| dc.description.abstract | This study investigates the link between surface albedo and temperature difference (T. diff.: the difference between the actual surface temperature and ambient temperature) for various vegetation types to ascertain if higher surface albedo corresponds to lower surface temperature and lower surface albedo corresponds to higher surface temperature. This is with particular emphasis on the effects of cloud cover, wind speed, and humidity.
The dataset compiled using albedo application (a reflectance app) for smartphones and BOSCH GTC 400 C handheld thermal camera, contains observations of albedo, temperature difference, cloud cover, humidity, and wind speed that were taken from several plots of blueberry, lichen, heather, tall grass, short grass and bare ground between August 28, and September 15, 2022, in Bø Central Telemark, Norway. The accuracy of the reflectance application for albedo measurements was also considered.
Exploratory analysis reveals variations in albedo and temperature difference among vegetation types. The vegetation types exhibit diverse albedo values with corresponding fluctuating temperature differences viz: Blueberry (95% - 100% cover) albedo values ranging from 0.02 to 0.13, and temperature difference ranging from -1.7 ᵒC and 6.6 ᵒC. Lichen (98% - 100% cover) albedo values range from 0.05 to 0.53, and temperature difference ranges from -4.1 ᵒC to 13.5 ᵒC. Heather (97% - 100% cover) albedo values range from 0.02 to 0.05, and temperature difference ranges from -4.0 ᵒC to 4.8 ᵒC. Tall grass (100% cover) albedo values range from 0.01 to 0.09, and temperature difference ranges from 0.3 ᵒC to 12.8 ᵒC. Short grass (100% cover) albedo values range from 0.02 to 0.1, and temperature difference values ranges from -0.7 ᵒC to 16.3 ᵒC. Whereas bare ground (with mixture of crushed gravel and stones) albedo values range from 0.08 to 0.27, and temperature difference values range from -1.6 ᵒC to 8.8 ᵒC.
In general, contrary to common perception, there is no apparent relationship between albedo and surface temperatures (i.e., higher albedo corresponding to lower canopy or surface temperatures and lower albedo corresponding to higher surface temperatures) in this study. However, for vegetation types (Blueberry and Short Grass), this relationship has been proven to be statistically significant.
Cloud cover appears to play a significant role, as higher values align with decreased albedo and increased temperature differences. Wind speed and humidity demonstrate varying impacts on temperature difference across different vegetation types.
This study, therefore, contributes valuable insights into the complex interplay of albedo, temperature difference, and environmental factors across diverse vegetation types, offering a foundation for further investigations into this climate-related phenomena.
Keywords: Surface albedo, surface temperature, temperature difference, blueberry, lichen, heather, tall and short grass, bare ground, Breisås, USN campus Bø, Central Telemark Norway. | |
