北极地区夏季太阳辐照度变化研究

Variation of Irradiance in the Arctic Pole during the Summer

辐照度变化影响着北极冰雪的消融速率,是全球气候变化研究的一个重要组成部分。基于2010年中国第4次北极科学考察光谱测量数据,通过对比、主成分变换等分析了北极地区夏季辐照度的变化,并探讨了其变化原因。太阳辐照度的变化与多种因素有关,最直接的影响因素是天气以及太阳高度;在北极高纬度地区,太阳高度角极低,太阳辐射能量受到的大气衰减作用明显,研究表明,较短波长的光谱对太阳高度变化更敏感,而天气对辐照度的影响随着波长的增大而增大。此外,大气中水分含量也影响着到达地面的太阳辐射,水分影响主要表现在特定的波段而不是整个光谱区间内。

The variation of irradiance affect the melting rate of the sea ice in the arctic pole,and the research on it is an important component of the global climate change research. The present research was based on the spectrum data collected during the 4th scientific research on the arctic of China in 2010, analyzed the variation of irradiance in the arctic pole during the summer and dis- cussed the reasons for the change. This research shows that many factors lead to the change, among which the weather and the solar elevation angle affect the irradiance directly. The weather factors determine the amount of solar radiation that reached the ground after the absorption and attenuation of the clouds; In high-latitude areas, there is a low solar elevation angle and the attenuation of solar radiation was obvious. Our research shows that the spectrum at shorter wavelength is more sensitive to the changes in altitude of the sun, while the impact of weather on the irradiance increases with wavelength. Moreover, moisture con- tent in the atmosphere also affects the solar radiation reaching the ground and the its impact is in a particular band but not for the entire spectrum range.