Unlocking pre-1850 instrumental meteorological records

A global inventory of early instrumental meteorological measurements is compiled that comprises thousands of mostly nondigitized series, pointing to the potential or weather data rescu

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

Climate of the Carpathian Region in the period 1961–2010: climatologies and trends of 10 variables

The Carpathians are the largest mountain range in Europe and they represent a geographic barrier between Central Europe, Eastern Europe, and the Balkans. In order to investigate the climate of the area, the CARPATCLIM project members compiled the Climate Atlas of the Carpathian Region, which consists of high-resolution daily grids (0.1˚ x 0.1˚) of sixteen meteorological variables and many derived indicators related to 1961-2010. We computed the gridded climatologies for 1961-2010 for eight variables (air pressure, cloudiness, precipitation, relative humidity, minimum and maximum temperature, sunshine duration, and wind speed) and we discuss their spatial patterns. For each variable, we calculated the gridded linear trends related to 1961-2010 both on annual and seasonal basis. In general, temperature was found to increase in every season in 1986-2010, confirming the trends occurring in Europe in the last decades. On the other way, wind speed decreased in every season. Cloudiness and relative humidity decreased in spring, summer, and winter, and increased in autumn, whilst sunshine duration, as expected, behaved in the opposite way. Precipitation slightly increased and air pressure showed no significant trend, except of a few grid points. Then, we dealt with the correlation between the variables: excluding the high elevation points, the most correlated are sunshine duration and temperature. In particular, positive and negative sunshine duration anomalies are found to be respectively correlated with positive and negative temperature anomalies during the global dimming (60’s and 70’s) and brightening (90’s and 2000’s) periods.JRC.H.7-Climate Risk Managemen

Instrumental Meteorological Records before 1850: An Inventory

A global inventory of early instrumental meteorological measurements is compiled that comprises thousands of mostly nondigitized series, pointing to the potential of weather data rescue