Home > Guidance > Journal of the Aerological Observatory > Vol.71
| Title | Author | |
|---|---|---|
| Foreword | in Japanese | Masanori SHITAMICHI |
| Calculation of Wind Vectors using Radial Doppler Velocities of Doppler LIDAR | in Japanese | Shunsuke HOSHINO and Masami IWABUCHI |
| Calibration of Instrumental Responsivity for the Grating Spectroradiometer (MS-710) and Observation of the Spectral Solar Radiation at Tsukuba | in Japanese | Osamu IJIMA and Tetsuya SHIMAMURA |
| Absolute Calibration of PFR by the Langley method at Mt. Tsukuba | in Japanese | Tetsuya SHIMAMURA and Osamu IJIMA |
| Transmission Characteristics for the Optical Wedge of Dobson Spectrophotometer | in Japanese | Yuji ESAKI and Noriaki OSHIKI |
| Correction Method of the Total Ozone Data with the Contaminated Optical Wedge of Dobson Ozone Spectrophotometer | in Japanese | Noriaki OSHIKI and Yuji ESAKI |
| Display Program of UVB Observation and Reference spectrum | in Japanese | Yoshiyuki NOTO |
| Development of the Recalculation Program for O3 Values by the Zenith Sky Observation Using Brewer Spectrophotometer | in Japanese | Itaru UESATO |
| Seasonal Variations of Global, Reflected, and Diffuse Spectral UV Observations based on Brewer Spectrophotometers at Tsukuba, 2004 to 2012 | [Abstract] | Mahito ITO, Osamu IJIMA, Tetsuya SHIMAMURA, Itaru UESATO,Yoshiyuki NOTO, Yuji ESAKI and Noriaki OSHIKI |
| Addendum to volume 70, List of participants to GRUAN ICM-4 site visit in Tateno | in Japanese | Kazumasa MORI |
Since December 2003, monitoring observations of spectral ultraviolet (UV) radiation reflected from the ground surface (RFuv) have been carried out at the Aerological Observatory in Tsukuba with a modified Brewer spectrophotometer, BR#059. Similar monitoring of diffuse spectral UV (DFuv) from the sky has been carried out with a Brewer spectrophotometer, BR#058, with an automated shadow unit, since August 2005 (Ito: 2004, 2006, 2007). In this paper, the results of these measurements are compared with global spectral UV (GLuv) and solar radiation data, GLsolar, DFsolar, and RFsolar, from 2004 to 2012. The results are summarized below.
(1) The monthly means of daily totals of GLuv, DFuv, and RFuv showed seasonal patterns different from GLsolar, DFsolar, and RFsolar, respectively. (2) The annual means of the daily total of DFuv have been increasing by small amounts from year to year since 2006, in contrast to the almost constant DFsolar. (3) The annual and monthly means of the daily total of RFuv are affected by UV absorption by vegetation and reflection from snow, but vegetation and snow had little effect on the means of RFsolar. (4) The monthly mean of daily UV diffusibility, RDFuv (DFuv/GLuv), averaged about 0.84 (84%) and was almost constant throughout the year, but the diffusibility of solar radiation, RDFsolar (DFsolar/GLsolar), averaged about 0.61 (61%)and showed seasonal variations. (5) The annual means of monthly means of daily UV reflectivity, RRFuv (RFuv/GLuv), averaged only about 0.02 (2%), compared to the average of about 0.21 (21%) for daily solar reflectivity, RRFsolar (RFsolar/GLsolar). The spectrum of RRFuv exhibited a small linear wavelength dependence, with higher reflectivity at longer wavelengths. (6) The contributions (percentages) of the daily totals of direct UV radiation, DRuv (GLuv?DFuv), DFuv, and RFuv relative to the daily total of GLuv, averaged about 20%, 80%, and 2%, respectively. In contrast, their contributions to the daily totals of DRsolar, DFsolar, and RFsolar relative to the daily total of GLsolar were different and averaged about 50%, 50%, and 20%, respectively.
The differences between the seasonality of the components of UV radiation, GLuv, DFuv, and RFuv, and the components of solar radiation, GLsolar, DFsolar, and RFsolar, were elucidated. Continuous observations with Brewer spectrophotometers are very important for, inter alia, ground truth calibration of satellite observations, clarification of aerosol distributions, and studies of vegetation growth.