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Physics Of Radiation And Climate



The Solar Radiation and Climate Experiment (SORCE) is a NASA-sponsored satellite mission that is providing state-of-the-art measurements of incoming x-ray, ultraviolet, visible, near-infrared, and total solar radiation. The measurements provided by SORCE specifically address long-term climate change, natural variability and enhanced climate prediction, and atmospheric ozone and UV-B radiation. These measurements are critical to studies of the Sun; its effect on our Earth system; and its influence on humankind.




Physics of Radiation and Climate



The Solar Radiation and Climate Experiment (SORCE) was a NASA mission that operated from 2003 to 2020 to provide key climate-monitoring measurements of total solar irradiance (TSI) and solar spectral irradiance (SSI). This topical collection provides an overview of some of the key SORCE science results, an overview of mission operations and how anomalies impacted the science observations, a detailed description of the updated algorithms used in producing the final data products of TSI and SSI from the four SORCE instruments, and results from an underflight calibration-rocket experiment flown in June 2018. The 17-year-long SORCE mission has made many contributions to the climate records of TSI and SSI that date back to the 1970s, and, fortunately, similar observations from the Total and Spectral Solar Irradiance Sensor (TSIS-1) are able to continue these Sun-climate records after SORCE without a gap.


The Climate and Radiation Laboratory seeks a better understanding of Earth's climate on all time scales, from daily, seasonal, and interannual variability through changes on geologic time scales. Our research focuses on integrated studies of atmospheric measurements from satellites, aircraft and in-situ platforms, numerical modeling, and climate analysis.We investigate atmospheric radiation, both as a driver for climate change and as a tool for the remote sensing of Earth's atmosphere and surface. The Laboratory research program strives to better understand how our planet reached its present state, and how it may respond to future drivers of change, both natural and anthropogenic.For further information, data, research, and other resources, see Climate and Radiation Projects.


Radiation theory and measurements are at the core of the climate change debate. This new book describes in detail the basic physics used in the radiative transfer codes that are a key part of climate prediction models. The basic principles are extended to the atmospheres of the Earth and the other planets, illustrating the greenhouse effect and other radiation-based phenomena at work. Several chapters deal with the techniques and measurements for monitoring the Earth's radiation budget and thus tracking global change and its effects. Remote sensing instruments on satellites and the theory of remote sensing are also covered. The book is the first comprehensive new publication on atmospheric radiation in more than a decade, and the first to link the theoretical and experimental aspects of the subject to the contemporary climate problem.


Covers important aspects of atmospheric radiation, and strikes a nice balance between fundamentals of atmospheric radiation and the application of these topics to climate. - Jeffrey Kiehl, National Center for Atmospheric Research, Boulder, CO


The Solar Radiation and Climate Experiment (SORCE) was a NASA mission that operated from 2003 to 2020 to provide key climate-monitoring measurements of total solar irradiance (TSI) and solar spectral irradiance (SSI). Three important accomplishments of the SORCE mission are i) the continuation of the 42-year-long TSI climate data record, ii) the continuation of the ultraviolet SSI record, and iii) the initiation of the near-ultraviolet, visible, and near-infrared SSI records. All of the SORCE instruments functioned well over the 17-year mission, which far exceeded its five-year prime mission goal. The SORCE spacecraft, having mostly redundant subsystems, was also robust over the mission. The end of the SORCE mission was a planned passivation of the spacecraft following a successful two-year overlap with the NASA Total and Spectral Solar Irradiance Sensor (TSIS) mission, which continues the TSI and SSI climate records. There were a couple of instrument anomalies and a few spacecraft anomalies during SORCE's long mission, but operational changes and updates to flight software enabled SORCE to remain productive to the end of its mission. The most challenging of the anomalies was the degradation of the battery capacity that began to impact operations in 2009 and was the cause for the largest SORCE data gap (August 2013 - February 2014). An overview of the SORCE mission is provided with a couple of science highlights and a discussion of flight anomalies that impacted the solar observations. Companion articles about the SORCE instruments and their final science data-processing algorithms provide additional details about the instrument measurements over the duration of the mission.


All matter in the universe that has a temperature above absolute zero (the temperature at which all atomic or molecular motion stops) radiates energy across a range of wavelengths in the electromagnetic spectrum. The hotter something is, the shorter its peak wavelength of radiated energy is. The hottest objects in the universe radiate mostly gamma rays and x-rays. Cooler objects emit mostly longer-wavelength radiation, including visible light, thermal infrared, radio, and microwaves.


The amount of sunlight the Earth absorbs depends on the reflectivness of the atmosphere and the ground surface. This satellite map shows the amount of solar radiation (watts per square meter) reflected during September 2008. Along the equator, clouds reflected a large proportion of sunlight, while the pale sands of the Sahara caused the high reflectivness in North Africa. Neither pole is receiving much incoming sunlight at this time of year, so they reflect little energy even though both are ice-covered. (NASA map by Robert Simmon, based on CERES data.)


This map of net radiation (incoming sunlight minus reflected light and outgoing heat) shows global energy imbalances in September 2008, the month of an equinox. Areas around the equator absorbed about 200 watts per square meter more on average (orange and red) than they reflected or radiated. Areas near the poles reflected and/or radiated about 200 more watts per square meter (green and blue) than they absorbed. Mid-latitudes were roughly in balance. (NASA map by Robert Simmon, based on CERES data.)


The changes we have seen in the climate so far are only part of the full response we can expect from the current energy imbalance, caused only by the greenhouse gases we have released so far. Global average surface temperature has risen between 0.6 and 0.9 degrees Celsius in the past century, and it will likely rise at least 0.6 degrees in response to the existing energy imbalance.


Radiation is energy that moves from one place to another in a form that can be described as waves or particles. We are exposed to radiation in our everyday life. Some of the most familiar sources of radiation include the sun, microwave ovens in our kitchens and the radios we listen to in our cars. Most of this radiation carries no risk to our health. But some does. In general, radiation has lower risk at lower doses but can be associated with higher risks at higher doses. Depending on the type of radiation, different measures must be taken to protect our bodies and the environment from its effects, while allowing us to benefit from its many applications.


Non-ionizing radiation is lower energy radiation that is not energetic enough to detach electrons from atoms or molecules, whether in matter or living organisms. However, its energy can make those molecules vibrate and so produce heat. This is, for instance, how microwave ovens work.


For most people, non-ionizing radiation does not pose a risk to their health. However, workers that are in regular contact with some sources of non-ionizing radiation may need special measures to protect themselves from, for example, the heat produced.


Some other examples of non-ionizing radiation include the radio waves and visible light. The visible light is a type of non-ionizing radiation that the human eye can perceive. And the radio waves are a type of non-ionizing radiation that is invisible to our eyes and other senses, but that can be decoded by traditional radios.


Some examples of ionizing radiation include some types of cancer treatments using gamma rays, the X-rays, and the radiation emitted from radioactive materials used in nuclear power plants (Infographic: Adriana Vargas/IAEA)


In high doses, ionizing radiation can damage cells or organs in our bodies or even cause death. In the correct uses and doses and with the necessary protective measures, this kind of radiation has many beneficial uses, such as in energy production, in industry, in research and in medical diagnostics and treatment of various diseases, such as cancer. While regulation of use of sources of radiation and radiation protection are national responsibility, the IAEA provides support to lawmakers and regulators through a comprehensive system of international safety standards aiming to protect workers and patients as well as members of the public and the environment from the potential harmful effects of ionizing radiation. 041b061a72


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