Temperature, relative humidity and cloud immersion data for Luquillo Mountains, eastern Puerto Rico, 2014-2019

Supplementary data for studies conducted in the Luquillo Experimental Forest (LEF), eastern Puerto Rico include measurements of temperature, relative humidity and cloud immersion at 30-minute resolution. Temperature and relative humidity were measured at five sites; two primary sites have records from March 2014 to June 2019; other sites have shorter records within that period. From these data, derived values of dew point, vapor pressure deficit (VPD), and evaporative fraction were calculated. Daily 13:00 temperature and VPD gradients with elevation along the windward forested slope were calculated using the 2 primary sites from from March 2014 to November 2014, then on days with data from at least 3 of the 5 sites (617, 675, 794, 904 and 1006 m), from November 2014 to June 2019. Cloud immersion frequency data are given for sites having the most complete records (675 m and 1006 m), representing the windward forested mountain slope near minimum cloud base altitude and the highest elevation in eastern Puerto Rico, respectively. Time-lapse camera images at 30-minute intervals were used to produce a binary series of cloud-immersed or clear conditions in the forest from April 2014 - November 2018. Briefly, contrast, luminance and colorfulness of daytime (color) and nighttime (grayscale) images were analyzed to determine cloud presence at the forested sites (methods in Bassiouni et al., 2017). Daily rainfall data and calculated long-term (27-year) semi-monthly mean rainfall amounts are given for Rio Icacos rain gage (USGS National Water Information System, site 50075000, 2019), for use in calculating departure from long-term mean rainfall in related publications. Also given are calculated data on the frequency of lowest-level cloud base observations below 1006 m altitude, from hourly ceilometer records at Roosevelt Roads, PR located at the coast to the east of the study area (NOAA National Centers for Environmental Information, 2020). These data are supplementary to Scholl et al., 2021. The following data are included in this data release but not supplementary to Scholl et al., 2021: Temperature and relative humidity data for leeward sites in the Luquillo Mountains, eastern Puerto Rico, 2015-2016. Air temperature and relative humidity (T/RH) sensors (Onset Computer Corp. model U23-002) were measured from June 2015 to August 2016 at 100-m elevation intervals, from approximately 600 to approximately1000 m, along a southeast-northwest trending ridge in the Luquillo Experimental Forest (LEF), eastern Puerto Rico. The prevailing wind direction is most frequently east to east-northeast and occasionally east-southeast so these locations are on the leeward side of the mountains; the data are within the timeframe and complementary to those collected at sites on the windward mountain slope. The T/RH sensors were installed with a custom-made PVC housing that had shade panels while allowing open air flow (Bassiouni et al., Fig. 2b). This housing was mounted on tree trunks 1.5-1.8 m above the ground. Air temperature and relative humidity data were downloaded every 2-3 months. Because air temperature and humidity were affected by site visits, data for one hour after downloading were excluded from the dataset. References: Bassiouni, M., Scholl, M. A., Torres-Sanchez, A. J., & Murphy, S. F. (2017). A method for quantifying cloud immersion in a tropical mountain forest using time-lapse photography. Agricultural and Forest Meteorology, 243, 100-112. doi:10.1016/j.agrformet.2017.04.010. Scholl, M.A., Bassiouni, M., and Torres-Sanchez, A.J. (2021), Drought stress and hurricane defoliation influence mountain clouds and moisture recycling in a tropical forest, Proceedings of the National Academy of Sciences, https://doi.org/10.1073/pnas.2021646118 National Centers for Environmental Information, N. (2019). Local Climatological Data, Roosevelt Roads station WBAN 11630. Retrieved February 2020 from https://www.ncdc.noaa.gov/cdo-web/datasets/LCD/stations/WBAN:11630/deta…. National Water Information System, U.S. Geological Survey, USGS 50075000 RIO ICACOS NR NAGUABO, PR, Summary of Available Data. Retrieved November 2019 from https://waterdata.usgs.gov/nwis/inventory?agency_code=USGS&site_no=5007….