No abstract

Observations of incoming longwave radiation (L 4) and air temperature were made using automobile transects across the small city of Brandon, Canada. Data were obtained during nighttime for 13 spring and summer days in 1979 under a variety" of sky cover conditions. A strong relationship between urban-rural differences in L4 and the urban heat island magnitude was found. Values ofL ~ were consistently larger for the urban situation with increases over the rural case ranging from 2.0 to 20.1% with an average of 10.7%. These increases are comparable to those found in past studies for much larger cities. Zusammenfassung N~ichfliche Beobachtungen der einfailenden iangwelligen Strahlung und der W~irmeinsel einer kleinen Pr~iriestadtBeobachtungen der einfallenden langwelligen Strahlung (L4) und der Lufttemperatur wurden in der KAeinstadt Brandon, Kanada, Rings Querschnitten mittels Automobfl angestellt. Daten wurden im Fltihling und Sommer 1979 erhatten. Eine signifikante Beziehung wurde zwischen Land-Stadt-Differenzen in der Gr6fie L $ und der st~idtischen W~rmeinsel festgestellt. Werte fiir L $ waren durchwegs in der Stadt gr6fier [und zwar zwischen 2 und 20,t% (Mittelwert 10,7%)] im Vergleich zu den l~ndlichen Strahlungs-verh~ltnissen. Diese erh6hten Werte sind vergleichbar mit denen, die in frtiheren Untersuchungen tiber wesentlich gr6geren St~dten gefunden wurden.

SummaryWinter minimum temperatures were recorded at four sites in Station Cove, a forested flat-bottomed ravine in the southern Appalachians of South Carolina, U.S.A. Unlike minimum temperatures found in frost hollows, cove minima were warmer than those found outside of the cove. Within the cove, minimum temperatures at study sites in the narrow, gorge4ike western portion near a 20 m high cascade were warmer than those in the broader, eastern portion. Additionally, minimum temperatures near the ground were warmer than those at 1.4 m height above the surface. Selected springflowering plant species bloomed earlier in the western portion of the cove, while for the same plant species, within cove flowering dates were 2 to 3 weeks earlier than those outside of the cove. Station Cove, therefore, appears to harbor a microclimate that allows for much earlier flowering and leafing out of plant species in spring than does the surrounding region. ZusammenfassungDer