<|begin_of_text|><|start_header_id|>system<|end_header_id|>

You are an expert at identifying data availability statements in scientific text. A data availability statement describes where research data can be found or how it can be accessed.<|eot_id|><|start_header_id|>user<|end_header_id|>

Determine if the following text contains a data availability statement. Answer with 'yes' or 'no'.

Text: Source for the observed NAO index: Hurrell, James & National Center for Atmospheric Research Staff 364 (Eds). Last modified 20 Oct 2015. "The Climate Data Guide: Hurrell North Atlantic Oscillation (NAO) 365 Index (station-based)." Retrieved from https://climatedataguide.ucar.edu/climate-data/hurrellnorth-atlantic-oscillation-nao-index-station-based. ECMWF-interim reanalysis data27 366 downloaded 367 from http://apps.ecmwf.int/datasets/data/interim_full_moda/. Observed sea ice extent obtained 368 from the National Snow and Ice Data Center (http://nsidc.org/data).<|eot_id|><|start_header_id|>assistant<|end_header_id|>

yes<|eot_id|>