We evaluate natural and anthropogenic impacts on cave micro-climate. The entrance to the cave used by tourists was artificially opened in 1866, and this has caused the cave to be well ventilated deep inside. Statistical comparisons between historical cave air temperature and recent monitoring show that the former average daytime cave air temperature was about 2°C lower than present temperatures. The increase is mostly attributed to changes in natural climatic conditions, because the mean annual exterior air temperature has been increasing for several decades. To a lesser degree the cave air temperature increase can also be attributed to the higher number of tourist visits, when cumulative effects were observed.
COBISS.SI-ID: 38764589
Parameters of cave atmosphere such as CO2, temperature and wind exhibit typical diurnal patterns.These cycles are conditioned by anthropogenic and natural phenomena. In both cases, a detailed observation and understanding of the daily cycles provide important insight into the dynamics of cave atmosphere and the and thus contribute to efficient protection of cave environment. In this paper we present a radial frequency diagram (sunflower) which allows fast and intuitive overview of diurnal cycles.
COBISS.SI-ID: 28621607
We present analysis of temperature records in Črna jama. The cave is connected to Postojnska jama and Pivka jama via closed artificial passage. Its particular geometry allows circulation of cold winter air which cools down the cave. During the warm period, circulation is diminished, which makes the cave a cold trap anomaly. The temperature is more than 2°C colder than in the rest of the cave.
COBISS.SI-ID: 42090285
We present technical solutions for the use of Disruption Tolerant Networks (DTN) for data transfer between cave meteorological stations and data servers.
COBISS.SI-ID: 28898343
The sub-surface flow of Pivka river is an important factor of cave micro-climate. Flow through the system has been monitored with 7 stations distributed along the flow path, monitoring stage and temperature. We have used the stage data to model flow through the cave system with the program package SWMM, simulating the active parts of Postojnska jama with simplified geometry. From the comparison of stage observations and predictions, we identified key sections in the cave, which control the sub-surface flow, such as passage constrictions, sumps and by-passes. Using a formal inverse procedure, we determined the geometry of this key sections by fitting predicted to observed stages, and we achieved a very high degree of correlation.
COBISS.SI-ID: 40739373