Remotely sensed thermal information applied to urban climate analysis

Urban heat island (UHI) effects on the ten most populated cities of Hungary, including the Budapest agglomeration area, were analyzed using remotely sensed data. Day- and night-time surface temperature time series observed by sensor MODIS on satellite Terra were used to determine UHI intensities. UHI intensity was defined as the difference in spatially averaged surface temperatures between urban and surrounding rural pixels. Spatial structures of UHIs were determined and compared for different seasons and macrocirculation conditions.     

Emerging magnetic flux,flares and filaments — FBS interval 16–23 June 1980

17 emerging magnetic flux regions with arch filaments related to new sunspots were identified in Hale Active Region No. 16918 during the 7 day interval from 16–22 June. Most of the new flux regions were clustered around the filament channel between the old opposite polarity fields as were most of the flares. The two largest regions of new magnetic flux and a few of the smaller flux regions developed very near the end points of filaments. This suggests that the emergence of flux in existing active regions might be non-random in position along a filament channel as well as in distance from a filament channel.We have analyzed the positions of 88 flares to date during about half of each day. We find that slightly more than half (50%) of the flares, irrespective of their size, are centered within the new flux regions. About 1/5 (20%) were centered on the border between the new flux and the adjacent older magnetic field. Less than 1/3 occurred outside of the newly emerging flux regions but in many cases were very close to the newly emerging flux. We conclude that at least 2/3 of the flares are intimately related to the emerging flux regions while the remaining 1/3 might be either indirectly related or unrelated to the emerging flux.