A Comparative Analysis of Radiation at Offshore and Inland Stations in Maoming

ZHAN Guowei; HUANG Huijun; ZHOU Mingsen; MAI Zongjian; LI Ziping; TAN Lunchan; ZHU Maobin

doi:10.16032/j.issn.1004-4965.2025.063

Abstract：Based on the radiation observations and the basic meteorological elements from the Dianbai National Climate Reference Station(Dianbai station)and the Integrated Observation Platform for Marine Meteorology of the Marine Meteorological Science Experiment Base(MMSEB)at Bohe(offshore platform)of China Meteorological Administration(CMA)in 2019,this study comparatively analyzes the annual average monthly variation,daily variation,and monthly average daily variation of radiation at two stations.The relationships between radiation and other meteorological elements are also analyzed.The main conclusions are as follows.(1)The monthly average maximum values for each radiation components at the two sites generally occur in summer and autumn(with the exception of upward shortwave radiation at the offshore platform,which peaks in December),while the minimum values occur in winter and spring.Due to differences in the underlying surface,the monthly average upward short-wave radiation at Dianbai station is significantly higher than that at the offshore platform,resulting in a notably lower annual net radiation of 103.8 W·m-2 at Dianbai station compared to 145.8 W·m-2 at the offshore platform.(2)The comparison of the daily variation of net radiation at the two stations reveals significant differences between the land and sea.During the daytime,the net radiation at the offshore platform is,on average,35.8%higher than that at Dianbai station,with an average value of 92.5 W·m-2.At nighttime,the net radiation at the offshore platform is,on average,33.1%lower than that at Dianbai station,with an average value of-7.34 W·m-2.(3)The downward shortwave radiation of offshore platforms is greater than that at Dianbai station,with its peak-values concentrated around noon from June to November.The upward short-wave radiation at Dianbai station is obviously higher than that at offshore platform,with the largest differences between the two stations occurring between summer and winter.The short-wave albedo at Dianbai station is generally higher than that at the offshore platform station,and both stations exhibit a high value area in the evening from September to January,while the offshore platform also shows a secondary peak in the morning.(4)The spatial distribution of the upward long-wave radiation at Dianbai station during the daytime are similar to the downward short-wave radiation.In contrast,the upward long-wave radiation at offshore platform reflects the seasonal characteristics of the overall sea temperature.The downward long-wave radiation at Dianbai station is generally greater than that at the offshore platform in the daytime,but smaller in the rest of the time,especially in winter.