Air temperature measurements using autonomous self-recording dataloggers in mountainous and snow covered areas

Autor: Cesar Azorin-Molina, Juan I. López-Moreno, Makki Khorchani, Esteban Alonso-González, Samuel Buisán, Alba Sanmiguel-Vallelado, Francisco Navarro-Serrano, Fernando Domínguez-Castro
Přispěvatelé: Ministerio de Economía y Competitividad (España), Ministerio de Educación, Cultura y Deporte (España)
Rok vydání: 2019
Předmět:
Zdroj: ARCIMIS. Archivo Climatológico y Meteorológico Institucional (AEMET)
Agencia Estatal de Meteorología (AEMET)
Digital.CSIC. Repositorio Institucional del CSIC
instname
ISSN: 0169-8095
DOI: 10.1016/j.atmosres.2019.03.034
Popis: High mountain areas are poorly represented by official weather observatories. It implies that new instruments must be evaluated over snow-covered and strongly insolated environments (i.e. mid-latitude mountain areas). We analyzed uncertainty sources over snow covered areas including: 1) temperature logger accuracy and bias of two widely used temperature sensors (Tinytag and iButton); 2) radiation shield performance under various radiation, snow, and wind conditions; 3) appropriate measurement height over snow covered ground; and 4) differences in air temperature measured among nearby devices over a horizontal band. The major results showed the following. 1) Tinytag performance device (mean absolute error: MAE ≈ 0.1–0.2 °C in relation to the reference thermistor) was superior to the iButton (MAE ≈ 0.7 °C), which was subject to operating errors. 2) Multi-plate radiation shield showed the best performance under all conditions (> 90% samples has bias between ±0.5 °C). The tube shield required wind (> 2.5 m s −1 ) for adequate performance, while the funnel shield required limited radiation (< 400 W m −2 ). Snow cover causes certain overheating. 3) Air temperatures were found to stabilize at 75–100 cm above the snow surface. Air temperature profile was more constant at night, showing a considerable cooling on near surface at midday. 4) Horizontal air temperature differences were larger at midday (0.5 °C). These findings indicate that to minimize errors air temperature measurements over snow surfaces should be carried out using multi-plate radiation shields with high-end thermistors such as Tinytags, and be made at a minimum height above the snow covered ground. © 2019 Elsevier B.V.
This study was funded by the research projects “ El papel de la nieve en la hidrología de la peninsula ibérica y su respuesta a procesos de cambio global-HIDROIBERNIEVE-CGL2017-82216-R ” and CLIMPY “ Characterization of the evolution of climate and provision of information for adaptation in the Pyrenees ” (FEDER-POCTEFA). We thank the Spanish Meteorological Agency (AEMET) and observers Y. Jimenez and S. Campo for the permissions to use official observatories and for the meteorological data used in this study. Navarro-Serrano, F. and Sanmiguel-Vallelado, A. are granted with a pre-doctoral FPU grant (Spanish Ministry of Education, Culture and Sports). Alonso-González, E. and Khorchani, M. are granted with a pre-doctoral FPI grant (Spanish Ministry of Economy and Competitiveness). The authors thank all colleagues who helped in the development of the experiments. Raw data is freely downloadable at https://zenodo.org/record/1495572 . The authors wish to acknowledge anonymous reviewers for their detailed and helpful comments to the original manuscript.
Databáze: OpenAIRE
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