Shortwave Research Articles

Thin Clouds Control the Cloud Radiative Effect Along the Sc‐Cu Transition

AbstractIn situ and spaceborne studies reveal the prevalence of thin clouds in the major Stratocumulus‐to‐Cumulus Transition (SCT) regions. Using instantaneous satellite and reanalysis data, this study investigates the properties of thin clouds in the Southeast Pacific Ocean and their impact on the cloud radiative effect (CRE). Our findings demonstrate that thin clouds are intrinsic to the SCT. The overcast stratocumulus‐dominated regime exhibits a minimal presence of thin clouds, which become notably prominent after the clouds breakup into the cumulus‐dominated regime. The regime dependence of the occurrence of thin clouds is also observed in terms of the marine cold‐air outbreak parameter and the sea surface temperature. Thin clouds at a given cloud cover significantly modulate the shortwave (SW) and longwave (LW) components of CRE. SW CRE decreases by 46 %–65 % with increasing thin cloud cover. They account for a larger variance in cloud albedo than the combined influence of the liquid water path and effective radius. Furthermore, LW CRE decreases by about 12 %–52 % with thin cloud cover. An increase in the fraction of thin clouds also leads to a larger fraction of negative SW CRE offset by positive LW CRE at a given cloud cover. This LW compensation ranges from approximately 8 % at overcast cloud cover to as much as 19 % at about 50 % cloud cover. These findings elucidate the crucial role of thin clouds, and thus cloud morphology, in modulating CRE and underscore the necessity of their accurate representation in climate models.

Arctic Sea Ice Albedo Estimation from Fengyun-3C/Visible and Infra-Red Radiometer

The sea ice albedo can amplify global climate change and affect the surface energy in the Arctic. In this paper, the data from Visible and Infra-Red Radiometer (VIRR) onboard Fengyun-3C satellite are applied to derive the Arctic sea ice albedo. Two radiative transfer models, namely, 6S and FluxNet, are used to simulate the reflectance and albedo in the shortwave band. Clear sky sea ice albedo in the Arctic region (60°~90°N) from 2016 to 2019 is derived through the physical process, including data preprocessing, narrowband to broadband conversion, anisotropy correction, and atmospheric correction. The results are compared with aircraft measurements and AVHRR Polar Pathfinder-Extended (APP-x) albedo product and OLCI MPF product. The bias and standard deviation of the difference between VIRR albedo and aircraft measurements are −0.040 and 0.071, respectively. Compared with APP-x product and OLCI MPF product, a good consistency of albedo is shown. And analyzed together with melt pond fraction, an obvious negative relationship can be seen. After processing the 4-year data, an obvious annual trend can be observed. Due to the influence of snow on the ice surface, the average surface albedo of the Arctic in March and April can reach more than 0.8. Starting in May, with the ice and snow melting and melt ponds forming, the albedo drops rapidly to 0.5–0.6. Into August, the melt ponds begin to freeze and the surface albedo increases.

Short wave attenuation by a kelp forest canopy

AbstractGiant kelp (Macrocystis pyrifera) forests are common along the California coast. Attached on the rocky bottom at depths of approximately 5–25 m, the kelp, when mature, spans the water column and develops dense, buoyant canopies that interact with waves and currents. We present two novel results based on observations of surface gravity waves in a kelp forest in Point Loma, California. First, we report short wave (1–3 s) attenuation in kelp, quantified by an exponential decay coefficient —comparable to the dampening effect of sea ice. Second, we identify seasonal and tidal changes in attenuation, peaking mid‐summer with maximum kelp cover, and during low tide when a greater proportion of the fronds are at the surface. Thus, the naturally occurring surface canopies of kelp forests can act as temporally varying, high‐frequency filters of wave energy.

Effect of katakaphala eye drops on Digital eye strain- A pilot study

The mandatory e-learning has emerged as a method for teaching during coronavirus disease 19 (COVID-19) pandemic. That now has become the usual routine for additional knowledge source for students, who spend most of the time (4-5 hrs per day) attending e-classes or reading e books in front of a computer or mobile screens. These devices cause harm by emitting short high energy waves that makes an individual vulnerable to a variety of eye problems ranging from dry eye to age-related macular degeneration. It is collectively known as digital eye strain (DES). Katakaphala (strychnos potatorum) is an herb commonly used for ophthalmic conditions like irritation, pain, redness etc. This study was aimed to conduct survey on digital eye strain among BAMS students and to evaluate the effect of katakaphala eye drops on digital eye strain. The survey was conducted using a questionnaire and first 100 students with features of digital eye strain were included for the study. Detailed examination including visual acuity ad shirmers test was done for the enrolled subjects. Katakaphala eye drops was administered to the subjects 2drops in each eye, 4 times a day for 15 days. All parameters were documented on before treatment, at the end of treatment and on day of follow up (30th day). There was significant improvement in all parameters clinically and statistically except in redness of eye. By virtue of properties of the ingredients this katakapahala eye drops helped in relieving Headache, Eye strain & Redness in digital eye strain and improved vision.

Assessing Lidar Ratio Impact on CALIPSO Retrievals Utilized for the Estimation of Aerosol SW Radiative Effects across North Africa, the Middle East, and Europe

North Africa, the Middle East, and Europe (NAMEE domain) host a variety of suspended particles characterized by different optical and microphysical properties. In the current study, we investigate the importance of the lidar ratio (LR) on Cloud-Aerosol Lidar with Orthogonal Polarization–Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIOP-CALIPSO) aerosol retrievals towards assessing aerosols’ impact on the Earth-atmosphere radiation budget. A holistic approach has been adopted involving collocated Aerosol Robotic Network (AERONET) observations, Radiative Transfer Model (RTM) simulations, as well as reference radiation measurements acquired using spaceborne (Clouds and the Earth’s Radiant Energy System-CERES) and ground-based (Baseline Surface Radiation Network-BSRN) instruments. We are assessing the clear-sky shortwave (SW) direct radiative effects (DREs) on 550 atmospheric scenes, identified within the 2007–2020 period, in which the primary tropospheric aerosol species (dust, marine, polluted continental/smoke, elevated smoke, and clean continental) are probed using CALIPSO. RTM runs have been performed relying on CALIOP retrievals in which the default and the DeLiAn (Depolarization ratio, Lidar ratio, and Ångström exponent)-based aerosol-speciated LRs are considered. The simulated fields from both configurations are compared against those produced when AERONET AODs are applied. Overall, the DeLiAn LRs leads to better results mainly when mineral particles are either solely recorded or coexist with other aerosol species (e.g., sea-salt). In quantitative terms, the errors in DREs are reduced by ~26–27% at the surface (from 5.3 to 3.9 W/m2) and within the atmosphere (from −3.3 to −2.4 W/m2). The improvements become more significant (reaching up to ~35%) for moderate-to-high aerosol loads (AOD ≥ 0.2).

Coupled Short-Ig Wave Dunamics Over A Shallow Barrier Reef

Reef barriers play a major role many coral islands, by sheltering the lagoon from the ocean wave energy and then creating a unique habitat for many species. This filtering action becomes increasingly crucial for ecosystems health and shoreline protection in the context of climate change and related sea level rise, degradation of coral systems and modification of wave conditions. A strong research effort has therefore been engaged by the coastal oceanographers community for the last two decades to improve our knowledge and prediction skills of wave dynamics over coral reef systems. A widely reported observation is the importance of infragravity waves (IG) over wave-driven reef systems, whether fringing or barrier reefs. IG are primarily forced by groups in the incoming short-wave (SW) field, either by the release of bound waves or the breakpoint oscillations (Bertin et al. 2018). IG period typically ranges between 30 and 200s, which makes them prone to excite or interact with natural seiching modes in reef-lagoon systems often ranging in the Very Low Frequency (VLF) band. Further research efforts are now necessary to better understand the interaction between long IG/VLF oscillations and SW field. In particular, long waves are expected to play a dynamic depth-filtering role on SW energy, acting as long carrier wave able to promote the propagation of larger SW groups by IG/VLF crests. More generally, the spectral energy transfers over the reef crest-flat system and their relative importance w.r.t. frictional and breaking dissipation are not fully understood over the complete range of surface waves. The aim of the present study is to analyse and to discuss a series of field observations performed on the barrier reef of Maupiti Island, French Polynesia. A particular focus is placed on the interaction between SW and IG wave fields across the reef crest-flat system.

Observationally constrained regional variations of shortwave absorption by iron oxides emphasize the cooling effect of dust

Abstract. The composition of soil dust aerosols derives from the mineral abundances in the parent soils that vary across dust source regions. Nonetheless, Earth system models (ESMs) have traditionally represented mineral dust as a globally homogeneous species. The growing interest in modeling dust mineralogy, facilitated by the recognized sensitivity of the dust climate impacts to composition, has motivated state-of-the-art ESMs to incorporate the mineral speciation of dust along with its effect upon the dust direct radiative effect (DRE). In this work, we enable the NASA Goddard Institute for Space Studies ModelE2.1 to calculate the shortwave (SW) DRE accounting for the regionally varying soil mineralogy. Mineral–radiation interaction at solar wavelengths is calculated according to two alternative coupling schemes: (1) external mixing of three mineral components that are optically distinguished, one of which contains embedded iron oxides; (2) a single internal mixture of all dust minerals with a dynamic fraction of iron oxides that varies regionally and temporally. We link dust absorption to the fractional mass of iron oxides based on recent chamber measurements using natural dust aerosol samples. We show that coupled mineralogy overall enhances the scattering by dust, and thus the global cooling, compared to our control run with globally uniform composition. According to the external mixing scheme, the SW DRE at the top of atmosphere (TOA) changes from −0.25 to -0.30Wm-2, corresponding to a change in the net DRE, including the longwave effect, from −0.08 to -0.12Wm-2. The cooling increase is accentuated when the internal mixing scheme is configured: the SW DRE at the TOA becomes -0.34Wm-2 with a net DRE of -0.15Wm-2. The varying composition modifies the regional distribution of single scattering albedo (SSA), whose variations in specific regions can be remarkable (above 0.03) and significantly modify the regional SW DRE. Evaluation against the AErosol RObotic NETwork (AERONET) shows that explicit representation of soil mineralogy and its regional variations reduces the low bias of model dust SSA while improving the range of variability across stations and calendar months. Despite these improvements, the moderate spatiotemporal correlation with AERONET reveals remaining modeling challenges and the need for more accurate measurements of mineral fractions in soils.

Observations of coastal infragravity wave characteristics under swell-dominated conditions

This study analyzed the characteristics of infragravity (hereafter IG) waves under a microtidal and swell-dominated wave climate based on the field observations collected in the nearshore waters (water depth: ∼ 13 m) of southern Sri Lanka. The main focus is on the dependence of nearshore IG waves on the incident short wave parameters, with particular attention to the influence of the short wave spectral shape on the IG wave characteristics. The observation results indicate that IG waves are primarily locally excited by incident swell wave energy, and accurate prediction of the IG wave height can be achieved using the parameter HS2Tm−1,0, which represents the short wave energy flux. Bound IG wave energy is much smaller than the free IG wave under conventional sea states but becomes significant under high-energy swell sea states.Higher levels of IG wave energy are found to be forced under narrower spectral shapes and smaller directional spreading short wave conditions, and these conditions typically correspond to stronger coupling strengths in the bound IG wave theory. Compared to the single-peaked spectra wave condition, the forced IG wave energy decreases under the double-peaked spectra wave condition. This is likely mainly because the latter tends to have a broader spectrum and a larger directional spreading. On the other hand, under the narrow-banded spectral short wave conditions, IG wave energy is inclined to be distributed over a lower and smaller frequency range. This is noteworthy because lower-frequency IG waves tend to be more difficult to break. In addition, the bound IG wave energy was found to increase at low tide, but for the intermediate water depths in which the observation site is located in this study, the influence of the small tidal range in the study area on the IG wave energy was not significant.

A Lagrangian perspective on the lifecycle and cloud radiative effect of deep convective clouds over Africa

Abstract. The anvil clouds of tropical deep convection have large radiative effects in both the shortwave (SW) and longwave (LW) spectra with the average magnitudes of both over 100 W m−2. Despite this, due to the opposite sign of these fluxes, the net average of the anvil cloud radiative effect (CRE) over the tropics is observed to be neutral. Research into the response of the anvil CRE to climate change has primarily focused on the feedbacks of anvil cloud height and anvil cloud area, in particular regarding the LW feedback. However, tropical deep convection over land has a strong diurnal cycle which may couple with the shortwave component of the anvil cloud radiative effect. As this diurnal cycle is poorly represented in climate models it is vital to gain a better understanding of how its changes impact the anvil CRE. To study the connection between the deep convective cloud (DCC) lifecycle and CRE, we investigate the behaviour of both isolated and organised DCCs in a 4-month case study over sub-Saharan Africa (May–August 2016). Using a novel cloud tracking algorithm, we detect and track growing convective cores and their associated anvil clouds using geostationary satellite observations from the Meteosat Spinning Enhanced Visible and Infrared Imager (SEVIRI). Retrieved cloud properties and derived broadband radiative fluxes are provided by the Community Cloud retrieval for CLimate (CC4CL) algorithm. By collecting the cloud properties of the tracked DCCs, we produce a dataset of anvil cloud properties along their lifetimes. While the majority of DCCs tracked in this dataset are isolated, with only a single core, the overall coverage of anvil clouds is dominated by those of clustered, multi-core anvils due to their larger areas and lifetimes. We find that the anvil cloud CRE of our tracked DCCs has a bimodal distribution. The interaction between the lifecycles of DCCs and the diurnal cycle of insolation results in a wide range of the SW anvil CRE, while the LW component remains in a comparatively narrow range of values. The CRE of individual anvil clouds varies widely, with isolated DCCs tending to have large negative or positive CREs, while larger, organised systems tend to have a CRE closer to 0. Despite this, we find that the net anvil cloud CRE across all tracked DCCs is close to neutral (−0.94 ± 0.91 W m−2). Changes in the lifecycle of DCCs, such as shifts in the time of triggering, or the length of the dissipating phase, could have large impacts on the SW anvil CRE and lead to complex responses that are not considered by theories of LW anvil CRE feedbacks.

Introduction: revisiting the “second (short) wave” of democratisation in Latin America, 1943–1962

Introduction: revisiting the “second (short) wave” of democratisation in Latin America, 1943–1962

Feminist movement and suffrage: how women obtained the right to vote in Bolivia (1920–1952)

ABSTRACT With its proclamation of universal suffrage in 1952, Bolivia fits into Samuel Huntington’s “second short wave of democratization” (1943–1963). In 1952, all women and men gained the right to vote, marking a significant step towards democratization by including previously excluded groups. Literate women had already obtained municipal voting rights in 1945 under a populist government aiming for broader political participation. However, women first voted in 1947, after the oligarchy overthrew this government in 1946 and sought to regain power by repressing the opposition parties and previously marginalized sectors. Unexpectedly, it supported women’s suffrage for national elections by the late 1940s. What prompted various political parties to support women’s suffrage in the late 1940s? This paper explores how women in Bolivia gained the right to vote and what role the feminist movement and power struggles played in obtaining women’s suffrage. Beginning in the 1920s with a study of the emergence of the feminist movement and its evolution during the decades of the 1930s (the Chaco War) and 1940s, the paper culminates with an assessment of feminism’s impact on public opinion as well as the importance of the growing politicization of women in the 1940s.

K-B2S+: A one-dimensional CNN model for AF detection with short single-lead ECG waves from wearable devices

Wearable signal analysis is an important technology for monitoring physiological signals without interfering with an individual's daily behavior. As detecting cardiovascular diseases can dramatically reduce mortality, arrhythmia recognition using ECG signals has attracted much attention. In this paper, we propose a single-channel convolutional neural network to detect Atrial Fibrillation (AF) based on ECG signals collected by wearable devices. It contains 3 primary modules. All recordings are firstly uniformly sized, normalized, and Butterworth low-pass filtered for noise removal. Then the preprocessed ECG signals are fed into convolutional layers for feature extraction. In the classification module, the preprocessed signals are fed into convolutional layers containing large kernels for feature extraction, and the fully connected layer provides probabilities. During the training process, the output of the previous pooling layer is concatenated with the vectors of the convolutional layer as a new feature map to reduce feature loss. Numerous comparison and ablation experiments are performed on the 2017 PhysioNet/CinC Challenge dataset, demonstrating the superiority of the proposed method.

Comparison of short-wave diathermy, Transcutaneous electrical nerve stimulation of electrotherapy methods and exercise therapy in chronic low back conditions

Background: Low back pain is a significant contributor to global disability, impacting individuals across different age groups. Research suggests that around 80% of people will encounter low back pain at some stage in their lives. This condition is more prevalent among middle-aged and elderly individuals, with a higher occurrence among females. The socioeconomic consequences of low back pain are substantial, including increased healthcare expenses, absenteeism from work, and a diminished quality of life. Objective: To compare the effectiveness of short-wave diathermy with exercise, transcutaneous electrical nerve stimulation with exercise, and exercise alone among patients with chronic low back pain. Patients and Methods: 75 patients who were diagnosed with chronic low back pain, ages 20–50, participated. They were divided into three groups: group A received shortwave with exercise, group B received TENS with exercise, and group C received just exercise. Treatment was given for 12 sessions over a period of 4 weeks. All patients were evaluated before and after treatment using a visual analog scale and the Oswestry Low Back Pain Disability Questionnaire. Results: The results showed that all three interventions were effective in reducing pain and improving physical activities, with varying degrees of success. But also, the result showed that the mean difference for the short wave with exercise is much higher than both the TENS with exercise and the exercise alone types of interventions in each of the different categories, respectively. Conclusion: This study has shown that shortwave exercise is more effective in the treatment of chronic low back pain than TENS with exercise and exercise alone.

Comparison of short-wave diathermy, Transcutaneous electrical nerve stimulation of electrotherapy methods and exercise therapy in chronic low back conditions

Background: Low back pain is a significant contributor to global disability, impacting individuals across different age groups. Research suggests that around 80% of people will encounter low back pain at some stage in their lives. This condition is more prevalent among middle-aged and elderly individuals, with a higher occurrence among females. The socioeconomic consequences of low back pain are substantial, including increased healthcare expenses, absenteeism from work, and a diminished quality of life. Objective: To compare the effectiveness of short-wave diathermy with exercise, transcutaneous electrical nerve stimulation with exercise, and exercise alone among patients with chronic low back pain. Patients and Methods: 75 patients who were diagnosed with chronic low back pain, ages 20–50, participated. They were divided into three groups: group A received shortwave with exercise, group B received TENS with exercise, and group C received just exercise. Treatment was given for 12 sessions over a period of 4 weeks. All patients were evaluated before and after treatment using a visual analog scale and the Oswestry Low Back Pain Disability Questionnaire. Results: The results showed that all three interventions were effective in reducing pain and improving physical activities, with varying degrees of success. But also, the result showed that the mean difference for the short wave with exercise is much higher than both the TENS with exercise and the exercise alone types of interventions in each of the different categories, respectively. Conclusion: This study has shown that shortwave exercise is more effective in the treatment of chronic low back pain than TENS with exercise and exercise alone. Keywords: Shortwave, TENS, Exercise, Chronic low back pain.

Carbon-silicon based hybrid quantum dot short wave infrared photodetector

Recently infrared photodetectors based on low-dimensional semiconductors have developed rapidly. However, due to its poor light absorption and incompatibility with traditional silicon-based readout circuit processes, the sensitivity and integration of such photodetectors are limited. In this work, we proposes a 64 × 64 quantum dot short-wavelength infrared (SWIR) photodetector composed of carbon nanotube thin film transistor (CNT TFT) and silicon-based ROIC. CNT TFT's gate is constructed by PbS colloidal quantum dots (PbS CQDs) which improve the absorption rate of infrared light. The generated photovoltage is amplified and converted in situ by CNT TFT. Notably, under infrared radiation of 1300 nm, the noise equivalent current reach up to 1.25*10−13A/Hz1/2. At a drain-source bias (Vds)= -0.1 V. The device exhibits detectivity of 5.6*1013 Jones and a fast response of 0.57 ms. The silicon-based ROIC is implemented by CMOS 0.18um process, with a power supply voltage of 1.8 V. It mainly includes a programmable integrator, a sampling and holding circuit, and a 10bit/2.5 MHz successive approximation analog-to-digital converter (SAR ADC). The programmable integrator has four levels of integral gain to meet the application requirements of different infrared light intensities. The experiment results show that the imaging function of the overall photodetector is correct, laying the foundation for the development of carbon-silicon based heterojunction integrated photodetector in the future.

Influences of bragg reflection on harbor resonance triggered by irregular wave groups

Gao et al. (2021b) attempted for the first time to use Bragg reflection to mitigate the harbor resonance induced by regular long waves and bi-chromatic short wave groups, revealing its remarkable effectiveness. However, in actual coastal/offshore areas, waves usually exist in the form of irregular wave groups. This article considers the more practical irregular wave groups as the incident waves that excite harbor resonance. The harbor resonance occurring inside an elongated harbor triggered by irregular wave groups and its interactions with Bragg reflection are simulated using a Boussinesq-type model, FUNWAVE 2.0. This article reveals for the first time the capabilities of Bragg resonant reflection to effectively alleviate both the main resonant mode and the whole resonance of the harbor triggered by irregular wave groups. The influences of the geometric parameters of bars (including the bar amplitude and the bar number), the spectral bandwidth parameter of incident irregular wave groups, and the main resonant mode on the following four key parameters are further studied comprehensively: (1) the optimal mitigation effect for the main resonant mode, and (2) its corresponding optimal bar wavelength, (3) the optimal mitigation effect for the whole resonance of the harbor, and (4) its corresponding optimal bar wavelength.

Analysis of turning ability of large tankers with and without bulbous bow in calm sea and waves

The present study introduces an experimental and numerical investigation of the turning ability of two ships with and without a bulbous bow: original and modified KVLCC2 hulls Experiments are performed via free-running model tests in a square basin, and a system-based simulation are performed. The maneuvering coefficients for the system-based solver are obtained via numerical planar motion mechanism (PMM) tests based on CFD computations, and other variables are obtained from reference ships. The effects of ship speed, wave direction, and wavelength are investigated. Results of a calm-water turning test obtained experimentally and numerically agree well. When the ship turns in the presence of incident waves, the overall behavior and evaluation parameters predicted in the simulation are similar to those obtained from experiments. However, the evaluation parameters show scattered values under severe turning-failure conditions. The most significant wave effects are observed in short waves. Additionally, the turning ability is compared between two ships, and slightly different maneuvering capabilities are observed. The time series for two hulls are further compared to investigate the reason for the difference showing the difference in the force and drift angle time series.

Mixed quantum dot film for dual-band infrared detection

Dual-band infrared detection offers enhanced spectral information crucial for improved target identification. Traditional dual-band infrared photodetectors have often relied on expensive epitaxial growth bulk materials, limiting their widespread use in civilian applications. Colloidal quantum dots present an affordable alternative for dual-band infrared detection, owing to their spectral tunability and solution processability. In this study, we have developed an approach utilizing mixed lead sulfide quantum dot films to achieve dual-band infrared detection spanning the NIR (Near Infrared) and SWIR (Short Wave Infrared) ranges. These films exhibit a broad absorption spectrum, ranging from 400 to 1600 nm. When operating within the near-infrared band, the device based on mixed quantum dot films demonstrates an responsivity of 0.18A/W and specific detectivity of 2.38 × 109cm∙Hz1/2/W near 900 nm.While operated in the SWIR band, the detector has responsivity of 0.17A/W and specific detectivity of 2.11 × 109cm∙Hz1/2/W near 1600 nm.

Effects of dynamic load application, irregular wave conditions, and base flexibility on the structural response of a vertical pile platform

The dynamic structural response of a vertical pile port platform under the action of irregular wave loads considering soil-structure interaction is studied. Deck displacement and bending moment on the piles were evaluated for a set of structural, hydraulic, and geotechnical parameters. Static structural analyses with the maximum base shear produced by wave loads and dynamic time-history analyses are performed to study the effects of dynamic amplification on the structural response of the platform. Two types of waves are analyzed, regular and irregular, to analyze the amplification effects due to the superposition of a wave train of different periods in the case of irregular waves. Cases with fixed base support and non-linear spring-modeled soil are considered to evaluate the effect of considering a flexible base for the platform. Eight structures composed of a different number of piles and with different heights were analyzed. Six wave conditions with different characteristics are used, varying the wave period and mean water height. Two sandy and two clayey soil profiles are considered with different densities and consistency. The results show that resonance effects associated with dynamic loading and small-period wave superposition in cases of irregular waves significantly affect the response. Furthermore, considering a flexible base tends to decrease the response for short wave periods, concluding that, in most cases, for wave periods close to 5 s, considering a fixed base model overestimates the response.

Next-generation radiance unfiltering process for the Clouds and the Earth's Radiant Energy System instrument

Abstract. The filtered radiances measured by the Clouds and the Earth's Radiant Energy System (CERES) instruments are converted to shortwave (SW), longwave (LW), and window unfiltered radiances based on regressions developed from theoretical radiative transfer simulations to relate filtered and unfiltered radiances. This paper describes an update to the existing Edition 4 CERES unfiltering algorithm (Loeb et al., 2001), incorporating the most recent developments in radiative transfer modeling, ancillary input datasets, and increased computational and storage capabilities during the past 20 years. Simulations are performed with the updated Moderate Resolution Atmospheric Transmission (MODTRAN) 5.4 version. Over land and snow, the surface bidirectional reflectance distribution function (BRDF) is characterized by a kernel-based representation in the simulations, instead of the Lambertian surface used in the Edition 4 unfiltering process. Radiance unfiltering is explicitly separated into four seasonally dependent land surface groups based on the spectral radiation similarities of different surface types (defined by the International Geosphere-Biosphere Programme); over snow, it is separated into fresh snow, permanent snow, and sea ice. This differs from the Edition 4 unfiltering process where only one set of regressions was used for land and snow, respectively. The instantaneous unfiltering errors are estimated with independent test cases generated from radiative transfer simulations in which the “true” unfiltered radiances from radiative transfer simulations are compared with the unfiltered radiances calculated from the regressions. Overall, the relative errors are mostly within ±0.5 % for SW, within ±0.2 % for daytime LW, and within ±0.1 % for nighttime LW for both CERES Terra Flight Model 1 (FM1) and Aqua FM3 instruments. The unfiltered radiances are converted to fluxes and compared to CERES Edition 4 fluxes. The global mean instantaneous fluxes for Aqua FM3 are reduced by 0.34 to 0.45 W m−2 for SW and increased by 0.25 to 0.46 W m−2 for daytime LW; for Terra FM1, they are reduced by 0.24 to 0.34 W m−2 for SW and increased by 0.08 to 0.28 W m−2 for daytime LW. Nighttime LW flux differences are negligible for both instruments.