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 Análisis de la respuesta productiva ante la variabilidad climática en tipos de vegetación exótica y nativa del Desierto Sonorense

2021 ◽  
Vol 20 (1) ◽  
pp. e2021203
Author(s):  
Sofía Choza-Farías ◽  
Jose Raúl Romo-Leon ◽  
Alejandro E. Castellanos-Villegas
Keyword(s):  
El Niño ◽  
El Nino ◽  
La Niña ◽  
Cenchrus Ciliaris ◽  
La Nina ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Para Determinar

La introducción de zacate buffel (Cenchrus ciliaris) para incrementar la producción de forraje ha provocado modificaciones en grandes extensiones de terreno del Desierto Sonorense. Aunado a lo anterior, nuestro conocimiento acerca de la influencia de fenómenos climáticos, como El Niño, sobre la dinámica de productividad en la vegetación, es limitado. El presente trabajo pretende analizar la actividad fotosintética/productiva de la vegetación del Desierto Sonorense en sitios con matorral subtropical y praderas de buffel para determinar diferencias entre fases del fenómeno El Niño Oscilación del Sur (ENSO acrónimo en inglés). Se establecieron sitios de estudio en comunidades vegetales con y sin buffel. Se adquirieron imágenes satelitales del “Moderate Resolution Imaging Spectroradiometer (MODIS)” para derivar el Índice de Vegetación de Diferencia Normalizada (NDVI, acrónimo en inglés) en compuestos de 16 días. Se obtuvo información acerca de las diferentes fases de El Niño desde 2001 hasta 2017. Los resultados sugieren actividad productiva mayor durante la fase Neutra que durante las fases El Niño o La Niña. También, el matorral subtropical presenta mayor actividad productiva que las praderas de buffel en cualquiera de las combinaciones estación-fase analizadas, excepto en La Niña durante el verano

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 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 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 Sediment plumes as a proxy for local ice-sheet runoff in Kangerlussuaq Fjord, West Greenland

2010 ◽  
Vol 56 (199) ◽  
pp. 813-821 ◽  
Author(s):  
Daniel McGrath ◽  
Konrad Steffen ◽  
Irina Overeem ◽  
Sebastian H. Mernild ◽  
Bent Hasholt ◽  
...  
Keyword(s):  
River Discharge ◽  
Water Storage ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
West Greenland ◽  
Meltwater Runoff ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer

AbstractMeltwater runoff is an important component of the mass balance of the Greenland ice sheet (GrIS) and contributes to eustatic sea-level rise. In situ measurements of river runoff at the ˜325 outlets are nonexistent due to logistical difficulties. We develop a novel methodology using satellite observations of sediment plumes as a proxy for the onset, duration and volume of meltwater runoff from a basin of the GrIS. Sediment plumes integrate numerous poorly constrained processes, including meltwater refreezing and supra- and englacial water storage, and are formed by meltwater that exits the GrIS and enters the ocean. Plume characteristics are measured in Moderate Resolution Imaging Spectroradiometer (MODIS, band 1, 250 m) satellite imagery during the 2001-08 melt seasons. Plume formation and cessation in Kangerlussuaq Fjord, West Greenland, are positively correlated (r2 = 0.88, n = 5, p < 0.05; r2 = 0.93, n = 5, p < 0.05) with ablation onset and cessation at the Kangerlussuaq Transect automatic weather station S5 (490 ma.s.l., 6 km from the ice margin). Plume length is positively correlated (r2 = 0.52, n = 35, p < 0.05) with observed 4 day mean Watson River discharge throughout the 2007 and 2008 melt seasons. Plume length is used to infer instantaneous and annual cumulative Watson River discharge between 2001 and 2008. Reconstructed cumulative discharge values overestimate observed cumulative discharge values for 2007 and 2008 by 15% and 29%, respectively.

scholarly journals Urban heat islands in the Arctic cities: an updated compilation of in situ and remote-sensing estimations

2021 ◽  
Vol 18 ◽  
pp. 51-57
Author(s):  
Igor Esau ◽  
Victoria Miles ◽  
Andrey Soromotin ◽  
Oleg Sizov ◽  
Mikhail Varentsov ◽  
...  
Keyword(s):  
Land Surface ◽  
Urban Infrastructure ◽  
Urban Heat Islands ◽  
The Arctic ◽  
Heat Islands ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Urban Heat ◽  
Moderate Resolution Imaging Spectroradiometer

Abstract. Persistent warm urban temperature anomalies – urban heat islands (UHIs) – significantly enhance already amplified climate warming in the Arctic. Vulnerability of urban infrastructure in the Arctic cities urges a region-wide study of the UHI intensity and its attribution to UHI drivers. This study presents an overview of the surface and atmospheric UHIs in all circum-Arctic settlements (118 in total) with the population larger than 3000 inhabitants. The surface UHI (SUHI) is obtained from the land surface temperature (LST) data products of the Moderate Resolution Imaging Spectroradiometer (MODIS) archive over 2000–2016. The atmospheric UHI is obtained from screen-level temperature provided by the Urban Heat Island Arctic Research Campaign (UHIARC) observational network over 2015–2018. Several other UHI studies are included for comparisons. The analysis reveals strong and persistent UHI during both summer and winter seasons. The annual mean surface UHI magnitudes vary from −0.6 ∘C (Hammerfest) to 4.3 ∘C (Murmansk). Thus, the observed UHI is likely an important climatic factor that must be included in future adjustment of urban construction, safety, and environmental quality codes.

scholarly journals Pre-melt-season sediment plume variability at Jökulsárlón, Iceland, a preliminary evaluation using in-situ spectroradiometry and satellite imagery

2016 ◽  
Vol 57 (73) ◽  
pp. 39-46 ◽  
Author(s):  
Richard Hodgkins ◽  
Robert Bryant ◽  
Eleanor Darlington ◽  
Mark Brandon
Keyword(s):  
Short Interval ◽  
Preliminary Evaluation ◽  
Linear Calibration ◽  
Tidewater Glaciers ◽  
Modis Imagery ◽  
Study Interval ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer

ABSTRACTHigh-latitude atmospheric warming is impacting freshwater cycling, requiring techniques for monitoring the hydrology of sparsely-gauged regions. The submarine runoff of tidewater glaciers presents a particular challenge. We evaluate the utility of Moderate Resolution Imaging Spectroradiometer (MODIS) imagery for monitoring turbid meltwater plume variability in the glacier lagoon Jökulsárlón, Iceland, for a short interval before the onset of the main melt season. Total Suspended Solids concentrations (TSS) of surface waters are related to remotely-sensed reflectance via empirical calibration between in-situ-sampled TSS and reflectance in a MODIS band 1-equivalent wavelength window. This study differs from previous ones in its application to an overturning tidewater glacier plume, rather than one derived from river runoff. The linear calibration improves on previous studies by facilitating a wider range of plume metrics than areal extent, notably pixel-by-pixel TSS values. Increasing values of minimum plume TSS over the study interval credibly represent rising overall turbidity in the lagoon as melting accumulates. Plume extent responds principally to consistently-strong offshore winds. Further work is required to determine the temporal persistence of the calibration, but remote plume observation holds promise for monitoring hydrological outputs from ungauged or ungaugeable systems.

scholarly journals KUALITAS LINGKUNGAN PERAIRAN DAN POTENSI PRODUKSI IKAN KAWASAN KONSERVASI TERUBUK BENGKALIS (Tenualosa macrura Bleeker, 1852)

2018 ◽  
Vol 1 (1) ◽  
pp. 37
Author(s):  
Khairul Amri ◽  
Gathot Winarso ◽  
Muchlizar Muchlizar
Keyword(s):  
Water Quality ◽  
Satellite Imagery ◽  
Primary Productivity ◽  
Landsat 8 ◽  
Productivity Level ◽  
Mangrove Vegetation ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer

Terubuk Bengkalis (Tenualosa macrura) yang hidup di perairan Bengkalis dinyatakan terancam punah akibat eksploitasi berlebih dan penurunan kualitas perairan. Penelitian ini bertujuan untuk menganalisa kualitas perairan habitat terubuk Bengkalis, menggunakan data parameter oseanografi hasil pengukuran in-situ. Selain itu, data penginderaan jauh berupa citra Landsat 8 digunakan untuk analisa tutupan mangrove (hutan bakau) serta citra MODIS-Aqua (Moderate-resolution Imaging Spectroradiometer) untuk analisis produktivitas primer (NPP). Penelitian dilaksanakan selama April-November 2015. Hasil penelitian menunjukkan total luas tutupan mangrove yang teridentifikasi citra Satelit Landsat 8 (2015) mencapai 11.736,2 Ha, berkurang sekitar 4.470,8 Ha dalam waktu 12 tahun (2003-2015) dengan laju kehilangan 372,5 Ha/tahun. Dari aspek oseanografi, kawasan konservasi ikan terubuk merupakan perairan dangkal dengan tingkat kecerahan rendah (0,54-0,95 m); suhu perairan relatif tinggi berkisar 29,15-31,87 0C (rata-rata 300C) dan salinitas rata-rata tergolong rendah (28,77-29,22 ppt). Nilai sebaran pH dan oksigen terlarut/DO juga rendah yakni pH 6,3-8,9 (rata-rata pH 7) dan DO 3,90-4,98 mg/l (di bawah Baku Mutu Air Laut). Komposisi substrat dasar didominasi lumpur, dengan prosentase 67,4-89,8%, sehingga perairan ini umumnya keruh. Perairan ini tergolong subur (eutropik) dengan kelimpahan fitoplankton tinggi (23.584 - 95.616 sel/l) terdiri dari 32-52 genera. Produktivitas primer juga tinggi, rata-rata 288,87 mgC/m2/hari dengan potensi produksi ikan 3.680,2 ton/tahun. Terubuk Bengkalis (Tenualosa macrura) is an endemic tropical shad fish that live in Bengkalis waters.This species has been declared endangered due to over exploitation and environmental degradation. The current research aimed to analyze the environmental quality of the species. The data used in this research were consited of in-situ measurement and remote sensing data: Landsat 8 Satellite imagery for mangrove cover observation and MODIS (Moderate-resolution Imaging Spectroradiometer) imagery for Net Primary Productivity (NPP). The results showed that the cover of mangrove vegetation along the coast of Bengkalis Island dentified by Landsat 8 Satellite imagery was11.736,24 Ha. The total loss of cover mangrove vegetation is estimated about 4.470,83 Ha, decreased drastically in 12 years (2003-2015) with a loss rate of 372.5 Ha/year. The habitat of shad fish is shallow water category. The water quality was too turbid (brightness level 0.54-0.95 m); warm water temperature of 29.,15-31.87 0C (average 300C); and low salinity (28,77-29,22 ppt). The relatively low pH and dissolved oxygen content were determined: pH ranged between 6,3-8,9 (mean7) and the DO: 3,90-4,98 mg/l (under the Sea Water Quality Standard).The substrat was dominated by mud (67,4-89,8%) in Bengkalis Strait sub area due to the turbidity. However, these waters are euthropic level category with a high abundance of phytoplankton ranging from 23,584-95,616 cells/l and the species richness varies from 32-52 species. The primary productivity level of waters was also quite high was average of 288,87 mgC/m2/day resulting an estimation of potential of fish biomass value about 3.680,2 ton/year.

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