No abstract

Abstract. The Martial Este Glacier in southern Tierra del Fuego was studied in order to estimate the surface mass balance from 1960 until 2099. For this reason a degree-day model was calibrated. Air temperature and precipitation data obtained from 3 weather stations as well as glaciological measurements were applied. The model was driven using a vertical air temperature gradient of 0.69 K/100 m, a degreeday factor for snow of 4.7 mm w.e. K −1 day −1 , a degree-day factor for ice of 9.4 mm w.e. K −1 day −1 and a precipitation gradient of 22%/100 m. For the purpose of surface mass balance reconstruction for the time period 1960 until 2006 a winter vertical air temperature gradient of 0.57 K/100 m and a summer vertical air temperature gradient of 0.71 K/100 m were added as well as a digital terrain model. The key finding is an almost continuous negative mass balance of −772 mm w.e. a −1 throughout this period. While the calculation of the mass balance for the period 1960-2006 is based on instrumental records, the mass balance for the years 2007 until 2099 was estimated based on the IPCC SRES A2-scenario. To accomplish this estimation, the dataset of the global climate model HadCM3 was statistically downscaled to fit local conditions at Martial Este Glacier. Subsequently, the downscaled air temperature and precipitation were applied to a volume-area scaling glacier change model. Findings reveal an enduring deglaciation resulting in a surface area reduction of nearly 93% until 2099. This implicates that the Martial Este Glacier might be melted off at the beginning of the 22nd century.

In different fields of applied local climate investigation, highly resolved data of air temperature are of great importance. As a part of the research programme entitled City2020+, which deals with future climate conditions in agglomerations, this study focuses on increasing the quantity of urban air temperature data intended for the analysis of their spatial distribution. A new measurement approach using local transport buses as "riding thermometers" is presented. By this means, temperature data with a very high temporal and spatial resolution could be collected during scheduled bus rides. The data obtained provide the basis for the identification of thermally affected areas and for the investigation of factors in urban structure which influence the thermal conditions. Initial results from the ongoing study, which show the temperature distribution along different traverses through the city of Aachen, are presented

In this paper we focus on air temperature and its distribution within a medium-sized European city (Aachen) to identify those areas where high levels of thermal load are likely to be observed. The temperatures for the whole city area are examined by means of a GIS-based model. This approach based on mobile measurements demonstrates the distribution of air temperature differences in relation to a reference station and allows for a detailed analysis of the influencing factors of urban structure and land use. Despite the fact that air temperature distribution in Aachen is largely determined by terrain, the influences of land use and urban structures are apparent in the model results. The evaluation of afternoon and evening air temperature data for the summer half-year (April-September) show that the importance of factors contributing to thermal load varies in the course of the day. During daytime the highest air temperature arises in industrial areas with a high degree of surface sealing. However, during the evening inner-city residential quarters with a dense building structure show the highest thermal load. Forest and green spaces also determine the specific air temperature patterns but their impact varies in the course of the day and with the size of neighborhood used for correlation statistics. The spatial structure of the modeled temperature distribution is in accordance with the spatial structure of the surface radiant temperatures from a thermal image over wide areas of Aachen. Deviations are obvious for buildings whose roof materials cause surface temperatures that differ significantly from air temperatures modeled for the 2 m level. Furthermore, the comparison makes obvious the limits of the model: the effects of cold air drainage flows and wind directions cannot be assessed. However, this is not considerably detrimental to the results. Zusammenfassung: Vorliegender Beitrag befasst sich mit der Temperaturverteilung innerhalb der Stadt Aachen und der Identifizierung potenziell thermischer Belastungsgebiete. Mittels eines GIS-gestützten Modells, das auf mobilen Lufttemperaturmessungen basiert, werden Temperaturdifferenzen zu einer Referenzstation dargestellt und Einflussfaktoren innerhalb der urbanen Struktur ausfindig gemacht. Obwohl die Temperaturverteilung in der Stadt u.a. stark von der Topographie abhängig ist, spiegelt sich auch der Einfluss der Landnutzung und der städtischen Oberflächenstrukturen in den Ergebnissen wider. Die Analyse mittäglicher und abendlicher Lufttemperaturen für das Sommerhalbjahr (April-September) zeigt, dass der Einfluss dieser Faktoren in Abhängigkeit der Tageszeit variiert. Während Industriegebiete mit einem hohen Versiegelungsgrad die höchsten Lufttemperaturen am Tag aufweisen, begünstigen dicht bebaute Gebiete in der Innenstadt vor allem abends und nachts hohe Lufttemperaturen. Wald und Grünflächen bestimmen ebenfalls das Temperaturmuster in der Stadt. Dieses ist neben der betrachteten Tageszeit auch abhängig vom gewählten Einzugsgebiet der Korrelationsfaktoren. Der Vergleic...

No abstract