Validation of the medium-range and sub-seasonal forecast of solar irradiance and wind speed using ECMWF

Abstract

Medium-range and sub-seasonal forecasts of solar irradiation and 10-m wind speed are commonly assessed with an ensemble forecast over the Indo-China region. In this paper, we forecast data of surface solar irradiance and 10-m wind using ensembles of forecasts from the European Centre for Medium-Range Weather Forecasts operational ensemble (ECMWF; EC-ENS) with a 6-h time-step. We compare our forecasts with observations derived from the China Meteorological Agency (CMA) as gridded observations over the Indo-China region. The assessment is carried out on both mid-range and sub-seasonal forecasts over Indo-China domain wise, using several metrics to assess different attributes of forecast quality. The results show that the errors of the forecasts depends on the choice of the climate variable, the period of the year. The major source of energy on Earth is solar irradiation and wind, and the amount of solar irradiation and wind hitting the Earth's surface is impacted by the atmosphere. Solar irradiation also plays an important role in global temperature, and even minor variations in the sun's energy output create significant changes in the earth's climate. All data cover a period from June 2021 to May 2022 in hourly and six-hourly total scales for CMA and EC-ENS. The validation demonstrates that the mean absolute error, root mean square error, and mean bias error amongst datasets are all different. Furthermore, the spatially continuous hourly predictions accurately capture regional variations and reconstruct the diurnal cycles of solar irradiation and wind on fine scales. Such accurate knowledge is useful for the prediction of site selection for solar and wind power plants and research on regional climate changes.