Thermal stress in the northern Carpathians and air circulation

In mountain areas, air circulation plays a major role in the forming of the climate. This paper examines how it influences thermal stress in the northern Carpathians. The Niedźwiedź’s classification of air circulation was applied. Thermal stress was assessed by Universal Thermal Climate Index (UTCI). Daily meteorological and circulation data for the period 1986–2015 were used for 20 stations in Poland, Slovakia and Ukraine. Air circulation was found to have a significant impact on thermal stress. The highest UTCI values are observed at Ca+Ka (centre of the high and anticyclonic wedge or ridge of high pressure) and the lowest values at N+NE and W+NW circulation; at the Southward stations, UTCI is higher than in the Northward ones; thermoneutral days are more frequent on the southward than on the northward slopes; during N+NE, E+SE and W+NW circulation and for heat stress days, the greatest thermal privilege of the southward slopes is observed at E+SE, S+SW, Ca+Ka and Cc+Bc (centre of low and through of low pressure) types of circulation

Data quality control and homogenization of daily precipitation and air temperature (mean, max and min) time series of Ukraine

In this paper we present the results of quality control and homogenization procedures applied to long time series of daily atmospheric precipitation sums (Rr) and daily mean (Tm), maximum (Tx) and minimum (Tn) air temperature collected in Ukraine. The daily data from 178 meteorological stations covering the period of 1946-2020 were analyzed. In order to perform a thorough quality assurance check, we used the R package INQC, while the Climatol homogenization software was used to detect and remove breaks from the time series. The INQC quality assurance tests revealed a relatively small number of erroneous records (around 0.01% for each variable) and suspicious values (up to 0.09%). The application of Climatol resulted in 195, 296, 355 and 359 break points, detected for Rr, Tm, Tx, and Tn, respectively

Evaluation of the homogenization adjustments applied to European temperature records in the Global Historical Climatology Network dataset

The widely used Global Historical Climatology Network (GHCN) monthly temperature dataset is available in two formats—non-homogenized and homogenized. Since 2011, this homogenized dataset has been updated almost daily by applying the “Pairwise Homogenization Algorithm” (PHA) to the non-homogenized datasets. Previous studies found that the PHA can perform well at correcting synthetic time series when certain artificial biases are introduced. However, its performance with real world data has been less well studied. Therefore, the homogenized GHCN datasets (Version 3 and 4) were downloaded almost daily over a 10-year period (2011–2021) yielding 3689 different updates to the datasets. The different breakpoints identified were analyzed for a set of stations from 24 European countries for which station history metadata were available. A remarkable inconsistency in the identified breakpoints (and hence adjustments applied) was revealed. Of the adjustments applied for GHCN Version 4, 64% (61% for Version 3) were identified on less than 25% of runs, while only 16% of the adjustments (21% for Version 3) were identified consistently for more than 75% of the runs. The consistency of PHA adjustments improved when the breakpoints corresponded to documented station history metadata events. However, only 19% of the breakpoints (18% for Version 3) were associated with a documented event within 1 year, and 67% (69% for Version 3) were not associated with any documented event. Therefore, while the PHA remains a useful tool in the community’s homogenization toolbox, many of the PHA adjustments applied to the homogenized GHCN dataset may have been spurious. Using station metadata to assess the reliability of PHA adjustments might potentially help to identify some of these spurious adjustments