scholarly journals Synoptic ozone, cloud reflectivity, and erythemal irradiance from sunrise to sunset for the whole earth as viewed by the DSCOVR spacecraft from the earth–sun Lagrange 1 orbit

2018 ◽  
Vol 11 (1) ◽  
pp. 177-194 ◽  
Author(s):  
Jay Herman ◽  
Liang Huang ◽  
Richard McPeters ◽  
Jerry Ziemke ◽  
Alexander Cede ◽  
...  

Abstract. EPIC (Earth Polychromatic Imaging Camera) on board the DSCOVR (Deep Space Climate Observatory) spacecraft is the first earth science instrument located near the earth–sun gravitational plus centrifugal force balance point, Lagrange 1. EPIC measures earth-reflected radiances in 10 wavelength channels ranging from 317.5 to 779.5 nm. Of these channels, four are in the UV range 317.5, 325, 340, and 388 nm, which are used to retrieve O3, 388 nm scene reflectivity (LER: Lambert equivalent reflectivity), SO2, and aerosol properties. These new synoptic quantities are retrieved for the entire sunlit globe from sunrise to sunset multiple times per day as the earth rotates in EPIC's field of view. Retrieved ozone amounts agree with ground-based measurements and satellite data to within 3 %. The ozone amounts and LER are combined to derive the erythemal irradiance for the earth's entire sunlit surface at a nadir resolution of 18 × 18 km2 using a computationally efficient approximation to a radiative transfer calculation of irradiance. The results show very high summertime values of the UV index (UVI) in the Andes and Himalayas (greater than 18), and high values of UVI near the Equator at equinox.

2017 ◽  
Author(s):  
Jay Herman ◽  
Liang Huang ◽  
Richard McPeters ◽  
Jerry Ziemke ◽  
Alexander Cede ◽  
...  

Abstract. The EPIC instrument onboard the DSCOVR spacecraft, located near the Earth-Sun gravitational plus centrifugal force balance point, Lagrange-1, measures Earth reflected radiances in 10 wavelength channels ranging from 317.5 nm to 779.5 nm. Of these channels, four are in the UV range 317.5, 325, 340, and 388 nm, which are used to retrieve O3, 388 nm scene reflectivity (LER Lambert Equivalent Reflectivity), SO2, and aerosol properties. These quantities are derived synoptically for the entire sunlit globe from sunrise to sunset every 68 minutes or 110 minutes for summer or winter at the receiving antenna in Wallops Island, Virginia, respectively. Depending on solar zenith angle, either 317.5 or 325 nm channels are combined with 340 and 388 nm to derive ozone amounts. As part of the ozone algorithm, the 388 nm channel is used to derive LER. The retrieved ozone amounts and LER are combined to derive the erythemal irradiance for the sunlit Earth's surface at a resolution of 18 × 18 km2 near the center of the Earth's disk using a computationally efficient approximation to a radiative transfer calculation of irradiance. Corrections are made for altitude above sea level and for the reduced transmission by clouds based on retrieved LER.


2021 ◽  
Vol 33 ◽  
pp. 31-39
Author(s):  
Rolf Werner ◽  
Veneta Guineva ◽  
Atanas Atanassov ◽  
Dimitar Valev ◽  
Dimitar Danov ◽  
...  

The UV-index (UVI) is a measure of the erythemally effective solar radiation reaching the Earth surface and it was introduced to alert people about the need of Sun protection. The present study applies a model that estimates the UVI over the high Bulgarian mountains for clear sky conditions considering the Total Ozone Content (TOC), which was taken from satellite measurements. The results show that during the periods from May to August at altitudes above 2 000 m a.s.l. very high UVI's (greater than 8) were observed for more than 18 days per month. The UVI values were very high practically for every day of July at altitudes higher than 1 500 m. Extremely high UVI result from episodes with TOC lower than 290 DU during June and July at the highest mountain parts with elevations greater than 2 500 m. High radiation risks were observed during April, especially when the preceding polar vortex was strong and the mountains were snow covered.


Radiocarbon ◽  
2001 ◽  
Vol 43 (2B) ◽  
pp. 731-742 ◽  
Author(s):  
D Lal ◽  
A J T Jull

Nuclear interactions of cosmic rays produce a number of stable and radioactive isotopes on the earth (Lai and Peters 1967). Two of these, 14C and 10Be, find applications as tracers in a wide variety of earth science problems by virtue of their special combination of attributes: 1) their source functions, 2) their half-lives, and 3) their chemical properties. The radioisotope, 14C (half-life = 5730 yr) produced in the earth's atmosphere was the first to be discovered (Anderson et al. 1947; Libby 1952). The next longer-lived isotope, also produced in the earth's atmosphere, 10Be (half-life = 1.5 myr) was discovered independently by two groups within a decade (Arnold 1956; Goel et al. 1957; Lal 1991a). Both the isotopes are produced efficiently in the earth's atmosphere, and also in solids on the earth's surface. Independently and jointly they serve as useful tracers for characterizing the evolutionary history of a wide range of materials and artifacts. Here, we specifically focus on the production of 14C in terrestrial solids, designated as in-situ-produced 14C (to differentiate it from atmospheric 14C, initially produced in the atmosphere). We also illustrate the application to several earth science problems. This is a relatively new area of investigations, using 14C as a tracer, which was made possible by the development of accelerator mass spectrometry (AMS). The availability of the in-situ 14C variety has enormously enhanced the overall scope of 14C as a tracer (singly or together with in-situ-produced 10Be), which eminently qualifies it as a unique tracer for studying earth sciences.


2003 ◽  
Vol 2 (1) ◽  
pp. 35-39 ◽  
Author(s):  
S. Franck ◽  
M. Cuntz ◽  
W. von Bloh ◽  
C. Bounama

In a previous paper, we showed that Earth-type habitable planets around 47 UMa are in principle possible if a distinct set of conditions is warranted. These conditions include that the Earth-type planets have successfully formed and are orbitally stable and, in addition, that the 47 UMa star–planet system is relatively young ([lsim ]6 Gyr). We now extend this study by considering Earth-like planets with different land/ocean coverages. This study is again based on the so-called integrated system approach, which describes the photosynthetic biomass production taking into account a variety of climatological, biogeochemical and geodynamical processes. This approach implies a special characterization of the habitable zone defined for a distinct type of planet. We show that the likelihood of finding a habitable Earth-like planet on a stable orbit around 47 UMa critically depends on the percentage of the planetary land/ocean coverage. The likelihood is significantly increased for planets with a very high percentage of ocean surface (‘water worlds’).


2020 ◽  
Vol 42 (4) ◽  
pp. 478-484
Author(s):  
Kirill Golikov ◽  
Ekaterina LAPTEVA ◽  
A. SOCHIVKO

The article discusses the use of live plants as the botanical exposition component supplement of the “Natural areas” (hall № 17 “Natural zonality and its components” and № 20 “Desert, subtropical, tropical countries, high-altitude zone”) and “Physico-georaphic regions” (hall № 24 “Continents and parts of the world”) departments in order to visualize information presented in the Earth Science Museum. Demonstration of plants originating from different regions of the world representing different life forms and being structural components of various plant communities allows to visually characterizing thematic aspects of an exposition. That in turn reveal such principles of systematic nature organization as ecobiomorphic and phytocenotic.


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