This database offers highly valuable climate information for the Sierra Nevada (SN) mountain range, identified as a double climate-change hotspot since it constitutes a semi-arid mountain system within the Mediterranean, a region especially vulnerable to climate change. Moreover, SN is an area where high-quality climate data are particularly scarce, largely due to its difficult accessibility. Present climate data (1991–2022) at very high spatial resolution (1 km) for Sierra Nevada (SN), the highest mountain range in the Iberian Peninsula (IP), located in southeastern Andalusia (Spain). The data were generated using version 4.3.3 of the Weather Research and Forecasting (WRF) model (Skamarock et al., 2021), driven by ERA5 reanalysis data (Hersbach et al., 2018). The planetary boundary layer (PBL) scheme used was the Asymmetric Convective Model version 2 (ACM2; Pleim, 2007). Both longwave and shortwave radiation were parameterized using the Community Atmosphere Model version 3.0 (CAM3.0; Collins et al., 2004). The microphysics scheme applied was the WRF Single-Moment 7-class scheme (WSM7; Bae et al., 2019), and the land surface model used was NOAH-MP (Niu et al., 2011). Convection was explicitly resolved (i.e., no cumulus parameterization was used). The dataset is organized into four categories: Primary Climate Variables (72 files): Daily values of relative humidity, net radiation, accumulated precipitation, surface pressure, maximum temperature, minimum temperature, mean temperature, and wind speed; and hourly values of accumulated precipitation and mean temperature for the entire period. Hourly Precipitation Extremes (3 files): Frequency and intensity (Fwet and Iwet respectively) of wet hours (precipitation > 0.1 mm/hour) and the maximum hourly precipitation during the wettest month. ETCCDI Extreme Indices (12 files): Annual values of selected indices from the Expert Team on Climate Change Detection and Indices (ETCCDI), including: Consecutive Dry Days (CDD), Daily Temperature Range (DTR), Growing Season Length (GSL), Icing Days (ID), Number of Wet Days (R1mm), Heavy Precipitation Days (R10mm), Very Heavy Precipitation Days (R20mm), Wettest Pentad (Rx5day), Simple Daily Intensity Index (SDII), Frost Days (TNltm2), Coldest Night (TNn), and Warmest Day (TXx). Bioclimatic Variables (18 files): Annual and seasonal mean temperature (BIO1 and BIO1*), annual mean maximum temperature (BIOmax and BIO1max*), annual mean minimum temperature (BIOmin and BIO1min*), isothermality (BIO3), temperature seasonality (BIO4), maximum temperature of the warmest month (BIO5), minimum temperature of the coldest month (BIO6), annual temperature range (BIO7), mean temperature of the wettest quarter (BIO8), mean temperature of the driest quarter (BIO9), annual precipitation (BIO12), seasonal mean precipitation (BIO12*), precipitation of the wettest month (BIO13), precipitation seasonality (BIO15), and precipitation of the coldest quarter (BIO19). For more detailed information on the variables, see García-Valdecasas Ojeda et al. (2025). This version has data updated to 2022 in the evaluation period and, as a new feature, adds hourly resolution climate information on temperature and precipitation, as well as new derived variables such as various ETCCDI indices or climate variables that are essential for characterizing the mountain climate in this region.

This database offers highly valuable climate information for the Sierra Nevada (SN) mountain range, identified as a double climate-change hotspot since it constitutes a semi-arid mountain system within the Mediterranean, a region especially vulnerable to climate change. Moreover, SN is an area where high-quality climate data are particularly scarce, largely due to its difficult accessibility. Pseudo-projected climate data (1991-2020 + climate change signal of a set of 24 CMIP6 GCMs for the period 2070-2099 under the SSP5-8.5) at very-high spatial resolution (1 km) for Sierra Nevada, the highest mountain region in the Iberian Peninsula (IP) located in southeastern Andalusia (Spain). Data obtained using the Weather Research & Forecasting (WRF) model v4.3.3 (Skamarock et al., 2021) driven by the ERA5 reanalysis (Hersbach et al., 2018) + climate change signal of a set of 24 CMIP6 GCMs for the period 2070-2099 under the SSP5-8.5. The planetary boundary layer (PBL) scheme used was the Asymmetric Convective Model version 2 (ACM2; Pleim, 2007). Both longwave and shortwave radiation were parameterized using the Community Atmosphere Model version 3.0 (CAM3.0; Collins et al., 2004). The microphysics scheme applied was the WRF Single-Moment 7-class scheme (WSM7; Bae et al., 2019), and the land surface model used was NOAH-MP (Niu et al., 2011). Convection was explicitly resolved (i.e., no cumulus parameterization was used). The dataset is organized into four categories: Primary Climate Variables (68 files): Daily values of relative humidity, net radiation, accumulated precipitation, surface pressure, maximum temperature, minimum temperature, mean temperature, and wind speed; and hourly values of accumulated precipitation and mean temperature for the entire period. Hourly Precipitation Extremes (3 files): Frequency and intensity (Fwet and Iwet respectively) of wet hours (precipitation > 0.1 mm/hour) and the maximum hourly precipitation during the wettest month. ETCCDI Extreme Indices (12 files): Annual values of selected indices from the Expert Team on Climate Change Detection and Indices (ETCCDI), including: Consecutive Dry Days (CDD), Daily Temperature Range (DTR), Growing Season Length (GSL), Icing Days (ID), Number of Wet Days (R1mm), Heavy Precipitation Days (R10mm), Very Heavy Precipitation Days (R20mm), Wettest Pentad (Rx5day), Simple Daily Intensity Index (SDII), Frost Days (TNltm2), Coldest Night (TNn), and Warmest Day (TXx). Bioclimatic Variables (18 files): Annual and seasonal mean temperature (BIO1 and BIO1*), annual mean maximum temperature (BIOmax and BIO1max*), annual mean minimum temperature (BIOmin and BIO1min*), isothermality (BIO3), temperature seasonality (BIO4), maximum temperature of the warmest month (BIO5), minimum temperature of the coldest month (BIO6), annual temperature range (BIO7), mean temperature of the wettest quarter (BIO8), mean temperature of the driest quarter (BIO9), annual precipitation (BIO12), seasonal mean precipitation (BIO12*), precipitation of the wettest month (BIO13), precipitation seasonality (BIO15), and precipitation of the coldest quarter (BIO19). This version has data updated to 2022 in the evaluation period and, as a new feature, adds hourly resolution climate information on temperature and precipitation, as well as new derived variables such as various ETCCDI indices or climate variables that are essential for characterizing the mountain climate in this region.

Climate data at very-high resolution (1 km spatial resolution) for Sierra Nevada, the highest mountain region in the Iberian Peninsula located in southeastern Andalusia (Spain). Data obtained using the Weather Research & Forecasting (WRF) model v4.3.3 (Skamarock et al., 2021) driven by ERA5 (Hersbach et al., 2018) plus a global warming signal calculated for the period 2070-2099 compared to 1985-2014 from an ensemble of 24 GCMs from CMIP6 under the SSP5-8.5 scenario. PBL was fixed to the Asymmetric Convective Model version 2 (ACM2, Pleim, 2007). Both long- and short-wave radiation were parametrized using the Community Atmosphere Model 3.0 (CAM3.0, Collins et al., 2004). The microphysics scheme used was WRF single-moment 6-class (WSM6, Hong and Lim 2006), and the land surface model the NOAH MP (Niu et al., 2011). The convection scheme was deactivated. A new version is available which has data updated to 2022 in the evaluation period and, as a new feature, adds hourly resolution climate information on temperature and precipitation, as well as new derived variables such as various ETCCDI indices or climate variables that are essential for characterizing the mountain climate in this region.

Climate data at very-high resolution (1 km spatial resolution) for Sierra Nevada, the highest mountain region in the Iberian Peninsula located in southeastern Andalusia (Spain). Data obtained using the Weather Research & Forecasting (WRF) model v4.3.3 (Skamarock et al., 2021) driven by the ERA5 reanalysis (Hersbach et al., 2018). The PBL was fixed to the Asymmetric Convective Model version 2 (ACM2, Pleim, 2007). Both, long- and short-wave radiation were parametrized using the Community Atmosphere Model 3.0 (CAM3.0, Collins et al., 2004). The microphysics scheme was the WRF single-moment 7-class (WSM7, Bae et al., 2019), and the land surface model the NOAH MP (Niu et al., 2011). The convection scheme was deactivated. A new version is available which has data updated to 2022 in the evaluation period and, as a new feature, adds hourly resolution climate information on temperature and precipitation, as well as new derived variables such as various ETCCDI indices or climate variables that are essential for characterizing the mountain climate in this region.

The geographical distribution of the EARLINET stations is particularly suitable for dust observation, with stations located all around the Mediterranean (from the Iberian Peninsula in the West to the Greece and Bulgaria and Romania in the East) and in the center of the Mediterranean (Italian stations) where dust intrusions are frequent, and with several stations in the central Europe where dust penetrates occasionally. A suitable observing methodology has been established within the network, based on Saharan dust alerts distributed to all EARLINET stations. The dust alert is based on the operational outputs (aerosol dust load) of the DREAM (Dust REgional Atmospheric Model), and the Skiron models. The alerts are diffused 24 to 36 hours prior to the arrival of dust aerosols over the EARLINET sites. Runs of measurements longer than 3-hour observations, typical for the EARLINET climatological measurements are performed at the EARLINET stations in order to investigate the temporal evolution of the dust events. All aerosol backscatter and extinction profiles related to observations of Saharan dust layers are collected in the "Saharan dust" category of the EARLINET database.

Since the beginning of CALIPSO observations in June 2006 EARLINET has performed correlative measurements during nearby overpasses of the satellite at individual stations following a dedicated observational strategy. The EARLINET-CALIPSO correlative measurement plan considers the criteria established in the CALIPSO validation plan (http://calipsovalidation.hamptonu.edu). Participating EARLINET stations perform measurements, as close in time as possible and for a period of at least 30 min up to several hours, when CALIPSO overpasses their location within a horizontal radius of 100 km. Within the 16-day observational cycle of CALIPSO each station is overpassed within this distance 1-2 times during daytime (typically between 1100 and 1400 UTC) and 1-2 times during night time (typically between 0000 and 0300 UTC). Additional measurements are performed, mainly on a non-regular basis, when CALIPSO overpasses a neighboring station in order to study the horizontal variability of the aerosol distribution. The time schedule for correlative observations is calculated starting from the high-resolution ground-track data provided by NASA, and is updated and distributed to whole network weekly. The EARLINET-CALIPSO correlative dataset represents a statistically significant data set to be used for the validation and full exploitation of the CALIPSO mission, for studying the representativeness of cross sections along an orbit against network observations on a continental scale, and for supporting the continuous, harmonized observation of aerosol and clouds with remote-sensing techniques from space over long time periods.

This collection contains all measurements that have been performed in the frame of the EARLINET project during the period April 2000 - December 2010. Some of these measurements are also part of the collections 'Calipso', 'Climatology', 'SaharanDust' or 'VolcanicEruption'. In addition this collection also contains measurements from the categories 'Cirrus', 'DiurnalCycles', 'ForrestFires', 'Photosmog', 'RuralUrban', and 'Stratosphere'. This collection also contains measurements not devoted to any of the above categories. More information about these categories and the contributing stations can be found in the file 'EARLINET_general_introduction.pdf' accompanying this dataset.

EARLINET climatological lidar observations are performed on a regular schedule of one daytime measurement per week around noon (on Monday), when the boundary layer is usually well developed, and two night-time measurements per week (on Monday and Thursday), with low background light, in order to perform Raman extinction measurements. This regular schedule for observations minimizes the bias in the dataset possibly related to specific measurement conditions. The resulting dataset is used to obtain unbiased data for climatological studies. This dataset contains profiles of aerosol extinction, backscatter and lidar ratio. Several aerosol extinction/backscatter datasets can be present for the same climatological measurement in order to provide profiles either with a better temporal resolution or with an extended height range by using a larger temporal average. This is by far the largest dataset on the aerosol vertical distribution, and it is the only one which is collected systematically and is covering a whole continent.

Aerosols originating from volcanic emissions have an impact on the climate: sulfate and ash particles from volcanic emissions reflect solar radiation, act as cloud condensation and ice nuclei, and modify the radiative properties and lifetime of clouds, and therefore influence the precipitation cycle. These volcanic particles can also have an impact on environmental conditions and could be very dangerous for aircraft in flight. In addition to the routine measurements, further EARLINET observations are devoted to monitor volcano eruptions. The EARLINET volcanic dataset includes extended observations related to two different volcanoes in Europe Mt. Etna (2001 and 2002 eruptions), and the Eyjafjallajökull volcano in Iceland (April - May 2010 eruption). This dataset includes also recent events of volcanic eruptions in the North Pacific region (2008-2010) that emitted sulfuric acid droplets into the upper troposphere - lower stratosphere (UTLS) height region of the northern hemisphere. The EARLINET volcanic observations in the UTLS are complemented by the long-term stratospheric aerosol observations collected in the Stratosphere category.

The geographical distribution of the EARLINET stations is particularlysuitable for dust observation, with stations located all around the Mediterranean(from the Iberian Peninsula in the West to the Greece and Bulgaria and Romania in the East) and in the center of the Mediterranean (Italian stations) where dust intrusions are frequent, and with several stations in the central Europe where dust penetrates occasionally. A suitable observing methodology has been established within the network, based on Saharan dust alerts distributed to all EARLINET stations. The dust alert is based on the operational outputs (aerosol dust load) of the SDS-WAS (Sand and Dust Storm- Warning and Advisory System of WMO), and the Skiron models. The alerts are diffused 24 to 36 hours prior to the arrival of dust aerosols over the EARLINET sites. Runs of measurements longer than 3-hour observations, typical for the EARLINET climatological measurements are performed at the EARLINET stations in order to investigate the temporal evolution of the dust events. All aerosol backscatter and extinction profiles related to observations of Saharan dust layers are collected in the "Saharan dust" category of the EARLINET database.