8a7ed92b-00d9-43c4-b086-54d9251cf22a CHELSA Swiss Federal Research Institute WSL Philipp Brun Technical Staff philipp.brun@wsl.ch https://orcid.org/0000-0001-6589-6635 Swiss Federal Research Institute WSL Niklaus E. Zimmermann Group Leader niklaus.zimmermann@wsl.ch https://orcid.org/0000-0003-3099-9604 Swiss Federal Research Institute WSL | University of Bern Chantal Hari https://orcid.org/0000-0003-2507-8747 Swiss Federal Research Institute WSL | ETH Zürich Loïc Pellissier Associate Professor loic.pellissier@usys.ethz.ch https://orcid.org/0000-0002-2289-8259 Swiss Federal Research Institute WSL Dirk Nikolaus Karger Senior Researcher dirk.karger@wsl.ch https://orcid.org/0000-0001-7770-6229 SIB Swiss Institute of Bioinformatics Chiara Bortoluzzi Data Manager chiara.bortoluzzi@sib.swiss https://orcid.org/0000-0001-6589-6635 2022-12-16 English CHELSA-bioclim is a global, kilometer-scale climate dataset generated with the CHELSA downscaling model. It consists of bioclimatic variables. This is version 2.1. abiotic climate bioclim CHELSA None This data package is released to the public domain under Creative Commons Zero - No Rights Reserved (CC0 1.0) Creative Commons Zero - No Rights Reserved (CC0 1.0) https://creativecommons.org/publicdomain/zero/1.0/ S3 cloud server https://envicloud.wsl.ch/#/?bucket=https%3A%2F%2Fos.unil.cloud.switch.ch%2Fchelsa02%2F&prefix=chelsa%2Fglobal%2Fbioclim%2F Global -180 180 90 -90 1971-01-01 2100-12-31 Based on mechanistically downscaled climate data, we developed a set of climate-related variables at yet unprecedented spatiotemporal detail as a basis for environmental and ecological analyses. We created gridded data for near-surface relative humidity (hurs), cloud area fraction (clt), near-surface wind speed (sfcWind), vapour pressure deficit (vpd), surface downwelling shortwave radiation (rsds), potential evapotranspiration (pet), climate moisture index (cmi), and site water balance (swb), at a monthly temporal and 30 arcsec spatial resolution globally starting 1980 until 2018. At the same spatial resolution, we further estimated climatological normals of frost change frequency (fcf), snow cover days (scd), potential net primary productivity (npp), growing degree days (gdd), and growing season characteristics for the periods 1981-2010, 2011-2040, 2041-2070, and 2071-2100, considering three shared socioeconomic pathways (SSP126, SSP370, SSP585) and five Earth system model. Brun, P., Zimmermann, N.E., Hari, C., Pellisier, L., Karger, D.N. (2022) Global climate-related predictors at kilometre resolution for the past and future Earth System Science Data. 14, 5573–5603 https://doi.org/10.5194/essd-14-5573-2022 A multitude of physical and biological processes on which ecosystems and human societies depend are governed by the climate, and understanding how these processes are altered by climate change is central to mitigation efforts. We developed a set of climate-related variables at as yet unprecedented spatiotemporal detail as a basis for environmental and ecological analyses. We downscaled time series of near-surface relative humidity (hurs) and cloud area fraction (clt) under the consideration of orography and wind as well as near-surface wind speed (sfcWind) using the delta-change method. Combining these grids with mechanistically downscaled information on temperature, precipitation, and solar radiation, we then calculated vapor pressure deficit (vpd), surface downwelling shortwave radiation (rsds), potential evapotranspiration (pet), the climate moisture index (cmi), and site water balance (swb) at a monthly temporal and 30 arcsec spatial resolution globally from 1980 until 2018 (time-series variables). At the same spatial resolution, we further estimated climatological normals of frost change frequency (fcf), snow cover days (scd), potential net primary productivity (npp), growing degree days (gdd), and growing season characteristics for the periods 1981–2010, 2011–2040, 2041–2070, and 2071–2100, considering three shared socioeconomic pathways (SSP126, SSP370, SSP585) and five Earth system models (projected variables). Time-series variables showed high accuracy when validated against observations from meteorological stations and when compared to alternative products. Projected variables were also highly correlated with observations, although some variables showed notable biases, e.g., snow cover days. Swiss Federal Research Institute WSL Philipp Brun Technical Staff Swiss Federal Research Institute WSL Dirk Nikolaus Karger Senior Researcher bioclim COG bio01 Mean annual near-surface air temperature Mean annual temperature calculated as the average of mean monthly temperatures over the year. celsius bio02 Mean diurnal near-surface air temperature range Mean diurnal temperature range computed as the average of monthly (tasmax - tasmin) celsius bio03 Isothermality Isothermality: 100 × (bio02 ÷ bio07); compares day–night variability to annual temperature range celsius bio04 Temperature seasonality Temperature seasonality given by the standard deviation of mean monthly temperatures. Unit: °C/100 bio05 Mean daily maximum near-surface air temperature of the warmest month Highest monthly mean of daily maximum temperatures (tasmax) across the year; indicates peak thermal conditions celsius bio06 Mean daily minimum near-surface air temperature of the coldest month Lowest monthly mean of daily minimum temperatures (tasmin) across the year; characterises winter cold intensity celsius bio07 Annual daily mean near-surface air temperature range Annual temperature range calculated as bio05 - bio06; measures amplitude between warmest and coldest months celsius bio08 Mean daily mean near-surface air of the wettest quarter Average monthly mean temperature over the wettest 3-month period of the year celsius bio09 Mean daily near-surface air temperature of the driest quarter Average monthly mean temperature over the driest 3-month period of the year celsius bio10 Mean daily mean near-surface air temperature of the warmest quarter Average monthly mean temperature over the warmest 3-month period of the year celsius bio11 Mean daily mean near-surface air temperature of the quarter Average monthly mean temperature over the coldest 3-month period of the year celsius bio12 Annual precipitation Sum of monthly precipitation totals across the year kilogramPerMeterSquaredPerYear bio13 Precipitation of the wettest month Maximum monthly precipitation total. Unit: kilogramPerMeterSquaredPerMonth bio14 Precipitation of the driest month Minimum monthly precipitation total. Unit: kilogramPerMeterSquaredPerMonth bio15 Precipitation seasonality Coefficient of variation (100 x SD ÷ mean) of monthly precipitation totals kilogramPerMeterSquared bio16 Mean monthly precipitation of the wettest quarter Average monthly precipitation during the wettest 3-month period of the year. Unit: kilogramPerMeterSquaredPerMoth bio17 Mean monthly precipitation of the driest quarter Average monthly precipitation during the driest 3-month period of the year. Unit: kilogramPerMeterSquaredPerMonth bio18 Mean monthly precipitation of the warmest quarter Average monthly precipitation during the warmest 3-month period of the year. Unit: kilogramPerMeterSquaredPerMonth bio19 Mean monthly precipitation of the coldest quarter Average monthly precipitation during the coldest 3-month period of the year. Unit: kilogramPerMeterSquaredPerMonth cltmax Total cloud cover percentage maximum Total cloud area fraction (reported as a percentage) for the whole atmospheric column as seen from the surface or the top of the atmosphere. Includes both large-scale and convective cloud percent cltmean Total cloud cover percentage mean Total cloud area fraction (reported as a percentage) for the whole atmospheric column as seen from the surface or the top of the atmosphere. Includes both large-scale and convective cloud percent cltmin Total cloud cover percentage minimum Total cloud area fraction (reported as a percentage) for the whole atmospheric column as seen from the surface or the top of the atmosphere. Includes both large-scale and convective cloud percent cltrange Total cloud cover percentage range Total cloud area fraction (reported as a percentage) for the whole atmospheric column as seen from the surface or the top of the atmosphere. Includes both large-scale and convective cloud percent cmimax Monthly climate moisture index maximum Monthly ratio of precipitation to potential evapotranspiration; indicator of climatic water availability cmimean Monthly climate moisture index mean Monthly ratio of precipitation to potential evapotranspiration; indicator of climatic water availability cmimin Monthly climate moisture index minimum Monthly ratio of precipitation to potential evapotranspiration; indicator of climatic water availability cmirange Monthly climate moisture index range Monthly ratio of precipitation to potential evapotranspiration; indicator of climatic water availability fcf Frost change frequency Number of freeze-thaw transitions per year. Unit: count fgd First day of the growing season TREELIM Julian day marking the first occurrence of growing season conditions. Unit: julian day gdd0 Growing degree days heat sum above 0 °C Sum of daily mean temperature above 0 °C accumulated over the year celsius gdd10 Growing degree days heat sum above 10 °C Sum of daily mean temperature above 10 °C accumulated over the year celsius gdd5 Growing degree days heat sum above 5 °C Sum of daily mean temperature above 5 °C accumulated over the year celsius gddlgd0 Last growing degree day above 0 °C Last day of the year above 0 °C gddlgd10 Last growing degree day above 10 °C Last day of the year above 10 °C gddlgd5 Last growing degree day above 5 °C Last day of the year above 5 °C gdgfgd10 First growing degree day above 10 °C Julian day of the first occurrence of a daily mean temperature above 10 °C. Unit: julian day gdgfgd5 First growing degree day above 5 °C Julian day of the first occurrence of a daily mean temperature above 5 °C. Unit: julian day gsl Growing season length Number of days between the first and last occurrence of growing season conditions. Unit: days gsp Accumulated precipiation amount on growing season days Total precipitation accumulated during the growing season period gst Mean temperature of growing season days Average daily mean temperature over all growing season days celsius hursmax Near-surface relative humidity maximum The relative humidity with respect to liquid water for T above 0 °C and with respect to ice for T hursmean Near-surface relative humidity mean The relative humidity with respect to liquid water for T above 0 °C and with respect to ice for T hursmin Near-surface relative humidity minimum The relative humidity with respect to liquid water for T above 0 °C and with respect to ice for T hursrange Near-surface relative humidity range The relative humidity with respect to liquid water for T above 0 °C and with respect to ice for T kg0 Köppen-Geiger climate classification Köppen–Geiger climate classification, 1=Af (equatorial fully humid), 2=Am (equatorial monsoonal), 3=As (equatorial summer dry), 4=Aw (equatorial winter dry), 5=BWk (cold desert), 6=BWh (hot desert), 7=BSk (cold steppe), 8=BSh (hot steppe), 9=Cfa (warm temperate fully humid hot summer), 10=Cfb (warm temperate fully humid warm summer), 11=Cfc (warm temperate fully humid cool summer), 12=Csa (warm temperate summer dry hot summer), 13=Csb (warm temperate summer dry warm summer), 14=Csc (warm temperate summer dry cool summer), 15=Cwa (warm temperate winter dry hot summer), 16=Cwb (warm temperate winter dry warm summer), 17=Cwc (warm temperate winter dry cool summer), 18=Dfa (snow fully humid hot summer), 19=Dfb (snow fully humid warm summer), 20=Dfc (snow fully humid cool summer), 21=Dfd (snow fully humid extremely continental), 22=Dsa (snow summer dry hot summer), 23=Dsb (snow summer dry warm summer), 24=Dsc (snow summer dry cool summer), 25=Dsd (snow summer dry extremely continental), 26=Dwa (snow winter dry hot summer), 27=Dwb (snow winter dry warm summer), 28=Dwc (snow winter dry cool summer), 29=Dwd (snow winter dry extremely continental), 30=ET (polar tundra), 31=EF (polar frost). Unit: category kg1 Köppen-Geiger climate classification Köppen–Geiger climate classification without As/Aw differenciation, 1=Af (equatorial fully humid), 2=Am (equatorial monsoonal), 3=As (equatorial summer dry), 4=Aw (equatorial winter dry), 5=BWk (cold desert), 6=BWh (hot desert), 7=BSk (cold steppe), 8=BSh (hot steppe), 9=Cfa (warm temperate fully humid hot summer), 10=Cfb (warm temperate fully humid warm summer), 11=Cfc (warm temperate fully humid cool summer), 12=Csa (warm temperate summer dry hot summer), 13=Csb (warm temperate summer dry warm summer), 14=Csc (warm temperate summer dry cool summer), 15=Cwa (warm temperate winter dry hot summer), 16=Cwb (warm temperate winter dry warm summer), 17=Cwc (warm temperate winter dry cool summer), 18=Dfa (snow fully humid hot summer), 19=Dfb (snow fully humid warm summer), 20=Dfc (snow fully humid cool summer), 21=Dfd (snow fully humid extremely continental), 22=Dsa (snow summer dry hot summer), 23=Dsb (snow summer dry warm summer), 24=Dsc (snow summer dry cool summer), 25=Dsd (snow summer dry extremely continental), 26=Dwa (snow winter dry hot summer), 27=Dwb (snow winter dry warm summer), 28=Dwc (snow winter dry cool summer), 29=Dwd (snow winter dry extremely continental), 30=ET (polar tundra), 31=EF (polar frost). kg2 Köppen-Geiger climate classification Köppen–Geiger climate classificationafter Peel et al. 2007, 1=Af (equatorial fully humid), 2=Am (equatorial monsoonal), 3=As (equatorial summer dry), 4=Aw (equatorial winter dry), 5=BWk (cold desert), 6=BWh (hot desert), 7=BSk (cold steppe), 8=BSh (hot steppe), 9=Cfa (warm temperate fully humid hot summer), 10=Cfb (warm temperate fully humid warm summer), 11=Cfc (warm temperate fully humid cool summer), 12=Csa (warm temperate summer dry hot summer), 13=Csb (warm temperate summer dry warm summer), 14=Csc (warm temperate summer dry cool summer), 15=Cwa (warm temperate winter dry hot summer), 16=Cwb (warm temperate winter dry warm summer), 17=Cwc (warm temperate winter dry cool summer), 18=Dfa (snow fully humid hot summer), 19=Dfb (snow fully humid warm summer), 20=Dfc (snow fully humid cool summer), 21=Dfd (snow fully humid extremely continental), 22=Dsa (snow summer dry hot summer), 23=Dsb (snow summer dry warm summer), 24=Dsc (snow summer dry cool summer), 25=Dsd (snow summer dry extremely continental), 26=Dwa (snow winter dry hot summer), 27=Dwb (snow winter dry warm summer), 28=Dwc (snow winter dry cool summer), 29=Dwd (snow winter dry extremely continental), 30=ET (polar tundra), 31=EF (polar frost). kg3 Köppen-Geiger climate classification Climate classification after Wissmann 1939, 1=I_A (Rainforest equatorial), 2=I_F (Rainforest weak dry period), 3=I_T (Savannah and monsoonal Rainforest), 4=I_S (Steppe tropical), 5=I_D (Desert tropical), 6=II_Fa (-), 7=II_Fb (-), 8=II_Tw (-), 9=II_Ts (-), 10=II_S (-), 11=II_D (-), 12=III_F (-), 13=III_Tw (Summer green and coniferous forest winter dry), 14=III_Ts (Summer green and coniferous forest cool etesien), 15=III_S (-), 16=III_D (-), 17=IV_F (Humid boreal forest), 18=IV_T (Winter dry boreal forest), 19=IV_S (Boreal steppe), 20=IV_D (Boreal desert), 21=V (Polar tundra), 22=VI (Polar frost). kg4 Köppen-Geiger climate classification Climate classification after Thornthwaite 1931, 1=Wet/Tropical, 2=Humid/Tropical, 3=Subhumid/Tropical, 4=Semiarid/Tropical, 5=Arid/Tropical, 6=Wet/Mesothermal, 7=Humid/Mesothermal, 8=Subhumid/Mesothermal, 9=Semiarid/Mesothermal, 10=Arid/Mesothermal, 11=Wet/Microthermal, 12=Humid/Microthermal, 13=Subhumid/Microthermal, 14=Semiarid/Microthermal, 15=Arid/Microthermal, 16=Wet/Taiga, 17=Humid/Taiga, 18=Subhumid/Taiga, 19=Semiarid/Taiga, 20=Arid/Taiga, 21=Wet/Tundra, 22=Humid/Tundra, 23=Subhumid/Tundra, 24=Semiarid/Tundra, 25=Arid/Tundra, 26=Wet/Frost, 27=Humid/Frost, 28=Subhumid/Frost, 29=Semiarid/Frost, 30=Arid/Frost. kg5 Köppen-Geiger climate classification Climate classification after Troll-Pfaffen, 1=I_1 (Polar ice-deserts), 2=I_2 (Polar frost-debris belt), 3=I_3 (Tundra), 4=I_4 (Sub-polar tussock grassland and moors), 5=II_1 (Oceanic humid coniferous woods), 6=II_2 (Continental coniferous woods), 7=II_3 (Highly continental dry coniferous woods), 8=III_1 (Evergreen broad-leaved and mixed woods), 9=III_2 (Oceanic deciduous broad-leaved and mixed woods), 10=III_3 (Sub-oceanic deciduous broad-leaved and mixed woods), 11=III_4 (Sub-continental deciduous broad-leaved and mixed woods), 12=III_5 (Continental deciduous broad-leaved and mixed woods as well as wooded steppe), 13=III_6 (Highly continental deciduous broad-leaved and mixed woods as well as wooded steppe), 14=III_7 (Deciduous broad-leaved and mixed wood and wooded steppe favoured by warmth but withstanding cold and aridity in winter), 15=III_7a (Thermophile dry wood and wooded steppe which withstands moderate to hard winters), 16=III_8 (Humid deciduous broad-leaved and mixed wood which favours warmth), 17=III_9 (High grass-steppe with perennial herbs), 18=III_9a (Humid steppe with mild winters), 19=III_10 (Short grass- or dwarf shrub-), 20=III_10a (Steppe with short grass dwarf shrubs and thorns), 21=III_11 (Central and East-Asian grass and dwarf shrub steppe), 22=III_12 (Semi-desert and desert with cold winters), 23=III_12a (Semi-desert and desert with mild winters), 24=IV_1 (Sub-tropical hard-leaved and coniferous wood), 25=IV_2 (Sub-tropical grass and shrub-steppe), 26=IV_3 (Sub-tropical thorn- and succulents-steppe), 27=IV_4 (Sub-tropical steppe with short grass hard-leaved monsoon wood and wooded-steppe), 28=IV_5 (Sub-tropical semi-deserts and deserts), 29=IV_6 (Sub-tropical high-grassland), 30=IV_7 (Sub-tropical humid forests (laurel and coniferous forests)), 31=V_1 (Evergreen tropical rain forest and half deciduous transition wood), 32=V_2 (Rain-green humid forest and humid grass-savannah), 33=V_2a (Half deciduous transition wood), 34=V_3 (Rain-green dry wood and dry savannah), 35=V_4 (Tropical thorn-succulent wood and savannah), 36=V_4a (Tropical dry climates with humid months in winter), 37=V_5 (Tropical semi-deserts and deserts). Unit: category lgd Last day of the growing season TREELIM Julian day of the last occurrence of growing season conditions. Unit: julian day ngd0 Number of growing degree days above 0 °C Total number of days in a year with mean daily temperature above 0 °C. Unit: number of days ngd10 Number of growing degree days above 10 °C Total number of days in a year with mean daily temperature above 10 °C. Unit: number of days ngd5 Number of growing degree days above 5 °C Total number of days in a year with mean daily temperature above 5 °C. Unit: number of days npp Net primary production on land as carbon mass flux Production of carbon' means the production of biomass expressed as the mass of carbon which it contains. Net primary production is the excess of gross primary production (rate of synthesis of biomass from inorganic precursors) by autotrophs ('producers') for example photosynthesis in plants or phytoplankton over the rate at which the autotrophs themselves respire some of this biomass. 'Productivity' means production per unit area. The phrase 'expressed_as' is used in the construction A_expressed_as_B where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A neglecting all other chemical constituents of A petmax Monthly potential evapotranspiration maximum Total potential evapotranspiration for the month assuming unlimited water availability calculated based on Penman Monteith petmean Monthly potential evapotranspiration mean Total potential evapotranspiration for the month assuming unlimited water availability calculated based on Penman Monteith petmin Monthly potential evapotranspiration minimum Total potential evapotranspiration for the month assuming unlimited water availability calculated based on Penman Monteith petrange Monthly potential evapotranspiration range Total potential evapotranspiration for the month assuming unlimited water availability calculated based on Penman Monteith rsdsmax Surface downwelling shortwave flux in air maximum Surface solar irradiance for UV calculations rsdsmean Surface downwelling shortwave flux in air mean Surface solar irradiance for UV calculations rsdsmin Surface downwelling shortwave flux in air minimum Surface solar irradiance for UV calculations rsdsrange Surface downwelling shortwave flux in air range Surface solar irradiance for UV calculations scd Snow cover days Number of days per year with snow cover present at the surface. Unit: days sfcWindmax Near-surface wind speed maximum Near-surface (usually 10 meters) wind speed sfcWindmean Near-surface wind speed mean Near-surface (usually 10 meters) wind speed sfcWindmin Near-surface wind speed minimum Near-surface (usually 10 meters) wind speed sfcWindrange Near-surface wind speed range Near-surface (usually 10 meters) wind speed swb Soil water balance Site water balance is the cumulative amount of water available throughout the year kilogramPerMeterSquaredPerYear swe Snow water equivalent Total water equivalent of snowpack accumulated over the year kilogramPerMeterSquaredPerYear vpdmax Vapor pressure deficit maximum Difference between the saturation vapor pressure and actual vapor pressure representing atmospheric drying power pascal vpdmean Vapor pressure deficit mean Difference between the saturation vapor pressure and actual vapor pressure representing atmospheric drying power pascal vpdmin Vapor pressure deficit minimum Difference between the saturation vapor pressure and actual vapor pressure representing atmospheric drying power pascal vpdrange Vapor pressure deficit range Difference between saturation vapor pressure and actual vapore pressure representing atmospheric drying power pascal