Product dependency of Fire-driven surface albedo radiative forcing global estimates: a spatial and temporal consistency analysis

2020 ◽  
Author(s):  
Bernardo Mota ◽  
Nadine Gobron ◽  
Christian Lanconelli ◽  
Fabrizio Capucci
Keyword(s):  
Land Surface ◽  
Radiative Forcing ◽  
Surface Albedo ◽  
Temporal Trends ◽  
Model Space ◽  
Earth Observation ◽  
Temporal Consistency ◽  
Burnt Area ◽  
Albedo Change ◽  
Global Land

<p><span>This paper addresses the product consistency in a cross-ECV model space driven ECV’s to estimate the radiative forcing (RF) due to the direct effect of fire- driven surface albedo change. </span><span>Monthly radiative forcing’s are modeled </span><span>using three Earth Observation land surface albedo (MCD43C3, GlobAlbedo and Copernicus Global Land Services) and five burnt area (FireCCIv4, FireCCIv5, MCD45C5, MCD64C6 and Copernicus Global Land Services) products, and the ERA5 downward Solar radiation at the Surface</span><span>. </span><span>The ensemble consistency is analyzed spatially and seasonally by vegetation cover type using the Land Cover CCI product, and using four spatial resolutions (0.05</span><span>°</span><span>, 0.10</span><span>°</span><span>, 025</span><span>°</span><span> and 0.5</span><span>°). </span><span>Results </span><span>show that depending on the combined products and spatial resolution, estimates can differ significantly. In general, higher estimates result at coarser resolutions and variation between product combinations can differ between 26% to 46%, depending on the type of vegetation. In addition, significant temporal trends of opposing signs can be detected. </span><span>This study presents an example of cross-ECV modelling. Due to the increasing number, and coverage, of Earth Observation satellite programs, these results highlight the need to assess the </span><span>fitness for purpose </span><span>of the derived products.</span></p>

scholarly journals Spatiotemporal Variability of Land Surface Albedo over the Tibet Plateau from 2001 to 2019

2020 ◽  
Vol 12 (7) ◽  
pp. 1188
Author(s):  
Xingwen Lin ◽  
Jianguang Wen ◽  
Qinhuo Liu ◽  
Dongqin You ◽  
Shengbiao Wu ◽  
...  
Keyword(s):  
Climate Change ◽  
Time Series ◽  
Land Cover ◽  
Snow Cover ◽  
Land Surface ◽  
Radiative Forcing ◽  
Surface Albedo ◽  
Tibet Plateau ◽  
Land Cover Types ◽  
Yearly Average

As an essential climate variable (ECV), land surface albedo plays an important role in the Earth surface radiation budget and regional or global climate change. The Tibetan Plateau (TP) is a sensitive environment to climate change, and understanding its albedo seasonal and inter-annual variations is thus important to help capture the climate change rules. In this paper, we analyzed the large-scale spatial patterns, temporal trends, and seasonal variability of land surface albedo overall the TP, based on the moderate resolution imaging spectroradiometer (MODIS) MCD43 albedo products from 2001 to 2019. Specifically, we assessed the correlations between the albedo anomaly and the anomalies of normalized difference vegetation index (NDVI), the fraction of snow cover (snow cover), and land surface temperature (LST). The results show that there are larger albedo variations distributed in the mountainous terrain of the TP. Approximately 10.06% of the land surface is identified to have been influenced by the significant albedo variation from the year 2001 to 2019. The yearly averaged albedo was decreased significantly at a rate of 0.0007 (Sen’s slope) over the TP. Additionally, the yearly average snow cover was decreased at a rate of 0.0756. However, the yearly average NDVI and LST were increased with slopes of 0.0004 and 0.0253 over the TP, respectively. The relative radiative forcing (RRF) caused by the land cover change (LCC) is larger than that caused by gradual albedo variation in steady land cover types. Overall, the RRF due to gradual albedo variation varied from 0.0005 to 0.0170 W/m2, and the RRF due to LCC variation varied from 0.0037 to 0.0243 W/m2 during the years 2001 to 2019. The positive RRF caused by gradual albedo variation or the LCC can strengthen the warming effects in the TP. The impact of the gradual albedo variations occurring in the steady land cover types was very low between 2001 and 2019 because the time series was short, and it therefore cannot be neglected when examining radiative forcing for a long time series regarding climate change.

scholarly journals The impact of deforestation in the Amazonian atmospheric radiative balance: a remote sensing assessment

2012 ◽  
Vol 12 (6) ◽  
pp. 14837-14874 ◽  
Author(s):  
E. T. Sena ◽  
P. Artaxo ◽  
A. L. Correia
Keyword(s):  
Water Vapour ◽  
Biomass Burning ◽  
Radiative Forcing ◽  
Surface Albedo ◽  
Radiative Effect ◽  
Water Vapour Content ◽  
Albedo Change ◽  
Direct Radiative Forcing ◽  
The Mean ◽  
The Impact

Abstract. This paper addresses the Amazonian radiative budget after considering three aspects of deforestation: (i) the emission of aerosols from biomass burning due to forest fires; (ii) changes in surface albedo after deforestation and (iii) modifications in the column water vapour amount over deforested areas. Simultaneous Clouds and the Earth's Radiant Energy System (CERES) shortwave fluxes and aerosol optical depth (AOD) retrievals from the Moderate Resolution Imaging SpectroRadiometer (MODIS) were analysed during the peak of the biomass burning seasons (August and September) from 2000 to 2009. A discrete-ordinate radiative transfer (DISORT) code was used to extend instantaneous remote sensing radiative forcing assessments into 24-h averages. The mean direct radiative forcing of aerosols at the top of the atmosphere (TOA) during the biomass burning season for the 10-yr studied period was −5.6 ± 1.7 W m−2. Furthermore, the spatial distribution of the direct radiative forcing of aerosols over Amazon was obtained for the biomass burning season of each year. It was observed that for high AOD (larger than 1 at 550 nm) the imbalance in the radiative forcing at the TOA may be as high as −20 W m−2 locally. The surface reflectance plays a major role in the aerosol direct radiative effect. The study of the effects of biomass burning aerosols over different surface types shows that the direct radiative forcing is systematically more negative over forest than over savannah-like covered areas. Values of −15.7 ± 2.4 W m−2/τ550 nm and −9.3 ± 1.7 W m−2/τ550 nm were calculated for the mean daily aerosol forcing efficiencies over forest and savannah-like vegetation respectively. The overall mean annual albedo-change radiative forcing due to deforestation over the state of Rondônia, Brazil, was determined as −7.3 ± 0.9 W m−2. Biomass burning aerosols impact the radiative budget for approximately two months per year, whereas the surface albedo impact is observed throughout the year. Because of this difference, the estimated impact in the Amazonian annual radiative budget due to surface albedo-change is approximately 6 times higher than the impact due to aerosol emissions. The influence of atmospheric water vapour content in the radiative budget was also studied using AERONET column water vapour. It was observed that column water vapour is in average smaller by about 0.35 cm over deforested areas compared to forested areas. Our results indicate that this drying impact contributes to an increase in the shortwave radiative effect that varies from 0.4 W m−2 to 1.2 W m−2, depending on the column water vapour content before deforestation. The large radiative forcing values presented in this study point out that deforestation has strong implications in convection, cloud development and photosynthesis rate over the Amazon region.

scholarly journals Global analysis of radiative forcing from fire-induced shortwave albedo change

2015 ◽  
Vol 12 (2) ◽  
pp. 557-565 ◽  
Author(s):  
G. López-Saldaña ◽  
I. Bistinas ◽  
J. M. C. Pereira
Keyword(s):  
Land Surface ◽  
Radiative Forcing ◽  
Global Analysis ◽  
Weather Prediction ◽  
Global Scale ◽  
Burned Area ◽  
Albedo Change ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Environmental Prediction ◽  
Area Product

Abstract. Land surface albedo, a key parameter to derive Earth's surface energy balance, is used in the parameterization of numerical weather prediction, climate monitoring and climate change impact assessments. Changes in albedo due to fire have not been fully investigated on a continental and global scale. The main goal of this study, therefore, is to quantify the changes in instantaneous shortwave albedo produced by biomass burning activities and their associated radiative forcing. The study relies on the MODerate-resolution Imaging Spectroradiometer (MODIS) MCD64A1 burned-area product to create an annual composite of areas affected by fire and the MCD43C2 bidirectional reflectance distribution function (BRDF) albedo snow-free product to compute a bihemispherical reflectance time series. The approximate day of burning is used to calculate the instantaneous change in shortwave albedo. Using the corresponding National Centers for Environmental Prediction (NCEP) monthly mean downward solar radiation flux at the surface, the global radiative forcing associated with fire was computed. The analysis reveals a mean decrease in shortwave albedo of −0.014 (1σ = 0.017), causing a mean positive radiative forcing of 3.99 Wm−2 (1σ = 4.89) over the 2002–20012 time period in areas affected by fire. The greatest drop in mean shortwave albedo change occurs in 2002, which corresponds to the highest total area burned (378 Mha) observed in the same year and produces the highest mean radiative forcing (4.5 Wm−2). Africa is the main contributor in terms of burned area, but forests globally give the highest radiative forcing per unit area and thus give detectable changes in shortwave albedo. The global mean radiative forcing for the whole period studied (~0.0275 Wm−2) shows that the contribution of fires to the Earth system is not insignificant.

scholarly journals Developing a monthly albedo change radiative forcing kernel from satellite climatologies of Earth's shortwave radiation budget: CACK v1.0

2019 ◽  
Author(s):  
Ryan M. Bright ◽  
Thomas L. O'Halloran
Keyword(s):  
Radiative Forcing ◽  
General Circulation ◽  
Surface Albedo ◽  
Radiant Energy ◽  
Radiation Budget ◽  
Shortwave Radiation ◽  
Attractive Alternative ◽  
Albedo Change ◽  
Science Community ◽  
Atmospheric State

Abstract. Due to the potential for land use/land cover change (LULCC) to alter surface albedo, there is need within the LULCC science community for simple and transparent tools for predicting radiative forcings (dF) from surface albedo changes (da). To that end, the radiative kernel technique – developed by the climate modeling community to diagnose internal feedbacks within general circulation models (GCMs) – has been adopted by the LULCC science community as a tool to perform offline dF calculations for da. However, the GCM codes are not readily transparent and the atmospheric state variables used as model input are limited to single years, thus being sensitive to anomalous weather conditions that may have occurred in those simulated years. Observation-based kernels founded on longer-term climatologies of Earth's atmospheric state offer an attractive alternative to GCM-based kernels and could be updated annually at relatively low costs. Here, we evaluate simplified models of shortwave radiative transfer as candidates for an albedo change kernel founded on the Clouds and the Earth's Radiant Energy System (CERES) Energy Balance and Filled (EBAF) products. We find that a new, simple model supported by statistical analyses gives remarkable agreement when benchmarked to the mean of four GCM kernels and to two GCM kernels following emulation with their own boundary fluxes as input. Our findings lend support to its candidacy as a satellite-based alternative to GCM kernels and to its application in land-climate studies.

scholarly journals Mapping global land surface albedo from NOAA AVHRR

1999 ◽  
Vol 104 (D6) ◽  
pp. 6215-6228 ◽  
Author(s):  
I. Csiszar ◽  
G. Gutman
Keyword(s):  
Land Surface ◽  
Surface Albedo ◽  
Noaa Avhrr ◽  
Global Land

scholarly journals The climatology of dust aerosol over the arabian peninsula

2015 ◽  
Vol 15 (2) ◽  
pp. 1523-1571 ◽  
Author(s):  
A. Shalaby ◽  
B. Rappenglueck ◽  
E. A. B. Eltahir
Keyword(s):  
Land Surface ◽  
Radiative Forcing ◽  
Large Scale ◽  
Surface Albedo ◽  
Arabian Peninsula ◽  
Mineral Dust ◽  
Dust Storms ◽  
Dust Aerosol ◽  
Dust Aerosols ◽  
Mineral Dust Aerosols

Abstract. Dust storms are considered to be a natural hazard over the Arabian Peninsula, since they occur all year round with maximum intensity and frequency in Spring and Summer. The Regional Climate Model version 4 (RegCM4) has been used to study the climatology of atmospheric dust over the Arabian Peninsula from 1999 to 2012. This relatively long simulation period samples the meteorological conditions that determine the climatology of mineral dust aerosols over the Arabian Peninsula. The modeled Aerosol Optical Depth (AOD) has been compared against ground-based observations of three Aerosol Robotic Network (AERONET) stations that are distributed over the Arabian Peninsula and daily space based observations from the Multi-angle Imaging SpectroRadiometer (MISR), the Moderate resolution Imaging SpectroRadimeter (MODIS) and Ozone Monitoring Instrument (OMI). The large scale atmospheric circulation and the land surface response that lead to dust uplifting have been analyzed. While the modeled AOD shows that the dust season extends from March to August with two pronounced maxima, one over the northern Arabian Peninsula in March with AOD equal to 0.4 and one over the southern Arabian Peninsula in July with AOD equal to 0.7, the observations show that the dust season extends from April to August with two pronounced maxima, one over the northern Arabian Peninsula in April with AOD equal to 0.5 and one over the southern Arabian Peninsula in July with AOD equal to 0.5. In spring a high pressure dominates the Arabian Peninsula and is responsible for advecting dust from southern and western part of the Arabian Peninsula to northern and eastern part of the Peninsula. Also, fast developed cyclones in northern Arabian Peninsula are responsible for producing strong dust storms over Iraq and Kuwait. However, in summer the main driver of the surface dust emission is the strong northerly wind ("Shamal") that transport dust from the northern Arabian Peninsula toward south parallel to the Arabian Gulf. The AERONET shortwave Top of Atmosphere Radiative Forcing (TOARF) and at the Bottom of Atmosphere Radiative Forcing (BOARF) have been analyzed and compared with the modeled direct radiative forcing of mineral dust aerosol. The annual modeled TOARF and BOARF are −3.3 and −12 W m−2, respectively. However, the annual observed TOARF and BOARF are significantly different at −10 and −52 W m−2, respectively. The analysis of observed and modeled TOARF agrees with previous studies in highlighting the need for more accurate specification of surface albedo over the region. Due to the high surface albedo of the central Arabian Peninsula, mineral dust aerosols tend to warm the atmosphere in summer (June–August).

scholarly journals Cross-Comparison of Global Surface Albedo Operational Products—MODIS, GLASS, and CGLS

2021 ◽  
Vol 13 (23) ◽  
pp. 4869
Author(s):  
Congying Shao ◽  
Yanmin Shuai ◽  
Latipa Tuerhanjiang ◽  
Xuexi Ma ◽  
Weijie Hu ◽  
...  
Keyword(s):  
Energy Balance ◽  
Land Surface ◽  
Surface Albedo ◽  
Relative Difference ◽  
Surface Radiation ◽  
Radiation Budget ◽  
Dynamic Monitoring ◽  
Absolute Difference ◽  
Global Land ◽  
Global Mean

Surface albedo, as an important parameter for land surface geo-biophysical and geo-biochemical processes, has been widely used in the research communities involved in surface energy balance, weather forecasting, atmospheric circulation, and land surface process models. In recent years, operational products using satellite-based surface albedo have, from time to time, been rapidly developed, contributing significantly to the estimation of energy balance at regional or global scales. The increasing number of research topics on dynamic monitoring at a decades-long scale requires a combination of albedo products generated from various sensors or programs, while the quantitative assessment of agreement or divergence among different surface albedo products still needs further understanding. In this paper, we investigated the consistency of three classical operational surface albedo products that have been frequently used by researchers globally via the official issued datasets-MODIS, GLASS (Global LAnd Surface Satellite), and CGLS (Copernicus Global Land Service). The cross-comparison was performed on all the identical dates available during 2000–2017 to represent four season-phases. We investigated the pixel-based validity of each product, consistency of global annual mean, spatial distribution and different temporal dynamics among the discussed products in white-sky (WSA) and black-sky (BSA) albedo at visible (VIS), near-infrared (NIR), and shortwave (SW) regimes. Further, varying features along with the change of seasons was also examined. In addition, the variation in accuracy of shortwave albedo magnitude was explored using ground measurements collected by the Baseline Surface Radiation Network (BSRN) and the Surface Radiation Budget Network (SUFRAD). Results show that: (1) All three products can provide valid long-term albedo for dominant land surface, while GLASS can provide additional estimation over sea surfaces, with the highest percentage of valid land surface pixels, at up to 93% in October 24. The invalid pixels mainly existed in the 50°N–60°N latitude belt in December for GLASS, Central Africa in April and August for MODIS, and northern high latitudes for CGLS. (2) The global mean albedo of CGLS at the investigated bands has significantly higher values than those of MODIS and GLASS, with a relative difference of ~20% among the three products. The global mean albedo of MODIS and GLASS show a generally increasing trend from April to December, with an abrupt rise at NIR and SW of CGLS in June of 2014. Compared with SW and VIS bands, the linear temporal trend of the NIR global albedo mean in three products continues to increase, but the slope of CGLS is 10–100 times greater than that of the other two products. (3) The differences in albedo, which are higher in April, October, and December than in August, exhibit a small variation over the main global land surface regions, except for Central Eurasia, North Africa, and middle North America. The magnitude of global absolute difference among the three products usually varies within 0.02–0.06, but with the largest value occasionally exceeding 0.1. The relative difference is mainly within 10%–20%, and can deviate more than 40% away from the baseline. In addition, CGLS has a greater opportunity to achieve the largest difference compared with MODIS and GLASS. (4) The comparison with ground measurements indicates that MODIS generally performs better than GLASS and CGLS at the sites discussed. This study demonstrates that apparent differences exist among the three investigated albedo products due to the ingested source data, algorithm, atmosphere correction etc., and also points at caution regarding data fusion when multiple albedo products were organized to serve the following applications.

scholarly journals CO<sub>2</sub>-equivalence metrics for surface albedo change based on the radiative forcing concept: a critical review

2021 ◽  
Vol 21 (12) ◽  
pp. 9887-9907
Author(s):  
Ryan M. Bright ◽  
Marianne T. Lund
Keyword(s):  
Radiative Forcing ◽  
Surface Albedo ◽  
Decision Makers ◽  
Spatial Disparity ◽  
Time Dependency ◽  
Considerable Research ◽  
Albedo Change ◽  
Co2 Equivalent ◽  
The Impact ◽  
Change Mitigation

Abstract. Management of Earth's surface albedo is increasingly viewed as an important climate change mitigation strategy both on (Seneviratne et al., 2018) and off (Field et al., 2018; Kravitz et al., 2018) the land. Assessing the impact of a surface albedo change involves employing a measure like radiative forcing (RF) which can be challenging to digest for decision-makers who deal in the currency of CO2-equivalent emissions. As a result, many researchers express albedo change (Δα) RFs in terms of their CO2-equivalent effects, despite the lack of a standard method for doing so, such as there is for emissions of well-mixed greenhouse gases (WMGHGs; e.g., IPCC AR5, Myhre et al., 2013). A major challenge for converting Δα RFs into their CO2-equivalent effects in a manner consistent with current IPCC emission metric approaches stems from the lack of a universal time dependency following the perturbation (perturbation “lifetime”). Here, we review existing methodologies based on the RF concept with the goal of highlighting the context(s) in which the resulting CO2-equivalent metrics may or may not have merit. To our knowledge this is the first review dedicated entirely to the topic since the first CO2-eq. metric for Δα surfaced 20 years ago. We find that, although there are some methods that sufficiently address the time-dependency issue, none address or sufficiently account for the spatial disparity between the climate response to CO2 emissions and Δα – a major critique of Δα metrics based on the RF concept (Jones et al., 2013). We conclude that considerable research efforts are needed to build consensus surrounding the RF “efficacy” of various surface forcing types associated with Δα (e.g., crop change, forest harvest), and the degree to which these are sensitive to the spatial pattern, extent, and magnitude of the underlying surface forcings.

scholarly journals CO<sub>2</sub>-equivalence metrics for surface albedo change based on the radiative forcing concept: A critical review

2020 ◽  
Author(s):  
Ryan M. Bright ◽  
Marianne T. Lund
Keyword(s):  
Radiative Forcing ◽  
Surface Albedo ◽  
Decision Makers ◽  
Spatial Disparity ◽  
Time Dependency ◽  
Considerable Research ◽  
Albedo Change ◽  
Co2 Equivalent ◽  
The Impact ◽  
Change Mitigation

Abstract. Management of Earth's surface albedo is increasingly viewed as an important climate change mitigation strategy both on (Seneviratne et al., 2018) and off (Field et al., 2018; Kravitz et al., 2018) the land. Assessing the impact of a surface albedo change involves employing a measure like radiative forcing (RF) which can be challenging to digest for decision-makers who deal in the currency of CO2-equivalent emissions. As a result, many researchers express albedo change (Δα) RFs in terms of their CO2-equivalent effects, despite the lack of a standard method for doing so, such as there is for emissions of well-mixed greenhouse gases (WMGHGs; e.g., IPCC AR5, Myhre et al. (2013)). A major challenge for converting Δα RFs into their CO2-equivalant effects in a manner consistent with current IPCC emission metric approaches stems from the lack of a universal time-dependency following the perturbation (perturbation lifetime). Here, we review existing methodologies based on the RF concept with the goal of highlighting the context(s) in which the resulting CO2-equivalent metrics may or may not have merit. To our knowledge this is the first review dedicated entirely to the topic since the first CO2-eq. metric for Δα surfaced 20 years ago. We find that, although there are some methods that sufficiently address the time-dependency issue, none address or sufficiently account for the spatial disparity between the climate response to CO2 emissions and Δα – a major critique of Δα metrics based on the RF concept (Jones et al., 2013). We conclude that considerable research efforts are needed to build consensus surrounding the RF efficacy of various surface forcing types associated with Δα (e.g., crop change, forest harvest, etc.), and the degree to which these are sensitive to the spatial pattern, extent, and magnitude of the underlying surface forcings.

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