples which coincide in

  9. BOREAS HYD-4 Areal Snow Course Data

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Knapp, David E. (Editor); Metcalfe, John R.; Goodison, Barry E.; Walker, Anne; Smith, David E. (Technical Monitor)

    2000-01-01

    The Boreal Ecosystem-Atmosphere Study (BOREAS) Hydrology (HYD)-4 team focused on collecting data during the 1994 winter focused field campaign (FFCW) to improve the understanding of winter processes within the boreal forest. Knowledge of snow cover and its variability in the boreal forest is fundamental if BOREAS is to achieve its goals of understanding the processes and states involved in the exchange of energy and water. The development and validation of remote sensing algorithms will provide the means to extend the knowledge of these processes and states from the local to the regional scale. A specific thrust of the hydrology research is the development and validation of snow cover algorithms from airborne passive microwave measurements. Airborne remote sensing data (gamma, passive microwave) were acquired along a series of flight lines established in the vicinity of the BOREAS study areas. Ground snow surveys were conducted along selected sections of these aircraft flight lines. These calibration segments were typically 10-20 km in length, and ground data were collected at one to two kilometer intervals. The data are provided in tabular ASCII files. The HYD-04 areal snow course data are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The data files are available on a CD-ROM (see document number 20010000884).

  10. Nutrition Services and Foods and Beverages Available at School: Results from the School Health Policies and Programs Study 2006

    ERIC Educational Resources Information Center

    O'Toole, Terrence P.; Anderson, Susan; Miller, Clare; Guthrie, Joanne

    2007-01-01

    Background: Schools are in a unique position to promote healthy dietary behaviors and help ensure appropriate nutrient intake. This article describes the characteristics of both school nutrition services and the foods and beverages sold outside of the school meals program in the United States, including state- and district-level policies and…

  11. Evaluation of calcium, phosphorus, and selected trace mineral status in commercially available dry foods formulated for dogs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Objective – To evaluate the mineral content including calcium, phosphorus, zinc, iron, copper, manganese, and selenium of canine commercial pet foods and compare them to current AAFCO recommendations for adult maintenance. Design - Descriptive study. Sample – Forty-five over the counter dry canine p...

  12. Earth Observing System (EOS) Moderate Resolution Imaging Spectroradiometer (MODIS) Global Snow-Cover Maps

    NASA Technical Reports Server (NTRS)

    Hall, Dorothy K.; Riggs, George A.; Salomonson, Vincent V.; Scharfen, Greg R.

    2000-01-01

    Following the 1999 launch of the Earth Observing System (EOS) Moderate Resolution Imaging Spectroradiometer (MODIS), the capability exists to produce global snow-cover maps on a daily basis at 500-m resolution. Eight-day composite snow-cover maps will also be available. MODIS snow-cover products are produced at Goddard Space Flight Center and archived and distributed by the National Snow and Ice Data Center (NSIDC) in Boulder, Colorado. The products are available in both orbital and gridded formats. An online search and order tool and user-services staff will be available at NSIDC to assist users with the snow products. The snow maps are available at a spatial resolution of 500 m, and 1/4 degree x 1/4 degree spatial resolution, and provide information on sub-pixel (fractional) snow cover. Pre-launch validation work has shown that the MODIS snow-mapping algorithms perform best under conditions of continuous snow cover in low vegetation areas, but can also map snow cover in dense forests. Post-launch validation activities will be performed using field and aircraft measurements from a February 2000 validation mission, as well as from existing satellite-derived snow-cover maps from NOAA and Landsat-7 Enhanced Thematic Mapper Plus (ETM+).

  13. Changes in agriculture and abundance of snow geese affect carrying capacity of sandhill cranes in Nebraska

    USGS Publications Warehouse

    Pearse, A.T.; Krapu, G.L.; Brandt, D.A.; Kinzel, P.J.

    2010-01-01

    The central Platte River valley (CPRV) in Nebraska, USA, is a key spring-staging area for approximately 80 of the midcontinent population of sandhill cranes (Grus canadensis; hereafter cranes). Evidence that staging cranes acquired less lipid reserves during the 1990s compared to the late 1970s and increases in use of the CPRV by snow geese (Chen caerulescens) prompted us to investigate availability of waste corn and quantify spatial and temporal patterns of crane and waterfowl use of the region. We developed a predictive model to assess impacts of changes in availability of corn and snow goose abundance under past, present, and potential future conditions. Over a hypothetical 60-day staging period, predicted energy demand of cranes and waterfowl increased 87 between the late 1970s and 19982007, primarily because peak abundances of snow geese increased by 650,000 and cranes by 110,000. Compared to spring 1979, corn available when cranes arrived was 20 less in 1998 and 68 less in 1999; consequently, the area of cornfields required to meet crane needs increased from 14,464 ha in 1979 to 32,751 ha in 1998 and 90,559 ha in 1999. Using a pooled estimate of 88 kg/ha from springs 19981999 and 20052007, the area of cornfields needed to supply food requirements of cranes and waterfowl increased to 65,587 ha and was greatest in the eastern region of the CPRV, where an estimated 54 of cranes, 47 of Canada geese (Branta canadensis), 45 of greater white-fronted geese (Anser albifrons), and 46 of snow geese occurred during ground surveys. We estimated that a future reduction of 25 in available corn or cornfields would increase daily foraging flight distances of cranes by 2738. Crane use and ability of cranes to store lipid reserves in the CPRV could be reduced substantially if flight distance required to locate adequate corn exceeded a physiological maximum distance cranes could fly in search of food. Options to increase carrying capacity for cranes include increasing

  14. Remote Sensing of Snow Cover. Section; Snow Extent

    NASA Technical Reports Server (NTRS)

    Hall, Dorothy K.; Frei, Allan; Drey, Stephen J.

    2012-01-01

    Snow was easily identified in the first image obtained from the Television Infrared Operational Satellite-1 (TIROS-1) weather satellite in 1960 because the high albedo of snow presents a good contrast with most other natural surfaces. Subsequently, the National Oceanic and Atmospheric Administration (NOAA) began to map snow using satellite-borne instruments in 1966. Snow plays an important role in the Earth s energy balance, causing more solar radiation to be reflected back into space as compared to most snow-free surfaces. Seasonal snow cover also provides a critical water resource through meltwater emanating from rivers that originate from high-mountain areas such as the Tibetan Plateau. Meltwater from mountain snow packs flows to some of the world s most densely-populated areas such as Southeast Asia, benefiting over 1 billion people (Immerzeel et al., 2010). In this section, we provide a brief overview of the remote sensing of snow cover using visible and near-infrared (VNIR) and passive-microwave (PM) data. Snow can be mapped using the microwave part of the electromagnetic spectrum, even in darkness and through cloud cover, but at a coarser spatial resolution than when using VNIR data. Fusing VNIR and PM algorithms to produce a blended product offers synergistic benefits. Snow-water equivalent (SWE), snow extent, and melt onset are important parameters for climate models and for the initialization of atmospheric forecasts at daily and seasonal time scales. Snowmelt data are also needed as input to hydrological models to improve flood control and irrigation management.

  15. A proposed approach to systematically identify and monitor the corporate political activity of the food industry with respect to public health using publicly available information.

    PubMed

    Mialon, M; Swinburn, B; Sacks, G

    2015-07-01

    Unhealthy diets represent one of the major risk factors for non-communicable diseases. There is currently a risk that the political influence of the food industry results in public health policies that do not adequately balance public and commercial interests. This paper aims to develop a framework for categorizing the corporate political activity of the food industry with respect to public health and proposes an approach to systematically identify and monitor it. The proposed framework includes six strategies used by the food industry to influence public health policies and outcomes: information and messaging; financial incentive; constituency building; legal; policy substitution; opposition fragmentation and destabilization. The corporate political activity of the food industry could be identified and monitored through publicly available data sourced from the industry itself, governments, the media and other sources. Steps for country-level monitoring include identification of key food industry actors and related sources of information, followed by systematic data collection and analysis of relevant documents, using the proposed framework as a basis for classification of results. The proposed monitoring approach should be pilot tested in different countries as part of efforts to increase the transparency and accountability of the food industry. This approach has the potential to help redress any imbalance of interests and thereby contribute to the prevention and control of non-communicable diseases. PMID:25988272

  16. 'Snow White' in Color

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This color image taken by the Surface Stereo Imager on NASA's Phoenix Mars Lander shows the trench dubbed 'Snow White,' after further digging on the 25th Martian day, or sol, of the mission (June 19, 2008). The lander's solar panel is casting a shadow over a portion of the trench.

    The trench is about 5 centimeters (2 inches) deep and 30 centimeters (12 inches) long.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  17. Quantifying Snow Transport Using Snow Fences and Sonic Sensors

    NASA Astrophysics Data System (ADS)

    Sturm, M.; Berezovskaya, S.; Hiemstra, C.; Gelvin, A.

    2010-12-01

    Accurate assessment of snow transport (T) during wind events is a prerequisite to reliable estimation of snow loads on infrastructure and prediction of avalanche danger in the mountains. It is also a critical term in the winter water balance, affecting snow sublimation. To assess T we constructed two snow fences in northern Alaska and used an existing municipal fence near Barrow, Alaska to trap the wind-blown flux of snow. On the leeward side of each fence we installed a line of SR50 sonic ranging sensors that could be used to track the increase in snow height with time. We also installed web-cameras to monitor changes in drift shape. Periodic snow surface elevation surveys using a DGPS system provided more detailed drift profiles during the winter. Wind speed and direction were monitored near the fences. The sonic sensor results have been combined with the DGPS surveys to produce a time series of drift cross-section from which the flux has been computed. We have related this flux to individual wind events in an effort to identify the optimal conditions for blowing snow transport and to derive an empirical expression for T from weather measurements.

  18. Development of a Community-Sensitive Strategy to Increase Availability of Fresh Fruits and Vegetables in Nashville’s Urban Food Deserts, 2010–2012

    PubMed Central

    Haushalter, Alisa; Buck, Tracy; Campbell, David; Henderson, Trevor; Schlundt, David

    2013-01-01

    Background Food deserts, areas that lack full-service grocery stores, may contribute to rising rates of obesity and chronic diseases among low-income and racial/ethnic minority residents. Our corner store project, part of the Centers for Disease Control and Prevention’s Communities Putting Prevention to Work initiative, aimed to increase availability of healthful foods in food deserts in Nashville, Tennessee. Community Context We identified 4 food deserts in which most residents are low-income and racially and ethnically diverse. Our objectives were to develop an approach to increase availability of fresh fruits and vegetables, low-fat or nonfat milk, and 100% whole-wheat bread in Nashville’s food deserts and to engage community members to inform our strategy. Methods Five corner stores located in food deserts met inclusion criteria for our intervention. We then conducted community listening sessions, proprietor surveys, store audits, and customer-intercept surveys to identify needs, challenges to retailing the products, and potential intervention strategies. Outcome Few stores offered fresh fruits, fresh vegetables, low-fat or nonfat milk, or 100% whole-wheat bread, and none stocked items from all 4 categories. Major barriers to retailing healthful options identified by community members are mistrust of store owners, history of poor-quality produce, and limited familiarity with healthful options. Store owners identified neighborhood crime as the major barrier. We used community input to develop strategies. Interpretation Engaging community residents and understanding neighborhood context is critical to developing strategies that increase access to healthful foods in corner stores. PMID:23886044

  19. Validation of snow characteristics and snow albedo feedback in the Canadian Regional Climate Model simulations over North America

    NASA Astrophysics Data System (ADS)

    Fang, B.; Sushama, L.; Diro, G. T.

    2015-12-01

    Snow characteristics and snow albedo feedback (SAF) over North America, as simulated by the fifth-generation Canadian Regional Climate Model (CRCM5), when driven by ERA-40/ERA-Interim, CanESM2 and MPI-ESM-LR at the lateral boundaries, are analyzed in this study. Validation of snow characteristics is performed by comparing simulations against available observations from MODIS, ISCCP and CMC. Results show that the model is able to represent the main spatial distribution of snow characteristics with some overestimation in snow mass and snow depth over the Canadian high Arctic. Some overestimation in surface albedo is also noted for the boreal region which is believed to be related to the snow unloading parameterization, as well as the overestimation of snow albedo. SAF is assessed both in seasonal and climate change contexts when possible. The strength of SAF is quantified as the amount of additional net shortwave radiation at the top of the atmosphere as surface albedo decreases in association with a 1°C increase in surface temperature. Following Qu and Hall (2007), this is expressed as the product of the variation in planetary albedo with surface albedo and the change in surface albedo for 1°C change in surface air temperature during the season, which in turn is determined by the strength of the snow cover and snowpack metamorphosis feedback loops. Analysis of the latter term in the seasonal cycle suggests that for CRCM5 simulations, the snow cover feedback loop is more dominant compared to the snowpack metamorphosis feedback loop, whereas for MODIS, the two feedback loops have more or less similar strength. Moreover, the SAF strength in the climate change context appears to be weaker than in the seasonal cycle and is sensitive to the driving GCM and the RCP scenario.

  20. The Airborne Snow Observatory: fusion of imaging spectrometer and scanning lidar for studies of mountain snow cover (Invited)

    NASA Astrophysics Data System (ADS)

    Painter, T. H.; Andreadis, K.; Berisford, D. F.; Goodale, C. E.; Hart, A. F.; Heneghan, C.; Deems, J. S.; Gehrke, F.; Marks, D. G.; Mattmann, C. A.; McGurk, B. J.; Ramirez, P.; Seidel, F. C.; Skiles, M.; Trangsrud, A.; Winstral, A. H.; Kirchner, P.; Zimdars, P. A.; Yaghoobi, R.; Boustani, M.; Khudikyan, S.; Richardson, M.; Atwater, R.; Horn, J.; Goods, D.; Verma, R.; Boardman, J. W.

    2013-12-01

    Snow cover and its melt dominate regional climate and water resources in many of the world's mountainous regions. However, we face significant water resource challenges due to the intersection of increasing demand from population growth and changes in runoff total and timing due to climate change. Moreover, increasing temperatures in desert systems will increase dust loading to mountain snow cover, thus reducing the snow cover albedo and accelerating snowmelt runoff. The two most critical properties for understanding snowmelt runoff and timing are the spatial and temporal distributions of snow water equivalent (SWE) and snow albedo. Despite their importance in controlling volume and timing of runoff, snowpack albedo and SWE are still poorly quantified in the US and not at all in most of the globe, leaving runoff models poorly constrained. Recognizing this need, JPL developed the Airborne Snow Observatory (ASO), an imaging spectrometer and imaging LiDAR system, to quantify snow water equivalent and snow albedo, provide unprecedented knowledge of snow properties, and provide complete, robust inputs to snowmelt runoff models, water management models, and systems of the future. Critical in the design of the ASO system is the availability of snow water equivalent and albedo products within 24 hours of acquisition for timely constraint of snowmelt runoff forecast models. In spring 2013, ASO was deployed for its first year of a multi-year Demonstration Mission of weekly acquisitions in the Tuolumne River Basin (Sierra Nevada) and monthly acquisitions in the Uncompahgre River Basin (Colorado). The ASO data were used to constrain spatially distributed models of varying complexities and integrated into the operations of the O'Shaughnessy Dam on the Hetch Hetchy reservoir on the Tuolumne River. Here we present the first results from the ASO Demonstration Mission 1 along with modeling results with and without the constraint by the ASO's high spatial resolution and spatially

  1. Research relative to angular distribution of snow reflectance/snow cover characterization and microwave emission

    NASA Technical Reports Server (NTRS)

    Dozier, Jeff; Davis, Robert E.

    1987-01-01

    Remote sensing has been applied in recent years to monitoring snow cover properties for applications in hydrologic and energy balance modeling. In addition, snow cover has been recently shown to exert a considerable local influence on weather variables. Of particular importance is the potential of sensors to provide data on the physical properties of snow with high spatial and temporal resolution. Visible and near-infrared measurements of upwelling radiance can be used to infer near-surface properties through the calculation of albedo. Microwave signals usually come from deeper within the snow pack and thus provide depth-integrated information, which can be measured through clouds and does not relay on solar illumination.Fundamental studies examining the influence of snow properties on signals from various parts of the electromagnetic spectrum continue in part because of the promise of new remote sensors with higher spectral and spatial accuracy. Information in the visible and near-infrared parts of the spectrum comprise nearly all available data with high spatial resolution. Current passive microwave sensors have poor spatial resolution and the data are problematic where the scenes consist of mixed landscape features, but they offer timely observations that are independent of cloud cover and solar illumination.

  2. Microtomography of macroscopic snow samples

    NASA Astrophysics Data System (ADS)

    Matzl, M.; Schneebeli, M.; Steinfeld, D.; Steiner, S.; Heggli, M.

    2010-12-01

    During the last 10 years X-ray microtomography (micro-CT) has proved to be the first successful method to measure the true three-dimensional (3-D) structure of snow on the ground. Micro-CT is used to reconstruct 3-D microstructures as a source for numerical simulations, to conduct long-term observations of metamorphism or the behavior of snow under stress and to derive macroscopic parameters describing the microstructure of snow like specific surface area or density. However, micro-CT was confined to small samples with a typically evaluated size of 5 x 5 x 5 mm3. One reason for the small size was the limited computational power, the other the sample preparation. Based on the replica method for 3-D micro-CT samples introduced by Heggli et al. (2009), we are now able to visualize snow samples up to 70 mm height, and about 10 mm diameter, with a resolution of 10 μm. Because inclusion of small air bubbles during the casting process can not be avoided, we make two scans, one before and one after sublimation, the two scans are then registered and subtracted. After image segmentation and morphological image processing the replica can be analysed in the same way as direct snow measurements. Based on such samples, we imaged highly fragile snow samples, like new snow, buried surface hoar and other weak layers. The samples show a fascinating new image of how complex snow layers are. Most samples show strong density gradients within a structurally similar layer. We think that this technique will improve our understanding of snow metamorphism and snow properties. Heggli, M.; Frei, E.; Schneebeli, M., 2009: Instruments and Methods. Snow Replica method for three-dimensional X-ray microtomographic imaging. J. Glaciol. 55, 192: 631-639.

  3. Two-stream theory of reflectance of snow

    NASA Technical Reports Server (NTRS)

    Choudhury, B. J.; Chang, A. T. C.

    1979-01-01

    Spectral reflectance of snow under diffuse illumination is studied using the two-stream approximation of the radiative transfer equation. The scattering and absorption parameters of the radiative transfer equation - the single scattering albedo, the optical depth, and the integrated phase function are obtained from the grain size and density of snow. Analytical expressions for the intensity within the snowpack, the reflectance, and the asymptotic flux extinction coefficient, are given. Good agreement is shown between the theory and available experimental data on visible and near-infrared reflectance, and the asymptotic flux extinction coefficient. The theory may also be used to explain the observed effect of aging on the snow reflectance.

  4. Continuity of MODIS and VIIRS Snow-Cover Maps during Snowmelt in the Catskill Mountains in New York

    NASA Astrophysics Data System (ADS)

    Hall, D. K.; Riggs, G. A., Jr.; Roman, M. O.; DiGirolamo, N. E.

    2015-12-01

    We investigate the local and regional differences and possible biases between the Moderate Resolution Imaging Spectroradiometer (MODIS) and Visible-Infrared Imager Radiometer Suite (VIIRS) snow-cover maps in the winter of 2012 during snowmelt conditions in the Catskill Mountains in New York using a time series of cloud-gap filled daily snow-cover maps. The MODIS Terra instrument has been providing daily global snow-cover maps since February 2000 (Riggs and Hall, 2015). Using the VIIRS instrument, launched in 2011, NASA snow products are being developed based on the heritage MODIS snow-mapping algorithms, and will soon be available to the science community. Continuity of the standard NASA MODIS and VIIRS snow-cover maps is essential to enable environmental-data records (EDR) to be developed for analysis of snow-cover trends using a consistent data record. For this work, we compare daily MODIS and VIIRS snow-cover maps of the Catskill Mountains from 29 February through 14 March 2012. The entire region was snow covered on 29 February and by 14 March the snow had melted; we therefore have a daily time series available to compare normalized difference snow index (NDSI), as an indicator of snow-cover fraction. The MODIS and VIIRS snow-cover maps have different spatial resolutions (500 m for MODIS and 375 m for VIIRS) and different nominal overpass times (10:30 AM for MODIS Terra and 2:30 PM for VIIRS) as well as different cloud masks. The results of this work will provide a quantitative assessment of the continuity of the snow-cover data records for use in development of an EDR of snow cover.http://modis-snow-ice.gsfc.nasa.gov/Riggs, G.A. and D.K. Hall, 2015: MODIS Snow Products User Guide to Collection 6, http://modis-snow-ice.gsfc.nasa.gov/?c=userguides

  5. An Evaluation of Snow Initializations for NCEP Global and Regional Forecasting Models

    NASA Astrophysics Data System (ADS)

    Dawson, N.; Broxton, P. D.; Zeng, X.; Leuthold, M.; Barlage, M. J.; Holbrook, V. P.

    2015-12-01

    Snow plays a major role in land-atmosphere interactions, affecting the forecasting of weather, climate, and water resources. At the same time, the strong spatial heterogeneity in snow depth and snow water equivalent (SWE) makes it challenging to evaluate gridded snow quantities using in situ point measurements. First, we have developed a new method to upscale point measurements into gridded datasets. This method is found to be superior to three other methods. It is then used to generate daily snow depth and SWE datasets for water years 2012-2014 at eight 2° X 2° areas using in situ measurements from the COOP and SNOTEL networks. These areas encompass a variety of terrain characteristics over North America. These datasets are used to quantify the performance of daily snow depth and SWE initialization in the NCEP global forecasting models (GFS and CFS) and regional models (NAM and RAP). Model initializations which utilize AFWA snow depths (GFS, CFS, and NAM) are found to have a too shallow snow depth compared to our area averaged method. Across all areas and water years, our method averaged 0.58m (0.57m) of snow while the models averaged 0.18m (0.19m) with a mean absolute error of 0.42m (0.47m) for the global (regional) models utilizing AFWA data. These models also ended the snow season much too early on average (by more than a month). The RAP model, which cycles snow instead of initializing with AFWA snow depths, underestimates snow depth to a lesser degree and has a mean absolute error of 0.26m while ending the snow season about two weeks early on average. Compared with snow depth errors, SWE errors from GFS, CFS, and NAM are even larger because of their use of globally constant snow densities. Furthermore, we have evaluated the daily snow depth gridded data produced by the Canadian Meteorological Centre (CMC), which has been utilized as the best available ground truth in multiple studies. It is found that the CMC product underestimates snow depth and has a mean

  6. Modeling bulk density and snow water equivalent using daily snow depth observations.

    NASA Astrophysics Data System (ADS)

    McCreight, J. L.; Small, E. E.

    2013-10-01

    Bulk density is a fundamental property of snow relating its depth and mass. Previously, two simple models of bulk density (depending on snow depth, date, and location) have been developed to convert snow depth observations to snow water equivalent (SWE) estimates. However, these models were not intended for application at the daily time step. We develop a new model of bulk density for the daily timestep and demonstrate its improved skill over the existing models. Snow depth and density are negatively correlated at short (10 days) timescales while positively correlated at longer (90 days) timescales. We separate these scales of variability by modeling smoothed, daily snow depth (long time scales) and the observed positive and negative anomalies from the smoothed timeseries (short timescales) as separate terms. A climatology of fit is also included as a predictor variable. Over a half-million, daily observations of depth and SWE at 345 SNOTEL sites are used to fit models and evaluate their performance. For each location, we train the three models to the neighboring stations within 70 km, transfer the parameters to the location to be modeled, and evaluate modeled timeseries against the observations at that site. Our model exhibits improved statistics and qualitatively more-realistic behavior at the daily time step when sufficient local training data are available. We reduce density RMSE by 9.6% and 4.2% compared to previous models. Similarly, R2 increases from 0.46 to 0.52 to 0.56 across models. Removing the challenge of parameter transfer increases R2 scores for both the existing and new models, but the gain is greatest for the new model (R2 = 0.75). Our model shows general improvement over the existing models when data are more frequent than once every 5 days and at least 3 stations are available for training.

  7. The value of snow cover

    NASA Astrophysics Data System (ADS)

    Sokratov, S. A.

    2009-04-01

    Snow is the natural resource, like soil and water. It has specific properties which allow its use not just for skiing but also for houses cooling in summer (Swedish experience), for air fields construction (Arctic and Antarctic), for dams (north of Russia), for buildings (not only snow-houses of some Polar peoples but artistic hotel attracting tourists in Sweden), and as art material (Sapporo snow festival, Finnish events), etc. "Adjustment" of snow distribution and amount is not only rather common practice (avalanche-protection constructions keeping snow on slopes) but also the practice with long history. So-called "snow irrigation" was used in Russia since XIX century to protect winter crop. What is now named "artificial snow production", is part of much larger pattern. What makes it special—it is unavoidable in present climate and economy situation. 5% of national income in Austria is winter tourism. 50% of the economy in Savoy relay on winter tourism. In terms of money this can be less, but in terms of jobs and income involved this would be even more considerable in Switzerland. As an example—the population of Davos is 14000 in Summer and 50000 in Winter. Skiing is growing business. In present time you can find ski slopes in Turkey and Lebanon. To keep a cite suitable for attracting tourists you need certain amount of sunny days and certain amount of snow. The snow cannons are often the only way to keep a place running. On the other hand, more artificial snow does not necessary attract more tourists, while heavy natural snowfall does attract them. Artificial snow making is costly and requires infrastructure (ponds and electric lines) with very narrow range of weather conditions. Related companies are searching for alternatives and one of them can be "weather regulation" by distribution of some chemical components in clouds. It did not happen yet, but can happen soon. The consequences of such interference in Nature is hardly known. The ski tourism is not the

  8. The Goddard Snow Radiance Assimilation Project: An Integrated Snow Radiance and Snow Physics Modeling Framework for Snow/cold Land Surface Modeling

    NASA Technical Reports Server (NTRS)

    Kim, E.; Tedesco, M.; Reichle, R.; Choudhury, B.; Peters-Lidard C.; Foster, J.; Hall, D.; Riggs, G.

    2006-01-01

    Microwave-based retrievals of snow parameters from satellite observations have a long heritage and have so far been generated primarily by regression-based empirical "inversion" methods based on snapshots in time. Direct assimilation of microwave radiance into physical land surface models can be used to avoid errors associated with such retrieval/inversion methods, instead utilizing more straightforward forward models and temporal information. This approach has been used for years for atmospheric parameters by the operational weather forecasting community with great success. Recent developments in forward radiative transfer modeling, physical land surface modeling, and land data assimilation are converging to allow the assembly of an integrated framework for snow/cold lands modeling and radiance assimilation. The objective of the Goddard snow radiance assimilation project is to develop such a framework and explore its capabilities. The key elements of this framework include: a forward radiative transfer model (FRTM) for snow, a snowpack physical model, a land surface water/energy cycle model, and a data assimilation scheme. In fact, multiple models are available for each element enabling optimization to match the needs of a particular study. Together these form a modular and flexible framework for self-consistent, physically-based remote sensing and water/energy cycle studies. In this paper we will describe the elements and the integration plan. All modules will operate within the framework of the Land Information System (LIS), a land surface modeling framework with data assimilation capabilities running on a parallel-node computing cluster. Capabilities for assimilation of snow retrieval products are already under development for LIS. We will describe plans to add radiance-based assimilation capabilities. Plans for validation activities using field measurements will also be discussed.

  9. Snow reflectance from thematic mapper

    NASA Technical Reports Server (NTRS)

    Dozier, J.

    1983-01-01

    Calculations of snow reflectance in all 6 TM reflective bands (i.e., 1,2,3,4,5, and 7) using a delta Eddington model show that snow reflectance in bands 4,5, and 7 is sensitive to grain size. Efforts to interpret the surface optical grain size for the spectral extension of albedo are described. Results show the TM data include spectral channels suitable for snow/cloud discrimination and for snow albedo measurements that can be extended throughout the solar spectrum. Except for band 1, the dynamic range is large enough that saturation occurs only occasionally. The finer resolution gives much better detail on the snowcovered area and might make it possible to use textural information instead of the snowline as an index to the amount of snow melt runoff.

  10. Retrievals of Dust and Black Carbon Radiative Forcing in Snow using Imaging Spectroscopy

    NASA Astrophysics Data System (ADS)

    Seidel, F. C.; Painter, T.; Bryant, A. C.; Skiles, M.; Rittger, K. E.

    2012-12-01

    The reduction of snow albedo due to impurities of dust and black carbon provides an additional energy flux into a snowpack. This positive radiative forcing accelerates snowmelt, reduces snow cover duration and water runoff. Extensive information in time and space on dust and black carbon radiative forcing in snow are therefore required to model and predict water availability from snow and ice reservoirs. We present a novel processing chain to retrieve dust and black carbon radiative forcing in snow from orthorectified remote sensing data. We use JPL's classic version of the Airborne Visible / Infrared Imaging Spectrometer (AVIRIS) to measure upwelling solar radiance at the sensor level. The first stage of processing comprises the modeling and compensation for atmospheric and topographic influences on the AVIRIS data. The resulting directional surface reflectance factor is used to determine snow cover and to retrieve the snow grain size distribution. The latter requires a simple inversion strategy using a look up table with pre-calculated values of spectral ice absorption features, which depend to the first order on the snow grain size. Spectral snow albedo is determined by generalizing the directional snow surface spectral reflectance with the anisotropy factor given by the bidirectional reflectance distribution function. The integration over the visible spectral range of solar light yields the broadband snow albedo. The difference of the latter with a modeled clean snow albedo multiplied by the irradiance provides the spatial distribution of the radiative forcing in snow. In addition, we validate the spectral irradiance and directional surface reflectance of snow against independent in-situ reference observations in the Senator Beck Basin Study Area, Upper Colorado River Basin, San Juan Mountains, Colorado, USA. The results indicate that the products derived from AVIRIS data enable us to retrieve and monitor quantitative snow surface properties relevant to

  11. MODIS Collection 6 Data at the National Snow and Ice Data Center (NSIDC)

    NASA Astrophysics Data System (ADS)

    Fowler, D. K.; Steiker, A. E.; Johnston, T.; Haran, T. M.; Fowler, C.; Wyatt, P.

    2015-12-01

    For over 15 years, the NASA National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC) has archived and distributed snow and sea ice products derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on the NASA Earth Observing System (EOS) Aqua and Terra satellites. Collection 6 represents the next revision to NSIDC's MODIS archive, mainly affecting the snow-cover products. Collection 6 specifically addresses the needs of the MODIS science community by targeting the scenarios that have historically confounded snow detection and introduced errors into the snow-cover and fractional snow-cover maps even though MODIS snow-cover maps are typically 90 percent accurate or better under good observing conditions, Collection 6 uses revised algorithms to discriminate between snow and clouds, resolve uncertainties along the edges of snow-covered regions, and detect summer snow cover in mountains. Furthermore, Collection 6 applies modified and additional snow detection screens and new Quality Assessment protocols that enhance the overall accuracy of the snow maps compared with Collection 5. Collection 6 also introduces several new MODIS snow products, including a daily Climate Modelling Grid (CMG) cloud gap-filled (CGF) snow-cover map which generates cloud-free maps by using the most recent clear observations.. The MODIS Collection 6 sea ice extent and ice surface temperature algorithms and products are much the same as Collection 5; however, Collection 6 updates to algorithm inputs—in particular, the L1B calibrated radiances, land and water mask, and cloud mask products—have improved the sea ice outputs. The MODIS sea ice products are currently available at NSIDC, and the snow cover products are soon to follow in 2016 NSIDC offers a variety of methods for obtaining these data. Users can download data directly from an online archive or use the NASA Reverb Search & Order Tool to perform spatial, temporal, and parameter

  12. Facilitating the exploitation of ERTS imagery using snow enhancement techniques

    NASA Technical Reports Server (NTRS)

    Wobber, F. J. (Principal Investigator); Martin, K. R.; Sheffield, C.; Russell, O.; Amato, R. V.

    1972-01-01

    The author has identified the following significant results. Analysis of all available (Gemini, Apollo, Nimbus, NASA aircraft) small scale snow covered imagery has been conducted to develop and refine snow enhancement techniques. A detailed photographic interpretation of ERTS-simulation imagery covering the Feather River/Lake Tahoe area was completed and the 580-680nm. band was determined to be the optimum band for fracture detection. ERTS-1 MSS bands 5 and 7 are best suited for detailed fracture mapping. The two bands should provide more complete fracture detail when utilized in combination. Analysis of early ERTS-1 data along with U-2 ERTS simulation imagery indicates that snow enhancement is a viable technique for geological fracture mapping. A wealth of fracture detail on snow-free terrain was noted during preliminary analysis of ERTS-1 images 1077-15005-6 and 7, 1077-15011-5 and 7, and 1079-15124-5 and 7. A direct comparison of data yield on snow-free versus snow-covered terrain will be conducted within these areas following receipt of snow-covered ERTS-1 imagery.

  13. Interannual variability of snow and fluvial regimes in Andorra

    NASA Astrophysics Data System (ADS)

    Pesado, Cristina; Riba, Sergi; Pons, Marc; Lopez-Moreno, Juan Ignacio

    2016-04-01

    Highlands in Andorra are snow-dominated areas during all the winter and most of the spring season. Interannual snow variability in these areas has a strong and straight influence on the amount and seasonality of river regimes at the bottom of the valley where most of the population and water requirements are concentrated. The present study analyzes the temporal and spatial variability of the fluvial regimes in Andorra and seeks to understand the interplay of different topographic and climatic variables on this variability. For example, in mountainous regions temperature determines the state of precipitation and this state can significantly affect runoff formation. The interannual temporal and spatial variability of temperatures, pluviometry and different snow indices such as snow heights and days with snow on the ground has been studied for the last decade and correlated with the fluvial dynamics and its variability using discharge measurements. This study focus especially in the assessment of the role of snow and its seasonality in the fluvial regime dynamics and the influence in the torrential flows and flood hazard. Flood hazard, force to take protection measures, which need information about flood frequency and magnitude. For this, flow instrumental series are used, but usually they do not consider phenomena like snowmelt. This study contributes intends to better understand the interplay between snow and fluvial dynamics and improve the assessment of the availability of water resources as well as the requirements in terms of protection measures.

  14. Snow water equivalent modeling components in NewAge-JGrass

    NASA Astrophysics Data System (ADS)

    Formetta, G.; Kampf, S. K.; David, O.; Rigon, R.

    2014-05-01

    This paper presents a package of modified temperature-index-based snow water equivalent models as part of the hydrological modeling system NewAge-JGrass. Three temperature-based snow models are integrated into the NewAge-JGrass modeling system and use many of its components such as those for radiation balance (short wave radiation balance, SWRB), kriging (KRIGING), automatic calibration algorithms (particle swarm optimization) and tests of goodness of fit (NewAge-V), to build suitable modeling solutions (MS). Similarly to all the NewAge-JGrass components, the models can be executed both in raster and in vector mode. The simulation time step can be daily, hourly or sub-hourly, depending on user needs and availability of input data. The MS are applied on the Cache la Poudre River basin (CO, USA) using three test applications. First, daily snow water equivalent is simulated for three different measurement stations for two snow model formulations. Second, hourly snow water equivalent is simulated using all the three different snow model formulae. Finally, a raster mode application is performed to compute snow water equivalent maps for the whole Cache la Poudre Basin.

  15. Associations of Fast Food Restaurant Availability With Dietary Intake and Weight Among African Americans in the Jackson Heart Study, 2000–2004

    PubMed Central

    Diez Roux, Ana V.; Smith, Adam E.; Tucker, Katherine L.; Gore, Larry D.; Zhang, Lei; Wyatt, Sharon B.

    2011-01-01

    Objectives. We examined the associations of fast food restaurant (FFR) availability with dietary intake and weight among African Americans in the southeastern United States. Methods. We investigated cross-sectional associations of FFR availability with dietary intake and body mass index (BMI) and waist circumference in 4740 African American Jackson Heart Study participants (55.2 ±12.6 years, 63.3% women). We estimated FFR availability using circular buffers with differing radii centered at each participant's geocoded residential location. Results. We observed no consistent associations between FFR availability and BMI or waist circumference. Greater FFR availability was associated with higher energy intake among men and women younger than 55 years, even after adjustment for individual socioeconomic status. For each standard deviation increase in 5-mile FFR availability, the energy intake increased by 138 kilocalories (confidence interval [CI] = 70.53, 204.75) for men and 58 kilocalories (CI = 8.55, 105.97) for women. We observed similar associations for the 2-mile FFR availability, especially in men. FFR availability was also unexpectedly positively associated with total fiber intake. Conclusions. FFR availability may contribute to greater energy intake in younger African Americans who are also more likely to consume fast food. PMID:21551382

  16. Invertebrate response to snow goose herbivory on moist-soil vegetation

    USGS Publications Warehouse

    Sherfy, M.H.; Kirkpatrick, R.L.

    2003-01-01

    Foraging activity by snow geese (Chen caerulescens) often creates large areas devoid of vegetation ("eat-outs") in moist-soil impoundments and coastal wetlands. Open-water habitats that result from eat-outs may be valuable foraging areas for other wetland-dependent birds (i.e., waterfowl and shorebirds). However, few studies have examined the effects of goose-induced habitat changes on invertebrates, an important food source for both waterfowl and shorebirds. We quantified changes in abundance and composition of benthic invertebrates in response to snow goose herbivory in moist-soil impoundments at Prime Hook National Wildlife Refuge, Delaware, USA. We found invertebrate taxon richness and diversity and abundance of Chironomidae, Coleoptera, and Total Invertebrates to be higher in goose-excluded sites than in adjacent eat-outs. These effects were most pronounced during January, February, and early April. We also measured invertebrate abundance in shorebird exclosures in eat-outs but found few detectable effects of shorebird predation on invertebrates. Our study demonstrated that abundant snow geese may negatively influence availability of invertebrates for other nonbreeding waterbirds, suggesting that management actions to reduce local goose populations or deter feeding in impoundments may be warranted.

  17. Gene expression changes associated with the developmental plasticity of sea urchin larvae in response to food availability

    PubMed Central

    Carrier, Tyler J.; King, Benjamin L.; Coffman, James A.

    2016-01-01

    Planktotrophic sea urchin larvae are developmentally plastic: in response to food scarcity, development of the juvenile rudiment is suspended and larvae instead develop elongated arms, increasing feeding capacity and extending larval life. Here, data are presented on the effect of different feeding regimes on gene expression in larvae of the green sea urchin Strongylocentrotus droebachiensis. These data indicate that during periods of starvation, larvae down-regulate genes involved in growth and metabolic activity while up-regulating genes involved in lipid transport, environmental sensing and defense. Additionally, we show that starvation increases FoxO activity, and that in well-fed larvae rapamycin treatment impedes rudiment growth, indicating that the latter requires TOR activity. These results suggest that the developmental plasticity of echinoplutei is regulated by genes known to control aging and longevity in other animals. PMID:26124444

  18. Integrated Northern Hemisphere Terrestrial Snow Extent Climate Datasets

    NASA Astrophysics Data System (ADS)

    Robinson, D. A.; Estilow, T. W.; Henderson, G.; Mote, T. L.; Hall, D. K.

    2011-12-01

    Multiple satellite-derived sources of snow cover extent (SCE), snow-cover fraction (SCF) and melting snow over Northern Hemisphere (NH) lands have been used to produce two integrated datasets. One dataset is long enough (over 30 years) to be considered a climate data record (CDR), a second has data of a quality suitable for a CDR but lacks the duration to be recognized as such. These datasets provide state-of-the-art NH snow information in multiple formats and on multiple time steps for the research community, decision-makers and stakeholders. To generate the CDR, a low-resolution, long-term SCE record available on a weekly timescale derived from a thorough reanalysis of NOAA satellite-derived maps of NH continental SCE dating back to the late 1966 was integrated with a newly generated 1979-present microwave SCE and melting snow product. A 100 km Equal-Area Scalable Earth version 2 grid (EASE2) developed at the National Snow and Ice Data Center is used for this CDR. The shorter-term integrated dataset has a higher spatial resolution (25km EASE2) and is daily. It was developed to assess the level of agreement between the NOAA Interactive Multisensor Snow and Ice Mapping System SCE, the previously mentioned microwave product and the MODIS cloud gap filled SCF product. The period of overlap for these three datasets spans from 2000-present. We will discuss methodologies of identifying SCE, melting snow and SCF amongst the contributing data sources, techniques of integrating these products into the CDR and 25km products and confidence assessments. We will also provide an overall evaluation of how these datasets improve regional to NH scale monitoring of snow cover.

  19. Satellite and Surface Perspectives of Snow Extent in the Southern Appalachian Mountains

    NASA Technical Reports Server (NTRS)

    Sugg, Johnathan W.; Perry, Baker L.; Hall, Dorothy K.

    2012-01-01

    Assessing snow cover patterns in mountain regions remains a challenge for a variety of reasons. Topography (e.g., elevation, exposure, aspect, and slope) strongly influences snowfall accumulation and subsequent ablation processes, leading to pronounced spatial variability of snow cover. In-situ observations are typically limited to open areas at lower elevations (<1000 m). In this paper, we use several products from the Moderate Resolution Imaging Spectroradiometer (MODIS) to assess snow cover extent in the Southern Appalachian Mountains (SAM). MODIS daily snow cover maps and true color imagery are analyzed after selected snow events (e.g., Gulf/Atlantic Lows, Alberta Clippers, and Northwest Upslope Flow) from 2006 to 2012 to assess the spatial patterns of snowfall across the SAM. For each event, we calculate snow cover area across the SAM using MODIS data and compare with the Interactive Multi-sensor Snow and ice mapping system (IMS) and available in-situ observations. Results indicate that Gulf/Atlantic Lows are typically responsible for greater snow extent across the entire SAM region due to intensified cyclogenesis associated with these events. Northwest Upslope Flow events result in snow cover extent that is limited to higher elevations (>1000 m) across the SAM, but also more pronounced along NW aspects. Despite some limitations related to the presence of ephemeral snow or cloud cover immediately after each event, we conclude that MODIS products are useful for assessing the spatial variability of snow cover in heavily forested mountain regions such as the SAM.

  20. The Snows of Enceladus

    NASA Astrophysics Data System (ADS)

    Schenk, P.; Schmidt, J.; White, O.

    2011-10-01

    The icy south polar plumes of Enceladus make for a spectacular effect in the Saturn system (e.g., the Ering), but also profoundly alter the surface of Enceladus itself. Recent models of the plume particle dynamics predict that the heavier particles will reaccrete, effectively "snowing" fine-grained debris back onto the surface in discrete patterns [1], depending on the actual distribution of ejection sites. The densest fallout pattern is dominated by two scytheshaped lobes extending northward from the South-Polar-Terrains along the 40 and 220W longitudes. Recent color mapping of Enceladus demonstrates that IR/UV color asymmetries across the surface match these predicted patterns astonishingly well [2]. Theory and observation therefore confirm the apparent formation of a blanket of very small particles covering most of the surface of Enceladus to different depths, depending on location and plume source changes.

  1. Recent increase in snow-melt area in the Greenland Ice sheet as an indicator of the effect of reduced surface albedo by snow impurities

    NASA Astrophysics Data System (ADS)

    Rikiishi, K.

    2008-12-01

    Recent rapid decline of cryosphere including mountain glaciers, sea ice, and seasonal snow cover tends to be associated with global warming. However, positive feedback is likely to operate between the cryosphere and air temperature, and then it may not be so simple to decide the cause-and-effect relation between them. The theory of heat budget for snow surface tells us that sensible heat transfer from the air to the snow by atmospheric warming by 1°C is about 10 W/m2, which is comparable with heat supply introduced by reduction of the snow surface albedo by only 0.02. Since snow impurities such as black carbon and soil- origin dusts have been accumulated every year on the snow surface in snow-melting season, it is very important to examine whether the snow-melting on the ice sheets, mountain glaciers, and sea ice is caused by global warming or by accumulated snow impurities originated from atmospheric pollutants. In this paper we analyze the dataset of snow-melt area in the Greenland ice sheet for the years 1979 - 2007 (available from the National Snow and Ice Data Center), which is reduced empirically from the satellite micro-wave observations by SMMR and SMM/I. It has been found that, seasonally, the snow-melt area extends most significantly from the second half of June to the first half of July when the sun is highest and sunshine duration is longest, while it doesn't extend any more from the second half of July to the first half of August when the air temperature is highest. This fact may imply that sensible heat required for snow-melting comes from the solar radiation rather than from the atmosphere. As for the interannual variation of snow-melt area, on the other hand, we have found that the growth rate of snow-melt area gradually increases from July, to August, and to the first half of September as the impurities come out to and accumulated at the snow surface. However, the growth rate is almost zero in June and the second half of September when fresh snow

  2. Effects of food availability and climate on activity patterns of western black-crested gibbons in an isolated forest fragment in southern Yunnan, China.

    PubMed

    Ni, Qingyong; Xie, Meng; Grueter, Cyril C; Jiang, Xuelong; Xu, Huailiang; Yao, Yongfang; Zhang, Mingwang; Li, Yan; Yang, Jiandong

    2015-10-01

    The critically endangered western black-crested gibbon (Nomascus concolor) is distributed in isolated habitat fragments in northern Vietnam, northwestern Laos, and southwestern China. To assess the behavioral adaptation of this species to forest fragments and its response to seasonal variation in food availability and climate, we present activity patterns of a group inhabiting an isolated forest based on two year-long studies in southern Yunnan, China. Annually, the gibbons spent nearly half of their active time resting, followed by moving and feeding. In both study periods, the time allocated to activities varied significantly between months, and was affected by food availability and climate factors. The group delayed retirement when tree fruit was abundant, and they decreased time spent moving and playing during periods of low fruit availability. In the cold months, the gibbons decreased time spent moving, and they decreased active time and resting time when rainfall was high. The results suggest that the group may seek to maximize net energy intake like energy maximizers when high quality food is most available, and adopt an energy-conserving strategy during periods of lower food availability and temperature. The gibbons showed similar diurnal variation in activity patterns to a group inhabiting a continuous forest at Dazhaizi, Mt. Wuliang, central Yunnan. However, they had a longer active period, and devoted more time to resting but less time to feeding. The individuals also spent lower percentages of time engaged in social behavior than those at Dazhaizi. These differences may be due to their smaller home range and unusual group composition caused by habitat fragmentation. PMID:26275664

  3. Snow Water Equivalent distribution in the Western Alps: the activities in Aosta Valley

    NASA Astrophysics Data System (ADS)

    Morra di Cella, Umberto; Cremonese, Edoardo; Diotri, Fabrizio; Pogliotti, Paolo; Galvagno, Marta

    2010-05-01

    Snow can be seen as a water reservoir; it plays an important role in the hydrological cycle and climatology of the Earth. Its importance is enhanced in mountainous region where yearly streamflow is strongly controlled by snowmelt dynamics. Climate Change can influence precipitation distribution and snow cover persistence and thus can negatively affect water availability. The knowledge of the amount of water stored in the snow, its spatial distribution and its temporal evolution dynamics, is an issue of increasing importance. The Aosta Valley is a region in the western Italian Alps with a continental climate which can be strongly affected by a reduction of water availabilty. For these reasons, from 2006, the Environmental Protection Agency of Aosta Valley (ARPA Valle d'Aosta) is developping modelling activities aiming to monitor Snow Water Equivalent (SWE) distribution at regional scale (3000 Km2). To estimate SWE distribution we need to know the extent of the snow covered area (SCA) and how snow height (SH) and snow density (SD) are distributed in space. Because of the specific spectral reflectance of snow, SCA can be discriminated from snow-free areas using optical remote sensing methods. The MODIS standard snow-cover products (MOD10A2 maximum snow extent - 8 days composite) can be freely downloaded from the web and their spatial resolution (500 m) is well suited for the application at regional scale. Snow height data can be obtained from automatic measurements (ultrasonic distance sensors) done by the regional meteorological station networks or by manual measurements of snow depth, while snow density has to be manually measured in snow pits. It follows that SH dataset are often more data-rich than SD ones. Snow height and snow density spatial distribution is modelled using multiple regression models between the snow parameters and many morphological variables (e.g. elevation, slope, incoming solar radiation, topographical parameters, ...). Regression models are

  4. Snow Cover Changes over Northern Eurasia from in Situ Observations

    NASA Astrophysics Data System (ADS)

    Bulygina, O. N.; Razuvaev, V. N.; Groisman, P. Ya; Korshunova, N. N.

    2012-04-01

    Data. In addition to a standard suite of synoptic snow observations (snow depth, snow type, state of the ground at the meteorological site and its surroundings), we used in our study the national snow survey data set archived at the Russian Institute for Hydrometeorological Information. This dataset has routine snow surveys run throughout the cold season each decade (during the intense snowmelt, each 5 days) at all meteorological stations of the former USSR, thereafter in Russia, since 1966. Prior to 1966 snow surveys are also available but the methodology of observations has substantially changed at that year and our analysis includes data of 958 Russian stations from 1966 to 2011 with a minimal number of missing observations. Surveys run separately along all types of environment typical for the site for 1 to 2 km, describing the current snow cover properties such as snow density, depth, water equivalent, and characteristics of snow and ice crust. Background. During the period of widespread instrumental observations in Northern Eurasia (since 1881), the annual surface air temperature has increased by 1.5°C (in the winter season by 3°C. Close to the north in the Arctic Ocean, the late summer sea ice extent has decreased by 40% providing a near-infinite source of water vapor for the dry Arctic atmosphere in the early cold season months. There is also evidence of more frequent thaw days over northern latitudes of western Eurasia. All these factors affect the state of snow cover. Methods. Regional analysis of snow cover data was carried out using quasi-homogeneous climatic regions. Maps (climatology, trends) are presented mostly for visualization purposes. The area-averaging technique using station values converted to anomalies with respect to a common reference period (in this study, 1966-2011). Anomalies were arithmetically averaged first within 1°N x 2°E grid cells and thereafter by a weighted average value derived over the quasi-homogeneous climatic regions

  5. Improving the Terrain-Based Parameter for the Assessment of Snow Redistribution in the Col du Lac Blanc Area and Comparisons with TLS Snow Depth Data

    NASA Astrophysics Data System (ADS)

    Schön, Peter; Prokop, Alexander; Naaim-Bouvet, Florence; Nishimura, Kouichi; Vionnet, Vincent; Guyomarc'h, Gilbert

    2014-05-01

    Wind and the associated snow drift are dominating factors determining the snow distribution and accumulation in alpine areas, resulting in a high spatial variability of snow depth that is difficult to evaluate and quantify. The terrain-based parameter Sx characterizes the degree of shelter or exposure of a grid point provided by the upwind terrain, without the computational complexity of numerical wind field models. The parameter has shown to qualitatively predict snow redistribution with good reproduction of spatial patterns, but has failed to quantitatively describe the snow redistribution, and correlations with measured snow heights were poor. The objective of our research was to a) identify the sources of poor correlations between predicted and measured snow re-distribution and b) improve the parameters ability to qualitatively and quantitatively describe snow redistribution in our research area, the Col du Lac Blanc in the French Alps. The area is at an elevation of 2700 m and particularly suited for our study due to its constant wind direction and the availability of data from a meteorological station. Our work focused on areas with terrain edges of approximately 10 m height, and we worked with 1-2 m resolution digital terrain and snow surface data. We first compared the results of the terrain-based parameter calculations to measured snow-depths, obtained by high-accuracy terrestrial laser scan measurements. The results were similar to previous studies: The parameter was able to reproduce observed patterns in snow distribution, but regression analyses showed poor correlations between terrain-based parameter and measured snow-depths. We demonstrate how the correlations between measured and calculated snow heights improve if the parameter is calculated based on a snow surface model instead of a digital terrain model. We show how changing the parameter's search distance and how raster re-sampling and raster smoothing improve the results. To improve the parameter

  6. Snow metamorphism: A fractal approach.

    PubMed

    Carbone, Anna; Chiaia, Bernardino M; Frigo, Barbara; Türk, Christian

    2010-09-01

    Snow is a porous disordered medium consisting of air and three water phases: ice, vapor, and liquid. The ice phase consists of an assemblage of grains, ice matrix, initially arranged over a random load bearing skeleton. The quantitative relationship between density and morphological characteristics of different snow microstructures is still an open issue. In this work, a three-dimensional fractal description of density corresponding to different snow microstructure is put forward. First, snow density is simulated in terms of a generalized Menger sponge model. Then, a fully three-dimensional compact stochastic fractal model is adopted. The latter approach yields a quantitative map of the randomness of the snow texture, which is described as a three-dimensional fractional Brownian field with the Hurst exponent H varying as continuous parameters. The Hurst exponent is found to be strongly dependent on snow morphology and density. The approach might be applied to all those cases where the morphological evolution of snow cover or ice sheets should be conveniently described at a quantitative level. PMID:21230135

  7. Application of snow models to snow removal operations on the Going-to-the-Sun Road, Glacier National Park

    USGS Publications Warehouse

    Fagre, Daniel B.; Klasner, Frederick L.

    2000-01-01

    Snow removal, and the attendant avalanche risk for road crews, is a major issue on mountain highways worldwide. The Going-to-the-Sun Road is the only road that crosses Glacier National Park, Montana. This 80-km highway ascends over 1200m along the wall of a glaciated basin and crosses the continental divide. The annual opening of the road is critical to the regional economy and there is public pressure to open the road as early as possible. Despite the 67-year history of snow removal activities, few stat on snow conditions at upper elevations were available to guide annual planning for the raod opening. We examined statistical relationships between the opening date and nearby SNOTEL data on snow water equivalence (WE) for 30 years. Early spring SWE (first Monday in April) accounted for only 33% of the variance in road opening dates. Because avalanche spotters, used to warn heavy equipment operators of danger, are ineffective during spring storms or low-visibility conditions, we incorporated the percentage of days with precipitation during plowing as a proxy for visibility. This improved the model's predictive power to 69%/ A mountain snow simulator (MTSNOW) was used to calculate the depth and density of snow at various points along the road and field data were collected for comparison. MTSNOW underestimated the observed snow conditions, in part because it does not yet account for wind redistribution of snow. The severe topography of the upper reaches of the road are subjected to extensive wind redistribution of snow as evidence by the formation of "The Big Drift" on the lee side of Logan Pass.

  8. Applications systems verification and transfer project. Volume 1: Operational applications of satellite snow cover observations: Executive summary. [usefulness of satellite snow-cover data for water yield prediction

    NASA Technical Reports Server (NTRS)

    Rango, A.

    1981-01-01

    Both LANDSAT and NOAA satellite data were used in improving snowmelt runoff forecasts. When the satellite snow cover data were tested in both empirical seasonal runoff estimation and short term modeling approaches, a definite potential for reducing forecast error was evident. A cost benefit analysis run in conjunction with the snow mapping indicated a $36.5 million annual benefit accruing from a one percent improvement in forecast accuracy using the snow cover data for the western United States. The annual cost of employing the system would be $505,000. The snow mapping has proven that satellite snow cover data can be used to reduce snowmelt runoff forecast error in a cost effective manner once all operational satellite data are available within 72 hours after acquisition. Executive summaries of the individual snow mapping projects are presented.

  9. Association between cerebral cannabinoid 1 receptor availability and body mass index in patients with food intake disorders and healthy subjects: a [(18)F]MK-9470 PET study.

    PubMed

    Ceccarini, J; Weltens, N; Ly, H G; Tack, J; Van Oudenhove, L; Van Laere, K

    2016-01-01

    Although of great public health relevance, the mechanisms underlying disordered eating behavior and body weight regulation remain insufficiently understood. Compelling preclinical evidence corroborates a critical role of the endocannabinoid system (ECS) in the central regulation of appetite and food intake. However, in vivo human evidence on ECS functioning in brain circuits involved in food intake regulation as well as its relationship with body weight is lacking, both in health and disease. Here, we measured cannabinoid 1 receptor (CB1R) availability using positron emission tomography (PET) with [(18)F]MK-9470 in 54 patients with food intake disorders (FID) covering a wide body mass index (BMI) range (anorexia nervosa, bulimia nervosa, functional dyspepsia with weight loss and obesity; BMI range=12.5-40.6 kg/m(2)) and 26 age-, gender- and average BMI-matched healthy subjects (BMI range=18.5-26.6 kg/m(2)). The association between regional CB1R availability and BMI was assessed within predefined homeostatic and reward-related regions of interest using voxel-based linear regression analyses. CB1R availability was inversely associated with BMI in homeostatic brain regions such as the hypothalamus and brainstem areas in both patients with FID and healthy subjects. However, in FID patients, CB1R availability was also negatively correlated with BMI throughout the mesolimbic reward system (midbrain, striatum, insula, amygdala and orbitofrontal cortex), which constitutes the key circuit implicated in processing appetitive motivation and hedonic value of perceived food rewards. Our results indicate that the cerebral homeostatic CB1R system is inextricably linked to BMI, with additional involvement of reward areas under conditions of disordered body weight. PMID:27404285

  10. Bioaccumulation and food-chain analysis for evaluating ecological risks in terrestrial and wetland habitats: Availability-transfer factors (ATFs) in soil {r_arrow} soil macroinvertebrate {r_arrow} amphibian food chains

    SciTech Connect

    Linder, G.; Bollman, M.; Callahan, C.; Gillette, C.; Nebeker, A.; Wilborn, D.

    1998-12-31

    As part of the ecological risk assessment process for terrestrial and wetland habitats, the evaluation of bioaccumulative chemicals of concern (BCCs) is frequently pursued through food-chain analysis with a subsequent comparison of daily doses to benchmark toxicity reference values, when available. Food-chain analysis has frequently been applied to the analysis of exposure to BCCs identified as chemicals of potential ecological concern (COPECs) in the ecological risk assessment process. Here, designed studies focused on wetland food-chains such as hydric soil {r_arrow} soil macroinvertebrate {r_arrow} amphibian and terrestrial food-chains such as soil {r_arrow} plant {r_arrow} small mammal illustrate an approach for the derivation and validation of trophic transfer factors for metals considered as COPECs such as cadmium, chromium, copper, lead, and zinc. The results clearly indicate that the transfer of chemicals between trophic levels is critical in the bioaccumulation process in wetland and terrestrial food-chains and is influenced by numerous interacting abiotic and biotic factors, including physicochemical properties of soil, and the role, if any, that the metal has in the receptor as a required trace element.

  11. Satellites - New global observing techniques for ice and snow

    NASA Technical Reports Server (NTRS)

    Gloersen, P.; Salomonson, V. V.

    1975-01-01

    The possibility that the variation in areal extent of the snow cover may be related by empirical means to the average monthly run-off in a given watershed was demonstrated by comparing run-off records from the Indus River Basin in south-east Asia with a series of snow-cover maps obtained from Nimbus-3 and 4 imagery. Similar studies using the higher spatial resolution available with ERTS-1 imagery were carried out for the Wind River Mountains watersheds in Wyoming, where it was found that the empirical relationship varied with mean elevation of the watershed. In addition, digital image enhancement techniques are shown to be useful for identifying glacier features thought to be related to extent of snow cover, moraine characteristics, debris coverage, and the like. Finally, longer wavelength observations using sensors on board the Nimbus-5 satellite are shown to be useful for indicating crystal size distributions and onset of melting on glacier snow cover.

  12. Remote sensing: Snow monitoring tool for today and tomorrow

    NASA Technical Reports Server (NTRS)

    Rango, A.

    1977-01-01

    Various types of remote sensing are now available or will be in the future for snowpack monitoring. Aircraft reconnaissance is now used in a conventional manner by various water resources agencies to obtain information on snowlines, depth, and melting of the snowpack for forecasting purposes. The use of earth resources satellites for mapping snowcovered area, snowlines, and changes in snowcover during the spring has increased during the last five years. Gamma ray aircraft flights, although confined to an extremely low altitude, provide a means for obtaining valuable information on snow water equivalent. The most recently developed remote sensing technology for snow, namely, microwave monitoring, has provided initial results that may eventually allow us to infer snow water equivalent or depth, snow wetness, and the hydrologic condition of the underlying soil.

  13. Exploitation of ERTS-1 imagery utilizing snow enhancement techniques

    NASA Technical Reports Server (NTRS)

    Wobber, F. J.; Martin, K. R.

    1973-01-01

    Photogeological analysis of ERTS-simulation and ERTS-1 imagery of snowcovered terrain within the ERAP Feather River site and within the New England (ERTS) test area provided new fracture detail which does not appear on available geological maps. Comparative analysis of snowfree ERTS-1 images has demonstrated that MSS Bands 5 and 7 supply the greatest amount of geological fracture detail. Interpretation of the first snow-covered ERTS-1 images in correlation with ground snow depth data indicates that a heavy blanket of snow (more than 9 inches) accentuates major structural features while a light "dusting", (less than 1 inch) accentuates more subtle topographic expressions. An effective mail-based method for acquiring timely ground-truth (snowdepth) information was established and provides a ready correlation of fracture detail with snow depth so as to establish the working limits of the technique. The method is both efficient and inexpensive compared with the cost of similarly scaled direct field observations.

  14. Advances in Airborne Altimetric Techniques for the Measurement of Snow on Arctic Sea Ice

    NASA Astrophysics Data System (ADS)

    Newman, T.; Farrell, S. L.; Richter-Menge, J.; Elder, B. C.; Ruth, J.; Connor, L. N.

    2014-12-01

    Current sea ice observations and models indicate a transition towards a more seasonal Arctic ice pack with a smaller, and geographically more variable, multiyear ice component. To gain a comprehensive understanding of the processes governing this transition it is important to include the impact of the snow cover, determining the mechanisms by which snow is both responding to and forcing changes to the sea ice pack. Data from NASA's Operation IceBridge (OIB) snow radar system, which has been making yearly surveys of the western Arctic since 2009, offers a key resource for investigating the snow cover. In this work, we characterize the OIB snow radar instrument response to ascertain the location of 'side-lobes', aiding the interpretation of snow radar data. We apply novel wavelet-based techniques to identify the primary reflecting interfaces within the snow pack from which snow depth estimates are derived. We apply these techniques to the range of available snow radar data collected over the last 6 years during the NASA OIB mission. Our results are validated through comparison with a range of in-situ data. We discuss the impact of sea ice surface morphology on snow radar returns (with respect to ice type) and the topographic conditions over which accurate snow-radar-derived snow depths may be obtained. Finally we present improvements to in situ survey design that will allow for both an improved sampling of the snow radar footprint and more accurate assessment of the uncertainties in radar-derived snow depths in the future.

  15. Nutritional treatment for inborn errors of metabolism: indications, regulations, and availability of medical foods and dietary supplements using phenylketonuria as an example.

    PubMed

    Camp, Kathryn M; Lloyd-Puryear, Michele A; Huntington, Kathleen L

    2012-09-01

    Medical foods and dietary supplements are used to treat rare inborn errors of metabolism (IEM) identified through state-based universal newborn screening. These products are regulated under Food and Drug Administration (FDA) food and dietary supplement statutes. The lack of harmony in terminology used to refer to medical foods and dietary supplements and the misuse of words that imply that FDA regulates these products as drugs have led to confusion. These products are expensive and, although they are used for medical treatment of IEM, third-party payer coverage of these products is inconsistent across the United States. Clinicians and families report termination of coverage in late adolescence, failure to cover treatment during pregnancy, coverage for select conditions only, or no coverage. We describe the indications for specific nutritional treatment products for IEM and their regulation, availability, and categorization. We conclude with a discussion of the problems that have contributed to the paradox of identifying individuals with IEM through newborn screening but not guaranteeing that they receive optimal treatment. Throughout the paper, we use the nutritional treatment of phenylketonuria as an example of IEM treatment. PMID:22854513

  16. Copepod community growth rates in relation to body size, temperature, and food availability in the East China Sea: a test of metabolic theory of ecology

    NASA Astrophysics Data System (ADS)

    Lin, K. Y.; Sastri, A. R.; Gong, G. C.; Hsieh, C. H.

    2013-03-01

    Zooplankton play an essential role in marine food webs, and understanding how community-level growth rates of zooplankton vary in the field is critical for predicting how marine ecosystem function may vary in the face of environmental changes. Here, we used the artificial cohort method to examine the effects of temperature, body size, and chlorophyll concentration (a proxy for food) on weight-specific growth rates for copepod communities in the East China Sea. Specifically, we tested the hypothesis that copepod community growth rates can be described by the metabolic theory of ecology (MTE), linking spatio-temporal variation of copepod growth rate with temperature and their body size. Our results generally agree with predictions made by the MTE and demonstrate that weight-specific growth rates of copepod communities in our study area are positively related with temperature and negatively related to body size. However, the regression coefficients of body size do not approach the theoretical predictions. Furthermore, we find that the deviation from the MTE predictions may be partly attributed to the effect of food availability (which is not explicitly accounted for by the MTE). In addition, significant difference in the coefficients of temperature and body size exists among taxonomic groups. Our results suggest that considering the effects of food limitation and taxonomy is necessary to better understand copepod growth rates under in situ conditions, and such effects on the MTE-based predictions need further investigation.

  17. Copepod community growth rates in relation to body size, temperature, and food availability in the East China Sea: a test of metabolic theory of ecology

    NASA Astrophysics Data System (ADS)

    Lin, K. Y.; Sastri, A.; Gong, G. C.; Hsieh, C. H.

    2012-11-01

    Zooplankton play an essential role in marine food webs and understanding how community-level growth rates of zooplankton vary in the field is critical for predicting how marine ecosystem function may vary in the face of environmental changes. Here, we used the artificial cohort method to examine the effects of temperature, body size, and chlorophyll concentration (a proxy for food) on weight-specific growth rates for copepod communities in the East China Sea. Specifically, we tested the hypothesis that copepod community growth rates can be described by the metabolic theory of ecology (MTE), linking spatio-temporal variation of copepod growth rate with temperature and their body size. Our results generally agree with predictions made by the MTE and demonstrate that weight-specific growth rates of copepod communities in our study area are positively related with temperature and negatively related to body size. However, the regression coefficients of body size do not approach the theoretical predictions. Furthermore, we find that the deviation from the MTE predictions may be partly attributed to the effect of food availability (which is not explicitly accounted for by the MTE). In addition, significant difference in the coefficients of temperature and body size exists among taxonomic groups. Our results suggest that considering the effects of food limitation and taxonomy is necessary to better understand copepod growth rates under in situ conditions, and such effects on the MTE-based prediction needs further investigation.

  18. Family Meal Frequency and Association with Household Food Availability in United States Multi-Person Households: National Health and Nutrition Examination Survey 2007-2010

    PubMed Central

    Newman, Sarah L.; Tumin, Rachel; Andridge, Rebecca; Anderson, Sarah E.

    2015-01-01

    Objective Family meals are associated with a healthier diet among children and adolescents, but how family meal frequency varies in the U.S. population overall by household food availability and sociodemographic characteristics is not well characterized. Design The U.S. National Health and Nutrition Examination Survey 2007–2010 assessed the frequency of family meals eaten at home in the past week and the household availability of fruits, dark green vegetables, salty snacks, and sugar-sweetened beverages. Setting Computer-assisted face-to-face interviews with a selected adult (≥18 years) who owned or rented the home (i.e., the household reference person). Subjects We analyzed information on family meal frequency for 18,031 participants living in multi-person households in relation to sociodemographic characteristics and food availability. Results Among the U.S. population living in households of two or more individuals, the prevalence (95% confidence interval) of having 0–2, 3–6 and ≥7 family meals/week was 18.0% (16.6–19.3), 32.4% (31.0–33.9), and 49.6% (47.8–51.4), respectively. Greater household availability of fruits and dark green vegetables and less availability of salty snacks and sugar-sweetened beverages was associated with more frequent family meals. Family meals were more prevalent in low-income households and those in which the reference person was ≥65 years, married, or had less than high school education. Conclusions About half of the US population living in households of 2 or more people shares meals frequently with their family at home. Family meal frequency was positively associated with a healthier pattern of household food availability. PMID:26636976

  19. An Integrated Snow Radiance and Snow Physics Modeling Framework for Cold Land Surface Modeling

    NASA Technical Reports Server (NTRS)

    Kim, Edward J.; Tedesco, Marco

    2006-01-01

    Recent developments in forward radiative transfer modeling and physical land surface modeling are converging to allow the assembly of an integrated snow/cold lands modeling framework for land surface modeling and data assimilation applications. The key elements of this framework include: a forward radiative transfer model (FRTM) for snow, a snowpack physical model, a land surface water/energy cycle model, and a data assimilation scheme. Together these form a flexible framework for self-consistent remote sensing and water/energy cycle studies. In this paper we will describe the elements and the integration plan. Each element of this framework is modular so the choice of element can be tailored to match the emphasis of a particular study. For example, within our framework, four choices of a FRTM are available to simulate the brightness temperature of snow: Two models are available to model the physical evolution of the snowpack and underlying soil, and two models are available to handle the water/energy balance at the land surface. Since the framework is modular, other models-physical or statistical--can be accommodated, too. All modules will operate within the framework of the Land Information System (LIS), a land surface modeling framework with data assimilation capabilities running on a parallel-node computing cluster at the NASA Goddard Space Flight Center. The advantages of such an integrated modular framework built on the LIS will be described through examples-e.g., studies to analyze snow field experiment observations, and simulations of future satellite missions for snow and cold land processes.

  20. Combining snowpack modeling and terrestrial laser scanner observations improves the simulation of small scale snow dynamics

    NASA Astrophysics Data System (ADS)

    Revuelto, Jesús; Vionnet, Vincent; López-Moreno, Juan-Ignacio; Lafaysse, Matthieu; Morin, Samuel

    2016-02-01

    Accurately determining the snowpack distribution in mountain areas is complex because of the difficulty of establishing over large areas the spatial distribution of all variables that define the state of the snowpack at any particular time. In this study we used distributed snowpack simulations that were corrected throughout the snow season using snow depth distributions measured using a terrestrial laser scanner (TLS). This enabled us to obtain a more realistic view of the small scale spatial evolution of the mass and depth of the snowpack. Several TLS snow depth data acquisitions were made during the 2012, 2013 and 2014 snow seasons in a small catchment (55 ha) located in the central Spanish Pyrenees. The Crocus snowpack model was used to simulate the snowpack evolution on a 5-m grid, based on downscaled meteorological variables obtained using SAFRAN reanalysis. The simulation was stopped when a snow depth distribution map measured using the TLS was available, and the modeled snow depth distribution was adjusted to match the observed snow depth. The snow simulation was then restarted and run until the next TLS acquisition was available. Prior to matching the simulation and observational data, both snowpack distributions were compared. The results for the three snow seasons showed an improvement in the snowpack simulation, especially with respect to simulating the influence of small scale topographic effects on the observed snowpack distribution, and also the timing of snow melt dynamics.

  1. Influence of temperature and precipitation variability on near-term snow trends

    NASA Astrophysics Data System (ADS)

    Mankin, Justin S.; Diffenbaugh, Noah S.

    2015-08-01

    Snow is a vital resource for a host of natural and human systems. Global warming is projected to drive widespread decreases in snow accumulation by the end of the century, potentially affecting water, food, and energy supplies, seasonal heat extremes, and wildfire risk. However, over the next few decades, when the planning and implementation of current adaptation responses are most relevant, the snow response is more uncertain, largely because of uncertainty in regional and local precipitation trends. We use a large (40-member) single-model ensemble climate model experiment to examine the influence of precipitation variability on the direction and magnitude of near-term Northern Hemisphere snow trends. We find that near-term uncertainty in the sign of regional precipitation change does not cascade into uncertainty in the sign of regional snow accumulation change. Rather, temperature increases drive statistically robust consistency in the sign of future near-term snow accumulation trends, with all regions exhibiting reductions in the fraction of precipitation falling as snow, along with mean decreases in late-season snow accumulation. However, internal variability does create uncertainty in the magnitude of hemispheric and regional snow changes, including uncertainty as large as 33 % of the baseline mean. In addition, within the 40-member ensemble, many mid-latitude grid points exhibit at least one realization with a statistically significant positive trend in net snow accumulation, and at least one realization with a statistically significant negative trend. These results suggest that the direction of near-term snow accumulation change is robust at the regional scale, but that internal variability can influence the magnitude and direction of snow accumulation changes at the local scale, even in areas that exhibit a high signal-to-noise ratio.

  2. Validating growth and development of a seabird as an indicator of food availability: captive-reared Caspian Tern chicks fed ad libitum and restricted diets

    USGS Publications Warehouse

    Lyons, Donald E.; Roby, Daniel D.

    2011-01-01

    For seabirds raising young under conditions of limited food availability, reducing chick provisioning and chick growth rates are the primary means available to avoid abandonment of a breeding effort. For most seabirds, however, baseline data characterizing chick growth and development under known feeding conditions are unavailable, so it is difficult to evaluate chick nutritional status as it relates to foraging conditions near breeding colonies. To address this need, we examined the growth and development of young Caspian Terns (Hydroprogne caspia), a cosmopolitan, generalist piscivore, reared in captivity and fed ad libitum and restricted (ca. one-third lower caloric intake) diets. Ad libitum-fed chicks grew at similar rates and achieved a similar size at fledging as previously documented for chicks in the wild and had energetic demands that closely matched allometric predictions. We identified three general characteristics of food-restricted Caspian Tern chicks compared to ad libitum chicks: (1) lower age-specific body mass, (2) lower age-specific skeletal and feather size, such as wing chord length, and (3) heightened levels of corticosterone in blood, both for baseline levels and in response to acute stress. Effects of diet restriction on feather growth (10-11% slower growth in diet-restricted chicks) were less pronounced than effects on structural growth (37-52% slower growth) and body mass (24% lower at fledging age), apparently due to preferential allocation of food resources to maintain plumage growth. Our results suggest that measurements of chick body mass and feather development (e.g., wing chord or primary length) or measurement of corticosterone levels in the blood would allow useful evaluation of the nutritional status of chicks reared in the wild and of food availability in the foraging range of adults. Such evaluations could also inform demography studies (e.g., predict future recruitment) and assist in evaluating designated piscivorous waterbird

  3. Using Snow to Teach Geology.

    ERIC Educational Resources Information Center

    Roth, Charles

    1991-01-01

    A lesson plan, directed at middle school students and older, describes using snow to study the geological processes of solidification of molten material, sedimentation, and metamorphosis. Provides background information on these geological processes. (MCO)

  4. Snow density climatology across the former USSR

    NASA Astrophysics Data System (ADS)

    Zhong, X.; Zhang, T.; Wang, K.

    2014-04-01

    Snow density is one of the basic properties used to describe snow cover characteristics, and it is a key factor for linking snow depth and snow water equivalent, which are critical for water resources assessment and modeling inputs. In this study, we used long-term data from ground-based measurements to investigate snow density (bulk density) climatology and its spatiotemporal variations across the former Soviet Union (USSR) from 1966 to 2008. The results showed that the long-term monthly mean snow density was approximately 0.22 ± 0.05 g cm-3 over the study area. The maximum and minimum monthly mean snow density was about 0.33 g cm-3 in June, and 0.14 g cm-3 in October, respectively. Maritime and ephemeral snow had the highest monthly mean snow density, while taiga snow had the lowest. The higher values of monthly snow density were mainly located in the European regions of the former USSR, on the coast of Arctic Russia, and the Kamchatka Peninsula, while the lower snow density occurred in central Siberia. Significant increasing trends of snow density from September through June of the next year were observed, however, the rate of the increase varied with different snow classes. The long-term (1966-2008) monthly and annual mean snow densities had significant decreasing trends, especially during the autumn months. Spatially, significant positive trends in monthly mean snow density lay in the southwestern areas of the former USSR in November and December and gradually expanded in Russia from February through April. Significant negative trends mainly lay in the European Russia and the southern Russia. There was a high correlation of snow density with elevation for tundra snow and snow density was highly correlated with latitude for prairie snow.

  5. Does availability of physical activity and food outlets differ by race and income? Findings from an enumeration study in a health disparate region

    PubMed Central

    2012-01-01

    Background Low-income, ethnic/racial minorities and rural populations are at increased risk for obesity and related chronic health conditions when compared to white, urban and higher-socio-economic status (SES) peers. Recent systematic reviews highlight the influence of the built environment on obesity, yet very few of these studies consider rural areas or populations. Utilizing a CBPR process, this study advances community-driven causal models to address obesity by exploring the difference in resources for physical activity and food outlets by block group race and income in a small regional city that anchors a rural health disparate region. To guide this inquiry we hypothesized that lower income and racially diverse block groups would have fewer food outlets, including fewer grocery stores and fewer physical activity outlets. We further hypothesized that walkability, as defined by a computed walkability index, would be lower in the lower income block groups. Methods Using census data and GIS, base maps of the region were created and block groups categorized by income and race. All food outlets and physical activity resources were enumerated and geocoded and a walkability index computed. Analyses included one-way MANOVA and spatial autocorrelation. Results In total, 49 stores, 160 restaurants and 79 physical activity outlets were enumerated. There were no differences in the number of outlets by block group income or race. Further, spatial analyses suggest that the distribution of outlets is dispersed across all block groups. Conclusions Under the larger CPBR process, this enumeration study advances the causal models set forth by the community members to address obesity by providing an overview of the food and physical activity environment in this region. This data reflects the food and physical activity resources available to residents in the region and will aid many of the community-academic partners as they pursue intervention strategies targeting obesity. PMID

  6. Changes in the snow water equivalent in mountainous basins in Slovakia over recent decades

    NASA Astrophysics Data System (ADS)

    Hlavčová, K.; Kotríková, K.; Kohnová, S.; Valent, P.

    2015-06-01

    Changes in snowpack and duration of snow cover can cause changes in the regime of snow and rain-snow induced floods. The recent IPCC report suggests that, in snow-dominated regions such as the Alps, the Carpathian Mountains and the northern parts of Europe, spring snowmelt floods may occur earlier in a future climate because of warmer winters, and flood hazards may increase during wetter and warmer winters, with more frequent rain and less frequent snowfall. The monitoring and modelling of snow accumulation and snow melting in mountainous catchments is rather complicated, especially due to the high spatial variability of snow characteristics and the limited availability of terrestrial hydrological data. An evaluation of changes in the snow water equivalent (SWE) during the period of 1961-2010 in the Upper Hron river basin, which is representative of the mountainous regions in Central Slovakia, is provided in this paper. An analysis of the snow cover was performed using simulated values of the snow water equivalent by a conceptual semi-distributed hydrological rainfall-runoff model. Due to the poor availability of the measured snow water equivalent data, the analysis was performed using its simulated values. Modelling of the SWE was performed in different altitude zones by a conceptual semi-distributed hydrological rainfall-runoff model. The evaluation of the results over the past five decades indicates a decrease in the simulated snow water equivalent and the snow duration in each altitude zone and in all months of the winter season. Significant decreasing trends were found for December, January and February, especially in the highest altitude zone.

  7. The Effect of Forest Structure on Snow Hydrology in the Canadian Rocky Mountains

    NASA Astrophysics Data System (ADS)

    Pomeroy, J.; Ellis, C.; MacDonald, J.

    2008-12-01

    Mountain evergreen forests exert two primary effects on the formation and ablation of the seasonal snowcover. The first is the interception of snowfall in the forest canopy, resulting in sublimation, melt or unloading from the canopy. Snow interception can capture a very large percentage of the seasonal snowfall and in cold conditions this snow can be held for many days in the canopy. In the canopy snow is exposed to high rates of turbulent transfer and so can sublimate rapidly where unsaturated conditions prevail. Snow also metamorphoses in the canopy and some intercepted snow is unloaded to the surface, depending on the mechanics of slippage between branch and intercepted snow and the failure of intercepted snow clumps. The result of the snow interception, sublimation and unloading processes is that snow accumulation usually declines with increasing forest cover. This effect is most pronounced in cold, dry and windy conditions. The second primary effect of mountain forests is that snow on the ground is subjected to modified radiation regimes due to the extinction of shortwave radiation and emission of longwave radiation by the forest canopy. Some extinguished shortwave energy is also emitted as longwave energy. The result is to sometimes reduce and sometimes increase the incoming radiation available to the snowpack compared to open areas, the direction of change depending on cloudiness, solar angle, canopy structure, snow albedo, degree of slope and aspect. In cold continental mountain environments, net radiation available for snowmelt is generally reduced by increasing forest cover on level sites and south facing slopes but is enhanced by increasing forest cover on north facing slopes. The dramatic implications of the combined effects on snow hydrology of changing snow interception and radiation regimes as mountain forest cover is reduced from insect infestation, logging and burning are demonstrated and discussed.

  8. The Fallacy of Drifting Snow

    NASA Astrophysics Data System (ADS)

    Andreas, Edgar L.

    2011-12-01

    A common parametrization over snow-covered surfaces that are undergoing saltation is that the aerodynamic roughness length for wind speed ( z 0) scales as {α u_ast^2/g}, where u * is the friction velocity, g is the acceleration of gravity, and α is an empirical constant. Data analyses seem to support this scaling: many published plots of z 0 measured over snow demonstrate proportionality to {u_ast^2 }. In fact, I show similar plots here that are based on two large eddy-covariance datasets: one collected over snow-covered Arctic sea ice; another collected over snow-covered Antarctic sea ice. But in these and in most such plots from the literature, the independent variable, u *, was used to compute z 0 in the first place; the plots thus suffer from fictitious correlation that causes z 0 to unavoidably increase with u * without any intervening physics. For these two datasets, when I plot z 0 against u * derived from a bulk flux algorithm—and thus minimize the fictitious correlation— z 0 is independent of u * in the drifting snow region, u * ≥ 0.30 ms-1. I conclude that the relation {z_0 = α u_ast^2/g} when snow is drifting is a fallacy fostered by analyses that suffer from fictitious correlation.

  9. Analysis of ingredient lists of commercially available gluten-free and gluten-containing food products using the text mining technique.

    PubMed

    do Nascimento, Amanda Bagolin; Fiates, Giovanna Medeiros Rataichesck; Dos Anjos, Adilson; Teixeira, Evanilda

    2013-03-01

    Ingredients mentioned on the labels of commercially available packaged gluten-free and similar gluten-containing food products were analyzed and compared, using the text mining technique. A total of 324 products' labels were analyzed for content (162 from gluten-free products), and ingredient diversity in gluten-free products was 28% lower. Raw materials used as ingredients of gluten-free products were limited to five varieties: rice, cassava, corn, soy, and potato. Sugar was the most frequently mentioned ingredient on both types of products' labels. Salt and sodium also were among these ingredients. Presence of hydrocolloids, enzymes or raw materials of high nutritional content such as pseudocereals, suggested by academic studies as alternatives to improve nutritional and sensorial quality of gluten-free food products, was not identified in the present study. Nutritional quality of gluten-free diets and health of celiac patients may be compromised. PMID:22946669

  10. MODIS Snow Cover Mapping Decision Tree Technique: Snow and Cloud Discrimination

    NASA Technical Reports Server (NTRS)

    Riggs, George A.; Hall, Dorothy K.

    2010-01-01

    Accurate mapping of snow cover continues to challenge cryospheric scientists and modelers. The Moderate-Resolution Imaging Spectroradiometer (MODIS) snow data products have been used since 2000 by many investigators to map and monitor snow cover extent for various applications. Users have reported on the utility of the products and also on problems encountered. Three problems or hindrances in the use of the MODIS snow data products that have been reported in the literature are: cloud obscuration, snow/cloud confusion, and snow omission errors in thin or sparse snow cover conditions. Implementation of the MODIS snow algorithm in a decision tree technique using surface reflectance input to mitigate those problems is being investigated. The objective of this work is to use a decision tree structure for the snow algorithm. This should alleviate snow/cloud confusion and omission errors and provide a snow map with classes that convey information on how snow was detected, e.g. snow under clear sky, snow tinder cloud, to enable users' flexibility in interpreting and deriving a snow map. Results of a snow cover decision tree algorithm are compared to the standard MODIS snow map and found to exhibit improved ability to alleviate snow/cloud confusion in some situations allowing up to about 5% increase in mapped snow cover extent, thus accuracy, in some scenes.

  11. Effect of oxygen availability and pH on the furan concentration formed during thermal preservation of plant-based foods.

    PubMed

    Palmers, Stijn; Grauwet, Tara; Vanden Avenne, Laura; Verhaeghe, Thomas; Kebede, Biniam T; Hendrickx, Marc E; Van Loey, Ann

    2016-04-01

    Thermally treated fruit- and vegetable-based foods are important contributors to the furan exposure of children and adults. Furan reduction by adding or removing precursors from the product has proven to be challenging because of major food constituents and interactions involved in the reaction pathways leading to furan formation. Instead of intervening at the precursor level, it might be more feasible to influence these formation pathways by adjusting the matrix properties of the product. As opposed to many previous literature sources, the present study investigated the effects of oxygen availability (normal versus reduced) and pH (acid versus low acid) on the furan formation in a real food system. Different combinations of both matrix properties were prepared in a reconstituted potato purée and subjected to a thermal treatment with a pasteurisation or sterilisation intensity. Irrespective of the addition of the furan precursors ascorbic acid, fructose and fatty acids, a considerable furan reduction was observed for the sterilised purées (F121(10) = 15 min) with either a reduced oxygen availability (0.1-1.8 mg l(-1)) or at pH 3. The effects of both matrix properties were less pronounced in the pasteurised purées (P90(10) = 10 min), because of the lower furan concentrations. Even though the mechanisms of furan reduction for both types of matrix properties could not be fully elucidated, the results showed that lowering the oxygen concentration or pH prior to thermal processing offers a powerful, additional strategy for furan mitigation in thermally treated plant-based foods. PMID:26879747

  12. Effects of snow ratio on annual runoff within Budyko framework

    NASA Astrophysics Data System (ADS)

    Zhang, D.; Cong, Z.; Ni, G.; Yang, D.; Hu, S.

    2015-01-01

    Warmer climate may lead to less winter precipitation falling as snow. Such a switch in the state of precipitation not only alters temporal distribution of intra-annual runoff, but tends to yield less total annual runoff. Long-term water balance for 282 catchments across China is investigated, showing that decreasing snow ratio reduces annual runoff for a given total precipitation. Within the Budyko framework, we develop an equation to quantify the relationship between snow ratio and annual runoff from a water-energy balance viewpoint. Based on the proposed equation, attribution of runoff change during past several decades and possible runoff change induced by projected snow ratio change using climate experiment outputs archived in the Coupled Model Intercomparison Project Phase 5 are analyzed. Results indicate that annual runoff in northwest mountainous and north high-latitude areas are sensitive to snow ratio change. The proposed model is applicable to other catchments easily and quantitatively for analyzing the effects of possible change in snow ratio on available water resources and evaluating the vulnerability of catchments to climate change.

  13. Spatial and Temporal Snow Grain Size Variability across Northwestern Greenland

    NASA Astrophysics Data System (ADS)

    Courville, Z.; Polashenski, C. M.; Domine, F.

    2015-12-01

    The albedo of snow-covered surfaces is influenced by several factors including the presence of water; the inclusion of impurities, in particular black carbon and dust; and snow grain size and shape. The SAGE project (Sunlight Absorption across the Greenland ice sheet Experiment) aims at determining the impact of these interdependent factors. The SAGE project consisted of two overland traverses in 2013 and 2014 between Summit Station in the center of the ice sheet and Thule Air Base, on the northwest coast. This route crosses over several facies of the ice sheet representing different accumulation and melt regimes. The SAGE field objectives included detailed shallow pit studies of snow grain size, stratigraphy, and chemistry. In addition to snow pit data from the SAGE traverses that can be used to examine spatial variations, snow grain size and chemistry data from seasonal campaigns at Summit Station are used to examine temporal variations. Here, we present snow grain and chemistry seasonal and spatial results, and compare the relative effects to available ground-based albedo and meteorological data from co-located weather stations and hand-held spectro-radiometer measurements.

  14. Aerosol Characterization and New Instrumentation for Better Understanding Snow Radiative Properties

    NASA Astrophysics Data System (ADS)

    Beres, N. D.

    2015-12-01

    Snow albedo is determined by snowpack thickness and grain size, but also affected by contamination with light-absorbing, microscopic (e.g., mineral dust, combustion aerosols, bio-aerosols) and macroscopic (e.g., microalgae, plant debris, sand, organisms) compounds. Most currently available instruments for measuring snow albedo utilize the natural, downward flux of solar radiation and the reflected upward flux. This reliance on solar radiation (and, thus, large zenith angles and clear-sky conditions) leads to severe constraints, preventing characterization of detailed diurnal snow albedo cycles. Here, we describe instrumentation and methodologies to address these limitations with the development and deployment of new snow radiation sensors for measuring surface spectral and in-snow radiative properties. This novel instrumentation will be tested at the CRREL/UCSB Eastern Sierra (CUES) Snow Study Site at Mammoth Mountain, which is extensively instrumented for characterizing snow properties including snow albedo and surface morphology. However, it has been lacking instrumentation for the characterization of aerosols that can be deposited on the snow surface through dry and wet deposition. Currently, we are installing aerosol instrumentation at the CUES site, which are also described. This includes instruments for the multi-wavelength measurement of aerosol scattering and absorption coefficients and for the characterization of aerosol size distribution. Knowledge of aerosol concentration and physical and optical properties will allow for the study of aerosol deposition and modification of snow albedo and for establishing an aerosol climatology for the CUES site.

  15. Understanding Uncertainty in Physics-based Snow Models

    NASA Astrophysics Data System (ADS)

    Clark, M. P.

    2011-12-01

    In spite of considerable efforts dedicated to understanding and simulating the accumulation and ablation of the snowpack, there is arguably still a colossal amount of uncertainty in physics-based snow models. The fidelity of model representations of snow processes remains compromised by limited process understanding, and limited data. Many modeling decisions are often represented using empirical formulations with model parameters defined based either on order-of-magnitude considerations or by fitting a curve through a limited amount of experimental data. An outstanding challenge for the snow modeling community is to understand the impact of differences among existing snow models on their physical validity and predictive performance, and use this to identify and address fundamental model weaknesses. We introduce an alternative methodology for understanding differences among snow models. We first define a single set of governing model equations - a "master modeling template" - from which many existing models can be reproduced, and new models derived. The master template is then implemented within a single robust numerical framework, and used to explore the impact of differences in the choice of modeling approaches and the choice of model parameter values. To keep the study tractable, we focus on a subset of modeling options available within the template, restricting attention to one-dimensional snow model applied over non-vegetated surfaces. Assessments of forest snow processes and spatial variability are deferred to a separate study. The differences among existing snow models can be broadly classified into three categories: (i) estimation of fluxes at the snow-atmosphere interface, including the approach used to estimate the surface albedo, the turbulent fluxes of sensible and latent heat, and the partitioning of precipitation between rain and snow; (ii) internal processes within the snowpack, including heat conduction, penetration of shortwave radiation, vertical

  16. Changes in Snow Cover Characteristics over Northern Eurasia since 1966

    NASA Astrophysics Data System (ADS)

    Bulygina, Olga; Groisman, Pavel; Razuvaev, Vyacheslav; Korshunova, Natalia

    2010-05-01

    Data. In addition to a standard suite of snow observations across Northern Eurasia and its surroundings, we used in our study the national snow survey data set archived at the Russian Institute for Hydrometeorological Information. The last dataset has routine snow surveys run throughout the cold season each decade (during the intense snowmelt, each 5 days) at all meteorological stations of the former USSR, thereafter, in Russia since 1966. Prior to 1966 snow surveys are also available but the methodology of observations has substantially changed at that year. Therefore, this analysis includes only data of more than1000 Russian stations from 1966 to 2009 that have a minimal number of missing observations. Surveys run separately along all types of environment typical for the site for 1 to 2 km, describing the current snow cover properties such as snow density, depth, water equivalent, and characteristics of snow and ice crust. Background. During the past 128 years (since 1881), the annual surface air temperature in Northern Eurasia has increased by 1.5° C and in the winter season by 3° C. Nearby to the north in the Arctic Ocean, the late summer sea ice extent decreased by 40% exposing a near-infinite source of water vapor for the dry Arctic atmosphere in early cold season months. As a result of these processes the following changes in snow cover characteristics have been observed: (a) in autumn the dates of the onset of snow cover have not changed noticeably despite the strong temperature increase in this season; (b) in late spring, snow cover extent has decreased, retreating by 1 to 2 weeks earlier during the past 40 years; and (c) in the cold season maximum snow depth and SWE (at open areas) have increased over most of Russia. In the western half of Eurasian continent days with thaw became more frequent. Snowmelt duration and ice crust changes. Over Northern Eurasia, the snowmelt process can be lengthy but even the first such melt initiates a process of snow

  17. Politics of Snow

    NASA Astrophysics Data System (ADS)

    Burko, D.

    2012-12-01

    In a 2010 catalog introduction for my exhibition titled: POLITICS OF SNOW, Eileen Claussen, President of the Pew Center on Global Climate Change wrote the following: "Climate change has been taken over by politics…We are awash in talking points, briefing papers, scientific studies, and communiqués from national governments… Diane Burko's paintings remind us that all these words can often obscure or even obstruct our view of what is truly happening …..There is only so much you can do with words. People need to see that the world is changing before our eyes. When we look at Diane's images of the effects of climate change, we connect to something much deeper and more profound (and more moving) than the latest political pitch from one side or another in this debate…These paintings also connect us to something else. Even as Diane documents how things are changing, she also reminds us of the stunning beauty of nature - and, in turn, the urgency of doing everything in our power to protect it." The creation of this body of work was made possible because of the collaboration of many glacial geologists and scientists who continually share their visual data with me. Since 2006 I've been gathering repeats from people like Bruce Molnia (USGS) and Tad Pfeffer of Alaskan glaciers, from Daniel Fagre (USGS) of Glacier National Park and Lonnie Thompson and Jason Box (Ohio University's Byrd Polar Center) about Kilimanjaro, Qori Kalis and Petermann glaciers as well as from photographer David Breashears on the disappearing Himalayan glaciers. In my practice, I acknowledge the photographers, or archive agencies, such as USGS, NASA or Snow and Ice Center, in the title and all printed material. As a landscape painter and photographer my intent is to not reproduce those images but rather use them as inspiration. At first I used the documentary evidence in sets of diptychs or triptychs. Since 2010 I have incorporated geological charts of recessional lines, graphs, symbols and

  18. Levels and temporal trends of persistent organic pollutants (POPs) in arctic foxes (Vulpes lagopus) from Svalbard in relation to dietary habits and food availability.

    PubMed

    Andersen, Martin S; Fuglei, Eva; König, Max; Lipasti, Inka; Pedersen, Åshild Ø; Polder, Anuschka; Yoccoz, Nigel G; Routti, Heli

    2015-04-01

    Temporal trends of persistent organic pollutants (POPs) in arctic foxes (Vulpes lagopus) from Svalbard, Norway, were investigated in relation to feeding habits and seasonal food availability. Arctic foxes from Svalbard forage in both marine and terrestrial ecosystems and the availability of their food items are impacted by climatic variability. Concentrations of polychlorinated biphenyls (PCBs), organochlorinated pesticides (OCPs) and brominated flame retardants (polybrominated diphenyl ethers [PBDEs] and hexabromocyclododecane [HBCDD]) were analyzed in the liver of 141 arctic foxes collected between 1997 and 2013. Stable carbon isotope values (δ13C) were used as a proxy for feeding on marine versus terrestrial prey. The annual number of recovered reindeer carcasses and sea ice cover were used as proxies for climate influenced food availability (reindeers, seals). Linear models revealed that concentrations of PCBs, chlordanes, p,p'-DDE, mirex and PBDEs decreased 4-11% per year, while no trends were observed for hexachlorobenzene (HCB) or β-hexachlorocyclohexane (β-HCH). Positive relationships between POP concentrations and δ13C indicate that concentrations of all compounds increase with increasing marine dietary input. Increasing reindeer mortality was related to lower HCB concentrations in the foxes based on the linear models. This suggests that concentrations of HCB in arctic foxes may be influenced by high mortality levels of Svalbard reindeer. Further, β-HCH concentrations showed a positive association with sea ice cover. These results in addition to the strong effect of δ13C on all POP concentrations suggest that climate-related changes in arctic fox diet are likely to influence contaminant concentrations in arctic foxes from Svalbard. PMID:25536177

  19. Detecting Falling Snow from Space

    NASA Technical Reports Server (NTRS)

    Jackson, Gail Skofronick; Johnson, Ben; Munchak, Joe

    2012-01-01

    There is an increased interest in detecting and estimating the amount of falling snow reaching the Earth's surface in order to fully capture the atmospheric water cycle. An initial step toward global spaceborne falling snow algorithms includes determining the thresholds of detection for various active and passive sensor channel configurations, snow event cloud structures and microphysics, snowflake particle electromagnetic properties, and surface types. In this work, cloud resolving model simulations of a lake effect and synoptic snow event were used to determine the minimum amount of snow (threshold) that could be detected by the following instruments: the W -band radar of CloudSat, Global Precipitation Measurement (GPM) Dual-frequency Precipitation Radar (DPR) Ku and Ka band, and the GPM Microwave Imager (GMI) channels from 10 to 183 plus or minus 7 GHz. Eleven different snowflake shapes were used to compute radar reflectivities and passive brightness temperatures. Notable results include: (1) the W-Band radar has detection thresholds more than an order of magnitude lower than the future GPM sensors, (2) the cloud structure macrophysics influences the thresholds of detection for passive channels, (3) the snowflake microphysics plays a large role in the detection threshold for active and passive instruments, (4) with reasonable assumptions, "the passive 166 GHz channel has detection threshold values comparable to the GPM DPR Ku and Ka band radars with approximately 0.05 g per cubic meter detected at the surface, or an approximately 0.5-1 millimeter per hr. melted snow rate (equivalent to 0.5-2 centimeters per hr. solid fluffy snowflake rate). With detection levels of falling snow known, we can focus current and future retrieval efforts on detectable storms and concentrate advances on achievable results. We will also have an understanding of the light snowfall events missed by the sensors and not captured in the global estimates.

  20. Sodankylä manual snow survey program

    NASA Astrophysics Data System (ADS)

    Leppänen, L.; Kontu, A.; Hannula, H.-R.; Sjöblom, H.; Pulliainen, J.

    2015-12-01

    The manual snow survey program of the Arctic Research Centre of Finnish Meteorological Institute (FMI-ARC) consists of numerous observations of natural seasonal taiga snowpack in Sodankylä, northern Finland. The easily accessible measurement areas represent the typical forest and soil types in the boreal forest zone. Systematic snow measurements began in 1909 with snow depth (SD) and snow water equivalent (SWE); however some older records of the snow and ice cover exists. In 2006 the manual snow survey program expanded to cover snow macro- and microstructure from regular snow pits at several sites using both traditional and novel measurement techniques. Present-day measurements include observations of SD, SWE, temperature, density, horizontal layers of snow, grain size, specific surface area (SSA), and liquid water content (LWC). Regular snow pit measurements are performed weekly during the snow season. Extensive time series of manual snow measurements are important for the monitoring of temporal and spatial changes in seasonal snowpack. This snow survey program is an excellent base for the future research of snow properties.

  1. Wind tunnel observations of drifting snow

    NASA Astrophysics Data System (ADS)

    Paterna, Enrico; Crivelli, Philip; Lehning, Michael

    2016-04-01

    Drifting snow has a significant impact on snow redistribution in mountains, prairies as well as on glaciers, ice shelves, and sea ice. In all these environments, the local mass balance is highly influenced by drifting snow. Understanding the dynamic of snow saltation is crucial to the accurate description of the process. We applied digital shadowgraphy in a cold wind tunnel to measure drifting snow over natural snow covers. The acquisition and evaluation of time-resolved shadowgraphy images allowed us to resolve a large part of the saltation layer. The technique has been successfully compared to the measurements obtained from a Snow Particle Counter, considered the most robust technique for snow mass-flux measurements so far. The streamwise snow transport is dominated by large-scale events. The vertical snow transport has a more equal distribution of energy across the scales, similarly to what is observed for the flow turbulence velocities. It is hypothesized that the vertical snow transport is a quantity that reflects the local entrainment of the snow crystals into the saltation layer while the streamwise snow transport results from the streamwise development of the trajectories of the snow particles once entrained, and therefore is rather a non-local quantity.

  2. Impacts of food availability and pCO2 on planulation, juvenile survival, and calcification of the azooxanthellate scleractinian coral Balanophyllia elegans

    NASA Astrophysics Data System (ADS)

    Crook, E. D.; Cooper, H.; Potts, D. C.; Lambert, T.; Paytan, A.

    2013-11-01

    Ocean acidification, the assimilation of atmospheric CO2 by the oceans that decreases the pH and CaCO3 saturation state (Ω) of seawater, is projected to have severe adverse consequences for calcifying organisms. While strong evidence suggests calcification by tropical reef-building corals containing algal symbionts (zooxanthellae) will decline over the next century, likely responses of azooxanthellate corals to ocean acidification are less well understood. Because azooxanthellate corals do not obtain photosynthetic energy from symbionts, they provide a system for studying the direct effects of acidification on energy available for calcification. The solitary azooxanthellate orange cup coral Balanophyllia elegans often lives in low-pH, upwelled waters along the California coast. In an 8-month factorial experiment, we measured the effects of three pCO2 treatments (410, 770, and 1220 μatm) and two feeding frequencies (3-day and 21-day intervals) on "planulation" (larval release) by adult B. elegans, and on the survival, skeletal growth, and calcification of newly settled juveniles. Planulation rates were affected by food level but not pCO2. Juvenile mortality was highest under high pCO2 (1220 μatm) and low food (21-day intervals). Feeding rate had a greater impact on calcification of B. elegans than pCO2. While net calcification was positive even at 1220 μatm (~3 times current atmospheric pCO2), overall calcification declined by ~25-45%, and skeletal density declined by ~35-45% as pCO2 increased from 410 to 1220 μatm. Aragonite crystal morphology changed at high pCO2, becoming significantly shorter but not wider at 1220 μatm. We conclude that food abundance is critical for azooxanthellate coral calcification, and that B. elegans may be partially protected from adverse consequences of ocean acidification in habitats with abundant heterotrophic food.

  3. Food availability and pCO2 impacts on planulation, juvenile survival, and calcification of the azooxanthellate scleractinian coral, Balanophyllia elegans

    NASA Astrophysics Data System (ADS)

    Crook, E. D.; Cooper, H.; Potts, D. C.; Lambert, T.; Paytan, A.

    2013-05-01

    Ocean acidification, the assimilation of atmospheric CO2 by the oceans that decreases the pH and CaCO3 saturation state (Ω) of seawater, is projected to have severe consequences for calcifying organisms. Strong evidence suggests that tropical reef-building corals containing algal symbionts (zooxanthellae) will experience dramatic declines in calcification over the next century. The responses of azooxanthellate corals to ocean acidification are less well understood, and because they cannot obtain extra photosynthetic energy from symbionts, they provide a system for studying the direct effects of acidification on the energy available for calcification. The orange cup coral Balanophyllia elegans is a solitary, azooxanthellate scleractinian species common on the California coast where it thrives in the low pH waters of an upwelling regime. During an 8 month study, we addressed the effects of three pCO2 treatments (410, 770, and 1230 μatm) and two feeding frequencies (High Food and Low Food) on adult Balanophyllia elegans planulation (larval release) rates, and on the survival, growth, and calcification of their juvenile offspring. Planulation rates were affected by food level but not pCO2, while juvenile survival was highest under 410 μatm and High Food conditions. Our results suggest that feeding rate has a greater impact on calcification of B. elegans than pCO2. Net calcification was positive even at 1230 μatm (~ 3 times current atmospheric pCO2), although the increase from 410 to 1230 μatm reduced overall calcification by ~ 25-45%, and reduced skeletal density by ~ 35-45%. Higher pCO2 also altered aragonite crystal morphology significantly. We discuss how feeding frequency affects azooxanthellate coral calcification, and how B. elegans may respond to ocean acidification in coastal upwelling waters.

  4. [Effects of seasonal snow cover on soil nitrogen transformation in alpine ecosystem: a review].

    PubMed

    Liu, Lin; Wu, Yan; He, Yi-xin; Wu, Ning; Sun, Geng; Zhang, Lin; Xu, Jun-jun

    2011-08-01

    Seasonal snow cover has pronounced effects on the soil nitrogen concentration and transformation in alpine ecosystem. Snowfall is an important form of nitrogen deposition, which directly affects the content of soil available nitrogen. Different depths and different duration of snow cover caused by snowfall may lead the heterogeneity of abiotic factors (soil temperature and moisture) and biotic factors (soil microbes, alpine plants, and alpine animals), and further, produce complicated effects on the mineralization and immobilization of soil nitrogen. This paper introduced in emphasis the inherent mechanisms of soil nitrogen mineralization and leaching under the effects of frequent freeze-thaw events during the durative melting of snow cover, and summarized the main research results of field in situ experiments about the effects of seasonal snow cover on soil nitrogen in alpine ecosystem based on the possible changes in snow cover in the future. Some suggestions with regard to the effects of seasonal snow cover on soil nitrogen were put forward. PMID:22097387

  5. Snow and Dust over Inner Mongolia

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A severe snow-and-sand storm hit an 80,000 square-mile (205,000-square-km) stretch of the Chinese province of Mongolia on New Year's Eve, killing 21 people and leaving thousands of people to face possible starvation. The affected area is located about 250 miles (400 km) northwest of Beijing. It is the worst snowstorm to hit the region in more than 50 years. Lasting about 3 days, the storm dumped 24 inches (60 cm) of snow mixed with sand from the Gobi Desert, stranding many residents in deep drifts. The Chinese Red Cross reports that almost 1 million people were affected by the storm and at least 10,000 head of livestock are confirmed dead. As many as 120,000 residents are in need of food and other supplies. The Sea-viewing Wide Field-of-view Sensor (SeaWiFS), flying aboard the OrbView-2 satellite, acquired this image of the storm on January 2, 2001, as it approached China's eastern provinces. You can see storm clouds (white pixels) and windblown dust (brownish pixels) crossing the Yellow Sea and East China Sea toward Japan and the western Pacific. Provided by the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  6. Sea Ice SAR Signature Dependence on Thaw and Refreeze Event in the Snow Cover

    NASA Astrophysics Data System (ADS)

    Hudier, E. J.; Tolszczuk-Leclerc, S.

    2010-12-01

    As a result of the dependence of microwaves on the dielectric properties of the material they interfere with, the microwave signature of sea ice changes dramatically with the seasons as well as overnight when the snow layer is at the freezing point While pure ice and dry snow do not cause significant scattering and can be considered transparent throughout the winter season, the presence of liquid water, later on at spring, on air-ice or air-snow interfaces or within the snow cover turns the snow layer into an opaque medium and makes the air-snow interface the main contributor of the microwave backscattered to the SAR antenna. The availability of liquid water in the snow is the result of a shift in the thermodynamic balance of the snow layer and sea ice sheet. At spring, with the irradiance and air temperature increasing, the snow media quickly becomes isothermal. The snow layer is then a tri-phasic medium in which water changes state to balance radiations (short and long waves) and conductive heat fluxes variations. As a consequence, the surface layer of the snow cover is subject to a diurnal cycle of thaw during day time and refreeze at night which translates into a parallel diurnal cycle on snow wetness content. This cycle is of major relevance to microwave remote sensing applications and specifically to sea ice morphological features extraction. Using the output of a thermodynamic model of an isothermal snow cover forced by incoming L↓ and outgoing L↑ long-wave radiations, incident S↓ and reflected S↑ short-wave radiations and a turbulent atmospheric heat flux Qatm, an evaluation of the volume and surface components of a backscattered SAR is computed as a function of the SAR incident angle. We observe that when heat fluxes (irradiative and conductive) are positive, liquid water available in the top layer of the snow cover turns the air-snow interface into a specular reflector. Conversely, with wetness decreasing overnight, more energy can penetrate the

  7. PHYSICS UPDATE: Observation of snow crystals using a chamber cooled by dry ice

    NASA Astrophysics Data System (ADS)

    Kagawa, S.; Kakehi, M.; Ito, F.; Kagawa, K.

    1999-01-01

    It is shown that microscopic observation of natural snow crystals is possible even at relatively high atmospheric temperature, around 0 °C. For this purpose, a partial cooling method was employed. That is, a snow crystal was placed in a chamber cooled by dry ice, which prevented frost production. By using this simple method, snow crystals can be observed in winter (where snow is available). This type of observational experiment is very successful in exciting students' interest in the beauty of natural forms.

  8. Examining the relationship between snow cover and reservoir storage in the American River Basin

    NASA Astrophysics Data System (ADS)

    McGillis-Moskaluk, Karen

    This study focused on finding evidence of a relationship between snow cover and reservoir storage in the American River basin. Water availability is very important to the future of California. Landsat Thematic Mapper images of the area taken from 1985-2011 were analyzed by calculating Normalized Difference Snow Index and calculating snow acres. The peak storage data were obtained for Folsom Lake for the same time period as the satellite images. The evaluation of these methods showed that over time there was a correlation between snow cover and reservoir storage downstream.

  9. Snow Micro-Structure Model

    Energy Science and Technology Software Center (ESTSC)

    2014-06-25

    PIKA is a MOOSE-based application for modeling micro-structure evolution of seasonal snow. The model will be useful for environmental, atmospheric, and climate scientists. Possible applications include application to energy balance models, ice sheet modeling, and avalanche forecasting. The model implements physics from published, peer-reviewed articles. The main purpose is to foster university and laboratory collaboration to build a larger multi-scale snow model using MOOSE. The main feature of the code is that it is implementedmore » using the MOOSE framework, thus making features such as multiphysics coupling, adaptive mesh refinement, and parallel scalability native to the application. PIKA implements three equations: the phase-field equation for tracking the evolution of the ice-air interface within seasonal snow at the grain-scale; the heat equation for computing the temperature of both the ice and air within the snow; and the mass transport equation for monitoring the diffusion of water vapor in the pore space of the snow.« less

  10. Snow Micro-Structure Model

    SciTech Connect

    Micah Johnson, Andrew Slaughter

    2014-06-25

    PIKA is a MOOSE-based application for modeling micro-structure evolution of seasonal snow. The model will be useful for environmental, atmospheric, and climate scientists. Possible applications include application to energy balance models, ice sheet modeling, and avalanche forecasting. The model implements physics from published, peer-reviewed articles. The main purpose is to foster university and laboratory collaboration to build a larger multi-scale snow model using MOOSE. The main feature of the code is that it is implemented using the MOOSE framework, thus making features such as multiphysics coupling, adaptive mesh refinement, and parallel scalability native to the application. PIKA implements three equations: the phase-field equation for tracking the evolution of the ice-air interface within seasonal snow at the grain-scale; the heat equation for computing the temperature of both the ice and air within the snow; and the mass transport equation for monitoring the diffusion of water vapor in the pore space of the snow.

  11. Metagenomic and satellite analyses of red snow in the Russian Arctic

    PubMed Central

    Hisakawa, Nao; Quistad, Steven D.; Hester, Eric R.; Martynova, Daria; Sala, Enric; Gavrilo, Maria V.

    2015-01-01

    Cryophilic algae thrive in liquid water within snow and ice in alpine and polar regions worldwide. Blooms of these algae lower albedo (reflection of sunlight), thereby altering melting patterns (Kohshima, Seko & Yoshimura, 1993; Lutz et al., 2014; Thomas & Duval, 1995). Here metagenomic DNA analysis and satellite imaging were used to investigate red snow in Franz Josef Land in the Russian Arctic. Franz Josef Land red snow metagenomes confirmed that the communities are composed of the autotroph Chlamydomonas nivalis that is supporting a complex viral and heterotrophic bacterial community. Comparisons with white snow communities from other sites suggest that white snow and ice are initially colonized by fungal-dominated communities and then succeeded by the more complex C. nivalis-heterotroph red snow. Satellite image analysis showed that red snow covers up to 80% of the surface of snow and ice fields in Franz Josef Land and globally. Together these results show that C. nivalis supports a local food web that is on the rise as temperatures warm, with potential widespread impacts on alpine and polar environments worldwide. PMID:26713242

  12. Metagenomic and satellite analyses of red snow in the Russian Arctic.

    PubMed

    Hisakawa, Nao; Quistad, Steven D; Hester, Eric R; Martynova, Daria; Maughan, Heather; Sala, Enric; Gavrilo, Maria V; Rohwer, Forest

    2015-01-01

    Cryophilic algae thrive in liquid water within snow and ice in alpine and polar regions worldwide. Blooms of these algae lower albedo (reflection of sunlight), thereby altering melting patterns (Kohshima, Seko & Yoshimura, 1993; Lutz et al., 2014; Thomas & Duval, 1995). Here metagenomic DNA analysis and satellite imaging were used to investigate red snow in Franz Josef Land in the Russian Arctic. Franz Josef Land red snow metagenomes confirmed that the communities are composed of the autotroph Chlamydomonas nivalis that is supporting a complex viral and heterotrophic bacterial community. Comparisons with white snow communities from other sites suggest that white snow and ice are initially colonized by fungal-dominated communities and then succeeded by the more complex C. nivalis-heterotroph red snow. Satellite image analysis showed that red snow covers up to 80% of the surface of snow and ice fields in Franz Josef Land and globally. Together these results show that C. nivalis supports a local food web that is on the rise as temperatures warm, with potential widespread impacts on alpine and polar environments worldwide. PMID:26713242

  13. Food availability and predation risk, rather than intrinsic attributes, are the main factors shaping the reproductive decisions of a long-lived predator.

    PubMed

    Hoy, Sarah R; Millon, Alexandre; Petty, Steve J; Whitfield, D Philip; Lambin, Xavier

    2016-07-01

    Deciphering the causes of variation in reproductive success is a fundamental issue in ecology, as the number of offspring produced is an important driver of individual fitness and population dynamics. Little is known, however, about how different factors interact to drive variation in reproduction, such as whether an individual's response to extrinsic conditions (e.g. food availability or predation) varies according to its intrinsic attributes (e.g. age, previous allocation of resources towards reproduction). We used 29 years of reproductive data from marked female tawny owls and natural variation in food availability (field vole) and predator abundance (northern goshawk) to quantify the extent to which extrinsic and intrinsic factors interact to influence owl reproductive traits (breeding propensity, clutch size and nest abandonment). Extrinsic and intrinsic factors appeared to interact to affect breeding propensity (which accounted for 83% of the variation in owl reproductive success). Breeding propensity increased with vole density, although increasing goshawk abundance reduced the strength of this relationship. Owls became slightly more likely to breed as they aged, although this was only apparent for individuals who had fledged chicks the year before. Owls laid larger clutches when food was more abundant. When owls were breeding in territories less exposed to goshawk predation, 99·5% of all breeding attempts reached the fledging stage. In contrast, the probability of breeding attempts reaching the fledging stage in territories more exposed to goshawk predation depended on the amount of resources an owl had already allocated towards reproduction (averaging 87·7% for owls with clutches of 1-2 eggs compared to 97·5% for owls with clutches of 4-6 eggs). Overall, our results suggested that changes in extrinsic conditions (predominantly food availability, but also predator abundance) had the greatest influence on owl reproduction. In response to deteriorating

  14. Food Preferences of Winter Bird Communities in Different Forest Types

    PubMed Central

    Renner, Swen C.; Baur, Sofia; Possler, Astrid; Winkler, Julia; Kalko, Elisabeth K. V.; Bates, Paul J. J.; Mello, Marco A. R.

    2012-01-01

    Food availability for forest birds is a function of habitat type, forest management regime, and season. In winter, it is also impacted by variations in the weather. In the current study we assessed the food preferences of wild bird populations in two types of forest (spruce and beech) during the months of November 2010 to April 2011 in the Schwäbische Alb Biodiversity Exploratory, south-western Germany. Our aim was to investigate whether local bird communities preferred fat-rich, carbohydrate-rich or wild fruits and to determine how forest structure, seasonality and local weather conditions affected food preferences. We found higher bird activity in beech forests for the eleven resident species. We observed a clear preference for fat-rich food for all birds in both forest types. Snow cover affected activity at food stations but did not affect food preferences. Periods of extreme low temperatures increased activity. PMID:23300878

  15. School Meal Programs: Competitive Foods Are Widely Available and Generate Substantial Revenues for Schools. Report to Congressional Requesters. GAO-05-563

    ERIC Educational Resources Information Center

    Bellis, David B.

    2005-01-01

    Recent increases in child obesity have sparked concerns about competitive foods--foods sold to students at school that are not part of federally reimbursable school meals. The nutritional value of these foods is largely unregulated, and students can often purchase these foods in addition to or instead of school meals. Nearly 9 out of 10 schools…

  16. School Meal Programs: Competitive Foods Are Available in Many Schools; Actions Taken To Restrict Them Differ by State and Locality. Report to Congressional Requesters. GAO-04-673

    ERIC Educational Resources Information Center

    Bellis, David D.

    2004-01-01

    Because of concerns about trends in children's health and eating habits and interest in further understanding issues related to competitive foods in schools, this study addressed: which foods and school food practices fell under the term "competitive foods" and what federal restrictions existed on their sale; what was known about the types of…

  17. The effect of socio-economic status and food availability on first birth interval in a pre-industrial human population

    PubMed Central

    Nenko, Ilona; Hayward, Adam D.; Lummaa, Virpi

    2014-01-01

    Individual variation in nutritional status has direct implications for fitness and thus is crucial in shaping patterns of life-history variation. Nevertheless, it is difficult to measure in natural populations, especially in humans. Here, we used longitudinal data on individual life-histories and annual crop yield variation collected from pre-industrial Finnish populations experiencing natural mortality and fertility to test the validity of first birth interval (FBI; time between marriage and first birth) as a surrogate measure of nutritional status. We evaluated whether women with different socio-economic groups differ in length of FBI, whether women of poorer socio-economic status and experiencing lower crop yields conceive slower following marriage, and whether shorter FBI is associated with higher lifetime breeding success. We found that poorer women had longer FBI and reduced probability of giving birth in months with low food availability, while the FBI of richer women was not affected by variation in food availability. Women with shorter FBI achieved higher lifetime breeding success and a faster reproductive rate. This is, to our knowledge, the first study to show a direct relationship between environmental conditions and speed of childbirth following marriage, highlighting the value of FBI as an indicator of nutritional status when direct data are lacking. PMID:24285194

  18. Zooplankton taxonomic and size diversity in Mediterranean coastal lagoons (NE Iberian Peninsula): Influence of hydrology, nutrient composition, food resource availability and predation

    NASA Astrophysics Data System (ADS)

    Badosa, Anna; Boix, Dani; Brucet, Sandra; López-Flores, Rocío; Gascón, Stéphanie; Quintana, Xavier D.

    2007-01-01

    The influence of hydrology, nutrient composition, food resource availability and predation on zooplankton taxonomic and size diversity was analyzed in several shallow lagoons of a Mediterranean salt marsh (Baix Ter Wetlands, NE Iberian Peninsula). Taxonomic diversity correlated better with variables related to the trophic state, such as nutrient concentrations, whereas size diversity was more sensitive to fish predation. However, the fish predation influence on the size diversity was only significant when fishes reached high densities. Under low fish densities no predation effects were observed and the food resource availability (FR a) appeared to be more important in structuring the zooplankton community. Nevertheless, the two diversity indexes showed opposite responses to this factor. With increasing FR a the taxonomic diversity increased and the size diversity decreased. Neither taxonomic nor size diversity of the zooplankton community correlated with other physical or biotic factors such as hydrological variability or macroinvertebrate predation. The relationships found suggest that the size diversity is mainly related to biotic interactions, such as fish predation or inter/intraspecific competition, while the taxonomic diversity appears to be more sensitive to abiotic factors such as the nutrient composition.

  19. Airborne laser scan measurements of winter snow accumulation in high alpine catchments - hydrological implications and verification by ground penetrating radar at glacier surface

    NASA Astrophysics Data System (ADS)

    Helfricht, K.; Keuschnig, M.; Heilig, A.; Mayer, C.; Kuhn, M.

    2012-04-01

    The snow cover as storage of winter precipitation is a substantial source for runoff generation in high mountain catchments. Redistribution of solid precipitation, caused by wind and gravity, leads to a characteristic spatial distribution of snow accumulation which differs from simple model assumption of a homogenous snowpack increasing with altitude. Both, the distinct distribution of snow accumulation and the total amount of SWE stored in the snow cover, affect the magnitude and seasonality of melt water runoff. Complex relations exist between the spatial pattern of snow accumulation and the presence of glaciers and vice versa. For proper hydrological modeling in high mountain catchments, knowledge about snow cover distribution is an important requirement. To date, to evaluate modeling results, spatially insufficient point data on snow depths and SWE are usually available. On catchment scale, optical space-borne remote sensing techniques deliver areal extent of snow cover, but no snow depths and hence no volume of snow cover. Multi-temporal airborne laser scanning (ALS) is an active remote sensing method to obtain elevation changes extensively even in inaccessible alpine terrain. Before the start and at the end of accumulation season of winter 2010/2011, two airborne laser scan acquisitions were performed in the Ötztal Alps (Tirol, Austria). Differences of the respective digital elevation models were interpreted as snow depths and converted into SWE using a simple regression method between snow depths and snow density. Preferred snow accumulation areas were determined, e.g. wind sheltered depressions, the base of steep mountain walls and flat glacier surfaces. At catchment scale, solid precipitation is obviously redistributed from wind exposed mountain ridges to lower elevations, inducing characteristic elevations of maximum snow accumulation. Overall, catchment precipitation derived from snow accumulation is a valuable reference for precipitation approaches in

  20. The spatial and seasonal variations in mineral particle composition on the snow surface and their possible effect on snow algae in the Tateyama Mountains, Japan

    NASA Astrophysics Data System (ADS)

    Umino, T.; Takeuchi, N.

    2012-12-01

    Snow algae are autotrophic microbes and play an important role as primary producers in food chain of glaciers and snowfield. Although their reproduction requires nutrients, snow and ice is extreamly poor in nutrients. One of the possible sources of nutrients is mineral particles blown by wind and deposited on the snow. They may contain variable elements and provide nutrients for snow algae. However, we scarcely know about the relationship between mineral particles and snow algae. In this study, we described spatial and seasonal variations in mineral particle composition and also snow algae on the snow surface in the Tateyama Mountains, Japan. We discussed the possible effect of mineral particles on snow algae. Tateyama Mountains are located in middle-north part of Japan ranging from 2000 - 3000 m above sea level and have heavy snow fall in winter due to strong monsoon wind from Siberia. The snow starts to thaw in April and remains until late summer as perennial snow patches in some valleys. Kosa eolian dust is known to be blown from Chinese deserts and deposited on the snow every spring. Also, snow algal bloom is often observed as red-colored snow in summer. Samples were collected from the snow surface during summer in 2008 - 2011 at four different sites (A - D) in this area. We examined them by X-ray diffractometer (XRD) and microscope to obtain composition of mineral particles and structure of snow algae community. XRD analysis revealed mineral particles on the snow surface were mainly composed of quartz, plagioclase, hornblende, mica, chlorite, and amorphous. In April, mineral compositions of all sites were almost similar to that of Kosa eolian dust, indicating that these mineral particles were derived from Chinese arid regions. After May, the mineral compositions changed according to sites. The proportion of hornblende at the site C significantly increased whereas that of mica increased at the site D. Since the site C was located near geological features mainly

  1. Boundary layer development and energy exchange over a patchy mountain snow cover

    NASA Astrophysics Data System (ADS)

    Mott, Rebecca; Daniels, Megan; Horender, Stefan; Crivelli, Philip; Lehning, Michael

    2014-05-01

    Once the snow cover gets patchy in spring, small-scale thermal internal boundary layers develop, involving strong vertical and horizontal flux divergences. Furthermore, the advection of warm air from bare ground towards snow-covered areas can promote strong atmospheric stabilities and boundary layer decoupling above snow, that suppress the net turbulent heat flux close to the snow surface, thus, changing the heat budget there. We experimentally and numerically investigated the small-scale boundary layer dynamics over snow patches and their effect on the energy balance at the snow surface. Local eddy flux measurements at an alpine test site revealed that wind velocity, wind fetch distance and topographical curvature control the boundary layer growth, boundary layer decoupling and the efficiency of advective heat transport to contribute to snow ablation. These results were verified in a wind tunnel experiment on the boundary layer development over a single snow patch. The experiments showed that heat advection was very efficient at short fetch distances and high wind velocities forming strong thermal gradients close to the snow surface. The heat potentially available from the advective heat transport was, however, not efficiently transferred towards the snow surface. The turbulent heat exchange was strongly suppressed at the lowest centimetres above the snow surface, where the Richardson number exceeded the critical value. Thus, boundary layer decoupling caused by very shallow layers of increased thermal stability could be shown to be very efficient, even for higher wind velocities. In addition to experiments, we numerically analysed the effect of heat advection, boundary layer decoupling and changing patterns of secondary flows on the energy balance of patchy snow cover characterized by different snow-cover fractions. The atmospheric boundary layer flows over patchy snow-covers were calculated with an atmospheric model (Advanced Regional Prediction System) on a very

  2. Sodankylä manual snow survey program

    NASA Astrophysics Data System (ADS)

    Leppänen, Leena; Kontu, Anna; Hannula, Henna-Reetta; Sjöblom, Heidi; Pulliainen, Jouni

    2016-05-01

    The manual snow survey program of the Arctic Research Centre of the Finnish Meteorological Institute (FMI-ARC) consists of numerous observations of natural seasonal taiga snowpack in Sodankylä, northern Finland. The easily accessible measurement areas represent the typical forest and soil types in the boreal forest zone. Systematic snow measurements began in 1909 with snow depth (HS) and snow water equivalent (SWE). In 2006 the manual snow survey program expanded to cover snow macro- and microstructure from regular snow pits at several sites using both traditional and novel measurement techniques. Present-day snow pit measurements include observations of HS, SWE, temperature, density, stratigraphy, grain size, specific surface area (SSA) and liquid water content (LWC). Regular snow pit measurements are performed weekly during the snow season. Extensive time series of manual snow measurements are important for the monitoring of temporal and spatial changes in seasonal snowpack. This snow survey program is an excellent base for the future research of snow properties.

  3. Radar spectral observations of snow

    NASA Technical Reports Server (NTRS)

    Stiles, W. H.; Ulaby, F. T.; Fung, A. K.; Aslam, A.

    1981-01-01

    Radar remote sensing experiments have been conducted at test sites in Kansas, Colorado, and South Dakota over the last six years to examine backscatter coefficient response to snowcovered terrain. Truck-mounted 1-35 GHz scatterometers were employed in conjunction with detailed ground-truth measurements. From these experiments and associated modeling efforts, most of the fundamental questions concerning backscatter behavior in response to important snow parameters have been, at least qualitatively, answered. The optimum angular range seems to be between 20 and 50 deg and, for these angles, the results indicate that the radar backscatter generally: (1) increases with increasing water equivalent, (2) decreases with increasing liquid water, (3) increases with increasing crystal size, (4) is insensitive to surface roughness for dry snow conditions, and (5) can be sensitive to soil state if the snowcover is dry. This paper gives a summary of these results, along with empirical and theoretical models for describing the backscatter from snow.

  4. Relating Snow Transport to Ecosystem Structure and Function: Lessons from Libby Flats

    NASA Astrophysics Data System (ADS)

    Hiemstra, C. A.; Reiners, W. A.

    2003-12-01

    . Snow is transported to areas where wind speeds are reduced, and once snowmelt ensues during the spring and summer, water is absorbed into the soil, evaporated, or transported downslope. These concatenated factors involving water movement produce temporally shifting gradients of available moisture and site conditions (e.g., soil temperature and moisture) that influence, and are influenced by, ecosystem structure and function.

  5. Physically based modelling of alpine snow hydrology in the Canadian Rockies (Invited)

    NASA Astrophysics Data System (ADS)

    Pomeroy, J. W.; Debeer, C.; MacDonald, M. K.; Fang, X.; Hopkinson, C.

    2010-12-01

    of field technology have been used to update a modular, object-oriented computer simulation of the cold regions hydrological cycle, the Cold Regions Hydrological Model, CRHM. CRHM can be easily and frequently updated as improved algorithms become available and used to predict both snow dynamics and streamflow from high mountain areas.

  6. Pan-Arctic linkages between snow accumulation and growing season air temperature, soil moisture and vegetation

    NASA Astrophysics Data System (ADS)

    Luus, K. A.; Gel, Y.; Lin, J. C.; Kelly, R. E. J.; Duguay, C. R.

    2013-01-01

    Arctic field studies have indicated that the air temperature, soil moisture and vegetation at a site influence the quantity of snow accumulated, and that snow accumulation can alter growing season soil moisture and vegetation. Climate change is predicted to bring about warmer air temperatures, greater snow accumulation and northward movements of the shrub and tree lines. Understanding the response of northern environments to changes in snow and growing season land surface characteristics requires: (1) insights into the present-day linkages between snow and growing season land surface characteristics; and (2) the ability to continue to monitor these associations over time across the vast pan-Arctic. The objective of this study was therefore to examine the pan-Arctic (north of 60° N) linkages between two temporally distinct data products created from AMSR-E satellite passive microwave observations: GlobSnow snow water equivalent, and NTSG (growing season air temperature, soil moisture and vegetation transmissivity). Due to the complex and interconnected nature of processes determining snow and growing season land surface characteristics, these associations were analyzed using the modern non-parametric technique of Alternating Conditional Expectations (ACE), as this approach does not impose a predefined analytic form. Findings indicate that regions with lower vegetation transmissivity (more biomass) at the start and end of the growing season tend to accumulate less snow at the start and end of the snow season, possibly due to interception and shading. Warmer air temperatures at the start and end of the growing season were associated with diminished snow accumulation at the start and end of the snow season. High latitude sites with warmer mean annual growing season temperatures tended to accumulate more snow, probably due to the greater availability of water vapor for snow season precipitation at warmer locations. Regions with drier soils preceding snow onset tended

  7. A New Approach to Measuring Precipitation over Snow Cover

    NASA Astrophysics Data System (ADS)

    Tian, Y.; Liu, Y.; Arsenault, K. R.; Behrangi, A.

    2013-12-01

    One of the great challenges for truly global precipitation measurement is the remote sensing of precipitation over snow cover. Due to the physical limitation in the current retrieval methodology, satellite-based measurements of precipitation over snow-covered areas are unreliable and largely unavailable. In this presentation, a new satellite-based approach to the estimation of precipitation over snow cover is proposed and tested. The method is based on the principle that precipitation can be inferred by the changes in the water content of the snowpack. During the EOS era operational remote sensing of snow water equivalent is available, with similar spatial and temporal resolutions of the precipitation-sensing passive microwave sensors. With these satellite-based snow water equivalent measurements, daily precipitation amounts can be derived. We tested the method for the Northern Hemisphere for three snow-accumulation seasons, with AMSR-E snow water equivalent data, and compared with existing datasets, including CPC gauge analysis and GPCP. The new precipitation estimates captured natural- and realistic-looking storm events over largely under-instrumented regions. The spatial distribution appeared more reasonable than existing global datasets over many boreal inland areas. The results indicate this approach is feasible and promising. Besides the capability to estimate precipitation over snow cover, this new approach has the following additional advantages over the conventional methods: 1. The relationship between precipitation and the observed variable (i.e., SWE) is more direct than the conventional methods, which have to rely on scattering signals from hydrometeors (passive microwave) or cloud top brightness temperatures (infrared) to infer precipitation; 2. Temporal sampling error is small. The method will not miss any precipitation amount even if there are no instantaneous satellite overpasses during the precipitation event. The memory of the snowpack stores the

  8. Estimation of daily Snow Cover Area combining MODIS and LANDSAT information by using cellular automata

    NASA Astrophysics Data System (ADS)

    Pardo-Iguzquiza, Eulogio; Juan Collados Lara, Antonio; Pulido-Velazquez, David

    2016-04-01

    The snow availability in Alpine catchments is essential for the economy of these areas. It plays an important role in tourist development but also in the management of the Water Resources Snow is an important water resource in many river basins with mountains in the catchment area. The determination of the snow water equivalent requires the estimation of the evolution of the snow pack (cover area, thickness and snow density) along the time. Although there are complex physical models of the dynamics of the snow pack, sometimes the data available are scarce and a stochastic model like the cellular automata (CA) can be of great practical interest. CA can be used to model the dynamics of growth and wane of the snow pack. The CA is calibrated with historical data. This requires the determination of transition rules that are capable of modeling the evolution of the spatial pattern of snow cover area. Furthermore, CA requires the definition of states and neighborhoods. We have included topographical variables and climatological variables in order to define the state of each pixel. The evolution of snow cover in a pixel depends on its state, the state of the neighboring pixels and the transition rules. The calibration of the CA is done using daily MODIS data, available for the period 24/02/2002 to present with a spatial resolution of 500 m, and the LANDSAT information available with a sixteen-day periodicity from 1984 to the present and with spatial resolution of 30 m. The methodology has been applied to estimation of the snow cover area of Sierra Nevada mountain range in the Southern of Spain to obtain snow cover area daily information with 500 m spatial resolution for the period 1980-2014. Acknowledgments: This research has been partially supported by the GESINHIMPADAPT project (CGL2013-48424-C2-2-R) with Spanish MINECO funds. We would also like to thank NASA DAAC and LANDSAT project for the data provided for this study.

  9. Modeling bulk density and snow water equivalent using daily snow depth observations

    NASA Astrophysics Data System (ADS)

    McCreight, J. L.; Small, E. E.

    2014-03-01

    Bulk density is a fundamental property of snow relating its depth and mass. Previously, two simple models of bulk density (depending on snow depth, date, and location) have been developed to convert snow depth observations to snow water equivalent (SWE) estimates. However, these models were not intended for application at the daily time step. We develop a new model of bulk density for the daily time step and demonstrate its improved skill over the existing models. Snow depth and density are negatively correlated at short (10 days) timescales while positively correlated at longer (90 days) timescales. We separate these scales of variability by modeling smoothed, daily snow depth (long timescales) and the observed positive and negative anomalies from the smoothed time series (short timescales) as separate terms. A climatology of fit is also included as a predictor variable. Over half a million daily observations of depth and SWE at 345 snowpack telemetry (SNOTEL) sites are used to fit models and evaluate their performance. For each location, we train the three models to the neighboring stations within 70 km, transfer the parameters to the location to be modeled, and evaluate modeled time series against the observations at that site. Our model exhibits improved statistics and qualitatively more-realistic behavior at the daily time step when sufficient local training data are available. We reduce density root mean square error (RMSE) by 9.9 and 4.5% compared to previous models while increasing R2 from 0.46 to 0.52 to 0.56 across models. Focusing on the 21-day window around peak SWE in each water year, our model reduces density RMSE by 24 and 17.4% relative to the previous models, with R2 increasing from 0.55 to 0.58 to 0.71 across models. Removing the challenge of parameter transfer over the full observational record increases R2 scores for both the existing and new models, but the gain is greatest for the new model (R2 = 0.75). Our model shows general improvement over

  10. Snow and Ice Products from the Moderate Resolution Imaging Spectroradiometer

    NASA Technical Reports Server (NTRS)

    Hall, Dorothy K.; Salomonson, Vincent V.; Riggs, George A.; Klein, Andrew G.

    2003-01-01

    Snow and sea ice products, derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument, flown on the Terra and Aqua satellites, are or will be available through the National Snow and Ice Data Center Distributed Active Archive Center (DAAC). The algorithms that produce the products are automated, thus providing a consistent global data set that is suitable for climate studies. The suite of MODIS snow products begins with a 500-m resolution, 2330-km swath snow-cover map that is then projected onto a sinusoidal grid to produce daily and 8-day composite tile products. The sequence proceeds to daily and 8-day composite climate-modeling grid (CMG) products at 0.05 resolution. A daily snow albedo product will be available in early 2003 as a beta test product. The sequence of sea ice products begins with a swath product at 1-km resolution that provides sea ice extent and ice-surface temperature (IST). The sea ice swath products are then mapped onto the Lambert azimuthal equal area or EASE-Grid projection to create a daily and 8-day composite sea ice tile product, also at 1 -km resolution. Climate-Modeling Grid (CMG) sea ice products in the EASE-Grid projection at 4-km resolution are planned for early 2003.

  11. Interpretation of AMSU microwave measurements for the retrievals of snow water equivalent and snow depth

    NASA Astrophysics Data System (ADS)

    Kongoli, Cezar; Grody, Norman C.; Ferraro, Ralph R.

    2004-12-01

    The objective of this paper is to interpret microwave scattering signatures over snow cover as observed by the Advanced Microwave Sounding Unit (AMSU) for the retrievals of snow water equivalent and snow depth. A case study involving seasonal snow cover over the U.S. Great Plains was analyzed in detail. Area-wide analysis of the relationship between snow depth and the AMSU scattering signatures in the 23-150 GHz window region showed weak correlation, deteriorated by the dependence of these signatures on snow metamorphism. The lower frequency scattering index, computed as the difference in the brightness temperature between 23 and 31 GHz channels, was low and insensitive to fresh snow predominant in December, but increased later in the season, and thus was more sensitive to snow depth for older snow cover. However, this seasonal increase in microwave scattering was observed for every snow depth range, suggesting a strong dependence on snow metamorphism. In contrast, the 89 GHz scattering index responded to relatively shallow snow cover in December, but was less sensitive to snow depth variability later in the season. A snow hydrology model was applied at specific locations to estimate snow water equivalent (other than snow depth) for comparisons with the AMSU measurements. Overall, the lower frequency index was the best predictor of snow water equivalent and snow depth. However, correlation was higher for snow density and snow water equivalent. This was attributed to the response of this scattering index to the grain size evolution with time, which correlated better with the snow density and water equivalent changes in the snow cover than snow depth. Correlation between the snow water equivalent and the lower frequency index for fresh snow cover was significantly improved by switching to the higher frequency index at 89 GHz as predictor when the lower frequency index at 31 GHz was less than the 5 K threshold. Correlation further improved for fresh snow cover

  12. BOREAS RSS-8 Snow Maps Derived from Landsat TM Imagery

    NASA Technical Reports Server (NTRS)

    Hall, Dorothy; Chang, Alfred T. C.; Foster, James L.; Chien, Janeet Y. L.; Hall, Forrest G. (Editor); Nickeson, Jaime (Editor); Smith, David E. (Technical Monitor)

    2000-01-01

    The Boreal Ecosystem-Atmosphere Study (BOREAS) Remote Sensing Science (RSS)-8 team utilized Landsat Thematic Mapper (TM) images to perform mapping of snow extent over the Southern Study Area (SSA). This data set consists of two Landsat TM images that were used to determine the snow-covered pixels over the BOREAS SSA on 18 Jan 1993 and on 06 Feb 1994. The data are stored in binary image format files. The RSS-08 snow map data are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The data files are available on a CD-ROM (see document number 20010000884).

  13. Snow wetness measurements for melt forecasting

    NASA Technical Reports Server (NTRS)

    Linlor, W. I.; Clapp, F. D.; Meier, M. F.; Smith, J. L.

    1975-01-01

    A microwave technique for directly measuring snow pack wetness in remote installations is described. The technique, which uses satellite telemetry for data gathering, is based on the attenuation of a microwave beam in transmission through snow.

  14. Alpine Snow Cover - Water Resources in Arid Regions

    NASA Astrophysics Data System (ADS)

    Czyzowska, E. H.; Van Leeuwen, W. J.; Hirschboeck, K. K.; Wisniewski, W. T.; Marsh, S. E.

    2013-12-01

    There is an undisputed need to increase accuracy of snow cover estimation in regions of complex terrain, especially in areas dependent on winter snow accumulation for a substantial portion of their water supply, such as the Western United States, Central Asia, and the Andes. Presently, the most pertinent monitoring and research needs related to alpine snow cover extent (SCE) are: (1) to improve SCE monitoring by providing detailed fractional snow cover (FSC) products which perform well in temporal/spatial heterogeneous forested and/or alpine terrains; (2) to provide accurate measurements of FSC at the watershed scale for use in snow water equivalent (SWE) estimation for regional water management; (3) to provide detailed distributions of FSC in mountainous regions to investigate the temporal/spatial distribution of SCE/SWE in relation to recent climate changes; (4) to use FSC products as input for climate models at multiple scales; and (5) to estimate SCE and SWE for use in ecological studies (e.g., vegetation cover, water stress, primary production, fire, insect outbreaks, and pulses in tree demography). To address the above our approach is based on Landsat/MODIS Fractional Snow Cover (LandsatFSC, ModisFSC), as a measure of the temporal/spatial distribution of alpine SCE. We used a fusion methodology between remotely sensed multispectral data from Landsat TM/ETM+/MODIS and Ikonos utilized at their highest respective spatial resolutions. Artificial Neural Networks (ANNs) are used to capture the multi-scale information structure of the data by means of the ANN training process, followed by the ANN extracting FSC from all available information in the Landsat images. The LandsatFSC/ModisFSC algorithms were validated (RMSE ~ 0.09; mean error ~ 0.001-0.01 FSC) in watersheds characterized by diverse environmental factors such as: terrain, slope, exposition, vegetation cover, and wide-ranging snow cover conditions.

  15. Skill of remote sensing snow products for distributed runoff prediction

    NASA Astrophysics Data System (ADS)

    Berezowski, Tomasz; Chormański, Jarosław; Batelaan, Okke

    2015-05-01

    With increasing availability of remote sensing snow cover products we aim to evaluate the skill of these datasets with regard to hydrological discharge simulation. In this paper ten model variants using different snow cover data (MOD10A1, IMS, AMSR-E SWE, GLOBSNOW SWE and observed in situ snow depth) and two different model structures for snow accumulation and snowmelt switching (based on snow cover data time series or temperature time series) are calibrated with a global optimisation algorithm. The simulated discharge is subjected to five criteria for validation, while the GLUE methodology is used for uncertainty analysis of the ten model variants. The skill of the datasets is tested for the Biebrza River catchment, which has a hydrological regime dominated by snowmelt. The discharge simulations are conducted with the distributed rainfall-runoff model WetSpa. MOD10A1 was the only data source which improved the validation Nash-Sutcliffe (NS) scores in reference to a standard model. However, other evaluation measures indicate that the following data sources performed better than the standard model: MOD10A1, observed snow depth and GLOBSNOW for Kling-Gupta efficiency and for high flows; IMS and MOD10A1 for bias; GLOBSNOW and MOD10A1 for coefficient of determination. MOD10A1 has the highest spatial resolution of all analysed data sources which might contribute to the high skill of this data. The use of the data-based switching model structure generally narrowed the behavioural parameter sets during the uncertainty analysis when compared to the temperature-based switching. However, no clear relation was observed between the prediction confidence interval and the two model structures. It is concluded that the skill of the remote sensing snow cover data for the model is positive, although, strongly varying with the data source used.

  16. Snow Mass Quantification and Avalanche Victim Search by Ground Penetrating Radar

    NASA Astrophysics Data System (ADS)

    Jaedicke, Christian

    2003-11-01

    Ground penetrating radar (GPR) systems can be used in many applications of snow and ice research. The information from the GPR is used to identify and interpret layers, objects and different structures in the snow. A commercially available GPR system was further developed to work in the rough environment of snow and ice. The applied GPR is a 900 MHz system that easily reaches snow depths of up to 10 meters. The system was calibrated in the course of several manual snow depth measurements during each survey. The depth resolution depends on the snow type and is around +/-0.1 m. The GPR system is carried alongside a line of interest and is triggered by an odometer wheel at regular adjustable steps. All equipment is mounted in a sledge and is pulled by a snowmobile over the snow surface. This setup allows for an efficient coverage of several kilometers of terrain profiles. The radar profiles give a real time two-dimensional impression of structures and objects and the interface between snow and the underlying ground. The actual radar profile is shown on a screen on the sledge allowing the immediate marking of objects and structures. During the past three years the instrument was successfully used for the study of snow distributions, for the detection of glacier crevasses under the snow cover, and for the search of avalanche victims in avalanche debris. The results show the capability of the instrument to detect persons and objects in the snow cover. In the future, this device may be a new tool for avalanche rescue operations. Today, the size and weight of the system prevents the accessing of very steep slopes and areas not accessible to snowmobiles. Further developments will decrease the size of the system and make it a valuable tool to quantify snow masses in avalanche release zones and run-out areas.

  17. Tracking Forest and Open Area Effects on Snow Accumulation by Unmanned Aerial Vehicle Photogrammetry

    NASA Astrophysics Data System (ADS)

    Lendzioch, T.; Langhammer, J.; Jenicek, M.

    2016-06-01

    Airborne digital photogrammetry is undergoing a renaissance. The availability of low-cost Unmanned Aerial Vehicle (UAV) platforms well adopted for digital photography and progress in software development now gives rise to apply this technique to different areas of research. Especially in determining snow depth spatial distributions, where repetitive mapping of cryosphere dynamics is crucial. Here, we introduce UAV-based digital photogrammetry as a rapid and robust approach for evaluating snow accumulation over small local areas (e.g., dead forest, open areas) and to reveal impacts related to changes in forest and snowpack. Due to the advancement of the technique, snow depth of selected study areas such as of healthy forest, disturbed forest, succession, dead forest, and of open areas can be estimated at a 1 cm spatial resolution. The approach is performed in two steps: 1) developing a high resolution Digital Elevation Model during snow-free and 2) during snow-covered conditions. By substracting these two models the snow depth can be accurately retrieved and volumetric changes of snow depth distribution can be achieved. This is a first proof-of-concept study combining snow depth determination and Leaf Area Index (LAI) retrieval to monitor the impact of forest canopy metrics on snow accumulation in coniferous forest within the Šumava National Park, Czech Republic. Both, downward-looking UAV images and upward-looking LAI-2200 canopy analyser measurements were applied to reveal the LAI, controlling interception and transmitting radiation. For the performance of downward-looking images the snow background instead of the sky fraction was used. In contrast to the classical determination of LAI by hemispherical photography or by LAI plant canopy analyser, our approach will also test the accuracy of LAI measurements by UAV that are taken simultaneously during the snow cover mapping campaigns. Since the LAI parameter is important for snowpack modelling, this method presents

  18. Creation of an Empirical Energy-Balance Based Snow Module Simulating Both Snowmelt and Snow Accumulation for Mountain Hydrology

    NASA Astrophysics Data System (ADS)

    Riboust, P.; Le Moine, N.; Thirel, G.; Ribstein, P.

    2015-12-01

    In Nordic and mountainous regions, hydrological processes are more complex than for regular rainfall-driven watersheds. Snow accumulates in winter, acting as a reservoir, and melts during late spring and summer. In order to take into account these additional natural processes present in mountainous watersheds, snow modules have been created in order to help rainfall-runoff models to simulate river discharge. Many empirical degree-day snow models have been designed to simulate snowmelt and river discharge when coupled to a rainfall runoff model, but few of them simulate correctly the amount of snow water equivalent (SWE) at point scale. Simulating correctly not only the amount of snowmelt but also the water content of the snowpack has several potential advantages: it allows improving the model reliability and performance for short-term and long-term prediction, spatial regionalization, and it makes it possible to perform data assimilation using observed snow measurements. The objective of our study is to create a new simple empirical snow module, with a structure allowing the use of snow data for calibration or assimilation. We used a model structure close to the snow model defined by M.T. Walter (2005) where each of the processes of the energy balance is parameterized using only temperature and precipitation data. The conductive fluxes into the snowpack have been modeled using analyticalsolutions to the heat equation with phase change. This model which is in-between the degree-day and the physical energy-balance approaches. It has the advantages to use only temperature and precipitation which arewidely available data and to take account of energy balance processes without being computationally intensive. Another advantage is that all state variables of the model should be comparable with observable measurements.For the moment, the snow module has been parameterized at point scale and has been tested over Switzerland and the US, using MeteoSwiss and SNOTEL USGS

  19. Snow Hydrology in a General Circulation Model.

    NASA Astrophysics Data System (ADS)

    Marshall, Susan; Roads, John O.; Glatzmaier, Gary

    1994-08-01

    A snow hydrology has been implemented in an atmospheric general circulation model (GCM). The snow hydrology consists of parameterizations of snowfall and snow cover fraction, a prognostic calculation of snow temperature, and a model of the snow mass and hydrologic budgets. Previously, only snow albedo had been included by a specified snow line. A 3-year GCM simulation with this now more complete surface hydrology is compared to a previous GCM control run with the specified snow line, as well as with observations. In particular, the authors discuss comparisons of the atmospheric and surface hydrologic budgets and the surface energy budget for U.S. and Canadian areas.The new snow hydrology changes the annual cycle of the surface moisture and energy budgets in the model. There is a noticeable shift in the runoff maximum from winter in the control run to spring in the snow hydrology run. A substantial amount of GCM winter precipitation is now stored in the seasonal snow pack. Snow cover also acts as an important insulating layer between the atmosphere and the ground. Wintertime soil temperatures are much higher in the snow hydrology experiment than in the control experiment. Seasonal snow cover is important for dampening large fluctuations in GCM continental skin temperature during the Northern Hemisphere winter.Snow depths and snow extent show good agreement with observations over North America. The geographic distribution of maximum depths is not as well simulated by the model due, in part, to the coarse resolution of the model. The patterns of runoff are qualitatively and quantitatively similar to observed patterns of streamflow averaged over the continental United States. The seasonal cycles of precipitation and evaporation are also reasonably well simulated by the model, although their magnitudes are larger than is observed. This is due, in part, to a cold bias in this model, which results in a dry model atmosphere and enhances the hydrologic cycle everywhere.

  20. A meteorological and snow observational data set from Snoqualmie Pass (921 m), Washington Cascades, USA

    NASA Astrophysics Data System (ADS)

    Wayand, Nicholas E.; Massmann, Adam; Butler, Colin; Keenan, Eric; Stimberis, John; Lundquist, Jessica D.

    2015-12-01

    We introduce a quality controlled observational atmospheric, snow, and soil data set from Snoqualmie Pass, Washington, USA, to enable testing of hydrometeorological and snow process representations within a rain-snow transitional climate where existing observations are sparse and limited. Continuous meteorological forcing (including air temperature, total precipitation, wind speed, specific humidity, air pressure, and short and longwave irradiance) are provided at hourly intervals for a 24 year historical period (water years 1989-2012) and at half-hourly intervals for a more recent period (water years 2013-2015), separated based on the availability of observations. The majority of missing data were filled with biased-corrected reanalysis model values (using NLDAS). Additional observations include 40 years of snow board new snow accumulation, multiple measurements of total snow depth, and manual snow pits, while more recent years include subdaily surface temperature, snowpack drainage, soil moisture and temperature profiles, and eddy covariance-derived turbulent heat flux. This data set is ideal for testing hypotheses about energy balance, soil, and snow processes in the rain-snow transition zone.

  1. Putting humans in the loop: Using crowdsourced snow information to inform water management

    NASA Astrophysics Data System (ADS)

    Fedorov, Roman; Giuliani, Matteo; Castelletti, Andrea; Fraternali, Piero

    2016-04-01

    The unprecedented availability of user generated data on the Web due to the advent of online services, social networks, and crowdsourcing, is opening new opportunities for enhancing real-time monitoring and modeling of environmental systems based on data that are public, low-cost, and spatio-temporally dense, possibly contributing to our ability of making better decisions. In this work, we contribute a novel crowdsourcing procedure for computing virtual snow indexes from public web images, either produced by users or generated by touristic webcams, which is based on a complex architecture designed for automatically crawling content from multiple web data sources. The procedure retains only geo-tagged images containing a mountain skyline, identifies the visible peaks in each image using a public online digital terrain model, and classifies the mountain image pixels as snow or no-snow. This operation yields a snow mask per image, from which it is possible to extract time series of virtual snow indexes representing a proxy of the snow covered area. The value of the obtained virtual snow indexes is estimated in a real world water management problem. We consider the snow-dominated catchment of Lake Como, a regulated lake in Northern Italy, where snowmelt represents the most important contribution to seasonal lake storage, and we used the virtual snow indexes for informing the daily operation of the lake's dam. Numerical results show that such information is effective in extending the anticipation capacity of the lake operations, ultimately improving the system performance.

  2. Global Snow-Cover Evolution from Twenty Years of Satellite Passive Microwave Data

    USGS Publications Warehouse

    Mognard, N.M.; Kouraev, A.V.; Josberger, E.G.

    2003-01-01

    Starting in 1979 with the SMMR (Scanning Multichannel Microwave Radiometer) instrument onboard the satellite NIMBUS-7 and continuing since 1987 with the SSMI (Special Sensor Microwave Imager) instrument on board the DMSP (Defence Meteorological Satellite Program) series, more then twenty years of satellite passive microwave data are now available. This dataset has been processed to analyse the evolution of the global snow cover. This work is part of the AICSEX project from the 5th Framework Programme of the European Community. The spatio-temporal evolution of the satellite-derived yearly snow maximum extent and the timing of the spring snow melt were estimated and analysed over the Northern Hemisphere. Significant differences between the evolution of the yearly maximum snow extent in Eurasia and in North America were found. A positive correlation between the maximum yearly snow cover extent and the ENSO index was obtained. High interannual spatio-temporal variability characterises the timing of snow melt in the spring. Twenty-year trends in the timing of spring snow melt have been computed and compared with spring air temperature trends for the same period and the same area. In most parts of Eurasia and in the central and western parts of North America the tendency has been for earlier snow melt. In northeastern Canada, a large area of positive trends, where snow melt timing starts later than in the early 1980s, corresponds to a region of positive trends of spring air temperature observed over the same period.

  3. Methods for Assessing the Impact of Fog Oil Smoke on Availability, Palatability, & Food Quality of Relevant Life Stages of Insects for Threatened and Endangered Species

    SciTech Connect

    Driver, Crystal J.; Strenge, Dennis L.; Su, Yin-Fong; Cullinan, Valerie I.; Herrington, Ricky S.; Saunders, Danielle L.; Rogers, Lee E.

    2007-04-01

    A methodology for quantifying population dynamics and food source value of insect fauna in areas subjected to fog oil smoke was developed. Our approach employed an environmentally controlled re-circulating wind tunnel outfitted with a high-heat vaporization and re-condensation fog oil generator that has been shown to produce aerosols of comparable chemistry and droplet-size distribution as those of field releases of the smoke. This method provides reproducible exposures of insects under realistic climatic and environmental conditions to fog oil aerosols that duplicate chemical and droplet-size characteristics of field releases of the smoke. The responses measured take into account reduction in food sources due to death and to changes in availability of relevant life stages of insects that form the prey base for the listed Threatened and Endangered Species. The influence of key environmental factors, wind speed and canopy structure on these responses were characterized. Data generated using this method was used to develop response functions related to particle size, concentration, wind speed, and canopy structure that will allow military personnel to assess and manage impacts to endangered species from fog oil smoke used in military training.

  4. Snow and Ice Crust Changes over Northern Eurasia since 1966

    NASA Astrophysics Data System (ADS)

    Bulygina, O.; Groisman, P. Y.; Razuvaev, V.; Radionov, V.

    2009-12-01

    When temperature of snow cover reaches zero Celsius first time since its establishment, snowmelt starts. In many parts of the world this process can be lengthy. The initial amount of heat that “arrives” to the snowpack might be insufficient for complete snowmelt, during the colder nights re-freeze of the melted snow may occur (thus creating the ice crust layers), and a new cold front (or the departure of the warm front that initiated melt) can decrease temperatures below the freezing point again and stop the snowmelt completely. It well can be that first such snowmelt occurs in winter (thaw day) and for several months thereafter snowpack stays on the ground. However, even the first such melt initiates a process of snow metamorphosis on its surface changing snow albedo and generating snow crust as well as on its bottom generating ice crust. Once emerged, the crusts will not disappear until the complete snowmelt. Furthermore, these crusts have numerous pathways of impact on the wild birds and animals in the Arctic environment as well as on domesticated reindeers. In extreme cases, the crusts may kill some wild species and prevent reindeers’ migration and feeding. Ongoing warming in high latitudes created situations when in the western half of Eurasian continent days with thaw became more frequent. Keeping in mind potential detrimental impacts of winter thaws and associated with them snow/ice crust development, it is worthwhile to study directly what are the major features of snow and ice crust over Eurasia and what is their dynamics. For the purpose of this study, we employed the national snow survey data set archived at the Russian Institute for Hydrometeorological Information. The dataset has routine snow surveys run throughout the cold season each decade (during the intense snowmelt, each 5 days) at all meteorological stations of the former USSR, thereafter, in Russia since 1966. Prior to 1966 snow surveys are also available but the methodology of

  5. Microwave emission from an irregular snow layer

    NASA Technical Reports Server (NTRS)

    Eom, H. J.; Lee, K. K.; Fung, A. K.

    1983-01-01

    Emission from an irregular snow layer is modeled by a layer of Mie scatterers using the radiative transfer method. Comparisons are made with measurements showing snow wetness effects and rough air-snow boundary effects. For convenience of reference, theoretical model behavior is also illustrated.

  6. Elevation dependency of mountain snow depth

    NASA Astrophysics Data System (ADS)

    Grünewald, T.; Bühler, Y.; Lehning, M.

    2014-12-01

    Elevation strongly affects quantity and distribution patterns of precipitation and snow. Positive elevation gradients were identified by many studies, usually based on data from sparse precipitation stations or snow depth measurements. We present a systematic evaluation of the elevation-snow depth relationship. We analyse areal snow depth data obtained by remote sensing for seven mountain sites near to the time of the maximum seasonal snow accumulation. Snow depths were averaged to 100 m elevation bands and then related to their respective elevation level. The assessment was performed at three scales: (i) the complete data sets (10 km scale), (ii) sub-catchments (km scale) and (iii) slope transects (100 m scale). We show that most elevation-snow depth curves at all scales are characterised through a single shape. Mean snow depths increase with elevation up to a certain level where they have a distinct peak followed by a decrease at the highest elevations. We explain this typical shape with a generally positive elevation gradient of snow fall that is modified by the interaction of snow cover and topography. These processes are preferential deposition of precipitation and redistribution of snow by wind, sloughing and avalanching. Furthermore, we show that the elevation level of the peak of mean snow depth correlates with the dominant elevation level of rocks (if present).

  7. 44 CFR 206.227 - Snow assistance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    .... Federal assistance will be provided for all costs eligible under 44 CFR 206.225 for a specified period of... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Snow assistance. 206.227... Snow assistance. Emergency or major disaster declarations based on snow or blizzard conditions will...

  8. Cold, Ice, and Snow Safety (For Parents)

    MedlinePlus

    ... to Know About Zika & Pregnancy Cold, Ice, and Snow Safety KidsHealth > For Parents > Cold, Ice, and Snow Safety Print A A A Text Size What's ... a few. Plus, someone has to shovel the snow, right? Once outdoors, however, take precautions to keep ...

  9. 44 CFR 206.227 - Snow assistance.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    .... Federal assistance will be provided for all costs eligible under 44 CFR 206.225 for a specified period of... 44 Emergency Management and Assistance 1 2013-10-01 2013-10-01 false Snow assistance. 206.227... Snow assistance. Emergency or major disaster declarations based on snow or blizzard conditions will...

  10. 44 CFR 206.227 - Snow assistance.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    .... Federal assistance will be provided for all costs eligible under 44 CFR 206.225 for a specified period of... 44 Emergency Management and Assistance 1 2011-10-01 2011-10-01 false Snow assistance. 206.227... Snow assistance. Emergency or major disaster declarations based on snow or blizzard conditions will...

  11. 44 CFR 206.227 - Snow assistance.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    .... Federal assistance will be provided for all costs eligible under 44 CFR 206.225 for a specified period of... 44 Emergency Management and Assistance 1 2014-10-01 2014-10-01 false Snow assistance. 206.227... Snow assistance. Emergency or major disaster declarations based on snow or blizzard conditions will...

  12. 44 CFR 206.227 - Snow assistance.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    .... Federal assistance will be provided for all costs eligible under 44 CFR 206.225 for a specified period of... 44 Emergency Management and Assistance 1 2012-10-01 2011-10-01 true Snow assistance. 206.227... Snow assistance. Emergency or major disaster declarations based on snow or blizzard conditions will...

  13. Merging the MODIS and NESDIS Monthly Snow-Cover Records to Study Decade-Scale Changes in Northern Hemisphere Snow Cover

    NASA Technical Reports Server (NTRS)

    Hall, Dorothy K.; Foster, James L.; Robinson, David A.; Riggs, George A.

    2004-01-01

    A decade-scale record of Northern Hemisphere snow cover has been available from the National Oceanic and Atmospheric Administration (NOAA) National Environmental Satellite Data and Information Service (NESDIS) and has been reconstructed and validated by Rutgers University following adjustments for inconsistencies that were discovered in the early years of the data set. This record provides weekly, monthly (and, in recent years, daily) snow cover from 1966 to the present for the Northern Hemisphere. With the December 1999 launch of NASA's Earth observing System (EOS) Terra satellite, snow maps are being produced globally, using automated algorithms, on a daily, weekly and monthly basis from the Moderate-Resolution Imaging Spectroradiometer (MODIS) instrument. The resolution of the MODIS monthly snow maps (0.05deg or about 5 km) is an improvement over that of the NESDIS-derived monthly snow maps (>approx.10 km) the maps, it is necessary to study the datasets carefully to determine if it is possible to merge the datasets into a continuous record. The months in which data are available for both the NESDIS and MODIS maps (March 2000 to the present) will be compared quantitatively to analyze differences in North American and Eurasian snow cover. Results from the NESDIS monthly maps show that for North America (including all 12 months), there is a trend toward slightly less snow cover in each succeeding decade. Interannual snow-cover extent has varied significantly since 2000 as seen in both the NESDIS and MODIS maps. As the length of the satellite record increases through the MODIS era, and into the National Polar-orbiting Environmental Satellite System (NPOESS) era, it should become easier to identify trends in areal extent of snow cover, if present, that may have climatic significance. Thus it is necessary to analyze the validity of merging the NESDIS and MODIS, and, in the future, the NPOESS datasets for determination of long-term continuity in measurement of Northern

  14. Photopolarimetric Retrievals of Snow Properties

    NASA Technical Reports Server (NTRS)

    Ottaviani, M.; van Diedenhoven, B.; Cairns, B.

    2015-01-01

    Polarimetric observations of snow surfaces, obtained in the 410-2264 nm range with the Research Scanning Polarimeter onboard the NASA ER-2 high-altitude aircraft, are analyzed and presented. These novel measurements are of interest to the remote sensing community because the overwhelming brightness of snow plagues aerosol and cloud retrievals based on airborne and spaceborne total reflection measurements. The spectral signatures of the polarized reflectance of snow are therefore worthwhile investigating in order to provide guidance for the adaptation of algorithms currently employed for the retrieval of aerosol properties over soil and vegetated surfaces. At the same time, the increased information content of polarimetric measurements allows for a meaningful characterization of the snow medium. In our case, the grains are modeled as hexagonal prisms of variable aspect ratios and microscale roughness, yielding retrievals of the grains' scattering asymmetry parameter, shape and size. The results agree with our previous findings based on a more limited data set, with the majority of retrievals leading to moderately rough crystals of extreme aspect ratios, for each scene corresponding to a single value of the asymmetry parameter.

  15. Photopolarimetric retrievals of snow properties

    NASA Astrophysics Data System (ADS)

    Ottaviani, M.; van Diedenhoven, B.; Cairns, B.

    2015-10-01

    Polarimetric observations of snow surfaces, obtained in the 410-2264 nm range with the Research Scanning Polarimeter onboard the NASA ER-2 high-altitude aircraft, are analyzed and presented. These novel measurements are of interest to the remote sensing community because the overwhelming brightness of snow plagues aerosol and cloud retrievals based on airborne and spaceborne total reflection measurements. The spectral signatures of the polarized reflectance of snow are therefore worthwhile investigating in order to provide guidance for the adaptation of algorithms currently employed for the retrieval of aerosol properties over soil and vegetated surfaces. At the same time, the increased information content of polarimetric measurements allows for a meaningful characterization of the snow medium. In our case, the grains are modeled as hexagonal prisms of variable aspect ratios and microscale roughness, yielding retrievals of the grains' scattering asymmetry parameter, shape and size. The results agree with our previous findings based on a more limited data set, with the majority of retrievals leading to moderately rough crystals of extreme aspect ratios, for each scene corresponding to a single value of the asymmetry parameter.

  16. Photopolarimetric retrievals of snow properties

    NASA Astrophysics Data System (ADS)

    Ottaviani, M.; van Diedenhoven, B.; Cairns, B.

    2015-05-01

    Polarimetric observations of snow surfaces, obtained in the 410-2264 nm range with the Research Scanning Polarimeter onboard the NASA ER-2 high-altitude aircraft, are analyzed and presented. These novel measurements are of interest to the remote sensing community because the overwhelming brightness of snow plagues aerosol and cloud retrievals based on air- and space-borne total reflection measurements. The spectral signatures of the polarized reflectance of snow are therefore worthwhile investigating in order to provide guidance for the adaptation of algorithms currently employed for the retrieval of aerosol properties over soil and vegetated surfaces. At the same time, the increased information content of polarimetric measurements allows for a meaningful characterization of the snow medium. In our case, the grains are modeled as hexagonal prisms of variable aspect ratios and microscale roughness, yielding retrievals of the grains' scattering asymmetry parameter, shape and size. The results agree with our previous findings based on a more limited dataset, with the majority of retrievals leading to moderately rough crystals of extreme aspect ratios, for each scene corresponding to a single value of the asymmetry parameter.

  17. Changes in Snow Albedo Resulting from Snow Darkening Caused by Black Carbon

    NASA Astrophysics Data System (ADS)

    Engels, J.; Kloster, S.; Bourgeois, Q.

    2014-12-01

    We investigate the potential impact of snow darkening caused by pre-industrial and present-day black carbon (BC) emissions on snow albedo and subsequently climate. To assess this impact, we implemented the effect of snow darkening caused by BC emitted from natural as well as anthropogenic sources into the Max Planck Institute for Meteorology Earth System Model (MPI-M ESM). Considerable amounts of BC are emitted e.g. from fires and are transported through the atmosphere for several days before being removed by rain or snow precipitation in snow covered regions. Already very small quantities of BC reduce the snow reflectance significantly, with consequences for snow melting and snow spatial coverage. We implemented the snow albedo reduction caused by BC contamination and snow aging in the one layer land surface component (JSBACH) of the atmospheric general circulation model ECHAM6, developed at MPI-M. For this we used the single-layer simulator of the SNow, Ice, and Aerosol Radiation (SNICAR-Online (Flanner et al., 2007); http://snow.engin.umich.edu) model to derive snow albedo values for BC in snow concentrations ranging between 0 and 1500 ng(BC)/g(snow) for different snow grain sizes for the visible (0.3 - 0.7 μm) and near infrared range (0.7 - 1.5 μm). As snow grains grow over time, we assign different snow ages to different snow grain sizes (50, 150, 500, and 1000 μm). Here, a radius of 50 μm corresponds to new snow, whereas a radius of 1000 μm corresponds to old snow. The deposition rates of BC on snow are prescribed from previous ECHAM6-HAM simulations for two time periods, pre-industrial (1880-1889) and present-day (2000-2009), respectively. We perform a sensitivity study regarding the scavenging of BC by snow melt. To evaluate the newly implemented albedo scheme we will compare the modeled black carbon in snow concentrations to observed ones. Moreover, we will show the impact of the BC contamination and snow aging on the simulated snow albedo. The

  18. The impact of beetle-induced conifer death on stand-scale canopy snow interception

    NASA Astrophysics Data System (ADS)

    Pugh, E. T.; Small, E. E.

    2011-12-01

    Snow that falls on a forest either passes through the canopy to the ground or is intercepted by the canopy on needles, branches or bark. The interception of snowfall in forest canopies impacts the water budget because intercepted snow is more likely to sublimate than subcanopy snow. Because forest canopy characteristics are a primary control of canopy snow interception, which in turn controls subcanopy snow accumulation, reductions in canopy density have important implications for snow accumulation on the forest floor. Forest structure can be drastically and rapidly altered by forest disturbance, such as insect attack, wildfire and blowdown. Here, we look at the impact that changing forest characteristics associated with beetle infestation have on canopy snow interception. The mountain pine beetle is currently impacting more than 100,000 km2 of pine forest in western North America. Trees killed by bark beetles eventually lose the majority of their canopy material. We hypothesize that tree death significantly reduces available interception platforms, leading to greater subcanopy snow accumulation than pre-infestation conditions. These potential impacts on snow accumulation are especially important for water resources in the western U.S., where the hydrologic cycle is dominated by snowmelt. We test this hypothesis using extensive data collected from adjacent living and grey phase dead stands. We employ multiple methods to measure canopy snow interception, at both the storm- and season-scales. During the winter of 2011, we made more than 10,000 spatially distributed measurements of subcanopy snow accumulation in three living and two dead lodgepole pine stands as well as three clearings. Measurements were made daily as well as immediately prior to and following storm events, allowing us to calculate storm-scale canopy interception. Interception is estimated by comparing subcanopy snow accumulation in clearings and forests. Additionally, by taking repeated daily

  19. Spatial estimates of snow water equivalent from reconstruction

    NASA Astrophysics Data System (ADS)

    Rittger, Karl; Bair, Edward H.; Kahl, Annelen; Dozier, Jeff

    2016-08-01

    Operational ground-based measurements of snow water equivalent (SWE) do not adequately explain spatial variability in mountainous terrain. To address this problem, we combine satellite-based retrievals of fractional snow cover for the period 2000 to 2011 with spatially distributed energy balance calculations to reconstruct SWE values throughout each melt season in the Sierra Nevada of California. Modeled solar radiation, longwave radiation, and air temperature from NLDAS drive the snowmelt model. The modeled solar radiation compares well to ground observations, but modeled longwave radiation is slightly lower than observations. Validation of reconstructed SWE with snow courses and our own snow surveys shows that the model can accurately estimate SWE at the sampled locations in a variety of topographic settings for a range of wet to dry years. The relationships of SWE with elevation and latitude are significantly different for wet, mean and dry years as well as between drainages. In all the basins studied, the relationship between remaining SWE and snow-covered area (SCA) becomes increasingly correlated from March to July as expected because SCA is an important model input. Though the SWE is calculated retrospectively SCA observations are available in near-real time and combined with historical reconstructions may be sufficient for estimating SWE with more confidence as the melt season progresses.

  20. Seasonal food use by white-tailed deer at Valley Forge National Historical Park, Pennsylvania, USA

    NASA Astrophysics Data System (ADS)

    Cypher, Brian L.; Yahner, Richard H.; Cypher, Ellen A.

    1988-03-01

    Food habits of white-tailed deer ( Odocoileus virginianus) were examined from January to November 1984 via fecal-pellet analysis at Valley Forge National Historical Park (VFNHP), which represents an “island” habitat for deer surrounded by extensive urbanization, in southeastern Pennsylvania. In addition, use of fields by deer was compared to food habits. Herbaceous vegetation (forbs, leaves of woody plants, and conifer needles) was the predominant food type in all seasons except fall. Acorns and graminoids (grasses and sedges) were important food resources in fall and spring, respectively. Use of woody browse (twigs) was similar among seasons. Field use was relatively high during fall, winter without snow cover (<20 cm), and spring when food resources in fields were readily available. In contrast, use of fields was lowest in summer when preferred woodland foods were available and in winter with snow cover when food in fields was not readily accessible. Patterns of food-type use by deer at VFNHP indicate the year-round importance of nonwoody foods and field habitats to deer populations on public lands such as national parks in the northeastern United States.

  1. Snow hydrology in a general circulation model

    NASA Technical Reports Server (NTRS)

    Marshall, Susan; Roads, John O.; Glatzmaier, Gary

    1994-01-01

    A snow hydrology has been implemented in an atmospheric general circulation model (GCM). The snow hydrology consists of parameterizations of snowfall and snow cover fraction, a prognostic calculation of snow temperature, and a model of the snow mass and hydrologic budgets. Previously, only snow albedo had been included by a specified snow line. A 3-year GCM simulation with this now more complete surface hydrology is compared to a previous GCM control run with the specified snow line, as well as with observations. In particular, the authors discuss comparisons of the atmospheric and surface hydrologic budgets and the surface energy budget for U.S. and Canadian areas. The new snow hydrology changes the annual cycle of the surface moisture and energy budgets in the model. There is a noticeable shift in the runoff maximum from winter in the control run to spring in the snow hydrology run. A substantial amount of GCM winter precipitation is now stored in the seasonal snowpack. Snow cover also acts as an important insulating layer between the atmosphere and the ground. Wintertime soil temperatures are much higher in the snow hydrology experiment than in the control experiment. Seasonal snow cover is important for dampening large fluctuations in GCM continental skin temperature during the Northern Hemisphere winter. Snow depths and snow extent show good agreement with observations over North America. The geographic distribution of maximum depths is not as well simulated by the model due, in part, to the coarse resolution of the model. The patterns of runoff are qualitatively and quantitatively similar to observed patterns of streamflow averaged over the continental United States. The seasonal cycles of precipitation and evaporation are also reasonably well simulated by the model, although their magnitudes are larger than is observed. This is due, in part, to a cold bias in this model, which results in a dry model atmosphere and enhances the hydrologic cycle everywhere.

  2. The Effect of Black Carbon and Snow Grain Size on Snow Surface Albedo

    NASA Astrophysics Data System (ADS)

    Hadley, O. L.; Kirchstetter, T.; Flanner, M.

    2009-12-01

    Black carbon (BC) has been measured in snow and ice cores at levels that climate models predict are high enough to be the second leading cause in arctic ice melt and glacial retreat after greenhouse gas warming. BC deposited on snow reduces the snow surface albedo; however, in addition to BC content, snow albedo also depends on sky cover, solar angle, snow grain size and shape, surface roughness, and depth. Quantifying the albedo reduction due to BC separately from these other variables is difficult to achieve in field measurements. We are conducting laboratory experiments that isolate the effect of BC and snow grain size on snow albedo. Snow is made by spraying and freezing drops of water; BC contaminated snow is made from BC hydrosol. Snow albedo is measured with a spectrometer equipped with an integrating sphere over the entire visible spectrum (400-1000 nm). Snow grain size distribution and shape are characterized using a digital microscope to calculate the effective radius of the snow. Measured snow albedo is compared to that predicted using the Snow, Ice, and Aerosol Radiative Model. Preliminary results indicate good agreement between measured and modeled albedo for pure and BC contaminated snow.

  3. Macroinvertebrate diets reflect tributary inputs and turbidity-driven changes in food availability in the Colorado River downstream of Glen Canyon Dam

    USGS Publications Warehouse

    Wellard Kelly, Holly A.; Rosi-Marshall, Emma J.; Kennedy, Theodore A.; Hall, Robert O., Jr.; Cross, Wyatt F.; Baxter, Colden V.

    2013-01-01

    Physical changes to rivers associated with large dams (e.g., water temperature) directly alter macroinvertebrate assemblages. Large dams also may indirectly alter these assemblages by changing the food resources available to support macroinvertebrate production. We examined the diets of the 4 most common macroinvertebrate taxa in the Colorado River through Glen and Grand Canyons, seasonally, at 6 sites for 2.5 y. We compared macroinvertebrate diet composition to the composition of epilithon (rock and cliff faces) communities and suspended organic seston to evaluate the degree to which macroinvertebrate diets tracked downstream changes in resource availability. Diets contained greater proportions of algal resources in the tailwater of Glen Canyon Dam and more terrestrial-based resources at sites downstream of the 1st major tributary. As predicted, macroinvertebrate diets tracked turbidity-driven changes in resource availability, and river turbidity partially explained variability in macroinvertebrate diets. The relative proportions of resources assimilated by macroinvertebrates ranged from dominance by algae to terrestrial-based resources, despite greater assimilation efficiencies for algal than terrestrial C. Terrestrial resources were most important during high turbidity conditions, which occurred during the late-summer monsoon season (July–October) when tributaries contributed large amounts of organic matter to the mainstem and suspended sediments reduced algal production. Macroinvertebrate diets were influenced by seasonal changes in tributary inputs and turbidity, a result suggesting macroinvertebrate diets in regulated rivers may be temporally dynamic and driven by tributary inputs.

  4. Snow complexity representation and GCM climate

    NASA Astrophysics Data System (ADS)

    Dutra, Emanuel; Viterbo, Pedro; Miranda, Pedro M. A.; Balsamo, Gianpaolo

    2010-05-01

    Accurate simulations of the snow cover strongly impact on the quality of weather and climate predictions as the solar radiation absorption at land-atmosphere interface is modified by a factor up to 4 in response to snow presence (albedo effect). In Northern latitudes and Mountainous regions snow acts also as an important energy and water reservoir and a correct representation of snow mass and snow density is crucial for temperature predictions at all time-scales, with direct consequences for soil hydrology (thermal insulation effect). Three different complexity snow schemes implemented in the ECMWF land surface scheme HTESSEL are tested within the EC-EARTH framework. The snow schemes are: 1) OLD, the original HTESSEL single bulk layer snow scheme (same as in the ERA-40 and ERA-Interim reanalysis); 2) OPER, a new snow scheme in operations since September 2009, with a liquid water reservoir and revised formulations of snow density, fractional cover and snow albedo; and 3) ML3, a multi-layer version of OPER. All three snow schemes in HTESSEL are energy- and mass- balance models. The multi-layer snow scheme, ML3, was validated in offline mode covering several spatial and temporal scales: (i) site simulations for several observation locations from the Snow Models intercomparison project-2 (SnowMip2) and (ii) global simulations driven by the meteorological forcing from the Global Soil Wetness Project-2 (GSWP2) and the ECMWF ERA-Interim re-analysis. On point locations ML3 improve snow mass simulations, while on a global scale the impacts are residual pointing to the need of coupled atmosphere simulations. The 3 schemes are compared in the framework of the atmospheric model of EC-EARTH, based on the current seasonal forecast system of ECMWF. The standard configuration runs at T159 horizontal spectral resolution with 62 vertical levels. Three member ensembles of 30 years (1979-2008) simulations, with prescribed SSTs and sea ice, were performed for each of the snow schemes

  5. Cladoceran zooplankton abundance under clear and snow-covered ice

    USGS Publications Warehouse

    DeBates, T.J.; Chipps, S.R.; Ward, M.C.; Werlin, K.B.; Lorenzen, P.B.

    2003-01-01

    We described the distribution of cladoceran zooplankton under the ice in a natural, glacial lake. Local light availability apparently altered the spatial distribution of cladocerans. Light levels measured under snow-covered areas (0.178 lux) were an order of magnitude less than those measured at the same depth under clear ice (1.750 lux). Cladoceran density under snow-covered areas was significantly higher (Bosmina spp.=3.34/L; Daphnia spp.=0.61/L) than cladoceran abundance under clear ice (Bosmina spp.=0.91/L; Daphnia spp.=0.19/L).

  6. Using Visual Range Data For Highway Operations In Blowing Snow

    NASA Astrophysics Data System (ADS)

    Tabler, Ronald D.

    1983-09-01

    This paper describes characteristics of visual range attenuation in blowing snow in rela-tion to motorist vision. Visual range V is related to wind speed U according to V = A U-5 with the A coefficient changing in response to snow availability. A lower limit for visual range is described with A = 1.1.108 m6.s-5 An operational monitoring system used on Interstate Highway 80 in Wyoming demonstrates how real-time computer analysis of photometric data can be used to determine the A value, interpret visual range in terms of vehicle operation, and provide automated traffic operations decisions.

  7. Two-stream theory of spectral reflectance of snow

    NASA Technical Reports Server (NTRS)

    Choudhury, B. J.; Chang, A. T. C.

    1978-01-01

    Spectral reflectance of snow under diffuse illumination is studied using the two-stream approximation of the radiative transfer equation. The scattering and absorption within the snowcover due to the randomly distributed ice grains are characterized by the single scattering albedo and anisotropic phase function. Geometric optics calculations are used to relate the scattering and absorption parameters to grain size and density of snow. Analytical expressions for the intensity within the snowpack and the asymptotic flux extinction coefficient are also obtained. Good agreement is shown between the theory and available experimental data on visible and near-infrared reflectance and asymptotic flux extinction coefficient. The theory also may be used to explain the observed effect of aging on the snow reflectance.

  8. Contrasting responses of root morphology and root-exuded organic acids to low phosphorus availability in three important food crops with divergent root traits.

    PubMed

    Wang, Yan-Liang; Almvik, Marit; Clarke, Nicholas; Eich-Greatorex, Susanne; Øgaard, Anne Falk; Krogstad, Tore; Lambers, Hans; Clarke, Jihong Liu

    2015-01-01

    Phosphorus (P) is an important element for crop productivity and is widely applied in fertilizers. Most P fertilizers applied to land are sorbed onto soil particles, so research on improving plant uptake of less easily available P is important. In the current study, we investigated the responses in root morphology and root-exuded organic acids (OAs) to low available P (1 μM P) and sufficient P (50 μM P) in barley, canola and micropropagated seedlings of potato-three important food crops with divergent root traits, using a hydroponic plant growth system. We hypothesized that the dicots canola and tuber-producing potato and the monocot barley would respond differently under various P availabilities. WinRHIZO and liquid chromatography triple quadrupole mass spectrometry results suggested that under low P availability, canola developed longer roots and exhibited the fastest root exudation rate for citric acid. Barley showed a reduction in root length and root surface area and an increase in root-exuded malic acid under low-P conditions. Potato exuded relatively small amounts of OAs under low P, while there was a marked increase in root tips. Based on the results, we conclude that different crops show divergent morphological and physiological responses to low P availability, having evolved specific traits of root morphology and root exudation that enhance their P-uptake capacity under low-P conditions. These results could underpin future efforts to improve P uptake of the three crops that are of importance for future sustainable crop production. PMID:26286222

  9. Contrasting responses of root morphology and root-exuded organic acids to low phosphorus availability in three important food crops with divergent root traits

    PubMed Central

    Wang, Yan-Liang; Almvik, Marit; Clarke, Nicholas; Eich-Greatorex, Susanne; Øgaard, Anne Falk; Krogstad, Tore; Lambers, Hans; Clarke, Jihong Liu

    2015-01-01

    Phosphorus (P) is an important element for crop productivity and is widely applied in fertilizers. Most P fertilizers applied to land are sorbed onto soil particles, so research on improving plant uptake of less easily available P is important. In the current study, we investigated the responses in root morphology and root-exuded organic acids (OAs) to low available P (1 μM P) and sufficient P (50 μM P) in barley, canola and micropropagated seedlings of potato—three important food crops with divergent root traits, using a hydroponic plant growth system. We hypothesized that the dicots canola and tuber-producing potato and the monocot barley would respond differently under various P availabilities. WinRHIZO and liquid chromatography triple quadrupole mass spectrometry results suggested that under low P availability, canola developed longer roots and exhibited the fastest root exudation rate for citric acid. Barley showed a reduction in root length and root surface area and an increase in root-exuded malic acid under low-P conditions. Potato exuded relatively small amounts of OAs under low P, while there was a marked increase in root tips. Based on the results, we conclude that different crops show divergent morphological and physiological responses to low P availability, having evolved specific traits of root morphology and root exudation that enhance their P-uptake capacity under low-P conditions. These results could underpin future efforts to improve P uptake of the three crops that are of importance for future sustainable crop production. PMID:26286222

  10. Comparison of the Snow Simulations in Community Land Model Using Two Snow Cover Fraction Parameterizations

    NASA Astrophysics Data System (ADS)

    Xie, Zhipeng; Hu, Zeyong

    2016-04-01

    Snow cover is an important component of local- and regional-scale energy and water budgets, especially in mountainous areas. This paper evaluates the snow simulations by using two snow cover fraction schemes in CLM4.5 (NY07 is the original snow-covered area parameterization used in CLM4, and SL12 is the default scheme in CLM4.5). Off-line simulations are carried out forced by the China Meteorological forcing dataset from January 1, 2001 to December 31, 2010 over the Tibetan Plateau. Simulated snow cover fraction (SCF), snow depth, and snow water equivalent (SWE) were compared against a set of observations including the Interactive Multisensor Snow and Ice Mapping System (IMS) snow cover product, the daily snow depth dataset of China, and China Meteorological Administration (CMA) in-situ snow depth and SWE observations. The comparison results indicate significant differences existing between those two SCF parameterizations simulations. Overall, the SL12 formulation shows a certain improvement compared to the NY07 scheme used in CLM4, with the percentage of correctly modeled snow/no snow being 75.8% and 81.8% when compared with the IMS snow product, respectively. Yet, this improvement varies both temporally and spatially. Both these two snow cover schemes overestimated the snow depth, in comparison with the daily snow depth dataset of China, the average biases of simulated snow depth are 7.38cm (8.77cm), 6.97cm (8.2cm) and 5.49cm (5.76cm) NY07 (and SL12) in the snow accumulation period (September through next February), snowmelt period (March through May) and snow-free period (June through August), respectively. When compared with the CMA in-situ snow depth observations, averaged biases are 3.18cm (4.38cm), 2.85cm (4.34cm) and 0.34cm (0.34cm) for NY07 (SL12), respectively. Though SL12 does worse snow depth simulation than NY07, the simulated SWE by SL12 is better than that by NY07, with average biases being 2.64mm, 6.22mm, 1.33mm for NY07, and 1.47mm, 2.63mm, 0.31mm

  11. Forest-snow interactions at Critical Zone Observatories of the Western U.S. (Invited)

    NASA Astrophysics Data System (ADS)

    Molotch, N. P.; Harpold, A. A.

    2013-12-01

    Forest structure exerts strong controls on the hydrology of mountainous regions by influencing snow accumulation, snowmelt, and partitioning of melt water to runoff and evapotranspiration. Predicting the hydrological fluxes and states of these montane systems has been limited by an inability to represent snow-vegetation interactions across complex terrain and variable climate. This is particularly important in Western U.S. forests, where recent evidence indicates forest disturbance from fire and insects has uneven impacts on water availability. Instrument clusters deployed in the Central and Southern Rockies and the Sierra Nevada reveal the dominant role of vegetation in controlling the timing and magnitude of snow accumulation and snowmelt. In this regard, vegetation structure largely controlled the distribution of snow accumulation with greater snow accumulation in open versus sub-canopy positions across the Critical Zone Observatory (CZO) network; 11% greater in the Jemez River Basin (JRB) CZO, 24% greater in the Boulder Creek (BC) CZO and 13% in the Southern Sierra (SS) CZO. Similarly, snow ablation rates were greater in open versus under-canopy positions; 17% greater at JRB, 6% greater in BC, and 2% greater in SS. The canopy structure had varying controls on the date of snow disappearance at the different sites. At JRB, snow disappeared an average of 3 days later in under canopy versus open positions. Conversely, at both the SS and BC snow persisted an average of 7 days longer in open versus under-canopy positions. Despite high inter-annual snowpack variability, the timing of peak soil moisture was strongly linked to the timing of snow disappearance at all sites. Peak soil moisture was nearly synchronous with snow disappearance at JRB and BC, with deviations of less than one week. Conversely, peak soil moisture consistently preceded snow disappearance by 1 to 2 weeks at the SS sites. These results highlight the importance of vegetation structure with regard to

  12. Challenges in simulation of snow microstructure and implications for remote sensing of snow mass

    NASA Astrophysics Data System (ADS)

    Sandells, M. J.; Essery, R.; Leppänen, L.; Lemmetyinen, J.; Rutter, N.

    2014-12-01

    One of the greatest challenges for global measurement of snow mass is quantification of the snow microstructure. Radiative transfer models are more sensitive to the snow structure metrics used than to snow depth, so microstructure must be well quantified in order to retrieve snow mass from satellite observations. Principles of physics have been used to simulate microstructure in many years of avalanche and climate research, although these have different accuracy requirements to remote sensing applications. Growth of snow crystals is dependent primarily on the snow temperature gradient, but also the temperature and density of the snow. Forced with the same meteorological data, different models simulate different snow temperatures. Even with the same grain growth assumptions, this leads to different rates of microstructure evolution. This must be taken into consideration if snow models are to be used to give the necessary parameters for retrieval of snow water equivalent. The JULES Investigation Model snow model (JIM) has a highly configurable structure that allows different layering assumptions to be used. It incorporates all major components from existing snow models, which enables the simulation of an ensemble of 1701 members. JIM was used to quantify the impact of different model parameterizations such as snow compaction and thermal conductivity on simulated microstructure (previously referred to as 'grain size') for each of four different grain size parameterizations from the Crocus, MOSES, SNICAR and SNTHERM models. The Helsinki University of Technology snow microwave emission model was then used to demonstrate the impact of different snow model assumptions on the simulation of microwave brightness temperature. This paper discusses potential snow mass retrieval errors due to uncertainties in snow parameters from snow evolution models, and how these may be mitigated through techniques such as data assimilation.

  13. Elevation dependency of mountain snow depth

    NASA Astrophysics Data System (ADS)

    Grünewald, T.; Bühler, Y.; Lehning, M.

    2014-07-01

    Elevation strongly affects quantity and distribution of precipitation and snow. Positive elevation gradients were identified by many studies, usually based on data from sparse precipitation stations or snow depth measurements. We present a systematic evaluation of the elevation - snow depth relationship. We analyse areal snow depth data obtained by remote sensing for seven mountain sites. Snow depths were averaged to 100 m elevation bands and then related to their respective elevation level. The assessment was performed at three scales ranging from the complete data sets by km-scale sub-catchments to slope transects. We show that most elevation - snow depth curves at all scales are characterised through a single shape. Mean snow depths increase with elevation up to a certain level where they have a distinct peak followed by a decrease at the highest elevations. We explain this typical shape with a generally positive elevation gradient of snow fall that is modified by the interaction of snow cover and topography. These processes are preferential deposition of precipitation and redistribution of snow by wind, sloughing and avalanching. Furthermore we show that the elevation level of the peak of mean snow depth correlates with the dominant elevation level of rocks.

  14. Snow multivariable data assimilation for hydrological predictions in mountain areas

    NASA Astrophysics Data System (ADS)

    Piazzi, Gaia; Campo, Lorenzo; Gabellani, Simone; Rudari, Roberto; Castelli, Fabio; Cremonese, Edoardo; Morra di Cella, Umberto; Stevenin, Hervé; Ratto, Sara Maria

    2016-04-01

    The seasonal presence of snow on alpine catchments strongly impacts both surface energy balance and water resource. Thus, the knowledge of the snowpack dynamics is of critical importance for several applications, such as water resource management, floods prediction and hydroelectric power production. Several independent data sources provide information about snowpack state: ground-based measurements, satellite data and physical models. Although all these data types are reliable, each of them is affected by specific flaws and errors (respectively dependency on local conditions, sensor biases and limitations, initialization and poor quality forcing data). Moreover, there are physical factors that make an exhaustive reconstruction of snow dynamics complicated: snow intermittence in space and time, stratification and slow phenomena like metamorphism processes, uncertainty in snowfall evaluation, wind transportation, etc. Data Assimilation (DA) techniques provide an objective methodology to combine observational and modeled information to obtain the most likely estimate of snowpack state. Indeed, by combining all the available sources of information, the implementation of DA schemes can quantify and reduce the uncertainties of the estimations. This study presents SMASH (Snow Multidata Assimilation System for Hydrology), a multi-layer snow dynamic model, strengthened by a robust multivariable data assimilation algorithm. The model is physically based on mass and energy balances and can be used to reproduce the main physical processes occurring within the snowpack: accumulation, density dynamics, melting, sublimation, radiative balance, heat and mass exchanges. The model is driven by observed forcing meteorological data (air temperature, wind velocity, relative air humidity, precipitation and incident solar radiation) to provide a complete estimate of snowpack state. The implementation of an Ensemble Kalman Filter (EnKF) scheme enables to assimilate simultaneously ground

  15. Modelling snow cover duration improves predictions of functional and taxonomic diversity for alpine plant communities

    PubMed Central

    Carlson, Bradley Z.; Choler, Philippe; Renaud, Julien; Dedieu, Jean-Pierre; Thuiller, Wilfried

    2015-01-01

    Background and Aims Quantifying relationships between snow cover duration and plant community properties remains an important challenge in alpine ecology. We developed a method to estimate spatial variation in energy availability in the context of a topographically complex, high-elevation watershed, which we used to test the explanatory power of environmental gradients both with and without snow cover in relation to taxonomic and functional plant diversity. Methods We mapped snow cover at 15 m resolution using Landsat imagery for five recent years and fitted a generalized additive model (GAM) for each year linking snow to time and topography. Predicted snow cover maps were combined with air temperature and solar radiation at daily resolution, summed for each year and averaged across years. Equivalent growing season energy gradients were also estimated without accounting for snow cover duration. Relationships were tested between environmental gradients and diversity metrics measured for 100 plots (including species richness, community weighted mean traits, functional diversity and hyperspectral estimates of canopy chlorophyll content). Key Results Accounting for snow cover in environmental variables consistently led to improved predictive power as well as more ecologically meaningful characterizations of plant diversity. Model parameters differed significantly when fitted with and without snow cover. Filtering solar radiation with snow as compared to without led to an average gain in R2 of 0.26 and also reversed slope direction to more intuitive relationships for several diversity metrics. Conclusions We show that in alpine environments, high-resolution data on snow cover duration are pivotal for capturing the spatial heterogeneity of both taxonomic and functional diversity. The use of climate variables without consideration of snow cover can lead to erroneous predictions of plant diversity. Our results further indicate that studies seeking to predict the response

  16. Improving the accuracy of MODIS 8-day snow products with in situ temperature and precipitation data

    NASA Astrophysics Data System (ADS)

    Dong, Chunyu; Menzel, Lucas

    2016-03-01

    MODIS snow data are appropriate for a wide range of eco-hydrological studies and applications in the fields of snow-related hazards, early warning systems and water resources management. However, the high spatio-temporal resolution of the remotely sensed data is often biased by snow misclassifications, and cloud cover frequently limits the availability of the MODIS-based snow cover information. In this study, we applied a four-step methodology that aims to optimize the accuracy of MODIS snow data. To reduce the cloud fraction, 8-day MODIS data from both the Aqua and Terra satellites were combined. Neighborhood analysis was applied as well for this purpose, and it also contributed to the retrieval of some omitted snow. Two meteorological filters were then applied to combine information from station-based measurements of minimum ground temperature, precipitation and air temperature. This procedure helped to reduce the overestimation of snow cover. To test this technique, the methodology was applied to the Rhineland-Palatinate region in southwestern Germany (approximately 20,000 km2), where cloud cover is especially high during winter and surface heterogeneity is complex. The results show that mean annual cloud coverage (reference period 2002-2013) of the 8-day MODIS snow maps could be reduced using this methodology from approximately 14% to 4.5%. During the snow season, obstruction by clouds could be reduced by even a higher degree, but still remains at about 11%. Further, the overall snow overestimation declined from 11.0-11.9% (using the original Aqua-Terra data) to 1.0-1.5%. The method is able to improve the overall accuracy of the 8-day MODIS snow product from originally 78% to 89% and even to 93% during cloud free periods.

  17. A snow extent time series assimilation using MODIS images and temperature data, case study Koohrang, Iran

    NASA Astrophysics Data System (ADS)

    Abdollahi, K.; Batelaan, O.

    2012-04-01

    A unique advantage of satellite data is the possibility for delineation of snow line and calculation of snow cover area. Recent availability of remote sensing data offers promise for better performance of hydrological models, which contain a snow component. The near-daily coverage of Moderate Resolution Imaging Spectrometer (MODIS) data and its moderate resolution provide a powerful capability for time series analysis of snow cover area. However, because of several reasons like cloud cover, technical problems, etc., images are not available or usable. This paper suggests a regional solution to fill the gap of missing data for purpose of snow cover assessment. In this study 27 images of MODIS from NASA have been used to calculate basin scale snow cover area by applying NDSI technique. Also a temperature dataset was collected from the Koohrang station, which was measured by the Iranian meteorological organization for the period 2004-2008. The elevation of the Koohrang station is 2285 m above sea level and geographically it is located at latitude 32 26' and longitude 50 07'. The study considered snow cover derived from satellite imagery as dependent variable and temperature as independent variable. To find a relationship between snow extent and temperature we used the CURVEEXPERT 1.4 package. This program uses the Levenberg-Marquardt algorithm to solve nonlinear regressions by combination of steepest-descent method and a Taylor series technique. Our methodology is applied each time when snow extent is not available and it estimates snow extend based on the remaining data. A wide range of built in models were tested for this purpose but finally a Logistic, Exponential, Richards, Gompertz, Linear Fit and Exponential model were adopted because of high correlation relationship and low variance.

  18. Methaemoglobinaemia due to mephedrone ('snow').

    PubMed

    Ahmed, Noor; Hoy, Brent Philip Sew; McInerney, J

    2010-01-01

    Acquired methaemoglobinaemia is a serious complication caused by many oxidising drugs. It presents as cyanosis unresponsive to oxygen therapy. The case of 33-year-old male patient who presented in our department after noticing blue lips and fingers is presented. He had sniffed 1 g of 'snow' after buying it from a head shop. His oxygen saturation by pulse oximeter on room air at presentation was 90%, which did not improve with supplemental oxygen. Arterial blood gas analyses showed partial pressure of oxygen 37 kPa while on supplemental oxygen and a methaemoglobin concentration greater than 25%. The patient denied using any other recreational drugs and was not on regular treatment. Therefore, a diagnosis of methaemoglobinaemia due to mephedrone, which is the active ingredient of 'snow', was made. Treatment is with intravenous methylene blue. Our patient started to improve so methylene blue was not used and he was discharged after 8 h. PMID:22791577

  19. Snow Densification in Greenland (Invited)

    NASA Astrophysics Data System (ADS)

    Morris, E.; Wingham, D.

    2010-12-01

    As part of the calibration and validation experiments for the radar altimeter carried by the ESA Cryosat-2 satellite, snow density profiles have been measured along the EGIG line from Spring 2004 to Summer 2010. Repeated measurements at the same site allow the development of the characteristic stratigraphy of the dry snow zone to be observed and the rate of densification to be measured directly. Densification rates below the surface layer are found to be compatible with a physics-based grain boundary sliding model (Alley, 1987) but near-surface rates are enhanced. Alley, R.B. (1987). Firn densification by grain-boundary sliding: A First Model. J. de. Physique 48 (Coll. C1, Suppl. No.3) 249-256.

  20. LANDSAT-D investigations in snow hydrology

    NASA Technical Reports Server (NTRS)

    Dozier, J. (Principal Investigator); Davis, R. E.; Dubayah, R. O.; Frew, J. E.; Li, S.; Marks, D.; Milliff, R. F.; Rousseau, D. D.; Wan, Z. M.

    1985-01-01

    Work undertaken during the contract and its results are described. Many of the results from this investigation are available in journal or conference proceedings literature - published, accepted for publication, or submitted for publication. For these the reference and the abstract are given. Those results that have not yet been submitted separately for publication are described in detail. Accomplishments during the contract period are summarized as follows: (1) analysis of the snow reflectance characteristics of the LANDSAT Thematic Mapper, including spectral suitability, dynamic range, and spectral resolution; (2) development of a variety of atmospheric models for use with LANDSAT Thematic Mapper data. These include a simple but fast two-stream approximation for inhomogeneous atmospheres over irregular surfaces, and a doubling model for calculation of the angular distribution of spectral radiance at any level in an plane-parallel atmosphere; (3) incorporation of digital elevation data into the atmospheric models and into the analysis of the satellite data; and (4) textural analysis of the spatial distribution of snow cover.

  1. Do Latino and non-Latino grocery stores differ in the availability and affordability of healthy food items in a low-income, metropolitan region?

    PubMed Central

    Emond, Jennifer A; Madanat, Hala N; Ayala, Guadalupe X

    2013-01-01

    Objective To compare non-ethnically based supermarkets and Latino grocery stores (tiendas) in a lower-income region with regard to the availability, quality and cost of several healthy v. unhealthy food items. Design A cross-sectional study conducted by three independent observers to audit twenty-five grocery stores identified as the main source of groceries for 80% of Latino families enrolled in a childhood obesity study. Stores were classified as supermarkets and tiendas on the basis of key characteristics. Setting South San Diego County. Subjects Ten tiendas and fifteen supermarkets. Results Tiendas were smaller than supermarkets (five v. twelve aisles, P=0·003). Availability of fresh produce did not differ by store type; quality differed for one fruit item. Price per unit (pound or piece) was lower in tiendas for most fresh produce. The cost of meeting the US Department of Agriculture’s recommended weekly servings of produce based on an 8368 kJ (2000 kcal)/d diet was $US 3·00 lower in tiendas compared with supermarkets (P<0·001). The cost of 1 gallon of skimmed milk was significantly higher in tiendas ($US 3·29 v. $US 2·69; P=0·005) and lean (7% fat) ground beef was available in only one tienda (10 %) compared with ten (67 %) supermarkets (P=0·01). Conclusions Barriers remain in the ability to purchase healthier dairy and meat options in tiendas; the same is not true for produce. These results highlight the potential that tiendas have in improving access to quality, fresh produce within lower-income communities. However, efforts are needed to increase the access and affordability of healthy dairy and meat products. PMID:21733278

  2. The Inverted Snow Globe Shadow

    NASA Astrophysics Data System (ADS)

    Ribeiro, Jair Lúcio Prados

    2015-01-01

    Our high school optics course finishes with an assignment that students usually appreciate. They must take pictures of everyday situations representing optical phenomena such as reflection, refraction, or dispersion, and post them on Instagram.1 When the photos were presented to the class, one student revealed an intriguing photo, similar to Fig. 1, showing a snow globe exposed to sunlight and its inverted shadow. This paper offers an explanation of the problem, which occurs due to light refraction from the globe.

  3. Dirty snow after nuclear war

    NASA Technical Reports Server (NTRS)

    Warren, S. G.; Wiscombe, W. J.

    1985-01-01

    It is shown that smoke from fires started by nuclear explosions could continue to cause significant disruption even after it has fallen from the atmosphere, by lowering the reflectivity of snow and sea ice surfaces, with possible effects on climate in northern latitudes caused by enhanced absorption of sunlight. The reduced reflectivity could persist for several years on Arctic sea ice and on the ablation area of the Greenland ice sheet.

  4. Snow Depth Spatial Distribution Using Microwave Remote Sensing at the Puna Tsang River Basin in Bhutan

    NASA Astrophysics Data System (ADS)

    Duran-Ballen, S.; Tsutsui, H.; Koike, T.

    2012-12-01

    Spatial distribution of snow amount derived from satellite observations has been previously achieved for flat region. But for mountainous regions, spatial distribution of snow amount has not been addressed because remote sensing instruments are very sensitive to the effect of the terrain slope; and because there is no available data for validation. This study focuses on the estimation of snow amount using a microwave radiative transfer model (RTM) in mountain region. AMSR-E satellite observations of brightness temperature (Tb) at 18.7GHz and 36.5GHz frequencies are compared to calculated values of Tb in Lookup Tables generated by the RTM model. The model uses a snow algorithm to derive the snow depth and temperature spatial distribution over the target region. This snow algorithm has been previously validated in a flat region using in-situ recorded snow-depth data. In this study, the local slope in mountainous terrain, where the local incidence angle is different than the 55 degree incidence angle from the satellite, is taken into account. The local incidence angle is calculated from the scalar product between the radiometer scanning vector and the surface normal vector of the local slope. The terrain DEM is used to calculate the slope and aspect of each terrain grid. Then, with the geolocation of the satellite as it passes over, the local incidence angle is computed. AMSR-E data resolution is about 25x25 km but at this resolution we can not meaningfully express the topographic terrain. Therefore, a DEM resolution of 1x1 km is used. To overcome the difference of spatial resolution between the satellite observation and the terrain grid, the approach is to estimate the Tb for the 18.7GHz and 36.5GHz frequencies with the local incidence angle for each terrain grid. Then, an averaged Tb for each footprint is computed from the weighted average of the Tb of each terrain grid based on the count of occurrence of the same local incidence angle. Then, the averaged Tb is

  5. Regional analysis of changes in snow pack in mountainous basins in the central Danube region

    NASA Astrophysics Data System (ADS)

    Balint, Gabor; Juričeková, Katarina; Gauzer, Balazs; Hlavčová, Kamila; Kohnová, Silvia; Szolgay, Jan; Zsideková, Beata

    2013-04-01

    Accurate estimation of the volume of water stored in the snow pack and its rate of release is essential to predict the flow during the snowmelt period. In mountainous drainage basins water stored in the snow pack represents an important component of the water budget. Two modelling tools are compared. The first, HOLV snowmelt model is developed by the Hungarian National Hydrological Forecasting Service (VITUKI NHFS) for regional assessment of snow accumulation and ablation of the central Danube. The model originates from the early 80's and it is under continuous development, while its recent distributed version over a grid with 0.1 degree resolution is in use. The snowmelt model has a flexible structure; it is able to change its own structure in function of data availability. In case when only precipitation and air temperature data are available temperature index method is used. When also other data are accessible (cloudiness, dew point, wind speed) using of energy balance model is to be preferred. If there are suitable data available for calculation of the energy terms, the energy balance method can be applied. The second semi-distributed Hron model, developed at the Slovak University of Technology was applied to a smaller sub-basin to represent spatial distribution of snow cover by simulated snow water equivalent. The upper Hron river basin with an area of 1766 km2 is located in central Slovakia. The conceptual semi-distributed tool applied contains three basic storage components with 15 calibrated parameters, as the flow routing component the cascade of linear reservoirs is used as opposed to the original simple triangular routing function. The snow sub-model uses the temperature index (degree-day) method for snow accumulation and snowmelt calculations. Uncertainty of model parameters was reduced by multi-calibration on the mean daily discharges in the basin outlet and measured stations data of snow water equivalent. Changes in the model parameters during the

  6. On charging of snow particles in blizzard

    NASA Technical Reports Server (NTRS)

    Shio, Hisashi

    1991-01-01

    The causes of the charge polarity on the blizzard, which consisted of fractured snow crystals and ice particles, were investigated. As a result, the charging phenomena showed that the characteristics of the blizzard are as follows: (1) In the case of the blizzard with snowfall, the fractured snow particles drifting near the surface of snow field (lower area: height 0.3 m) had positive charge, while those drifting at higher area (height 2 m) from the surface of snow field had negative charge. However, during the series of blizzards two kinds of particles positively and negatively charged were collected in equal amounts in a Faraday Cage. It may be considered that snow crystals with electrically neutral properties were separated into two kinds of snow flakes (charged positively and negatively) by destruction of the snow crystals. (2) In the case of the blizzard which consisted of irregularly formed ice drops (generated by peeling off the hardened snow field), the charge polarity of these ice drops salting over the snow field was particularly controlled by the crystallographic characteristics of the surface of the snow field hardened by the powerful wind pressure.

  7. Spatiotemporal analysis of snow trends in Austria

    NASA Astrophysics Data System (ADS)

    Koch, Roland; Schöner, Wolfgang

    2015-04-01

    This study presents the spatiotemporal analysis of Austrian snow observations. A set of consistent and reliable long-term time series of snow depth on a daily scale from selected meteorological sites across Austria is used. The time series were collected by the Central Institute for Meteorology and Geodynamics (ZAMG) and the Hydrographical Central Bureau of Austria (HZB). The data cover a time period from the late nineteenth century until today. In the first part of the study spatiotemporal characteristics of seasonal snow depth observations were investigated by the method of principal component analysis (PCA). Furthermore, the spatial patterns of variability have been used for a regionalisation, identifying regions with similar conditions during the base period 1961 to 2010. The results show a clear separation of four major regions including various sub-regions. However, the regionalisation was limited due to sparse data coverage. The non-parametric Mann-Kendall statistical test had been used to assess the significance of trends in snow indices, e.g. snow depth, maximum snow depth, snow cover duration, at monthly and seasonal time scales. In order to remove the influence of the lag-1 serial correlation from the snow data, the trend-free pre-whitening approach was applied. In the monthly and seasonal time series during the period 1961-2010, negative trends in snow indices were significant at the 95% confidence level primarily at stations in the Western and Southern part of Austria. In addition, the correlation between snow observations and gridded HISTALP winter temperature and precipitation fields was investigated. The analysis has shown an increased temperature and decreased precipitation during the 1990s, yielding a pronounced reduction in snow depth and duration. As a matter of fact, the results indicate major shifts of the snow depth and snow cover duration around the 1970s and especially the 1990s, which are predominantly responsible for trends.

  8. Spatiotemporal changes of snow cover and its correlation with temperature and precipitation over the upstream area of Heihe River basin based on MODIS snow cover product from hydrological year 2001 to 2012

    NASA Astrophysics Data System (ADS)

    Bi, Y.; Xie, H.

    2013-12-01

    Snow cover is an important water source of major Asian rivers and greatly influences water availability in the downstream areas. In this study, snow cover dynamics of the upstream areas of Heihe River in the northwestern China during hydrological years 2001-2012 (September through August) are examined using the flexible multiday combined MODIS snow cover products. The time series of multiday, seasonal, and annual snow covered area (SCA), snow covered days (SCD), peaks of maximum SCA, and snow cover index (SCI) for each hydrological year (HY) are examined. Further analysis is also based on the four elevation zones based on the distribution of vegetation. Results show that for high elevation zones (3400 to 3800m, 3800 to 4200 m, and above 4200 m), there are two peaks of snow cover area (SCA) for each hydrological years (Sep to Oct and Mar to Apr). For low elevation zones ( below 2400 m and 2400 m to 3400 m), the large peaks appear in Nov to Dec for each year. Regression analysis is used to assess the role of elevation zone in determining the relative performance of temperature and precipitation as predictors of snow cover area. The results indicate that temperature is the main explanatory variable for snow cover at low elevation zone and precipitation is a better predictor of snow cover area at high elevation zone. Upstream area of Heihe River Basin

  9. Response of snow-dependent hydrologic extremes to continued global warming

    PubMed Central

    Diffenbaugh, Noah S.; Scherer, Martin; Ashfaq, Moetasim

    2013-01-01

    Snow accumulation is critical for water availability in the northern hemisphere 1,2, raising concern that global warming could have important impacts on natural and human systems in snow-dependent regions 1,3. Although regional hydrologic changes have been observed (e.g., 1,3–5), the time of emergence of extreme changes in snow accumulation and melt remains a key unknown for assessing climate change impacts 3,6,7. We find that the CMIP5 global climate model ensemble exhibits an imminent shift towards low snow years in the northern hemisphere, with areas of western North America, northeastern Europe, and the Greater Himalaya showing the strongest emergence during the near-term decades and at 2°C global warming. The occurrence of extremely low snow years becomes widespread by the late-21st century, as do the occurrence of extremely high early-season snowmelt and runoff (implying increasing flood risk), and extremely low late-season snowmelt and runoff (implying increasing water stress). Our results suggest that many snow-dependent regions of the northern hemisphere are likely to experience increasing stress from low snow years within the next three decades, and from extreme changes in snow-dominated water resources if global warming exceeds 2°C above the pre-industrial baseline. PMID:24015153

  10. Assessment of the Relative Accuracy of Hemispheric-Scale Snow-Cover Maps

    NASA Technical Reports Server (NTRS)

    Hall, Dorothy K.; Kelly, Richard E.; Riggs, George A.; Chang, Alfred T. C.; Foster, James L.; Houser, Paul (Technical Monitor)

    2001-01-01

    There are several hemispheric-scale satellite-derived snow-cover maps available, but none has been fully validated. For the period October 23 - December 25, 2000, we compare snow maps of North America derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the National Oceanic and Atmospheric Administration (NOAA) National Operational Hydrologic Remote Sensing Center (NOHRSC), which both rely on satellite data from the visible and near-infrared parts of the spectrum; we also compare MODIS and Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave/Imager (SSM/I) passive-microwave snow maps. The maps derived from visible and near-infrared data are more accurate for mapping snow cover than are the passive-microwave-derived maps, however discrepancies exist as to the location and extent of the snow cover among those maps. The large (approx. 30 km) footprint of the SSM/I data and the difficulty in distinguishing wet and shallow snow from wet or snow-free ground, reveal differences up to 5.32 million sq km in the amount of snow mapped using MODIS versus SSM/I data. Algorithms that utilize both visible and passive-microwave data, which would take advantage of the all-weather mapping ability of the passive-microwave data, will be refined following the launch of the Advanced Microwave Scanning Radiometer (AMSR) in the fall of 2001.

  11. Response of snow-dependent hydrologic extremes to continued global warming

    NASA Astrophysics Data System (ADS)

    Diffenbaugh, Noah S.; Scherer, Martin; Ashfaq, Moetasim

    2013-04-01

    Snow accumulation is critical for water availability in the Northern Hemisphere, raising concern that global warming could have important impacts on natural and human systems in snow-dependent regions. Although regional hydrologic changes have been observed (for example, refs , , , ), the time of emergence of extreme changes in snow accumulation and melt remains a key unknown for assessing climate-change impacts. We find that the CMIP5 global climate model ensemble exhibits an imminent shift towards low snow years in the Northern Hemisphere, with areas of western North America, northeastern Europe and the Greater Himalaya showing the strongest emergence during the near-term decades and at 2°C global warming. The occurrence of extremely low snow years becomes widespread by the late twenty-first century, as do the occurrences of extremely high early-season snowmelt and runoff (implying increasing flood risk), and extremely low late-season snowmelt and runoff (implying increasing water stress). Our results suggest that many snow-dependent regions of the Northern Hemisphere are likely to experience increasing stress from low snow years within the next three decades, and from extreme changes in snow-dominated water resources if global warming exceeds 2°C above the pre-industrial baseline.

  12. Response of snow-dependent hydrologic extremes to continued global warming.

    PubMed

    Diffenbaugh, Noah S; Scherer, Martin; Ashfaq, Moetasim

    2013-04-01

    Snow accumulation is critical for water availability in the northern hemisphere (1,2), raising concern that global warming could have important impacts on natural and human systems in snow-dependent regions (1,3). Although regional hydrologic changes have been observed (e.g., (1,3-5)), the time of emergence of extreme changes in snow accumulation and melt remains a key unknown for assessing climate change impacts (3,6,7). We find that the CMIP5 global climate model ensemble exhibits an imminent shift towards low snow years in the northern hemisphere, with areas of western North America, northeastern Europe, and the Greater Himalaya showing the strongest emergence during the near-term decades and at 2°C global warming. The occurrence of extremely low snow years becomes widespread by the late-21(st) century, as do the occurrence of extremely high early-season snowmelt and runoff (implying increasing flood risk), and extremely low late-season snowmelt and runoff (implying increasing water stress). Our results suggest that many snow-dependent regions of the northern hemisphere are likely to experience increasing stress from low snow years within the next three decades, and from extreme changes in snow-dominated water resources if global warming exceeds 2°C above the pre-industrial baseline. PMID:24015153

  13. Response of snow-dependent hydrologic extremes to continued global warming

    SciTech Connect

    Diffenbaugh, Noah; Scherer, Martin; Ashfaq, Moetasim

    2012-01-01

    Snow accumulation is critical for water availability in the Northern Hemisphere1,2, raising concern that global warming could have important impacts on natural and human systems in snow-dependent regions1,3. Although regional hydrologic changes have been observed (for example, refs 1,3 5), the time of emergence of extreme changes in snow accumulation and melt remains a key unknown for assessing climate- change impacts3,6,7. We find that the CMIP5 global climate model ensemble exhibits an imminent shift towards low snow years in the Northern Hemisphere, with areas of western North America, northeastern Europe and the Greater Himalaya showing the strongest emergence during the near- termdecadesandat2 Cglobalwarming.Theoccurrenceof extremely low snow years becomes widespread by the late twenty-first century, as do the occurrences of extremely high early-season snowmelt and runoff (implying increasing flood risk), and extremely low late-season snowmelt and runoff (implying increasing water stress). Our results suggest that many snow-dependent regions of the Northern Hemisphere are likely to experience increasing stress from low snow years within the next three decades, and from extreme changes in snow-dominated water resources if global warming exceeds 2 C above the pre-industrial baseline.

  14. Spatial and Temporal Variability of Surface Snow Accumulation and Snow Chemistry at East Antarctic Ice Sheet

    NASA Astrophysics Data System (ADS)

    Motoyama, H.; Ito, K.; Hirabayashi, M.

    2014-12-01

    Snow stakes along the traverse routes have been observed for long term monitoring program 'the variation of ice sheet surface mass balance' from the 1960's by the Japanese Antarctic Research Expedition in Shirase glacier drainage basin, East Antarctica. During the traverse route between coastal S16 point (69 02'S, 40 03'E, 580m a.s.l.) to inland Dome Fuji (77 22'S, 39 42'E, 3,810m a.s.l.), the snow stake observations every 2 km have been carried out from 1993. Yearly net snow accumulations from S16 to Dome Fuji were calculated. Heavy, modern and light snow events were observed. They were different in way accumulating spatial pattern depending on places. The yearly accumulation rates were compared with seasonal change of AAO-index (SAM). As a result, yearly accumulation rate and AAO-index showed the positive correlation.Surface snow samplings were conducted every 10km along the traverse route. Generally, the snow surface features are classified into three regions. (1) the coastal region: smooth surface, high snow accumulation (2) the katabatic slope region: rough sastrugi surface and smooth glazed surface(3) the high plateau region: smooth surface, little snow accumulation The chemistry of surface snow changes from the coast to inland. Furthermore, the chemical properties of snow are different for each surface at the same area. We can classify the surface snow with fresh drifting snow, deposited drift snow, soft and hard surface snow, sustrugi, surface hoar and so on. The value of each isotope ration and ion concentration greatly varied. Sometimes, snow might deposit thick equally. But the deposited snow was redistributed by the wind. When the snowstorm occurred, the blowing snow started to deposit in a certain opportunity. As for it, the area was not the uniform. It is necessary to discuss inhomogeneity of the depositional condition quantitatively.

  15. Quantifying the crucial role of snow in supplying human water demand

    NASA Astrophysics Data System (ADS)

    Mankin, J. S.; Viviroli, D.; Mekonnen, M. M.; Hoekstra, A. Y. Y.; Diffenbaugh, N. S.

    2014-12-01

    Snow is considered essential to ecosystems, people, and climate, regulating water availability by mediating runoff and soil moisture throughout the year, and altering planetary radiative balance. Like canary in a coalmine, snow also serves as a kind of sentinel system, providing a benchmark by which we can measure the advance of global warming. Yet recent analyses reveal that the relationship between snow and warming is more complex: Despite warming, for example, the magnitude of internal climate variability suggests some Northern Hemisphere regions may experience snow increases for at least the next 50 years. While studies demonstrate that snow supply is vital and in critical danger, such assessments are based only on projections of annualized supply-side changes, such as the fraction of total annual runoff coming from snowfall. These measures do not consider a region's unique seasonal patterns of water supply and, in particular, water demand. We therefore do not know snow's relative importance to each region's water supply portfolio, and thus how great a risk global warming presents to regional water availability. Here we present the first quantification of snow's observed role in fulfilling monthly water demand for people in the Northern Hemisphere given each basin's unique sub-annual patterns of snow accumulation and melt. This quantification also reconciles the requirements of ecosystems and includes the buffering capacity of existing artificial storage, such as dams and reservoirs. Our results provide a meaningful baseline against which projected snow changes (from global warming) or demand changes (from population or land-use change) can be evaluated to identify regions at acute risk of disequilibria between future snow water supply and its demand.

  16. Snow cover characteristics in a glacierized catchment in the Tyrolean Alps - Improved spatially distributed modelling by usage of Lidar data

    NASA Astrophysics Data System (ADS)

    Schöber, Johannes; Schneider, K.; Helfricht, K.; Schattan, P.; Achleitner, S.; Schöberl, F.; Kirnbauer, R.

    2014-11-01

    In the present paper multi-temporal Lidar (Light detection and ranging) data and Landsat images are used to assess the spatial variability of snow at the end of the accumulation season (April-May) in a glacierized catchment (167 km2) in Tyrol, Austria. Snow cover characteristics in the Tyrolean Alps have been analysed using regular snow measurements and snow course data. Results are used for the conversion of basin-wide Lidar snow depth into snow water equivalent (SWE). When considering different possible error sources, uncertainties of the mean basin-wide SWE obtained from Lidar are between 12% and 16%. Available distributions of SWE and snow covered area (SCA) in the catchment are used for the calibration and validation of the fully distributed hydrological model SES. The study focuses especially on the simulation of snow accumulation and the corresponding variability of snow. Observed accumulation patterns are related to the topography (elevation, slope and curvature), and according parameter settings of the hydrological model are derived by means of Monte Carlo simulations. The majority of the model runs simulates SCA for various datasets with an accuracy of 85-95%. The paper demonstrates that using SWE data is superior to SCA for constraining model parameter ranges. Results at the watershed scale are in agreement with respect to the total water volume of the snow cover with deviations lower than 5% between SWE from Lidar or from the hydrological model.

  17. Early-winter diet of woodland caribou in relation to snow accumulation, Selkirk Mountains, British Columbia, Canada

    USGS Publications Warehouse

    Rominger, Eric M.; Oldemeyer, John L.

    1990-01-01

    Woodland caribou (Rangifer tarandus caribou) in the southern Selkirk Mountains of British Columbia shift from a diet of primarily vascular taxa during snow-free months to an arboreal lichen – conifer diet during late winter. We present evidence that caribou diets, during the early-winter transition period, are influenced by snow accumulation rates. Caribou shift to an arboreal lichen – conifer diet earlier during winters of rapid snow accumulation and forage extensively on myrtle boxwood (Pachistima myrsinites), an evergreen shrub, and other vascular plants during years of slower snow accumulation. The role of coniferous forage in early-winter food habits is examined. Forest management strategies can be developed to provide habitat that will enable caribou to forage in response to varying snow accumulation rates.

  18. Effects of wind-hardened snow on foraging by reindeer (Rangifer tarandus)

    USGS Publications Warehouse

    Collins, W.B.; Smith, T.S.

    1991-01-01

    Various methods were investigated for assessing the relationship between wind-hardened snow (upsik) and forage availability to reindeer. Mean bottom area of individual craters was not a function of depth, hardness or integrated hardness. Individual crater area was partially dependent on specific cratering time (r2 = .60). Cratering time per active period increased with integrated snow hardness (r2 = .88). Number of craters and total area cratered increased with decreasing site hardness. Reindeer always cratered microsites of lesser depth and hardness than found in the general feeding site. A threefold decrease in snow hardness resulted in a fourfold increase in forage availability

  19. Probabilistic approach to cloud and snow detection on AVHRR imagery

    NASA Astrophysics Data System (ADS)

    Musial, J. P.; Hüsler, F.; Sütterlin, M.; Neuhaus, C.; Wunderle, S.

    2013-09-01

    The derivation of probability estimates complementary to geophysical data sets has gained special attention over the last years. The information about a confidence level of provided physical quantities is required to construct an error budget of higher level products and to correctly interpret final results of a particular analysis. Regarding the generation of products based on satellite data the common input consists of a cloud mask which allows discrimination between surface and cloud signals. Further the surface information is divided between snow and snow-free components. At any step of this discrimination process a misclassification in a cloud/snow mask propagates to higher level products and may alter their usability. Within this scope a novel Probabilistic Cloud Mask (PCM) algorithm suited for the 1×1 km Advanced Very High Resolution Radiometer (AVHRR) data is proposed which provides three types of probability estimates between: cloudy/clear-sky, cloudy/snow and clear-sky/snow conditions. As opposed to the majority of available techniques which are usually based on a decision-tree approach in the PCM algorithm all spectral, angular and ancillary information is used in a single step to retrieve the probability estimates from the pre-computed Look Up Tables (LUTs). Moreover, the issue of derivation of a single threshold value for a spectral test was overcome by the concept of multidimensional information space which is divided into small bins by an extensive set of thresholds. The discrimination between snow and ice clouds and detection of broken, thin clouds was enhanced by means of the Invariant Coordinate System (ICS) transformation. The study area covers a wide range of environmental conditions spanning from Iceland through central Europe to northern parts of Africa which exhibit diverse difficulties for cloud/snow masking algorithms. The retrieved PCM cloud classification was compared to the PPSv2012 and MOD35 collection 6 cloud masks, SYNOP weather

  20. Using Commercial Digital Cameras and Structure-for-Motion Software to Map Snow Cover Depth from Small Aircraft

    NASA Astrophysics Data System (ADS)

    Sturm, M.; Nolan, M.; Larsen, C. F.

    2014-12-01

    A long-standing goal in snow hydrology has been to map snow cover in detail, either mapping snow depth or snow water equivalent (SWE) with sub-meter resolution. Airborne LiDAR and air photogrammetry have been used successfully for this purpose, but both require significant investments in equipment and substantial processing effort. Here we detail a relatively inexpensive and simple airborne photogrammetric technique that can be used to measure snow depth. The main airborne hardware consists of a consumer-grade digital camera attached to a survey-quality, dual-frequency GPS. Photogrammetric processing is done using commercially available Structure from Motion (SfM) software that does not require ground control points. Digital elevation models (DEMs) are made from snow-free acquisitions in the summer and snow-covered acquisitions in winter, and the maps are then differenced to arrive at snow thickness. We tested the accuracy and precision of snow depths measured using this system through 1) a comparison with airborne scanning LiDAR, 2) a comparison of results from two independent and slightly different photogrameteric systems, and 3) comparison to extensive on-the-ground measured snow depths. Vertical accuracy and precision are on the order of +/-30 cm and +/- 8 cm, respectively. The accuracy can be made to approach that of the precision if suitable snow-free ground control points exists and are used to co-register summer to winter DEM maps. Final snow depth accuracy from our series of tests was on the order of ±15 cm. This photogrammetric method substantially lowers the economic and expertise barriers to entry for mapping snow.

  1. Comparison of Coordinated Satellite and Ground-based X-Band Radar Collections for the Retrieval of Snow Parameters

    NASA Astrophysics Data System (ADS)

    Deeb, E. J.; Marshall, H.; LeWinter, A. L.; Finnegan, D. C.; Deems, J. S.; Landry, C.

    2012-12-01

    In many regions of the world, snow is a major source of runoff contributing to human existence/sustenance, agriculture, and industry. The uncertainties in quantifying snow mass at both spatial and temporal scales have limited the vital management of this significant component to the global water cycle. With the sensitivity of radar backscatter to physical properties of snow at higher frequencies and the availability of high resolution commercial satellite imaging radars at X-Band frequencies (e.g. 9.6 GHz), snow experiments have been conducted to examine these relationships at finer spatial and temporal scales. For the past several winters, satellite radar acquisitions (at X-Band with co- and cross-polarizations) have been coordinated with ground-based radar collections within a well-instrumented southwestern Colorado basin exhibiting a wide range of snow conditions. Snow-free satellite radar collections (at X-Band with the same viewing geometry) have also been acquired to separate the backscatter contributions of the snow volume from the underlying background target. Ancillary data sets including ground-based LiDAR-derived snow depths and scientific snow pit sampling are also incorporated into the analysis. Despite the fact that it may not be possible to retrieve snow water equivalent from multi-polarization X-Band frequency alone, preliminary results of these comparisons are shown where the ground-based radar transects overlap the satellite radar coverage. Snow parameters such as saturated surface or internal snow layers, snow surface and stratigraphic roughness, and grain size variations may be of particular interest.

  2. Some fundamentals of handheld snow surface thermography

    NASA Astrophysics Data System (ADS)

    Shea, C.; Jamieson, B.

    2011-02-01

    This paper presents the concepts needed to perform snow surface thermography with a modern thermal imager. Snow-specific issues in the 7.5 to 13 μm spectrum such as ice emissivity, photographic angle, operator heating, and others receive detailed review and discussion. To illustrate the usefulness of this measurement technique, various applications are presented. These include detecting spatial temperature variation on snow pit walls and measuring the dependence of heat conduction on grain type.

  3. Some fundamentals of handheld snow surface thermography

    NASA Astrophysics Data System (ADS)

    Shea, C.; Jamieson, B.

    2010-08-01

    This paper presents the concepts needed to perform snow surface thermography with a modern thermal imager. Snow-specific issues in the 7.5 to 13 μm spectrum such as ice emissivity, photographic angle, operator heating, and others receive detailed review and discussion. To illustrate the usefulness of this measurement technique, various applications are presented. These include detecting spatial temperature variation on snow pit walls and measuring the dependence of heat conduction on grain type.

  4. Wideband Instrument for Snow Measurements (WISM)

    NASA Technical Reports Server (NTRS)

    Miranda, Felix A.

    2015-01-01

    This presentation provides a brief summary of the utility of a wideband active and passive (radar and radiometer, respectively) instrument (8-40 GHz) to support the snow science community. The effort seeks to improve snow measurements through advanced calibration and expanded frequency of active and passive sensors and to demonstrate their science utility through airborne retrievals of snow water equivalent (SWE). In addition the effort seeks to advance the technology readiness of broadband current sheet array (CSA) antenna technology for spaceflight applications.

  5. Mobility of lightweight robots over snow

    NASA Astrophysics Data System (ADS)

    Lever, James H.; Shoop, Sally A.

    2006-05-01

    Snowfields are challenging terrain for lightweight (<50 kg) unmanned ground vehicles. Deep sinkage, high snowcompaction resistance, traction loss while turning and ingestion of snow into the drive train can cause immobility within a few meters of travel. However, for suitably designed vehicles, deep snow offers a smooth, uniform surface that can obliterate obstacles. Key requirements for good over-snow mobility are low ground pressure, large clearance relative to vehicle size and a drive system that tolerates cohesive snow. A small robot will invariably encounter deep snow relative to its ground clearance. Because a single snowstorm can easily deposit 30 cm of fresh snow, robots with ground clearance less than about 10 cm must travel over the snow rather than gain support from the underlying ground. This can be accomplished using low-pressure tracks (< 1.5 kPa). Even still, snow-compaction resistance can exceed 20% of vehicle weight. Also, despite relatively high traction coefficients for low track pressures, differential or skid steering is difficult because the outboard track can easily break traction as the vehicle attempts to turn against the snow. Short track lengths (relative to track separation) or coupled articulated robots offer steering solutions for deep snow. This paper presents preliminary guidance to design lightweight robots for good mobility over snow based on mobility theory and tests of PackBot, Talon and SnoBot, a custom-designed research robot. Because many other considerations constrain robot designs, this guidance can help with development of winterization kits to improve the over-snow performance of existing robots.

  6. Beyond peak water storage? A global estimate of declining water storage in reservoirs and snow packs

    NASA Astrophysics Data System (ADS)

    Wisser, D.; Frolking, S.; Wada, Y.; Bierkens, M. F.

    2012-12-01

    Water storage is one of the primary mechanisms for coping with increasing variability of water supply and demand that can be expected with growing population and a changing climate. Man-made reservoirs can currently store about 15% of the global annual runoff. A similar amount of water is stored in one of the most important natural storage components - seasonal snow packs. The amount of water stored in each of those man-made and natural systems is roughly equivalent to the total annual anthropogenic water withdrawals. Storage in seasonal snow packs is declining as a result of climate-driven changes in snowfall and snowmelt. At the same time, reservoir storage is declining as a result of sedimentation and limited construction of new reservoirs. We use a global hydrological model, combined with a global data set of ~6000 large reservoirs to simulate changes in reservoir and snow pack water storage and analyze impacts of those changes on seasonal water availability using a set of scenarios for changing climate conditions. Reservoir sedimentation is simulated using global erosion and sedimentation data sets and validated with observed reservoir storage loss. Results indicate annual loss rates between 0.5 and 1.0% of the installed capacity for most reservoirs, outpacing the storage increases through the construction of new reservoirs for the last decades so that reservoir storage is declining globally. With most reservoirs being about 50 years old, these losses threaten the sustainability of reservoir operation and can pose significant challenges to water resources management. Similarly, seasonal snow storage is declining at about 0.5% per year for the last 20 years. Even without changes in the magnitude of total precipitation, there can be significant changes in basin hydrology if there are climate-driven changes in snowfall and snowmelt, potentially away from the period (summer) when demand for irrigation, water supply, or hydropower production is high. These shifts

  7. A lee-side eddy and its influence on snow accumulation

    NASA Astrophysics Data System (ADS)

    Gerber, Franziska; Mott, Rebecca; Hoch, Sebastian W.; Lehning, Michael

    2016-04-01

    additional flow component around the eastern edge of Sattelhorn introduces a cross-loading component along the Sattelhorn ridge. Snow depth data is, however, only available for the slope and thus covers only the upper part of the eddy. Thus, this winter we will collect more complete snow depth data to reveal the overall influence of the eddy on snow accumulation.

  8. From Snow Depth Distribution to Small-Scale Variability of Soil Temperatures

    NASA Astrophysics Data System (ADS)

    Gisnås, Kjersti; Westermann, Sebastian; Etzelmüller, Bernd; Schuler, Thomas V.

    2013-04-01

    Permafrost is a temperature phenomenon on the local scale. Soil temperatures are not only influenced by atmospheric conditions varying on scales of kilometers, but are also determined by the land cover and soil properties, which display large variability on the meter-scale in many permafrost areas. In mountain areas the seasonal snow cover is crucial for the ground thermal regime, and the redistribution of snow by wind can create a pattern of different snow depths, which results in spatially variable permafrost temperatures. Existing permafrost models (CryoGRID1.0 and CryoGRID2.0) are implemented at 1x1km spatial resolution for Norway, and have proven to capture the regional distribution of permafrost. One of the principal uncertainties of these models is the effect of sub-grid variability in snow cover, and downscaling approaches for snow are therefore required to get a satisfactorily representation of the ground thermal regime. An extensive dataset including ground temperatures of 7 boreholes and data of 5 stations measuring snow depth and air/ground surface temperature is available from Juvflye, a high-mountain site in central southern Norway (1800-1900m a.s.l.). The area has a rough topography and a seasonal snow cover dominated by heavy wind redistribution. A Ground Penetration Radar (GPR) survey of snow depth was conducted in March 2012, covering an 8km2 area including the 7 boreholes. This GPR-survey will be repeated in 2013. The measured snow depths form the basis for probability density functions (PDFs) of snow cover within each 1x1km grid cell for this area. A 1-D numerical model including both a soil thermal model and snow pack scheme are calibrated for all 7 boreholes. Several model runs are performed for different snow depths, intended to cover the range of observed values. We present the effects of different snow depths on the thermal regime of the underlying permafrost, based on this model attempt. Furthermore, we outline a probabilistic approach for

  9. Retrievals of Falling Snow from Satellite-borne Active and Passive Sensors

    NASA Astrophysics Data System (ADS)

    Jackson, Gail; Munchak, S. Joseph; Johnson, Benjamin

    2014-05-01

    will be presented for active radar at Ku, Ka, and W-band and for passive radiometer channels from 10 to 183 GHz. We also helped to develop the GPM mission's at-launch retrieval algorithm code for falling snow. We will report on our tests to evaluate performance in terms of Bayesian database representativeness and database profile selection methodologies for the various surfaces, precipitation types, and real-time ancillary data. We will also describe implementation of specific algorithm enhancements such as database updates, code processing of profile selection methodologies and/or adjusting Bayesian channel weights for the falling snow retrievals. Early imagery of GPM's retrievals of falling snow will be presented if available at the end of April 2014 (2 months after launch).

  10. Snow Dynamics in a Polar Desert, McMurdo Dry Valleys, Antarctica

    NASA Astrophysics Data System (ADS)

    Eveland, J. W.; Gooseff, M. N.; Lampkin, D. J.; Barrett, J. E.; Takacs-Vesbach, C. D.

    2010-12-01

    The McMurdo Dry Valleys of Antarctica are a hyper-arid polar desert, receiving less than 10 cm of water equivalent each year. Snow dynamics of the McMurdo Dry Valleys are important to understanding the microbial ecology and possibly the long term hydrology of the region. Snow in the valleys collects in small nivation hollows to form discontinuous patches of snow across the landscape. We propose that seasonal snow on valley floors is ecologically important because it increases the availability of moisture to subnivian soils and insulates the subnivian soils from temperature extremes. In addition, seasonal snow cover may also be responsible for preserving permafrost in areas of greater accumulation. Our study sites in Taylor and Wright Valey include the surrounding areas of Lake Fryxell, Lake Hoare, Lake Bonney, Lake Brownworth, Lake Vanda, and the Labyrinth. Throughout the 2009-10 summer season, the outlines of 3 snow patches at each site were surveyed several times to monitor the areal ablation of snow cover. Snow pits at adjacent snow patches provided snow density profiles. In addition to small-scale observations, remotely sensed images from the WorldView-1 and Quickbird platforms provide valley-scale data at a spatial resolution of up to 60 cm and a temporal resolution of one week on average. Using data available from nearby meteorological stations, an energy balance approach is used in conjunction with field measurements to calculate the ablation rates over the course of the 2009-10 summer for each region. To test how the field measurements reflect ablation rates at the valley scale, an object-based classification technique is used to extract a time series of areal snow cover across the valleys from the remotely sensed imagery. Results show similar ablation rates across the 3 regions in Taylor Valley. However, the three regions in Wright Valley are markedly different. Snow cover near Lake Vanda ablated rapidly, while a significant amount of snow cover on the

  11. International Conference on Harmonisation; Electronic Transmission of Postmarket Individual Case Safety Reports for Drugs and Biologics, Excluding Vaccines; Availability of Food and Drug Administration Regional Implementation Specifications for ICH E2B(R3) Reporting to the Food and Drug Administration Adverse Event Reporting System. Notice of Availability.

    PubMed

    2016-06-23

    The Food and Drug Administration (FDA) is announcing the availability of its FDA Adverse Event Reporting System (FAERS) Regional Implementation Specifications for the International Conference on Harmonisation (ICH) E2B(R3) Specification. FDA is making this technical specifications document available to assist interested parties in electronically submitting individual case safety reports (ICSRs) (and ICSR attachments) to the Center for Drug Evaluation and Research (CDER) and the Center for Biologics Evaluation and Research (CBER). This document, entitled "FDA Regional Implementation Specifications for ICH E2B(R3) Implementation: Postmarket Submission of Individual Case Safety Reports (ICSRs) for Drugs and Biologics, Excluding Vaccines" supplements the "E2B(R3) Electronic Transmission of Individual Case Safety Reports (ICSRs) Implementation Guide--Data Elements and Message Specification" final guidance for industry and describes FDA's technical approach for receiving ICSRs, for incorporating regionally controlled terminology, and for adding region-specific data elements when reporting to FAERS. PMID:27373012

  12. Brief communication "Snow profile associated measurements (SPAM) - a new instrument for quick snow profile measurements"

    NASA Astrophysics Data System (ADS)

    Lahtinen, P.

    2011-06-01

    A new instrument concept (SPAM) for snow profile associated measurements is presented. The potential of the concept is demonstrated by presenting preliminary results obtained with the prototype instrument. With this concept it is possible to retrieve rapid snow profiles of e.g. light extinction, reflectance, temperature and snow layer structure with high vertical resolution. As a side-product, also snow depth is retrieved.

  13. Effect of unsteady wind on drifting snow

    NASA Astrophysics Data System (ADS)

    Cierco, F.-X.; Naaim-Bouvet, F.; Naaim, M.

    2003-04-01

    Wind is not always a steady flow. It can oscillate producing blasts. However most of the current numerical models of drifting snow are constrained by one major assumption : forcing winds are steady and uniform. Experiments done in the CSTB climatic wind tunnel (with a data acquisition frequency of 1 Hz both for wind and drifting snow) showed that drifting snow is in a state of permanent disequilibrium in the presence of fluctuating airflows : mass flux and velocity were poorly matched. However, the study of wind and drifting snow gust factors done at Col du Lac Blanc (parameters recorded every 15 min with a scan rate of 1 s) shown that the largest drifting snow episodes appear during periods of roughly constant strong wind whereas a short but strong blast does not produce significant drifting snow. In order to better understand the effect of unsteady wind on drifting snow processes, these first investigations have been completed during winter 2003 by increasing the acquisition frequency during snow storms at Col du Lac Blanc using an ultrasonic anemometer and a profile of six drifting snow acoustic sensors set up side by side.

  14. Wideband Instrument for Snow Measurements (WISM)

    NASA Technical Reports Server (NTRS)

    Miranda, Felix A.; Lambert, Kevin M.; Romanofsky, Robert R.; Durham, Tim; Speed, Kerry; Lange, Robert; Olsen, Art; Smith, Brett; Taylor, Robert; Schmidt, Mark; Racette, Paul; Bonds, Quenton; Brucker, Ludovic; Koenig, Lora; Marshall, Hans-Peter; Vanhille, Ken; Borissenko, Anatoly; Tsang, Leung; Tan, Shurun

    2016-01-01

    This presentation discusses current efforts to develop a Wideband Instrument for Snow Measurements (WISM). The objective of the effort are as follows: to advance the utility of a wideband active and passive instrument (8-40 gigahertz) to support the snow science community; improve snow measurements through advanced calibration and expanded frequency of active and passive sensors; demonstrate science utility through airborne retrievals of snow water equivalent (SWE); and advance the technology readiness of broadband current sheet array (CSA) antenna technology for spaceflight applications.

  15. Snow Conditions Near Barrow in Spring 2012

    NASA Astrophysics Data System (ADS)

    Webster, M.; Rigor, I.; Nghiem, S. V.; Sturm, M.; Kurtz, N. T.; Farrell, S. L.; Gleason, E.; Lieb-Lappen, R.; Saiet, E.

    2012-12-01

    Snow has a dual role in the growth and decay of Arctic sea ice. It provides insulation from colder air temperatures during the winter, which hinders sea ice formation. Snow is highly reflective and, as a result, it delays the surface ice melt during the spring. Summer snow melt influences the formation and location of melt ponds on sea ice, which further modifies heat transport into sea ice and the underlying ocean. Identifying snow thickness and extent is of key importance in understanding the surface heat budget, particularly during the early spring when the maximum snowfall has surpassed, and surface melt has not yet occurred. Regarding Arctic atmospheric chemical processes, snow may sustain or terminate halogen chemical recycling and distribution, depending on the state of the snow cover. Therefore, an accurate assessment of the snow cover state in the changing Arctic is important to identify subsequent impacts of snow change on both physical and chemical processes in the Arctic environment. In this study, we assess the springtime snow conditions near Barrow, Alaska using coordinated airborne and in situ measurements taken during the NASA Operation IceBridge and BRomine, Ozone, and Mercury EXperiment (BROMEX) field campaigns in March 2012, and compare these to climatological records. Operation IceBridge was conceived to bridge the gap between satellite retrievals ice thickness by ICESat which ceased operating in 2009 and ICESat-2 which is planned for launch in 2016. As part of the IceBridge mission, snow depth may be estimated by taking the difference between the snow/air surface and the snow/ice interface measured by University of Kansas's snow radar installed on a P-3 Orion and the measurements have an approximate spatial resolution of 40 m along-track and 16 m across-track. The in situ snow depth measurements were measured by an Automatic Snow Depth Probe (Magnaprobe), which has an accuracy of 0.5 cm. Samples were taken every one-to-two meters at two sites

  16. Automatic monitoring of the effective thermal conductivity of snow in a low Arctic shrub tundra

    NASA Astrophysics Data System (ADS)

    Domine, F.; Barrere, M.; Sarrazin, D.; Morin, S.

    2015-03-01

    The effective thermal conductivity of snow, keff, is a critical variable which determines the temperature gradient in the snowpack and heat exchanges between the ground and the atmosphere through the snow. Its accurate knowledge is therefore required to simulate snow metamorphism, the ground thermal regime, permafrost stability, nutrient recycling and vegetation growth. Yet, few data are available on the seasonal evolution of snow thermal conductivity in the Arctic. We have deployed heated needle probes on low Arctic shrub tundra near Umiujaq, Quebec, (56°34´ N; 76°29´ W) and monitored automatically the evolution of keff for two consecutive winters, 2012-2013 and 2013-2014, at 4 heights in the snowpack. Shrubs are 20 cm high dwarf birch. Here, we develop an algorithm for the automatic determination of keff from the heating curves and obtain 404 keff values. We evaluate possible errors and biases associated with the use of the heated needles. The time-evolution of keff is very different for both winters. This is explained by comparing the meteorological conditions in both winters, which induced different conditions for snow metamorphism. In particular, important melting events the second year increased snow hardness, impeding subsequent densification and increase in thermal conductivity. Shrubs are observed to have very important impacts on snow physical evolution: (1) shrubs absorb light and facilitate snow melt under intense radiation; (2) the dense twig network of dwarf birch prevents snow compaction and therefore keff increase; (3) the low density depth hoar that forms within shrubs collapsed in late winter, leaving a void that was not filled by snow.