scholarly journals Satellite-Based Estimation of Temporally Resolved Dust Radiative Forcing in Snow Cover

2016 ◽  
Vol 17 (7) ◽  
pp. 1999-2011 ◽  
Author(s):  
Steven D. Miller ◽  
Fang Wang ◽  
Ann B. Burgess ◽  
S. McKenzie Skiles ◽  
Matthew Rogers ◽  
...  
Keyword(s):  
Solar Irradiance ◽  
Radiative Forcing ◽  
Hydrological Cycle ◽  
Clear Sky ◽  
Operational Management ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Sky Conditions

Abstract Runoff from mountain snowpack is an important freshwater supply for many parts of the world. The deposition of aeolian dust on snow decreases snow albedo and increases the absorption of solar irradiance. This absorption accelerates melting, impacting the regional hydrological cycle in terms of timing and magnitude of runoff. The Moderate Resolution Imaging Spectroradiometer (MODIS) Dust Radiative Forcing in Snow (MODDRFS) satellite product allows estimation of the instantaneous (at time of satellite overpass) surface radiative forcing caused by dust. While such snapshots are useful, energy balance modeling requires temporally resolved radiative forcing to represent energy fluxes to the snowpack, as modulated primarily by varying cloud cover. Here, the instantaneous MODDRFS estimate is used as a tie point to calculate temporally resolved surface radiative forcing. Dust radiative forcing scenarios were considered for 1) clear-sky conditions and 2) all-sky conditions using satellite-based cloud observations. Comparisons against in situ stations in the Rocky Mountains show that accounting for the temporally resolved all-sky solar irradiance via satellite retrievals yields a more representative time series of dust radiative effects compared to the clear-sky assumption. The modeled impact of dust on enhanced snowmelt was found to be significant, accounting for nearly 50% of the total melt at the more contaminated station sites. The algorithm is applicable to regional basins worldwide, bearing relevance to both climate process research and the operational management of water resources.

scholarly journals Snow Albedo Seasonality and Trend from MODIS Sensor and Ground Data at Johnsons Glacier, Livingston Island, Maritime Antarctica

Sensors ◽  
2019 ◽  
Vol 19 (16) ◽  
pp. 3569
Author(s):  
Calleja ◽  
Corbea-Pérez ◽  
Fernández ◽  
Recondo ◽  
Peón ◽  
...  
Keyword(s):  
Moving Average ◽  
Data Sets ◽  
Snow Albedo ◽  
Livingston Island ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Sky Conditions ◽  
Cloud Mask

The aim of this work is to investigate whether snow albedo seasonality and trend under all sky conditions at Johnsons Glacier (Livingston Island, Antarctica) can be tracked using the Moderate Resolution Imaging Spectroradiometer (MODIS) snow albedo daily product MOD10A1. The time span is from December 2006 to February 2015. As the MOD10A1 snow albedo product has never been used in Antarctica before, we also assess the performance for the MOD10A1 cloud mask. The motivation for this work is the need for a description of snow albedo under all sky conditions (including overcast days) using satellite data with mid-spatial resolution. In-situ albedo was filtered with a 5-day windowed moving average, while the MOD10A1 data were filtered using a maximum filter. Both in-situ and MOD10A1 data follow an exponential decay during the melting season, with a maximum decay of 0.049/0.094 day−1 (in-situ/MOD10A1) for the 2006–2007 season and a minimum of 0.016/0.016 day−1 for the 2009–2010 season. The duration of the decay varies from 85 days (2007–2008) to 167 days (2013–2014). Regarding the albedo trend, both data sets exhibit a slight increase of albedo, which may be explained by an increase of snowfall along with a decrease of snowmelt in the study area. Annual albedo increases of 0.2% and 0.7% are obtained for in-situ and MOD10A1 data, respectively, which amount to respective increases of 2% and 6% in the period 2006–2015. We conclude that MOD10A1 can be used to characterize snow albedo seasonality and trend on Livingston Island when filtered with a maximum filter.

scholarly journals Differences in Fine Particle Chemical Composition on Clear and Cloudy Days

2020 ◽  
Author(s):  
Amy E. Christiansen ◽  
Annmarie G. Carlton ◽  
Barron H. Henderson
Keyword(s):  
Chemical Composition ◽  
Fine Particulate Matter ◽  
The United States ◽  
Chemical Constituent ◽  
Clear Sky ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Aerosol Cloud Interactions

Abstract. Clouds are prevalent and alter fine particulate matter (PM2.5) mass and chemical composition. Cloud-affected satellite retrievals are subject to higher uncertainty and are often removed from data products, hindering quantitative estimates of tropospheric chemical composition during cloudy times. We examine surface PM2.5 chemical constituent concentrations in the Interagency Monitoring of PROtected Visual Environments (IMPROVE) network in the United States during Cloudy and Clear Sky times defined using Moderate Resolution Imaging Spectroradiometer (MODIS) cloud flags from 2010-2014 with a focus on differences in particle hygroscopicity and aerosol liquid water (ALW). Cloudy and Clear Sky periods exhibit significant differences in PM2.5 mass and chemical composition that vary regionally and seasonally. In the eastern US, relative humidity alone cannot explain differences in ALW, suggesting emissions and in situ chemistry exert determining impacts. An implicit clear sky bias may hinder efforts to quantitatively understand and improve representation of aerosol-cloud interactions, which remain dominant uncertainties in models.

scholarly journals Observation-Based Longwave Cloud Radiative Kernels Derived from the A-Train

2016 ◽  
Vol 29 (6) ◽  
pp. 2023-2040 ◽  
Author(s):  
Qing Yue ◽  
Brian H. Kahn ◽  
Eric J. Fetzer ◽  
Mathias Schreier ◽  
Sun Wong ◽  
...  
Keyword(s):  
Radiative Forcing ◽  
Single Layer ◽  
Cloud Fraction ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Clear Sky ◽  
Cloud Properties ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer

Abstract The authors present a new method to derive both the broadband and spectral longwave observation-based cloud radiative kernels (CRKs) using cloud radiative forcing (CRF) and cloud fraction (CF) for different cloud types using multisensor A-Train observations and MERRA data collocated on the pixel scale. Both observation-based CRKs and model-based CRKs derived from the Fu–Liou radiative transfer model are shown. Good agreement between observation- and model-derived CRKs is found for optically thick clouds. For optically thin clouds, the observation-based CRKs show a larger radiative sensitivity at TOA to cloud-cover change than model-derived CRKs. Four types of possible uncertainties in the observed CRKs are investigated: 1) uncertainties in Moderate Resolution Imaging Spectroradiometer cloud properties, 2) the contributions of clear-sky changes to the CRF, 3) the assumptions regarding clear-sky thresholds in the observations, and 4) the assumption of a single-layer cloud. The observation-based CRKs show the TOA radiative sensitivity of cloud types to unit cloud fraction change as observed by the A-Train. Therefore, a combination of observation-based CRKs with cloud changes observed by these instruments over time will provide an estimate of the short-term cloud feedback by maintaining consistency between CRKs and cloud responses to climate variability.

scholarly journals Consequences of the 2019 Greenland Ice Sheet Melt Episode on Albedo

2021 ◽  
Vol 13 (2) ◽  
pp. 227
Author(s):  
Arthur Elmes ◽  
Charlotte Levy ◽  
Angela Erb ◽  
Dorothy K. Hall ◽  
Ted A. Scambos ◽  
...  
Keyword(s):  
Radiative Forcing ◽  
Surface Albedo ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Surface Energy Budget ◽  
Landsat 8 ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Seasonal Snow Cover

In mid-June 2019, the Greenland ice sheet (GrIS) experienced an extreme early-season melt event. This, coupled with an earlier-than-average melt onset and low prior winter snowfall over western Greenland, led to a rapid decrease in surface albedo and greater solar energy absorption over the melt season. The 2019 melt season resulted in significantly more melt than other recent years, even compared to exceptional melt years previously identified in the moderate-resolution imaging spectroradiometer (MODIS) record. The increased solar radiation absorbance in 2019 warmed the surface and increased the rate of meltwater production. We use two decades of satellite-derived albedo from the MODIS MCD43 record to show a significant and extended decrease in albedo in Greenland during 2019. This decrease, early in the melt season and continuing during peak summer insolation, caused increased radiative forcing of the ice sheet of 2.33 Wm−2 for 2019. Radiative forcing is strongly influenced by the dramatic seasonal differences in surface albedo experienced by any location experiencing persistent and seasonal snow-cover. We also illustrate the utility of the newly developed Landsat-8 albedo product for better capturing the detailed spatial heterogeneity of the landscape, leading to a more refined representation of the surface energy budget. While the MCD43 data accurately capture the albedo for a given 500 m pixel, the higher spatial resolution 30 m Landsat-8 albedos more fully represent the detailed landscape variations.

scholarly journals The decreasing albedo of Zhadang glacier on western Nyainqentanglha and the role of light-absorbing impurities

2014 ◽  
Vol 14 (9) ◽  
pp. 13109-13131 ◽  
Author(s):  
B. Qu ◽  
J. Ming ◽  
S.-C. Kang ◽  
G.-S. Zhang ◽  
Y.-W. Li ◽  
...  
Keyword(s):  
Mass Balance ◽  
Atmospheric Aerosols ◽  
Radiative Forcing ◽  
Large Change ◽  
In Situ Data ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Glacier Ablation ◽  
Terra Satellite

Abstract. The large change in albedo has a great effect on glacier ablation. Atmospheric aerosols (e.g. black carbon (BC) and dust) can reduce the albedo of glaciers and thus contribute to their melting. In this study, we investigated the measured albedo as well as the relationship between albedo and mass balance in Zhadang glacier on Mt. Nyanqentanglha associated with MODIS (10A1) data. The impacts of BC and dust in albedo reduction in different melting conditions were identified with SNow ICe Aerosol Radiative (SNICAR) model and in-situ data. It was founded that the mass balance of the glacier has a significant correlation with its surface albedo derived from Moderate Resolution Imaging Spectroradiometer (MODIS) onboard Terra satellite. The average albedo of Zhadang glacier from MODIS increased with the altitude and fluctuated but overall had a decreasing trend during 2001–2010, with the highest (0.722) in 2003 and the lowest (0.597) in 2009 and 2010, respectively. The sensitivity analysis via SNICAR showed that BC was a major factor in albedo reduction when the glacier was covered by newly fallen snow. Nevertheless, the contribution of dust to albedo reduction can be as high as 58% when the glacier experienced strong surficial melting that the surface was almost bare ice. And the average radiative forcing (RF) caused by dust could increase from 1.1 to 8.6 W m−2 exceeding the forcings caused by BC after snow was deposited and surface melting occurred in Zhadang glacier. This suggest that it may be dust rather than BC, dominating the melting of some glaciers in the TP during melting seasons.

Test of a Modified Infrared-Only ABI Cloud Mask Algorithm for AHI Radiance Observations

2016 ◽  
Vol 55 (11) ◽  
pp. 2529-2546 ◽  
Author(s):  
X. Zhuge ◽  
X. Zou
Keyword(s):  
Near Infrared ◽  
Extended System ◽  
Clear Sky ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Cloud Mask ◽  
Very High ◽  
Lower False Alarm Rate ◽  
Infrared Channel

AbstractAssimilation of infrared channel radiances from geostationary imagers requires an algorithm that can separate cloudy radiances from clear-sky ones. An infrared-only cloud mask (CM) algorithm has been developed using the Advanced Himawari Imager (AHI) radiance observations. It consists of a new CM test for optically thin clouds, two modified Advanced Baseline Imager (ABI) CM tests, and seven other ABI CM tests. These 10 CM tests are used to generate composite CMs for AHI data, which are validated by using the Moderate Resolution Imaging Spectroradiometer (MODIS) CMs. It is shown that the probability of correct typing (PCT) of the new CM algorithm over ocean and over land is 89.73% and 90.30%, respectively and that the corresponding leakage rates (LR) are 6.11% and 4.21%, respectively. The new infrared-only CM algorithm achieves a higher PCT and a lower false-alarm rate (FAR) over ocean than does the Clouds from the Advanced Very High Resolution Radiometer (AVHRR) Extended System (CLAVR-x), which uses not only the infrared channels but also visible and near-infrared channels. A slightly higher FAR of 7.92% and LR of 6.18% occurred over land during daytime. This result requires further investigation.

scholarly journals Global White-Sky and Black-Sky FAPAR Retrieval Using the Energy Balance Residual Method: Algorithm and Validation

2019 ◽  
Vol 11 (9) ◽  
pp. 1004 ◽  
Author(s):  
Liu ◽  
Zhang ◽  
Xie ◽  
Liu ◽  
Song ◽  
...  
Keyword(s):  
Energy Balance ◽  
Area Index ◽  
Global Soil ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Comparison Of The Results ◽  
Spectral Mixture ◽  
Sky Conditions ◽  
Absorbed Photosynthetically Active Radiation

The fraction of absorbed photosynthetically active radiation by vegetation (FAPAR) is a key variable in describing the light absorption ability of the vegetation canopy. Most global FAPAR products, such as MCD15A2H and GEOV1, correspond to FAPAR under black-sky conditions at the satellite overpass time only. In this paper, we aim to produce both the global white-sky and black-sky FAPAR products based on the moderate resolution imaging spectroradiometer (MODIS) visible (VIS) albedo, leaf area index (LAI), and clumping index (CI) products. Firstly, a non-linear spectral mixture model (NSM) was designed to retrieve the soil visible (VIS) albedo. The global soil VIS albedo and its dynamics were successfully mapped at a resolution of 500 m using the MCD43A3 VIS albedo product and the MCD15A2H LAI product. Secondly, a method based on the energy balance residual (EBR) principle was presented to retrieve the white-sky and black-sky FAPAR using the MODIS broadband VIS albedo (white-sky and black-sky) product (MCD43A3), the LAI product (MCD15A2H) and CI products. Finally, the two EBR FAPAR products were compared with the MCD15A2H and Geoland2/BioPar version 1 (GEOV1) black-sky FAPAR products. A comparison of the results indicates that these FAPAR products show similar spatial and seasonal patterns. Direct validation using FAPAR observations from the Validation of Land European Remote sensing Instrument (VALERI) project demonstrates that the EBR black-sky FAPAR product was more accurate and had a lower bias (R2 = 0.917, RMSE = 0.088, and bias = −2.8 %) than MCD15A2H (R2 = 0.901, RMSE = 0.096, and bias = 7.6 % ) and GEOV1 (R2 = 0.868, RMSE = 0.105, and bias = 6.1%).

scholarly journals Seguimiento satelital de las condiciones océano-atmosféricas asociadas a los eventos de precipitación en Colombia durante el evento La Niña 2010–2011

2014 ◽  
pp. 123-134
Author(s):  
Martha Lucero Bastidas Salamanca ◽  
Apolinar Figueroa Casas
Keyword(s):  
La Niña ◽  
La Nina ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
La Niña 2010

La comprensión de la variabilidad climática es un tema de gran interés científico debido a que puede repercutir en las condiciones ambientales y socio-económicas de un país. Este estudio hace uso de datos satelitales para describir los eventos de precipitación ocurridos en el territorio colombiano durante el evento de La Niña 2010-2011 y registrados en estaciones meteorológicas costeras del Caribe. Se utilizaron datos de la temperatura de brillo de las nubes, medida por el Geostationary Operational Envirormental Satellite -GOES-12; datos de temperatura superficial del mar derivados de imágenes mensuales del Moderate Resolution Imaging Spectroradiometer – MODIS, y datos de precipitación intisituto de dos estaciones meteorológicas costeras (Cartagena y Santa Marta). Las imágenes satelitales GOES permitieron describir el evento La Niña 2010-2011 a partir de la identificación de nubes altas y complejos convectivos de mesoescala, los cuales se asocian a elevadas precipitaciones; mientras que las imágenes MODIS evidenciaron un comportamiento oceánico opuesto entre el Caribe colombiano, que exhibió anomalías positivas, y el Pacífico Oriental Tropical, que experimentó la influencia del evento y lo reflejó en anomalías negativas. Modelos lineales empleando datos satelitales de temperatura superficial del mar, in situ de precipitación y del Índice de Oscilación del Sur, revelaron que solamente para la estación ubicada en El Rodadero (Santa Marta), la precipitación fue explicada por la temperatura superficial del mar adyacente, mientras que el IOS no resultó significativo.

scholarly journals Satellite-based radiative forcing by light-absorbing particles in snow across the Northern Hemisphere

2020 ◽  
Author(s):  
Jiecan Cui ◽  
Tenglong Shi ◽  
Yue Zhou ◽  
Dongyou Wu ◽  
Xin Wang ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Northern Hemisphere ◽  
Radiative Forcing ◽  
Remote Sensing Data ◽  
The Arctic ◽  
Snow Albedo ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Earth’S Climate

Abstract. Snow is the most reflective natural surface on Earth and consequently plays an important role in Earth’s climate. Light-absorbing particles (LAPs) deposited on the snow surface can effectively decrease snow albedo, resulting in positive radiative forcing. In this study, we used remote sensing data from NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) and the Snow, Ice, and Aerosol Radiative (SNICAR) model to quantify the reduction in snow albedo due to LAPs, before validating and correcting the data against in situ observations. We then incorporated these corrected albedo reduction data in the Santa Barbara DISORT Atmospheric Radiative Transfer (SBDART) model to estimate Northern Hemisphere radiative forcing in January and February for the period 2003–2018. Our analysis reveals an average corrected reduction in snow albedo of ~0.0246, with instantaneous radiative forcing and daily radiative forcing values of ~5.87 and ~1.69 W m−2, respectively. We also observed significant spatial variations in corrected snow albedo reduction, instantaneous radiative forcing and daily radiative forcing throughout the Northern Hemisphere, with the lowest respective values (~0.0123, ~1.09 W m−2, and ~0.29 W m−2) occurring in the Arctic and the highest (~0.1669, ~36.02 W m−2, and ~10.60 W m−2) in northeastern China. From MODIS retrievals, we determined that the LAP content of snow accounts for 57.6 % and 37.2 % of the spatial variability in Northern Hemisphere albedo reduction and radiative forcing, respectively. We also compared retrieved radiative forcing values with those of earlier studies, including local-scale observations, remote-sensing retrievals, and model-based estimates. Ultimately, estimates of radiative forcing based on satellite-retrieved data are shown to represent true conditions on both regional and global scales.

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