Shortwave Albedo Research Articles

Tillage and surface moisture effects on bare-soil albedo of a tropical loamy sand

Effects of four tillage systems on the albedo of a tropical loamy sand were studied under dry and moist surface conditions. The aim was to determine whether tillage-induced roughness and soil wetness significantly affected soil albedo. Changes in smooth reference surface albedo with respect to four roughness conditions were used to assess tillage effects. Surface albedo ( α), soil moisture content ( θ m) and soil surface roughness ( δ) were measured. Two types of pyranometers used for albedometers are CM 3 and SP LITE. Mean albedo of a reference smooth surface (<2 mm sieved soil) was 0.16 and 0.20 for CM 3 and SP LITE under moist condition, and 0.29 and 0.28 under dry condition, respectively. Bare-soil shortwave albedo generally increased with an increase in solar zenith angle, whereas albedo decreased with an increase in surface roughness and soil wetness. Linear relationships of albedo with surface roughness and soil moisture content indicated that albedo was more sensitive to surface roughness under dry condition. The goodness-of-fit of a multiple linear regression model combining the effects of roughness and wetness on surface albedo was 0.96 with a standard error of 0.01. This simple model could be used to estimate albedo of bare soil similar to the tropical loamy sand reported in this study. This study provides useful information for modelling tillage effects on the energy budget at the soil surface.

An improved derivation of the top‐of‐atmosphere albedo from POLDER/ADEOS‐2: Narrowband albedos

The Polarization and Directionality of Earth Reflectances (POLDER) instrument was routinely functioning aboard the second Advanced Earth Observing Satellite (ADEOS‐2) from April to October 2003. A series of algorithms dedicated to Earth radiation budget, water vapor, and clouds are applied to the POLDER data. This paper presents the derivation scheme of the narrowband albedos at the top of the atmosphere from POLDER measurements at 443, 670, and 865 nm. These narrowband albedos are used to estimate the broadband shortwave albedo at the top of atmosphere in a companion paper. Here we focus on the 670 nm (over land)/865 nm (over ocean) albedo. Although our derivation is based on the plane‐parallel hypothesis, and thanks to the multidirectional capability of POLDER, results appear reliable for both cloudy and clear‐sky scenes. A quality index is introduced from the comparison between the angular variability of the retrieved “directional” albedo values and that of the measured reflectances. This quality index is “good” in 80% of the cases. Moreover, the retrieved albedo values are found to be statistically little dependent on the viewing direction.

Solar radiative transfer for stratiform clouds with horizontal variations in liquid‐water path and droplet effective radius

AbstractEffects of horizontal variations in liquid‐water path (LWP) and droplet effective radius (re) on solar radiative‐transfer properties of stratiform clouds are addressed. To this end, a broadband Monte Carlo solar radiation code and in situ aircraft observations of cloud properties collected in the Radiation, Aerosol and Cloud Experiment are used. The experiments confirm that the radiative impact of cloud horizontal inhomogeneity is dominated by variations in LWP, which make cloud short‐wave albedo smaller than that for a corresponding plane‐parallel horizontally homogeneous cloud. When horizontal variations in re are accounted for, however, the impact due to horizontal variations in LWP is usually reduced. When re and LWP are highly correlated, as is typically the case, the impact on albedo due to LWP variations alone can be reduced easily by 30% when variations in re are included. Uncertainty factors involved in the calculations are also discussed. Copyright © 2003 Royal Meteorological Society.

An experimental study of radiative fluxes in the south Bay of Bengal during BOBMEX 1999

Time series measurements of radiative fluxes were made onboard INS Sagardhwani (SD) in the south Bay of Bengal near DS3 (13‡N and 87‡E) during the BOBMEX field experiment. An inter-comparison experiment conducted at DS3 showed that the radiative fluxes measured by Kipp and Zonen, Albedo meter and net Pyrgeometer onboard SD and by Eppley radiometers onboard ORV Sagar Kanya (SK) are well matched. It may be mentioned that the measurements showed consistency and good agreement between SD and SK ships, even though no Gimbal mounting was used for radiation instruments onboard SD.The main aim of the experiment was collection of high quality radiation data during the monsoon period, which can give an insight into the nature of the ocean-atmosphere coupling. The data on the four radiative fluxes collected on SD are averaged at 5 minute intervals and then hourly and daily averages have been computed. The hourly shortwave albedo and the atmospheric transmission factor are also computed and the variation of albedo in relation to the solar altitude and the transmissivity factor (TF) are studied. The mean albedo over the south Bay of Bengal under clear, partly cloudy and overcast skies are found to be 0.05, 0.07 and 0.2 respectively.

Consistency of MODIS surface bidirectional reflectance distribution function and albedo retrievals: 2. Validation

The evaluation of the first available satellite‐based global albedo product at 1‐km resolution is essential for its application in climate studies. We evaluate the accuracy of the Moderate‐Resolution Imaging Spectroradiometer (MODIS) albedo product using available field measurements at Surface Radiation Budget Network (SURFRAD) and Cloud and Radiation Testbed–Southern Great Plains (CART/SGP) stations and examine the consistency between the MODIS surface albedos and the Clouds and Earth's Radiant Energy System (CERES) top‐of‐the‐atmosphere albedos as well as historical global albedos from advanced very high resolution radiometer (AVHRR) and Earth Radiation Budget Experiment (ERBE) observations. A comparison with the field measurements shows that the MODIS surface albedo generally meets an absolute accuracy requirement of 0.02 for our study sites during April–September 2001, with the root mean square errors less than 0.018. Larger differences appear in the winter season probably due to the increased heterogeneity of surface reflectivity in the presence of snow. To examine the effect of spatial heterogeneity on the validation of the MODIS albedos using fine resolution field measurements, we derive an intermediate albedo product from four Landsat Enhanced Thematic Mapper Plus (ETM+) images at 30‐m spatial resolution as a surrogate for the distributed field measurements. The surface albedo is relatively homogeneous over the study stations in growing seasons, and therefore the validation during April–September is supported. A case study over three SURFRAD stations reveals that the MODIS bidirectional reflectance distribution function model is able to capture the solar zenith angle dependence of surface albedo as shown by the field measurements. We also find that the MODIS surface shortwave albedo is consistent with the contemporary and collocated CERES top‐of atmosphere albedos derived directly from broadband observations. The MODIS albedo is also well correlated with historical surface albedos derived from AVHRR and ERBE observations, and a high bias of 0.016 and a low bias of 0.034 compared to those of the latter albedos are reasonable considering the differences in instruments and retrieval algorithms as well as environmental changes.

Consistency of MODIS surface bidirectional reflectance distribution function and albedo retrievals: 1. Algorithm performance

The first consistent year (November 2000 to November 2001) of global albedo product was produced at 1‐km resolution every 16 days from the observations of the Moderate‐Resolution Imaging Spectroradiometer (MODIS) instrument aboard NASA's Terra spacecraft. We evaluated the quality of the operational albedo retrievals in two ways: (1) by examining the algorithm performance using the product quality assurance (QA) fields (this paper) and (2) by comparing retrieved albedos with those observed at ground stations and by other satellite instruments (in a companion paper). The internal diagnostics of the retrieval algorithm adequately reflect the goodness of the model fit and the random noise amplification in the retrieved albedo. Global QA statistics show that the RossThick‐LiSparse‐Reciprocal model fits the atmospherically corrected surface reflectances very well, and the random noise amplification factors for white sky albedo and reflectance are generally less than 1.0. Cloud obscuration is the main reason for the activation of the backup magnitude retrieval algorithm. Over the 60°S to 60°N latitude band, 50% of the land pixels acquire more than six clear looks during 14–29 September 2001, and only 5% of these pixels are inverted with the backup algorithm. The latitude dependence and temporal distribution of the QA fields further demonstrate that the retrieval status mainly follows the pattern of angular sampling determined by cloud climatology and the instrument/orbit characteristics. A case study over the west coast of the United States shows that white sky shortwave albedos retrieved from magnitude inversions agree on average with those from full inversions to within 0.033 in reflectance units and have a slightly lower bias ranging from 0.014 to 0.023. We also explored the effect of residual cloud and aerosol contamination in the atmospherically corrected surface reflectance inputs in another case study over southern Africa. The quality assurance procedure of the operational MODIS bidirectional reflectance distribution function and albedo algorithm compensates for some of these residual effects and improves the albedo retrieval results by an order of 0.005 (10%) in the visible for more than 12% of pixels.

How does snow impact the albedo of vegetated land surfaces as analyzed with MODIS data?

Albedo derived from MODIS observations is found to be very stable during November 2000–January 2001. We analyze shortwave albedo under snow and snow‐free conditions by IGBP land cover types. Snow changes the spectral property of the surface reflectivity and causes high heterogeneity in the surface albedo between and within land types. The mean black sky (or direct beam) albedo at local solar noon for snow‐covered forests is less than 0.30 in the shortwave (0.3–5.0 μm), but it reaches 0.57 for snow‐covered grassland and barren. Although we are unable to further separate within‐class albedos with fractional tree cover, we find that the normalized difference snow index (NDSI) is highly correlated with surface albedo and hence can be taken as a measure of snow, soil and canopy fraction.

Surface Albedo over the Arctic Ocean Derived from AVHRR and Its Validation with SHEBA Data

A method is presented for retrieving the broadband albedo over the Arctic Ocean using advanced very high resolution radiometer (AVHRR) data obtained from NOAA polar-orbiting satellites. Visible and near-infrared albedos over snow and ice surfaces are retrieved from AVHRR channels 1 and 2, respectively, and the broadband shortwave albedo is derived through narrow-to-broadband conversion (NTBC). It is found that field measurements taken under different conditions yield different NTBC coefficients. Model simulations over snow and ice surfaces based on rigorous radiative transfer theory support this finding. The lack of a universal set of NTBC coefficients implies a 5%‐10% error in the retrieved broadband albedo. An empirical formula is derived for converting albedo values from AVHRR channels 1 and 2 into a broadband albedo under different snow and ice surface conditions. Uncertain calibration of AVHRR channels 1 and 2 is the largest source of uncertainty, and an error of 5% in satellite-measured radiance leads to an error of 5%‐10% in the retrieved albedo. NOAA-14 AVHRR data obtained over the Surface Heat Budget of the Arctic Ocean (SHEBA) ice camp are used to derive the seasonal variation of the surface albedo over the Arctic Ocean between April and August of 1998. Comparison with surface measurements of albedo by Perovich and others near the SHEBA ice camp shows very good agreement. On average, the retrieval error of albedo from AVHRR is 5%‐10%.

On the estimation of spring melt in the North Water polynya using RADARSAT‐1

This paper evaluates the utility of time series RADARSAT‐1 Synthetic Aperture Radar (SAR) to detect melt onset (MO) and pond onset (PO) in the North Water (NOW) Polynya. SAR detected MO was associated with the approach of the daily average near‐surface air temperature (Tair) toward freezing, the beginning of a daily average surplus in the net all‐wave radiation flux (Q*), and a sharp decrease in the integrated shortwave albedo (α) at the surface. Relationships between microwave scattering and air, snow surface and ice surface temperature, up until MO, proved sensitive to the diurnal acquisition times of RADARSAT‐1. Time series results demonstrate that, despite its ‘uncalibrated’ status, RADARSAT‐1 ScanSAR data unambiguously identifies MO and PO over landfast First‐Year Ice (FYI) within the NOW Polynya. Spatially, results suggest a significantly earlier spring melt on the Greenland coast compared to the Ellesmere coast (10 to 15 days for regions between 77°N and 79°N and up to 45 days for regions between 76°N and 77°N). The regional near‐surface air temperature pattern was consistent with the spatial pattern of a SAR detected date of MO and PO.

Narrowband to broadband conversions of land surface albedo I: Algorithms

Land surface broadband albedo is a critical variable for many scientific applications. High-resolution narrowband satellite observations contain important information that enables us to map land surface albedo globally, and validate the coarse-resolution albedo products from the broadband sensors using ground “point/plot” measurements. However, the conversions from narrowband to broadband albedos of a general surface type have not been well established. Most studies compute total shortwave albedo based on either the empirical relations between surface total shortwave albedo measurements and satellite observations or radiative transfer simulations with the limited number of surface reflectance spectra because of the computational constraints. As a result, many conversion formulae for the same sensors are quite different. In this study, we applied an approach that decouples surface reflectance spectra from the real-time radiative transfer simulations so that many different surface reflectance spectra and the atmospheric conditions can be effectively incorporated. The conversion formulae, based on extensive radiative transfer simulations, are provided in this paper for calculating the total shortwave albedo, total-, direct-, and diffuse-visible, and near-infrared broadband albedos for several narrowband sensors, including ASTER, AVHRR, ETM+/TM, GOES, MODIS, MISR, POLDER, and VEGETATION. Some of these formulae were compared with the published formulae of the same sensors and further validations using extensive ground measurements will be discussed in the companion paper.

Melt ponds on sea ice in the Canadian Archipelago: 1. Variability in morphological and radiative properties

The morphological and radiative properties of melt ponds on first‐year sea ice (FYI) were investigated during the summer of 1997 in the Canadian Archipelago as part of the Collaborative‐Interdisciplinary Cryospheric Experiment (C‐ICE) near Resolute Bay, Nunavut. In this paper we (1) describe a classification technique used to identify surface cover types from airborne videography during the melt pond season, (2) use the classification results to examine the fractional coverage of surface types and morphological characteristics of melt ponds, and (3) provide an estimate of the integrated shortwave albedo of this surface. Cluster analysis on the videography data identified four distinct surface cover types during the summer melt season: snow, saturated snow, light‐colored melt ponds, and dark‐colored melt ponds. Melt pond coverage was found to be highly variable over our study area. We found that pond sizes tended to be twice as large in areas of high melt pond density compared to ponds in areas of low pond density owing to their interconnective nature. Video data also identified an elongated melt pond morphology pattern over the smoothest FYI within our study region. A derived estimate of the integrated shortwave albedo was strongly related to the fractional cover of snow on the surface (R2 = 0.86). An analysis of combined fractional coverage of light and dark melt ponds from two aerial survey dates (Julian Days 181 and 184) revealed an aerial increase in melt ponds of ∼10.3%.

Melt ponds on sea ice in the Canadian Archipelago: 2. On the use of RADARSAT‐1 synthetic aperture radar for geophysical inversion

Microwave scattering from a first‐year sea ice (FYI) melt ponded surface is examined using RADARSAT‐1 synthetic aperture radar (SAR) data collected during the 1997 Collaborative‐Interdisciplinary Cryospheric Experiment (C‐ICE'97) near Resolute Bay, Nunavut. This paper (1) investigates the utility of time series of microwave scattering to detect melt pond formation and (2) investigates approaches toward geophysically inverting information on the physical and radiative properties of this surface. We found melt pond formation to coincide with a sharp rise in the temporal evolution of the microwave scattering coefficient (σ°) over FYI. RADARSAT‐1 incidence angle and surface wind speed explained &gt;90% of the variation in σ°. RADARSAT‐1 σ° was sensitive (R2 = 0.80) to the fractional coverage of melt ponds during windy conditions (∼ 5.3 m s−1). Spatial and temporal coincident measurements of RADARSAT‐1 σ° and the integrated shortwave albedo revealed a strong negative statistical correlation (R2 = 0.91) during windy conditions (∼ 5.3 m s−1). A weaker, but strong, negative relationship (R2 = 0.78) was observed for less windy conditions (∼ 3.2 m s−1), and a very weak positive relationship (R2 = 0.19) was found for low wind speed conditions (∼ 1.5 m s−1). All relationships were observed for melt pond fractions between 13 and 34%.

RADIOMETRIC MEASUREMENTS FROM THE RESURS-1 SATELLITE

Some preliminary results of processing of radiometer measurements from the Resurs-1 (No. 4) heliosynchronous satellite are given. Values of the solar constant, recorded using a second-generation “solar-constant measuring instrument” are presented for 48 days of observations. Measurements of outgoing short-wave radiation and albedo (IKOR measuring instrument) were made on 109 days of observations, distributed over the course of eight months.

Retrieval of Land Surface Albedo from Satellite Observations: A Simulation Study

Land surface albedo is a critical parameter affecting the earth's climate and is required by global and regional climatic modeling and surface energy balance monitoring. Surface albedo retrieved from satellite observations at one atmospheric condition may not be suitable for applicati to other atmospheric conditions. In this paper the authors separate the apparent surface albedo from the inherent surface albedo, which is independent of atmospheric conditions, based on extensive radiative transfer simulations under a variety of atmospheric conditions. The results show that spectral inherent albedos are different from spectral apparent albedos in many cases. Total shortwave apparent albedos under both clear and cloudy conditions are also significantly different from their inherent total shortwave albedos. The conversion coefficients of the surface inherent narrowband albedos derived from the MODIS (Moderate-Resolution Imaging Spectroradiometer) and the MISR (Multiangle Imaging Spectroradiometer) instruments to the surface broadband inherent albedo are reported. A new approach of predicting broadband surface inherent albedos from MODIS or MISR top of atmosphere (TOA) narrowband albedos using a neural network is proposed. The simulations show that surface total shortwave and near-infrared inherent albedos can be predicted accurately from TOA narrowband albedos without atmospheric information, whereas visible inherent albedo cannot.

A Study toward an Improved Understanding of the Relationship between Visible and Shortwave Measurements

Abstract Narrowband (NB) to broadband (BB) conversion is a common practice to acquire radiation budget data from operational imagery data. This study attempts to gain further insights into the relationship between NB visible (VIS) albedo and BB shortwave (SW) albedo by means of observational analysis and radiative transfer modeling. Multiple observation datasets were employed including Scanner for Radiation Budget (ScaRaB) satellite measurements, National Centers for Environmental Prediction–National Center for Atmospheric Research reanalysis of precipitable water and temperature profiles, Total Ozone Mapping Spectrometer ozone amount, etc. Radiative transfer modeling was done with an adding–doubling model of high spectral resolution for a range of surface, atmospheric, and cloud conditions. ScaRaB provided calibrated synergistic measurements of VIS and SW albedos. The two types of albedos were found to be linearly correlated with much higher correlation coefficients than previously obtained from other in...

An Improved Method to Derive Surface Albedo from Narrowband AVHRR Satellite Data: Narrowband to Broadband Conversion

A method was investigated to estimate broadband surface shortwave albedo from the narrowband reflectances obtained by the Advanced Very High Resolution Radiometers (AVHRRs) on board the polar orbiting satellites. Field experiments were conducted to measure simultaneously multispectral narrowband reflectances and broadband albedo over various vegetation and soil surfaces. These data were combined to examine the behavior of narrowband-to-broadband (NTB) conversion factors for different surfaces. Many previous studies have used constant NTB conversion factors for the AVHRR data. The results from this investigation indicate that the optimal NTB conversion factors for AVHRR channels 1 and 2 have a strong dependence on the amount of green vegetation within the field of view. Two conversion factors, f1 and f2, were established to quantify, respectively, 1) the relationship between the reflectance in the narrow red wave band and the total reflectance within the whole visible subregion (0.3–0.685 μm) and 2) the relationship between the reflectance in the narrow near-infrared wave band and the total reflectance within the whole near-infrared subregion (0.685–2.8 μm). Values of f1 and f2, calculated from field data, correlated well with the normalized difference vegetation index (NDVI), largely because of the unique characteristics of light absorption and scattering within the red and near-infrared wave bands by green leaves. The f1–NDVI and f2–NDVI relationships developed from this study were used to infer empirical coefficients needed to estimate surface albedo from AVHRR data. The surface albedo values calculated by the new method agreed with ground-based measurements within a root-mean-square error of 0.02, which is better than other methods that use constant empirical coefficients. Testing with albedo measurements made by unmanned aerospace vehicles during a field campaign also indicates that the new method provides an improved estimate of surface albedo.

Characterization of the Reflectance Anisotropy of Three Boreal Forest Canopies in Spring–Summer

As a part of the Boreal Ecosystem-Atmosphere Study (BOREAS), measurements of the spectral reflectance anisotropy of three boreal forest canopies were studied for cloudless sky conditions at the phenological growth stages which were at or near maximum leaf area index at each site. The three sites were relatively homogeneous mature stands of black spruce, jack pine, and aspen located in the southern boreal zone of central Saskatchewan. Measurements of the spectal bidirectional reflectance factors with a 15° instrument field of view in three spectral bands centered at 662 nm, 826 nm, and 1658 nm were made with the PARABOLA instrument over a range of solar zenith angles typically varying from 35° (near solar noon) to 70°. The measured reflectance factors showed large anisotropy at all three sites and for all three wavelengths, with prominant backscatter peak reflectances, and strong retro solar view angle (hot spot) maximum reflectances in the visible (662 nm) and shortwave infrared (1658 nm) for the jack pine and black spruce sites, with a less pronounced hot spot at the aspen site. Pronounced effects of canopy and understory shadowing in the visible, as a function of solar zenith angle (SZA), were observed for the black spruce and jack pine sites, with resultant large linear increases in computed normalized difference and simple ratio vegetation indices as SZA increased for near-nadir view angles. Hemispheric spectral reflectances or spectral albedos were computed from angular integration of PARABOLA measured bidirectional reflectances. Visible (662 nm) hemispheric reflectances for the jack pine and black spruce canopies showed very little variation with solar zenith angle, while near-infrared hemispheric reflectances increased strongly with increasing SZA. Estimates were made of the total shortwave albedo for the aspen and jack pine sites from irradiance and reflectance weighting of the spectral hemispheric reflectances in the three measured wavelengths. Comparison of estimated to pyranometer measured total albedo showed all estimates to be biased high, but only by about 0.007–0.018, depending on which of two sets of pyranometer measured albedos were utilized for the comparison. The measured bidirectional reflectance factor (BRF) data sets reported in this study coupled with ancillary data of biophysical parameters collected at the same sites by BOREAS researchers provide a unique data set for the development and characterization of canopy bidirectional reflectance modeling and for the interpretation of remotely sensed data for boreal forest canopies.

Physical characteristics of summer sea ice across the Arctic Ocean

Sea ice characteristics were investigated during July and August on the 1994 transect across the Arctic Ocean. Properties examined from ice cores included salinity, temperature, and ice structure. Salinities measured near zero at the surface, increasing to 3–4‰ at the ice‐water interface. Ice crystal texture was dominated by columnar ice, comprising 90% of the ice sampled. Surface albedos of various ice types, measured with radiometers, showed integrated shortwave albedos of 0.1 to 0.3 for melt ponds, 0.5 for bare, discolored ice, and 0.6 to 0.8 for a deteriorated surface or snow‐covered ice. Aerial photography was utilized to document the distribution of open melt ponds, which decreased from 12% coverage of the ice surface in late July at 76°N to almost none in mid‐August at 88°N. Most melt ponds were shallow, and depth bore no relationship to size. Sediment was pervasive from the southern Chukchi Sea to the north pole, occurring in bands or patches. It was absent in the Eurasian Arctic, where it had been observed on earlier expeditions. Calculations of reverse trajectories of the sediment‐bearing floes suggest that the southernmost sediment was entrained during ice formation in the Beaufort Sea while more northerly samples probably originated in the East Siberian Sea, some as far west as the New Siberian Islands.

The physical, radiative and microwave scattering characteristics of melt ponds on Arctic landfast sea ice

Melt ponds are an important characteristic of Arctic sea ice because of their control on the surface radiation balance. Little is known about the physical nature of these features and to date there is no operational method for detection of their formation or estimation of their aerial fraction. Coincident in situ observations, aerial surveys and synthetic aperture radar data from a field site in Arctic Canada are compared in an evaluation of the physical, radiative and electrical properties of melt ponds on first-year and multiyear sea ice. Results show that the interrelationships between the thermal diffusivity and conductivity of the snow cover control the mechanisms of snow ablation. Aerial fractions of snow patches, and light and dark coloured melt ponds, show considerable variation both as a function of proximity to land and due to ice type. First-year sea ice is shown to have a water background with discrete snow patches distributed throughout. Multiyear sea ice consists of discrete 'particles' within a snow background. Morphological measurements indicate that snow patches range in size with average areas of from 5 to 20m2 . Pond sizes over multiyear sea ice are also highly variable with averages ranging from 15 to 20m2. The integrated shortwave albedo was measured in the field and averaged to: snow patches (0.64 0.07); light melt ponds (0.29 0.04); and dark melt ponds (0.14 0.03). Snow patch size statistics explained a statistically significant proportion of the surface shortwave albedo. We found that microwave scattering could be used to obtain a measure of the onset ofmelt and had utility in detecting subtle details ofthe thermodynamic transition from winter through early melt into pond formation. We formalized a statistical relationship between microwave scattering and surface climatological albedo (sigma-alpha relationship). We found the relationship valid only for landfast firstyear sea ice under windy conditions. We conclude with a discussion of the role of surface wind stress and diurnal cycling in specification of the sigma-alpha relationship.

On the effect of cloud inhomogeneity an area averaged radiative properties of contrails

Certainly cloud inhomogeneity is not only important for cumulus or stratocumulus clouds on which the focus of most of the current studies is. To show that the impact of contrail cirrus microphysical inhomogeneity on cloud albedo can be deduced, fields of ice water content, effective radius, number density, and size distribution of ice particles generated by large eddy simulations (LESs) have been used within two‐dimensional radiative transfer schemes to elucidate the effect of cloud inhomogeneity on area average radiative properties of contrails at evolution stages in the late dispersion regime. The results obtained indicate that differences in shortwave cloud albedo between homogeneous and inhomogeneous conditions remain small for fresh contrails but can become important if contrails would attain larger optical depths. In that case larger differences were obtained at which the albedo for horizontal homogeneous conditions is always larger than the corresponding value for inhomogeneous conditions.