Meteorology data 2025 from Villum Research Station, Greenland

File: YYYYMM_MetMast_5min.csv. This file contains the final meteorological values after quality control. Where two sensors are accepted, their measurements are averaged. Where only one sensor is ac-cepted, its measurement is used directly. If neither sensor is accepted, the output is NaN. Wind direction is calculated using a circular mean rather than an arithmetic mean. Meteorological variables Column Description Unit Tid Timestamp, UTC Date and time WD9 Wind direction at 9 m degrees WS9 Wind speed at 9 m m/s WS3 Wind speed at 3 m m/s Temp9 Air temperature at 9 m °C Temp3 Air temperature at 3 m °C RH9 Relative humidity at 9 m % RH3 Relative humidity at 3 m % SWin Incoming shortwave radiation W/m² SWout Outgoing shortwave radiation W/m² SWnetto Net shortwave radiation W/m² LWin Incoming longwave radiation W/m² LWout Outgoing longwave radiation W/m² LWnetto Net longwave radiation W/m² Albedo Surface albedo dimensionless PAR Photosynthetically active radiation µmol m⁻² s⁻¹ rad660 Radiation channel at 660 nm µmol m⁻² s⁻¹ rad730 Radiation channel at 730 nm µmol m⁻² s⁻¹ UVA UVA radiation, single sensor Original instrument unit UVB UVB radiation, single sensor Original instrument unit SnowDepth Snow-depth measurement, single sensor Original instrument unit For each parameter measured by two sensors, an additional column with the suffix _QC describes the quality and origin of the calculated value. QC codes for averaged measurements QC Meaning Interpretation 0 Two accepted sensors Mean calculated from both sensors 1 One accepted sensor Value taken from the remaining accepted sensor 2 No usable measurement Output is NaN 3 Unresolved sensor disagreement Both measurements included, but the average is uncertain Important: QC = 3 does not mean that a measurement has been rejected. It indicates that the sensors disagree sufficiently to warrant further investigation. File: YYYYMM_MetMast_Statistics.csv. This file contains one row for each duplicated meteorological parameter. The statistics are calculated using valid simultaneous measurements from the entire month. The programme uses a paired t-test, which is appropriate for comparing two instruments measuring at the same time. Column Description Parameter Meteorological parameter Npaired Number of accepted simultaneous sensor pairs MeanA Mean measurement from sensor A for accepted pairs MeanB Mean measurement from sensor B for accepted pairs MeanDifference_AminusB Mean paired difference, A minus B SDdifference Standard deviation of paired differences MedianRatio_AoverB Median ratio A/B for wind speed h Hypothesis-test result p p-value of paired t-test CI_lower Lower limit of 95% confidence interval CI_upper Upper limit of 95% confidence interval tstat Paired t-test statistic df Degrees of freedom SDpairedDifference Standard deviation reported by the paired t-test The columns SDdifference and SDpairedDifference describe the same variability for ordinary non-degenerate paired comparisons.