Meteorology data 2024 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 accepted, 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.