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The upcoming Libera mission, NASA’s first Earth Venture Continuity selection, will provide seamless continuity to current broadband radiance measurements obtained by the Clouds and Earth’s Radiant Energy System (CERES) project since March 2000. Leveraging advanced detector technologies, Libera will measure the broadband total, longwave, and shortwave radiances akin to CERES and carry a fourth radiometer to measure shortwave near-infrared radiances to advance our understanding of processes relevant to shortwave absorption by the climate system, radiative feedbacks, and Earth’s albedo variability with added insight into hemispheric albedo symmetry. We use Nimbus-7 observations, global model simulations and radiative transfer calculations to demonstrate applications of the added spectral knowledge in climate science. Although Libera’s absolute accuracy is unprecedented, it is insufficient to adequately close Earth’s energy budget. We will therefore discuss current and future avenues to indirectly and directly measure EEI from space. The latter is potentially feasible through sensing radiation pressure-induced accelerations acting on near-spherical spacecrafts, which under optimal conditions, are directly proportional to the net radiative flux experienced at the satellite’s location. This approach has been considered in the past, and the mission requirements to achieve a measurement accuracy within 0.3 Wm-2 are currently under investigation.&nbsp, The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

The Sun’s irradiance varies with changes in solar magnetic activity, such as bright faculae and dark sunspots. The “contrast” of these magnetic features, relative to a specified baseline, is therefore a key element in modeling the time- and/or wavelength-dependent variability of the Sun’s irradiance. In theoretical solar and stellar atmosphere models, the contrasts are derived from the ratio of the feature atmosphere (i.e. faculae, sunspot, etc.) at some specified temperature to that of a baseline model atmosphere associated with a different temperature. Faculae and sunspot contrasts can also be derived from irradiance observations. For example, multiple linear regression of direct solar irradiance observations with proxies of faculae and sunspot activity gives wavelength-dependent coefficients that relate change in the proxies into equivalent irradiance change. Observationally-derived contrasts can be compared directly to the theoretical contrasts after applying a constant, wavelength-independent, offset factor.In this work, we use the high-fidelity solar spectral irradiance observations from the Total and Spectral Solar Irradiance Sensor (TSIS-1) Spectral Irradiance Monitor (SIM) instrument to derive faculae and sunspot contrasts. We compare the TSIS-1 SIM derived contrasts with those derived from the predecessor Solar Radiation and Climate Experiment (SORCE) mission and to the theoretical contrasts of solar and stellar atmosphere models. We conclude by discussing uncertainties in faculae and sunspot contrasts on modeled solar irradiance as, for example, by the Version 2 of the Naval Research Laboratory’s solar variability models that specify the operational NOAA Solar Irradiance Climate Data Record from the year 1610 to present day., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Not only total solar irradiance (TSI) but also spectral solar irradiance (SSI) matter for our climate. On top of spectrally dependent gas absorptions in the atmosphere, different surfaces can have different reflectivity for the visible (VIS) and near-infrared (NIR). The TSI observed by the most recent NASA SSI monitoring mission, TSIS-1, differs from the counterpart used by the CMIP6 climate models by no more than 1 W m−2; however, the SSI difference in a given VIS band (e.g., 0.44–0.63 μm) and NIR band (e.g., 0.78–1.24 μm) can be as large as 4 W m−2 but with opposite signs. Jing et al. (2021) showed that such a difference in the spectral partitioning of TSI could cause noticeable differences in the simulated high-latitude surface climate. Using the CESM 2.1.3, we continue this line of research to understand the underlying physical mechanisms for the SSI partitioning to affect the simulated climate. We carried out a series of sensitivity runs by varying the partitioning between the VIS and NIR SSI while keeping the TSI unchanged. Radiative kernels are used to diagnose radiative feedback in response to such configuration (i.e., the different partitioning configurations of the VIS and NIR SSI). Our results show that the surface albedo feedbacks derived from different sensitivity runs are consistent regarding the magnitude and the spatial map. However, the hemispherical averaged broadband albedo changes little throughout all the sensitivity runs. The implications of our findings on future climate-change projection and paleoclimate studies are also discussed., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

The Libera Mission will provide continuity of the Clouds and the Earth’s Radiant Energy System (CERES) Earth radiation budget (ERB) observations from space. Libera’s attributes enable a seamless extension of the current 23-year ERB climate data record from CERES. Libera will acquire spectrally integrated radiance over the CERES FM6-heritage broad spectral bands in the shortwave (0.3 – 5 μm), longwave (5 – 50 μm) and total (0.3 – beyond 100 μm) and adds a split-shortwave band (0.7 – 5 μm) to provide deeper insight into shortwave energy deposition. Libera leverages advanced detector technologies using vertically aligned black-carbon nanotubes with closed-loop electrical substitution radiometry to achieve radiometric uncertainty of approximately 0.2%. Libera will also employ a wide field-of-view camera to accelerate the development of the split-shortwave angular distribution models.Libera’s stewardship of the ERB record begins in the latter part of this decade, at an important juncture in the monitoring of climate trends. Libera is currently slated for a launch aboard JPSS-3 in December 2027, when the probability of a CERES data gap will be approaching 50%. The Libera science objectives associated with continuity and extension of the ERB data record are to identify and quantify processes responsible for ERB variability on various times scales. Beyond data continuity, Libera’s new and enhanced observational capabilities will advance our understanding of spatiotemporal variations of radiative energy flow in the visible and near-infrared spectral regions in addition to facilitating the rapid development of new angular distribution models for near-infrared and visible radiance-to-irradiance conversion., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

We will present an overview of early airborne results obtained aboard the Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRP AS) Twin Otter aircraft during the Atmospheric Radiation Measurement (ARM) program aerosol intensive observation period in May 2003.

In spring 2001 the Asian Pacific Regional Aerosol Characterization Experiment (ACE-Asia) made extensive measurements from land, ocean, air and space platforms. A primary objective was to quantify the interactions between aerosols and radiation. This talk presents illustrative results from each type of platform, with initial assessments of regional aerosol radiative forcing obtained by combining satellite and suborbital results.