33 research outputs found
A Study of the Breakup Characteristics of the Chena River Basin Using ERTS Imagery: Completion Report
ERTS Project 110-5Snowmelt and rainfall floodinq is a major water resource problem in
Alaska. At the present time, forecastinq of these floods is based on a
sparse hydrological and climatological network. Numerous basins with
drainage areas of 5,000 km2 and less remain completely ungaged. The lack
of data causes uncertainty in the design of transportation schemes such as
tile Trans-Alaska oil pipeline. This project studied the utility of using
ERTS-l imagery as a source of additional data for the prediction of snowmelt
runoff, the most dynamic hydroloqic event in arctic and subarctic
basins. Snow distribution as determined from the satellite imagery was
compared with values determined from the conventional snow course stations
and with the results of a snowmelt energy model. The Chena River Basin
was selected because of the availability of ground truth data for comparison.
Very good agreement for snow distribution and rates of ablation was
found between the ERTS-l imagery, the snowmelt model, and field measurements.
Monitoring snowmelt rates for relatively small basins appears to be practical.
The main limitation of the ERTS-l imagery is the interval of coverage.
More frequent overflights providing coverage are needed for the study of
transient hydrologic events. ERTS-l data is most useful when used in conjunction
with snowmelt prediction models and existing snow course data.
These results should prove very useful in preliminary assessment of hydrologic
conditions in ungaged watersheds and will provide a tool for month-to-month
volume forecasting.This work was supported by National Aeronautics and Space Administration,
Grant NAS 5-21833
A Century of Climate Change for Fairbanks, Alaska
Climatological observations are available for Fairbanks, Interior Alaska, for up to 100 years. This is a unique data set for Alaska, insofar as it is of relatively high quality and without major breaks. Applying the best linear fit, we conclude that the mean annual temperature rose from -3.6°C to -2.2°C over the century, an increase of 1.4°C (compared to 0.8°C worldwide). This comparison clearly demonstrates the well-known amplification or temperature change for the polar regions. The observed temperature increase is neither uniform over the time period nor uniform throughout the course of a year. The winter, spring, and summer seasons showed a temperature increase, while autumn showed a slight decrease in temperature. For many activities, the frequencies of extremes are more important than the average values. For example, the frequency of very low temperatures (below -40°C, or -40°F) has decreased substantially, while the frequency of very high temperatures (above 26.7°C, or 80°F) increased only slightly. Finally, the length of the growing season increased substantially (by 45%) as a result of an earlier start in spring and a later first frost in autumn. Precipitation decreased for Fairbanks. This is a somewhat counter-intuitive result, as warmer air can hold more water vapor. The date of the establishment of the permanent snow cover in autumn showed little change; however, the melting of the snow cover now occurs earlier in the spring, a finding in agreement with the seasonal temperature trends. The records for wind, atmospheric pressure, humidity, and cloudiness are shorter, more broken, or of lower quality. The observed increase in cloudiness and the decreasing trend for atmospheric pressure in winter are related to more advection and warmer temperatures during this season.
Il existe des observations climatologiques pour Fairbanks, Ă l\u27intĂ©rieur de l\u27Alaska, Ă©chelonnĂ©es sur 100 ans. Cet ensemble de donnĂ©es est unique en Alaska en ce sens que les donnĂ©es sont de relativement grande qualitĂ© et qu\u27elles ne comportent pas d\u27interruptions majeures. Au moyen du meilleur appariement linĂ©aire, nous concluons que la tempĂ©rature moyenne annuelle s\u27est Ă©levĂ©e de -3,6 °C Ă -2,2 °C au cours du siècle, ce qui reprĂ©sente une augmentation de 1,4 °C (compar- ativement Ă la moyenne mondiale de 0,8 °C). Cette comparaison montre clairement l\u27amplification ou le changement de tempĂ©rature bien connu des rĂ©gions polaires. L\u27augmentation de tempĂ©rature qui a Ă©tĂ© observĂ©e n\u27est ni uniforme pendant la pĂ©riode visĂ©e ni uniforme au cours d\u27une mĂŞme annĂ©e. La tempĂ©rature s\u27est en fait accrue pendant les saisons de l\u27hiver, du printemps et de l\u27Ă©tĂ©, tandis que la tempĂ©rature a baissĂ© quelque peu l\u27automne. Pour bien des activitĂ©s, la frĂ©quence des extrĂŞmes est plus importante que les valeurs moyennes. Par exemple, la frĂ©quence de tempĂ©ratures très basses (en bas de -40 °C, ou -40 °F) a diminuĂ© considĂ©rablement, tandis que la frĂ©quence de tempĂ©ratures très Ă©levĂ©es (au-dessus de 26,7 °C, ou 80 °F) n\u27a augmentĂ© que lĂ©gèrement. Et enfin, la longueur de la saison de croissance a augmentĂ© considĂ©rablement (de 45 %) parce que le printemps commence plus tĂ´t et que les premières gelĂ©es de l\u27automne se manifestent plus tard. Les prĂ©cipitations ont diminuĂ© Ă Fairbanks. Ce rĂ©sultat est un peu contre-intuitif car l\u27air plus chaud peut contenir plus de vapeur d\u27eau. La date de l\u27Ă©tablissement de la couverture de neige permanente Ă l\u27automne a peu fluctuĂ©. Cependant, la fonte de la couverture de neige se produit maintenant plus tĂ´t au printemps, observation qui cadre avec les tendances caractĂ©risant les tempĂ©ratures saison- nières. Les donnĂ©es relatives au vent, Ă la pression atmosphĂ©rique, Ă l\u27humiditĂ© et Ă l\u27ennuagement s\u27Ă©tendent sur une moins longue pĂ©riode, comportent plus d\u27interruptions ou sont de moins bonne qualitĂ©. L\u27augmentation d\u27ennuagement observĂ©e et la tendance de pression atmosphĂ©rique Ă la baisse l\u27hiver sont attribuables Ă une plus grande advection et Ă des tempĂ©ratures plus chaudes pendant cette saison-lĂ
A Century of Climate Change for Fairbanks, Alaska
Climatological observations are available for Fairbanks, Interior Alaska, for up to 100 years. This is a unique data set for Alaska, insofar as it is of relatively high quality and without major breaks. Applying the best linear fit, we conclude that the mean annual temperature rose from -3.6°C to -2.2°C over the century, an increase of 1.4°C (compared to 0.8°C worldwide). This comparison clearly demonstrates the well-known amplification or temperature change for the polar regions. The observed temperature increase is neither uniform over the time period nor uniform throughout the course of a year. The winter, spring, and summer seasons showed a temperature increase, while autumn showed a slight decrease in temperature. For many activities, the frequencies of extremes are more important than the average values. For example, the frequency of very low temperatures (below -40°C, or -40°F) has decreased substantially, while the frequency of very high temperatures (above 26.7°C, or 80°F) increased only slightly. Finally, the length of the growing season increased substantially (by 45%) as a result of an earlier start in spring and a later first frost in autumn. Precipitation decreased for Fairbanks. This is a somewhat counter-intuitive result, as warmer air can hold more water vapor. The date of the establishment of the permanent snow cover in autumn showed little change; however, the melting of the snow cover now occurs earlier in the spring, a finding in agreement with the seasonal temperature trends. The records for wind, atmospheric pressure, humidity, and cloudiness are shorter, more broken, or of lower quality. The observed increase in cloudiness and the decreasing trend for atmospheric pressure in winter are related to more advection and warmer temperatures during this season.Il existe des observations climatologiques pour Fairbanks, Ă l’intĂ©rieur de l’Alaska, Ă©chelonnĂ©es sur 100 ans. Cet ensemble de donnĂ©es est unique en Alaska en ce sens que les donnĂ©es sont de relativement grande qualitĂ© et qu’elles ne comportent pas d’interruptions majeures. Au moyen du meilleur appariement linĂ©aire, nous concluons que la tempĂ©rature moyenne annuelle s’est Ă©levĂ©e de -3,6 °C Ă -2,2 °C au cours du siècle, ce qui reprĂ©sente une augmentation de 1,4 °C (comparativement Ă la moyenne mondiale de 0,8 °C). Cette comparaison montre clairement l’amplification ou le changement de tempĂ©rature bien connu des rĂ©gions polaires. L’augmentation de tempĂ©rature qui a Ă©tĂ© observĂ©e n’est ni uniforme pendant la pĂ©riode visĂ©e ni uniforme au cours d’une mĂŞme annĂ©e. La tempĂ©rature s’est en fait accrue pendant les saisons de l’hiver, du printemps et de l’étĂ©, tandis que la tempĂ©rature a baissĂ© quelque peu l’automne. Pour bien des activitĂ©s, la frĂ©quence des extrĂŞmes est plus importante que les valeurs moyennes. Par exemple, la frĂ©quence de tempĂ©ratures très basses (en bas de -40 °C, ou -40 °F) a diminuĂ© considĂ©rablement, tandis que la frĂ©quence de tempĂ©ratures très Ă©levĂ©es (au-dessus de 26,7 °C, ou 80 °F) n’a augmentĂ© que lĂ©gèrement. Et enfin, la longueur de la saison de croissance a augmentĂ© considĂ©rablement (de 45 %) parce que le printemps commence plus tĂ´t et que les premières gelĂ©es de l’automne se manifestent plus tard. Les prĂ©cipitations ont diminuĂ© Ă Fairbanks. Ce rĂ©sultat est un peu contre-intuitif car l’air plus chaud peut contenir plus de vapeur d’eau. La date de l’établissement de la couverture de neige permanente Ă l’automne a peu fluctuĂ©. Cependant, la fonte de la couverture de neige se produit maintenant plus tĂ´t au printemps, observation qui cadre avec les tendances caractĂ©risant les tempĂ©ratures saisonnières. Les donnĂ©es relatives au vent, Ă la pression atmosphĂ©rique, Ă l’humiditĂ© et Ă l’ennuagement s’étendent sur une moins longue pĂ©riode, comportent plus d’interruptions ou sont de moins bonne qualitĂ©. L’augmentation d’ennuagement observĂ©e et la tendance de pression atmosphĂ©rique Ă la baisse l’hiver sont attribuables Ă une plus grande advection et Ă des tempĂ©ratures plus chaudes pendant cette saison-lĂ
A Century of Climate Change for Fairbanks, Alaska
Climatological observations are available for Fairbanks, Interior Alaska, for up to 100 years. This is a unique data set for Alaska, insofar as it is of relatively high quality and without major breaks. Applying the best linear fit, we conclude that the mean annual temperature rose from -3.6°C to -2.2°C over the century, an increase of 1.4°C (compared to 0.8°C worldwide). This comparison clearly demonstrates the well-known amplification or temperature change for the polar regions. The observed temperature increase is neither uniform over the time period nor uniform throughout the course of a year. The winter, spring, and summer seasons showed a temperature increase, while autumn showed a slight decrease in temperature. For many activities, the frequencies of extremes are more important than the average values. For example, the frequency of very low temperatures (below -40°C, or -40°F) has decreased substantially, while the frequency of very high temperatures (above 26.7°C, or 80°F) increased only slightly. Finally, the length of the growing season increased substantially (by 45%) as a result of an earlier start in spring and a later first frost in autumn. Precipitation decreased for Fairbanks. This is a somewhat counter-intuitive result, as warmer air can hold more water vapor. The date of the establishment of the permanent snow cover in autumn showed little change; however, the melting of the snow cover now occurs earlier in the spring, a finding in agreement with the seasonal temperature trends. The records for wind, atmospheric pressure, humidity, and cloudiness are shorter, more broken, or of lower quality. The observed increase in cloudiness and the decreasing trend for atmospheric pressure in winter are related to more advection and warmer temperatures during this season.Il existe des observations climatologiques pour Fairbanks, Ă l’intĂ©rieur de l’Alaska, Ă©chelonnĂ©es sur 100 ans. Cet ensemble de donnĂ©es est unique en Alaska en ce sens que les donnĂ©es sont de relativement grande qualitĂ© et qu’elles ne comportent pas d’interruptions majeures. Au moyen du meilleur appariement linĂ©aire, nous concluons que la tempĂ©rature moyenne annuelle s’est Ă©levĂ©e de -3,6 °C Ă -2,2 °C au cours du siècle, ce qui reprĂ©sente une augmentation de 1,4 °C (comparativement Ă la moyenne mondiale de 0,8 °C). Cette comparaison montre clairement l’amplification ou le changement de tempĂ©rature bien connu des rĂ©gions polaires. L’augmentation de tempĂ©rature qui a Ă©tĂ© observĂ©e n’est ni uniforme pendant la pĂ©riode visĂ©e ni uniforme au cours d’une mĂŞme annĂ©e. La tempĂ©rature s’est en fait accrue pendant les saisons de l’hiver, du printemps et de l’étĂ©, tandis que la tempĂ©rature a baissĂ© quelque peu l’automne. Pour bien des activitĂ©s, la frĂ©quence des extrĂŞmes est plus importante que les valeurs moyennes. Par exemple, la frĂ©quence de tempĂ©ratures très basses (en bas de -40 °C, ou -40 °F) a diminuĂ© considĂ©rablement, tandis que la frĂ©quence de tempĂ©ratures très Ă©levĂ©es (au-dessus de 26,7 °C, ou 80 °F) n’a augmentĂ© que lĂ©gèrement. Et enfin, la longueur de la saison de croissance a augmentĂ© considĂ©rablement (de 45 %) parce que le printemps commence plus tĂ´t et que les premières gelĂ©es de l’automne se manifestent plus tard. Les prĂ©cipitations ont diminuĂ© Ă Fairbanks. Ce rĂ©sultat est un peu contre-intuitif car l’air plus chaud peut contenir plus de vapeur d’eau. La date de l’établissement de la couverture de neige permanente Ă l’automne a peu fluctuĂ©. Cependant, la fonte de la couverture de neige se produit maintenant plus tĂ´t au printemps, observation qui cadre avec les tendances caractĂ©risant les tempĂ©ratures saisonnières. Les donnĂ©es relatives au vent, Ă la pression atmosphĂ©rique, Ă l’humiditĂ© et Ă l’ennuagement s’étendent sur une moins longue pĂ©riode, comportent plus d’interruptions ou sont de moins bonne qualitĂ©. L’augmentation d’ennuagement observĂ©e et la tendance de pression atmosphĂ©rique Ă la baisse l’hiver sont attribuables Ă une plus grande advection et Ă des tempĂ©ratures plus chaudes pendant cette saison-lĂ
Fifty Years of McCall Glacier Research: From the International Geophysical Year 1957–58 to the International Polar Year 2007–08
Cryo-EM structures reveal intricate Fe-S cluster arrangement and charging in Rhodobacter capsulatus formate dehydrogenase
Metal-containing formate dehydrogenases (FDH) catalyse the reversible oxidation of formate to carbon dioxide at their molybdenum or tungsten active site. They display a diverse subunit and cofactor composition, but structural information on these enzymes is limited. Here we report the cryo-electron microscopic structures of the soluble Rhodobacter capsulatus FDH (RcFDH) as isolated and in the presence of reduced nicotinamide adenine dinucleotide (NADH). RcFDH assembles into a 360 kDa dimer of heterotetramers revealing a putative interconnection of electron pathway chains. In the presence of NADH, the RcFDH structure shows charging of cofactors, indicative of an increased electron load
Globales Lernen und Biodiversität in der außerschulischen Bildung in Deutschland. Ausgewählte Ergebnisse einer empirischen Studie
Die Autoren analysieren in ihrem Beitrag Anbieter außerschulischer Bildung hinsichtlich der Inhaltsaspekte ihres Bildungsangebots, ihrer Zielgruppen, der Kernaspekte der Bildung für eine nachhaltige Entwicklung (BNE) sowie ihres Nachhaltigkeitsmanagements. Dabei werden Anbieter des Globalen Lernens mit Einrichtungen ohne explizit entwicklungspolitischen Hintergrund verglichen. Besonderes Augenmerk liegt auf dem Themenbereich der Biodiversität. (DIPF/Orig.)In this article the authors analyse providers of non-formal education with regard to the topics of their educational opportunities, their target groups, core issues of education for sustainable development (ESD) and their sustainability management. Providers of Global Education are compared to institutions without a background in development policy. Particular attention is given to the subject of biodiversity. (DIPF/Orig.