Instituto de Estudos Avançados (IEAv), São José dos Campos, SP, Brazil.
Instituto Nacional de Pesquisas Espaciais (INPE), São José dos Campos, SP, Brazil.
Photochem Photobiol. 2022 Sep;98(5):1245-1251. doi: 10.1111/php.13608. Epub 2022 Feb 23.
The solar radiation has been monitored through ground-based and satellite instruments all over the world for decades. This is also important for both checking and validation of satellite probing. In this work, we compare spectral irradiances at 305 nm (UV-B) and 380 nm (UV-A) from a ground-based radiometer and the Ozone monitoring instrument (OMI) for a tropical site in 2019-2020. Measurements had the auxiliary support of a ground-based imager to identify cloud cover. The presence of clouds introduces the largest differences between satellite and ground-based measurements. In fact, on average, for all-sky (AS, only cloudy skies) conditions such differences (satellite - ground-based) were 46% and 30% at 305 nm and 380 nm, respectively, while for cloud-free-sky (CFS) conditions, the differences dropped to 17% and 8%. In addition, the linear fitting between ground-based and satellite measurements yielded a coefficient of determination (r ) of 0.857 (for AS) and 0.984 (for CFS) at 305 nm and 0.774 (for AS) and 0.950 (for CFS) at 380 nm. The differences between these AS and CFS values of r were 95% statistically significant. Such results imply the hindrance clouds (and also aerosols based on the results for CFS) still set to obtain UV-B and UV-A surface irradiance from satellite probing.
几十年来，世界各地的地面仪器和卫星一直在监测太阳辐射。这对于卫星探测的检查和验证也很重要。在这项工作中，我们比较了 2019-2020 年热带地区地面辐射计和臭氧监测仪在 305nm（UV-B）和 380nm（UV-A）处的光谱辐照度。测量结果得到了地面成像仪的辅助支持，以识别云覆盖。云层的存在导致卫星和地面测量之间存在最大差异。事实上，对于全天空（AS，仅云层天空）条件，在 305nm 和 380nm 处，这些差异（卫星-地面）分别为 46%和 30%，而对于无云天空（CFS）条件，差异降至 17%和 8%。此外，地面和卫星测量之间的线性拟合在 305nm 处得到的决定系数（r）为 0.857（AS）和 0.984（CFS），在 380nm 处为 0.774（AS）和 0.950（CFS）。这些 AS 和 CFS 值 r 之间的差异具有 95%的统计学意义。这些结果意味着云层（以及基于 CFS 的气溶胶）仍然会阻碍从卫星探测中获得 UV-B 和 UV-A 地表辐照度。
