Table XXXVII. Summer 1970 climatic data from several 

 stations in interior Alaska.* 



Avg 



temp 



Month CC) 



Departure 



Precip 



(mm) 



Departure 



* Table and narrative by R. Haugen, USA CRREL. 



Thermocouples were installed at both sites at 10, 5, and Im, and 20, 10 and 5 cm above the 

 soil surface, and at 5, 10, 20, 50 cm and 1 m below the soil surface. The thermocouples above the 

 ground were attached to trees, extending approximately 5 cm away from the tree trunk on the nath 

 side. They were painted white to reduce radiation errors. In September two 2.5-cm-diam 12-m-high 

 aluminum towers were placed in small natural clearings in both tree stands. Ventilated thermo- 

 couples were attached to the towers at the above six heights. A small 34-v dc ventilation motor 

 at each level ensured proper ventilation of each thermocouple. 



Thermocouples were wired into a crossbar scanner and automatic data logger that recorded 

 readings on punched paper tape. This datalogger was also used to record readings from areas in 

 the hot-pipe disturbed area and was operated by the Institute of Arctic Biology. Unfortunately, 

 the data logger operated for a short period only at the beginning of the summer. Electronic diffi- 

 culties still are not solved. Very little data were therefore collected since a manual reading of 

 the data would have involved a substantial amount of time to make the data meaningful. 



The data collected in June indicated that air temperatures in the spruce forest were higher 

 than those in the birch forest, but ground and underground temperatures in the spruce stand were 

 lower than those in the birch stand (Fig. 38). 



_-'■ Spruce, lOm 



10 - 



i 

 I 



5 - 



2 4 6 8 10 12 14 16 18 20 22 24 2 4 6 8 



r/Me OF DAY (Hows) 



Figure 38. Diurnal temperatures in spruce and birch forests. 



100 



