scholarly journals Lake surface water temperature retrieval using advanced very high resolution radiometer and Moderate Resolution Imaging Spectroradiometer data: Validation and feasibility study

2005 ◽  
Vol 110 (C12) ◽  
Author(s):  
D. C. Oesch ◽  
J.-M. Jaquet ◽  
A. Hauser ◽  
S. Wunderle
Keyword(s):  
Surface Water ◽  
High Resolution ◽  
Data Validation ◽  
Surface Water Temperature ◽  
Lake Surface ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Temperature Retrieval ◽  
Very High

scholarly journals Inter-calibration of polar imager solar channels using SEVIRI

2013 ◽  
Vol 6 (2) ◽  
pp. 3215-3247 ◽  
Author(s):  
J. F. Meirink ◽  
R. A. Roebeling ◽  
P. Stammes
Keyword(s):  
High Resolution ◽  
Spectral Response ◽  
Calibration Method ◽  
Infrared Imager ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Aqua Satellite ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Direct Inter ◽  
Very High

Abstract. Accurate calibration of satellite imagers is a prerequisite for using their measurements in climate applications. Here we present a method for the inter-calibration of geostationary and polar-orbiting imager solar channels based on regressions of collocated near-nadir radiances. Specific attention is paid to correcting for differences in spectral response between instruments. The method is used to calibrate the solar channels of the Spinning Enhanced Visible and Infrared Imager (SEVIRI) on the geostationary Meteosat satellite with corresponding channels of the Moderate Resolution Imaging Spectroradiometer (MODIS) on the polar-orbiting Aqua satellite. The SEVIRI operational calibration is found to be stable during the years 2004 to 2009 but off by −8, −6, and +3.5% for channels 1 (0.6 μm), 2 (0.8 μm), and 3 (1.6 μm), respectively. These results are robust for a range of choices that can be made regarding data collocation and selection, as long as the viewing and illumination geometries of the two instruments are matched. Uncertainties in the inter-calibration method are estimated to be 1% for channel 1 and 1.5% for channels 2 and 3. A specific application of the method is the inter-calibration of polar imagers using SEVIRI as a transfer instrument. This offers an alternative to direct inter-calibration, which in general has to rely on high-latitude collocations. Using this method we have tied MODIS-Terra and Advanced Very High Resolution Radiometer (AVHRR) instruments on National Oceanic and Atmospheric Administration (NOAA) satellites 17 and 18 to MODIS-Aqua for the years 2007 to 2009. While reflectances of the two MODIS instruments differ less than 2% for all channels considered, deviations of an existing AVHRR calibration from MODIS-Aqua reach −3.5 and +2.5% for the 0.8 and 1.6 μm channels, respectively.

scholarly journals Padrões temporais da precipitação e variabilidade da vegetação sobre a bacia do rio Iriri em anos de ocorrência do El Niño Oscilação Sul (Temporal patterns of precipitation and vegetation variability over Iriri River basin during El Niño/Southern Oscilation)

2019 ◽  
Vol 12 (3) ◽  
pp. 789
Author(s):  
Jefferson Inayan Souto ◽  
Ariadne Reinaldo Trindade ◽  
Paulo Amador Tavares ◽  
Norma Ely Santos Beltrão ◽  
Altem Nascimento Pontes
Keyword(s):  
High Resolution ◽  
River Basin ◽  
El Niño ◽  
El Nino ◽  
Rainy Period ◽  
La Nina ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Very High

Este estudo investiga a evolução temporal do regime pluviométrico para a bacia do rio Iriri, e sua relação com o ciclo de crescimento da vegetação. Dados de precipitação baseados na técnica do CPC Morphing (CMORPH) e dados de índice de vegetação por diferença normalizada (NDVI) pelos sensores AVHRR (Advanced Very High Resolution Radiometer) e MODIS (Moderate Resolution Imaging Spectroradiometer) são analisados para o período de junho de 2009 a maio de 2014. Os resultados confirmam que o ciclo anual de precipitação da bacia do rio Iriri é caracterizado por uma variação intra-sazonal, que é ressoada na cobertura vegetal no decorrer dos meses. Durante o ano com ocorrência de La Niña, os excedentes mais extremos de precipitação mensal foram observados no meio da estação chuvosa (novembro a abril). Embora no período menos chuvoso os totais de precipitação possam não ser os mais altos, o NDVI varia de forma senoidal em decorrência da sazonalidade da região. Épocas chuvosas podem ser distinguidas das estações chuvosas que não sofrem influência de mecanismos de precipitação, examinando seus padrões de pico mensais. Além disso, foi identificado através do NDVI, que o período menos chuvoso pouco influência no índice vegetativo durante a ocorrência dos fenômenos do El Niño Oscilação Sul (ENOS). Estes resultados podem ter implicações importantes para compreensão da dinâmica dos recursos hídricos e provisões naturais para uma bacia composta por áreas protegidas.  A B S T R A C TThis study investigates the temporal evolution of the precipitation regime for the Iriri river basin, and its relation with the vegetation growth cycle. Precipitation data based on CPC Morphing (CMORPH) and normalized differential vegetation index (NDVI) data by AVHRR (Advanced Very High Resolution Radiometer) and MODIS (Moderate Resolution Imaging Spectroradiometer) are analyzed for the period June 2009 to May 2014. The results confirm that the annual precipitation cycle of the Iriri River basin is characterized by an intra-seasonal variation, which is resounded in the vegetation cover during the months. During the year with the occurrence of La Niña, the most extreme surpluses of monthly precipitation were observed in the middle of the rainy season (November to April). Although in the less rainy period precipitation totals may not be higher, the NDVI varies in sinusoidal form due to the seasonality of the region. Rainy seasons can be distinguished from rainy seasons that are not influenced by precipitation mechanisms by examining their monthly peak patterns. In addition, it was identified through the NDVI, that the less rainy period had little influence on the vegetative index during the occurrence of El Niño Southern Oscillation (ENSO) phenomena. These results may have important implications for understanding the dynamics of water resources and natural provisions for a basin composed of protected areas.Keywords: Climatology, remote sensing, vegetation. 

scholarly journals Inter-calibration of polar imager solar channels using SEVIRI

2013 ◽  
Vol 6 (9) ◽  
pp. 2495-2508 ◽  
Author(s):  
J. F. Meirink ◽  
R. A. Roebeling ◽  
P. Stammes
Keyword(s):  
High Resolution ◽  
Spectral Response ◽  
Calibration Method ◽  
Infrared Imager ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Aqua Satellite ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Direct Inter ◽  
Very High

Abstract. Accurate calibration of satellite imagers is a prerequisite for using their measurements in climate applications. Here we present a method for the inter-calibration of geostationary and polar-orbiting imager solar channels based on regressions of collocated near-nadir reflectances. Specific attention is paid to correcting for differences in spectral response between instruments. The method is used to calibrate the solar channels of the Spinning Enhanced Visible and Infrared Imager (SEVIRI) on the geostationary Meteosat satellite with corresponding channels of the Moderate Resolution Imaging Spectroradiometer (MODIS) on the polar-orbiting Aqua satellite. The SEVIRI operational calibration is found to be stable during the years 2004 to 2009, but offset by −8, −6, and +3.5 % for channels 1 (0.6 μm), 2 (0.8 μm), and 3 (1.6 μm), respectively. These results are robust for a range of choices that can be made regarding data collocation and selection, as long as the viewing and illumination geometries of the two instruments are matched. Uncertainties in the inter-calibration method are estimated to be 1 % for channel 1 and 1.5 % for channels 2 and 3. A specific application of our method is the inter-calibration of polar imagers using SEVIRI as a transfer instrument. This offers an alternative to direct inter-calibration, which in general has to rely on high-latitude collocations. Using this method we have tied MODIS-Terra and Advanced Very High Resolution Radiometer (AVHRR) instruments on National Oceanic and Atmospheric Administration (NOAA) satellites 17 and 18 to MODIS-Aqua for the years 2007 to 2009. While reflectances of the two MODIS instruments differ less than 2 % for all channels considered, deviations of an existing AVHRR calibration from MODIS-Aqua reach −3.5 and +2.5 % for the 0.8 and 1.6 μm channels, respectively.

scholarly journals Vegetative growth of grasslands based on hyper-temporal NDVI data from the Modis sensor

2016 ◽  
Vol 51 (7) ◽  
pp. 858-868
Author(s):  
Marcos Cicarini Hott ◽  
Luis Marcelo Tavares de Carvalho ◽  
Mauro Antonio Homem Antunes ◽  
Polyanne Aguiar dos Santos ◽  
Tássia Borges Arantes ◽  
...  
Keyword(s):  
Vegetative Growth ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
High Growth ◽  
Growth Index ◽  
Data Series ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Very High

Abstract: The objective of this work was to analyze the development of grasslands in Zona da Mata, in the state of Minas Gerais, Brazil, between 2000 and 2013, using a parameter based on the growth index of the normalized difference vegetation index (NDVI) from the moderate resolution imaging spectroradiometer (Modis) data series. Based on temporal NDVI profiles, which were used as indicators of edaphoclimatic conditions, the growth index (GI) was estimated for 16-day periods throughout the spring season of 2012 to early 2013, being compared with the average GI from 2000 to 2011, used as the reference period. Currently, the grassland areas in Zona da Mata occupy approximately 1.2 million hectares. According to the used methods, 177,322 ha (14.61%) of these grassland areas have very low vegetative growth; 577,698 ha (45.96%) have low growth; 433,475 ha (35.72%) have balanced growth; 39,980 ha (3.29%) have high growth; and 5,032 ha (0.41%) have very high vegetative growth. The grasslands had predominantly low vegetative growth during the studied period, and the NDVI/Modis series is a useful source of data for regional assessments.

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 Evaluating the skill of high-resolution WRF-Chem simulations in describing drivers of aerosol direct climate forcing on the regional scale

2016 ◽  
Vol 16 (1) ◽  
pp. 397-416 ◽  
Author(s):  
P. Crippa ◽  
R. C. Sullivan ◽  
A. Thota ◽  
S. C. Pryor
Keyword(s):  
High Resolution ◽  
Spatial Correlation ◽  
Radiative Forcing ◽  
Regional Scale ◽  
Climate Forcing ◽  
Spatiotemporal Variability ◽  
Aerosol Loading ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer

Abstract. Assessing the ability of global and regional models to describe aerosol optical properties is essential to reducing uncertainty in aerosol direct radiative forcing in the contemporary climate and to improving confidence in future projections. Here we evaluate the performance of high-resolution simulations conducted using the Weather Research and Forecasting model with coupled with Chemistry (WRF-Chem) in capturing spatiotemporal variability of aerosol optical depth (AOD) and the Ångström exponent (AE) by comparison with ground- and space-based remotely sensed observations. WRF-Chem is run over eastern North America at a resolution of 12 km for a representative year (2008). A systematic positive bias in simulated AOD relative to observations is found (annual mean fractional bias (MFB) is 0.15 and 0.50 relative to MODIS (MODerate resolution Imaging Spectroradiometer) and AERONET, respectively), whereas the spatial variability is well captured during most months. The spatial correlation of observed and simulated AOD shows a clear seasonal cycle with highest correlation during summer months (r = 0.5–0.7) when the aerosol loading is large and more observations are available. The model is biased towards the simulation of coarse-mode aerosols (annual MFB for AE  =  −0.10 relative to MODIS and −0.59 for AERONET), but the spatial correlation for AE with observations is 0.3–0.5 during most months, despite the fact that AE is retrieved with higher uncertainty from the remote-sensing observations. WRF-Chem also exhibits high skill in identifying areas of extreme and non-extreme aerosol loading, and its ability to correctly simulate the location and relative intensity of extreme aerosol events (i.e., AOD  >  75th percentile) varies between 30 and 70 % during winter and summer months, respectively.

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