In this paper the characteristics of surface radiative fluxes and cloud radiative forcing are reviewed with a focus on the Arctic. Three aspects are addressed, including (i) changes in radiation flux over the global s...In this paper the characteristics of surface radiative fluxes and cloud radiative forcing are reviewed with a focus on the Arctic. Three aspects are addressed, including (i) changes in radiation flux over the global surface; (ii) characteristics of surface fluxes in the Arctic; and (iii) characteristics of cloud radiative forcing in the Arctic. The clouds not only significantly reduce the peak summer radiative heating of the surface but also reduce the wintertime radiative cooling at the surface inhigher latitudes. The downward longwave fluxes dominates the incident radiative fluxes in the Arctic during most of the year. Incoming shortwave fluxes are negligible during late fall, winter and early spring, and even during the midsummer the incoming shortwave fluxes are only slightly greater than the downward longwave fluxes. The total net surface radiative flux is negative for most of the year and only positive during midsummer in the Arctic. The global net cloud radiative forcing is negative, but the cloud radiative forcing is positive in the Arctic, showing a warming effect, except for a short period in mid-summer. Positive cloud-radiative forcing in the Arctic is attributedto the presence of snow and ice with high albedo and the absence of solar radiation during the polar night.展开更多
Gamma radiation measurements integrated between 200 keV and 10.0 MeV were performed between 03/07/2017 and 05/24/2017 from a tower of 25 meters of altitude in the region of S^o Jos6 dos Campos, SP, Brazil. Throughout ...Gamma radiation measurements integrated between 200 keV and 10.0 MeV were performed between 03/07/2017 and 05/24/2017 from a tower of 25 meters of altitude in the region of S^o Jos6 dos Campos, SP, Brazil. Throughout this period, there were 9 intense and moderate rains with 11 arrivals of cold fronts coming from southern Brazil. Through measurements of gamma radiation integrated in the energy range mentioned above, the presence of these meteorological parameters and their variations in the region can clearly be observed. Through a potential calibration between the measured gamma radiation intensity and the observed rainfall intensity, it is possible to monitor rains by time interval using this gamma ray detector. Another very important parameter for the region consists of monitoring the number of passages of cold fronts that interfere in the local climatology. This low-cost, easy-to-operate technique can be applied and used in any tropical and equatorial region of the earth＇s surface.展开更多
文摘In this paper the characteristics of surface radiative fluxes and cloud radiative forcing are reviewed with a focus on the Arctic. Three aspects are addressed, including (i) changes in radiation flux over the global surface; (ii) characteristics of surface fluxes in the Arctic; and (iii) characteristics of cloud radiative forcing in the Arctic. The clouds not only significantly reduce the peak summer radiative heating of the surface but also reduce the wintertime radiative cooling at the surface inhigher latitudes. The downward longwave fluxes dominates the incident radiative fluxes in the Arctic during most of the year. Incoming shortwave fluxes are negligible during late fall, winter and early spring, and even during the midsummer the incoming shortwave fluxes are only slightly greater than the downward longwave fluxes. The total net surface radiative flux is negative for most of the year and only positive during midsummer in the Arctic. The global net cloud radiative forcing is negative, but the cloud radiative forcing is positive in the Arctic, showing a warming effect, except for a short period in mid-summer. Positive cloud-radiative forcing in the Arctic is attributedto the presence of snow and ice with high albedo and the absence of solar radiation during the polar night.
文摘Gamma radiation measurements integrated between 200 keV and 10.0 MeV were performed between 03/07/2017 and 05/24/2017 from a tower of 25 meters of altitude in the region of S^o Jos6 dos Campos, SP, Brazil. Throughout this period, there were 9 intense and moderate rains with 11 arrivals of cold fronts coming from southern Brazil. Through measurements of gamma radiation integrated in the energy range mentioned above, the presence of these meteorological parameters and their variations in the region can clearly be observed. Through a potential calibration between the measured gamma radiation intensity and the observed rainfall intensity, it is possible to monitor rains by time interval using this gamma ray detector. Another very important parameter for the region consists of monitoring the number of passages of cold fronts that interfere in the local climatology. This low-cost, easy-to-operate technique can be applied and used in any tropical and equatorial region of the earth＇s surface.
