Comparison of spectrally resolved outgoing longwave radiation between 1970 and 2003: The ν 4 band of methane

Spectrally resolved outgoing longwave radiation and its applications for the study of climate The ERC advanced “IASI-FT” project exploits the space-based instantaneous spectrally resolved observations provided by the family of IASI thermal infrared instruments to (1) monitor atmospheric composition changes and (2) establish climate records. More than 3.5 million of data are available each day, from which near-real-time information on the atmospheric state can be inferred.

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Trends in spectrally resolved outgoing longwave radiation from 10 years of satellite measurements

npj Climate and Atmospheric Science ◽

10.1038/s41612-021-00205-7 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Simon Whitburn ◽

Lieven Clarisse ◽

Marie Bouillon ◽

Sarah Safieddine ◽

Maya George ◽

...

Keyword(s):

Outgoing Longwave Radiation ◽

Southern Oscillation ◽

Longwave Radiation ◽

Atmospheric Temperature ◽

Natural Variability ◽

Satellite Measurements ◽

Clear Sky ◽

The Individual ◽

Spectrally Resolved

AbstractIn recent years, the interest has grown in satellite-derived hyperspectral radiance measurements for assessing the individual impact of climate drivers and their cascade of feedbacks on the outgoing longwave radiation (OLR). In this paper, we use 10 years (2008–2017) of reprocessed radiances from the infrared atmospheric sounding interferometer (IASI) to evaluate the linear trends in clear-sky spectrally resolved OLR (SOLR) in the range [645–2300] cm−1. Spatial inhomogeneities are observed in most of the analyzed spectral regions. These mostly reflected the natural variability of the atmospheric temperature and composition but long-term changes in greenhouse gases concentrations are also highlighted. In particular, the increase of atmospheric CO2 and CH4 led to significant negative trends in the SOLR of −0.05 to −0.3% per year in the spectral region corresponding to the ν2 and the ν3 CO2 and in the ν4 CH4 band. Most of the trends associated with the natural variability of the OLR can be related to the El Niño/Southern Oscillation activity and its teleconnections in the studied period. This is the case for the channels most affected by the temperature variations of the surface and the first layers of the atmosphere but also for the channels corresponding to the ν2 H2O and the ν3 O3 bands.

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Comparison of Spectrally Resolved Outgoing Longwave Radiation over the Tropical Pacific between 1970 and 2003 Using IRIS, IMG, and AIRS

Journal of Climate ◽

10.1175/jcli4204.1 ◽

2007 ◽

Vol 20 (15) ◽

pp. 3982-4001 ◽

Cited By ~ 5

Author(s):

J. A. Griggs ◽

J. E. Harries

Keyword(s):

Greenhouse Gas ◽

Outgoing Longwave Radiation ◽

Radiative Forcing ◽

Direct Method ◽

Longwave Radiation ◽

Difference Spectrum ◽

Reanalysis Data ◽

Temperature Structure ◽

The Difference ◽

Spectrally Resolved

Abstract The observation of changes in the earth’s spectrally resolved outgoing longwave radiation (OLR) provides a direct method of determining changes in the radiative forcing of the climate system. An earlier study showed that satellite-observed changes in the clear-sky outgoing longwave spectrum between 1997 and 1970 from the Infrared Interferometer Spectrometer (IRIS) and Interferometic Monitor of Greenhouse Gases (IMG) instruments could be related to changes in greenhouse gas composition. The authors present a new study that extends this to 2003, through the first use of a new, independent source of global atmospheric infrared spectra, from the Atmospheric Infrared Sounder (AIRS) experiment. AIRS is a dispersion grating spectrometer, while the other two were Fourier transform spectrometers, and this is taken into account in the analysis. The observed difference spectrum between the years 2003 and 1970 generally shows the signatures of greenhouse gas forcing, and also shows the sensitivity of the signatures to interannual variations in temperature. The new 2003 data support the conclusions found in the earlier work, though, interestingly, the methane (CH4) Q branch centered at 1304 cm−1 exhibits more complex behavior, showing a decrease in intensity in the difference spectrum between 1997 and 2003. Sensitivity analysis indicates that this is due to changes in temperature structure, superposed on an underlying increase in CH4. Radiative transfer calculations based on reanalysis data are used to simulate the changes in the OLR spectrum; limitations in such data and possible variations that could account for several observed effects are discussed.

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Estimating the Earth’s Outgoing Longwave Radiation Measured from a Moon-Based Platform

Remote Sensing ◽

10.3390/rs13112201 ◽

2021 ◽

Vol 13 (11) ◽

pp. 2201

Author(s):

Hanlin Ye ◽

Huadong Guo ◽

Guang Liu ◽

Jinsong Ping ◽

Lu Zhang ◽

...

Keyword(s):

Outgoing Longwave Radiation ◽

Large Scale ◽

Single Point ◽

Longwave Radiation ◽

Earth Observation ◽

Artificial Satellites ◽

Earth Observations ◽

The Earth ◽

Observation Geometry ◽

Global Mean

Moon-based Earth observations have attracted significant attention across many large-scale phenomena. As the only natural satellite of the Earth, and having a stable lunar surface as well as a particular orbit, Moon-based Earth observations allow the Earth to be viewed as a single point. Furthermore, in contrast with artificial satellites, the varied inclination of Moon-based observations can improve angular samplings of specific locations on Earth. However, the potential for estimating the global outgoing longwave radiation (OLR) from the Earth with such a platform has not yet been fully explored. To evaluate the possibility of calculating OLR using specific Earth observation geometry, we constructed a model to estimate Moon-based OLR measurements and investigated the potential of a Moon-based platform to acquire the necessary data to estimate global mean OLR. The primary method of our study is the discretization of the observational scope into various elements and the consequent integration of the OLR of all elements. Our results indicate that a Moon-based platform is suitable for global sampling related to the calculation of global mean OLR. By separating the geometric and anisotropic factors from the measurement calculations, we ensured that measured values include the effects of the Moon-based Earth observation geometry and the anisotropy of the scenes in the observational scope. Although our results indicate that higher measured values can be achieved if the platform is located near the center of the lunar disk, a maximum difference between locations of approximately 9 × 10−4 W m−2 indicates that the effect of location is too small to remarkably improve observation performance of the platform. In conclusion, our analysis demonstrates that a Moon-based platform has the potential to provide continuous, adequate, and long-term data for estimating global mean OLR.

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