This article aims to analyse the influence of weather types on meteorological
conditions in Petuniabukta (Svalbard) during July and August of 2016. The paper analyses
the daily courses of air temperature and humidity at four measurement points located on
the west bank of Petuniabukta near Adam Mickiewicz University Polar Station during
two different types of weather conditions: (i) cloudy and windy, (ii) calm and clear.
These weather types, distinguished on the basis of wind speed and cloudiness, allowed
for the creation of composite maps of the synoptic situation (SLP and geopotential
height of 500 hPa distribution) and its anomalies. In the study area, the air temperature
range in windy and cloudy weather conditions was larger (-10°C to 15°C) than that in
sunny and calm weather (0°C to 15°C), which contrasts the range of humidity values.
The diurnal cycle of meteorological elements in sunny and calm days is strongly related
to the sun elevation angle. In the above-mentioned weather types, the air temperature
was higher by several degrees (median 5°C to 8°C) than on windy and cloudy days
(median about 0°C to 6°C) at each measurement point. On days with sunny and calm
weather, a smaller vertical temperature gradient of air is observed (for sunny and calm
days 0.63°C and for windy weather 0.8°C).
This paper constitutes the sensitivity study of application the Polar WRF
model to the Svalbard area with testing selected parameterizations, including planetary
boundary layer, radiation and microphysics schemes. The model was configured, using
three one-way nested domains with 27 km, 9 km and 3 km grid cell resolutions. Results
from the innermost domain were presented and compared against measured wind speed
and air temperature at 10 meteorological stations. The study period covers two months:
June 2008 and January 2009. Significant differences between simulations results occurred
for planetary boundary layer (PBL) schemes in January 2009. The Mellor-Yamada-Janjic
(MYJ) planetary boundary layer (PBL) scheme resulted in the lowest errors for air
temperature, according to mean error (ME), mean absolute error (MAE) and correlation
coefficient values, where for wind speed this scheme was the worst from all the PBL
schemes tested. In the case of June 2008, shortwave and longwave radiation schemes
influenced the results the most. Generally, higher correlations were obtained for January,
both for air temperature and wind speed. However, the model performs better for June
in terms of ME and MAE error statistics. The results were also analyzed spatially, to
summarize the uncertainty of the model results related to the analyzed parameterization
schemes groups. Significant variability among simulations was calculated for January
2009 over the northern part of Spitsbergen and fjords for the PBL schemes. Standard
deviations for monthly average simulated values were up to 3.5°C for air temperature
and around 1 m s-1 for wind speed.