ABSTRACTS 



Authors of scientific papers are requested to see that abstracts, preferably 

 prepared and signed by themselves, are forwarded promptly i the editors. Each 

 of the scientific bureaus in Washington has a representative authorized to for- 

 ward such material to this journal and abstracts of official publications should 

 be transmitted through the representative of the bureau in which they originate. 

 The abstracts should conform in length and general style to those appearing in 

 this issue. 



METEOROLOGY. — Variations of temperature at summit and base 

 stations in the central Rocky Mountain region. Alfred J. Henry. 

 Bulletin of the Mount Weather Observatory, 4: 103-116. 1911. 



In this and a previous paper the author discusses the temperatures 

 at summit and base stations in the high Rocky Mountain region of 

 eastern Colorado, as recorded simultaneously by Richard thermographs, 

 the latter being controlled by eye readings of standard mercurial ther- 

 mometers. 



It is shown that as a rule, the course of the temperature at both levels 

 is very nearly parallel, that the accidental changes occur nearly simul- 

 taneously, with the exception that changes to warmer weather set in 

 at the upper station earlier than on lower levels, that while the course 

 of the temperature at both levels is generally similarly directed, there 

 are times when it is oppositely directed, as when the temperature rises 

 on the mountain summits and falls on the plains to the eastward. Such 

 instances indicate that the temperature control is occasionally shifted 

 from one side of the mountain to the other and that the mountains then 

 become a real climatic barrier. Ordinarily they offer little or no hin- 

 drance to the movement of atmospheric disturbances on which temper- 

 ature changes depend. In the cold season when the Great Basin is 

 occupied by an area of high pressure the latter seems to dominate the 

 winds and temperature on the higher mountain summits of Colorado 

 and New Mexico but not the plains to the eastward. 



The dependence of temperature on altitude is discussed for the pair 

 of stations, Fraser, in Middle Park, Colorado, altitude 2,609 meters, 

 8,560 feet, and Corona, the latter on the summit of the continental 

 divide, altitude 3,554 meters, 11,660 feet. Although Eraser is 945 

 meters, 3,100 feet, lower than Corona, it has a temperature that during 

 the night hours and under certain weather conditions is considerably 

 lower than that of Corona notwithstanding the difference in altitude. 

 The cause of the abnormally low temperatures observed at Fraser are 



233 



