Search results for "surface temperature"
showing 10 items of 218 documents
Satellite-derived land surface temperature: Current status and perspectives
2013
Abstract Land surface temperature (LST) is one of the key parameters in the physics of land surface processes from local through global scales. The importance of LST is being increasingly recognized and there is a strong interest in developing methodologies to measure LST from space. However, retrieving LST is still a challenging task since the LST retrieval problem is ill-posed. This paper reviews the current status of selected remote sensing algorithms for estimating LST from thermal infrared (TIR) data. A brief theoretical background of the subject is presented along with a survey of the algorithms employed for obtaining LST from space-based TIR measurements. The discussion focuses on TI…
(Table 1) Sea surface temperature reconstruction for eastern equatorial Pacific surface sediment samples
2012
Significant uncertainties persist in the reconstruction of past sea surface temperatures in the eastern equatorial Pacific, especially regarding the amplitude of the glacial cooling and the details of the post-glacial warming. Here we present the first regional calibration of alkenone unsaturation in surface sediments versus mean annual sea surface temperatures (maSST). Based on 81 new and 48 previously published data points, it is shown that open ocean samples conform to established global regressions of Uk'37 versus maSST and that there is no systematic bias from seasonality in the production or export of alkenones, or from surface ocean nutrient concentrations or salinity. The flattening…
Thermal remote sensing from Airborne Hyperspectral Scanner data in the framework of the SPARC and SEN2FLEX projects: an overview
2009
Abstract. The AHS (Airborne Hyperspectral Scanner) instrument has 80 spectral bands covering the visible and near infrared (VNIR), short wave infrared (SWIR), mid infrared (MIR) and thermal infrared (TIR) spectral range. The instrument is operated by Instituto Nacional de Técnica Aerospacial (INTA), and it has been involved in several field campaigns since 2004. This paper presents an overview of the work performed with the AHS thermal imagery provided in the framework of the SPARC and SEN2FLEX campaigns, carried out respectively in 2004 and 2005 over an agricultural area in Spain. The data collected in both campaigns allowed for the first time the development and testing of algorithms for …
Night Thermal Unmixing for the Study of Microscale Surface Urban Heat Islands with TRISHNA-Like Data
2019
International audience; Urban Heat Islands (UHIs) at the surface and canopy levels are major issues in urban planification and development. For this reason, the comprehension and quantification of the influence that the different land-uses/land-covers have on UHIs is of particular importance. In order to perform a detailed thermal characterisation of the city, measures covering the whole scenario (city and surroundings) and with a recurrent revisit are needed. In addition, a resolution of tens of meters is needed to characterise the urban heterogeneities. Spaceborne remote sensing meets the first and the second requirements but the Land Surface Temperature (LST) resolutions remain too rough…
Vermetid reefs in the Mediterranean Sea as archives of sea-level and surface temperature changes
2011
Vermetid reefs are among the most important bioconstructions in the Mediterranean Sea, with a distribution restricted to the warmest part of the basin. Their structure, and vertical and geographical distribution make them good biological indicators of changes in sea level and sea-surface temperature over the last two millennia.
<title>Surface temperature retrieval from MODIS data</title>
2001
12 MODIS (Moderate Resolution Imaging Spectroradiometer) was launched on board the NASA's Terra Earth Observing System (EOS AM-1) Satellite on December 18, 1999. We propose in this work operative split-window algorithms for retrieving sea surface temperature (SST) and land surface temperature (LST) using MODIS data. In order to attain our goal, the MODTRAN 3.5 radiative transfer code was used to predict radiances for MODIS channels 31 and 32. To analyze atmospheric effects, a set of radiosoundings was used to cover the variability of surface temperature and water vapor concentration on a worldwide scale. These simulated data were split into two sets which have very similar distributions in …
An improvement of June-September rainfall forecasting in the Sahel based upon region April-May moist static energy content (1968-1997)
1999
This study provides statistical evidence that June–September Sahelian rainfall hindcasts currently based on oceanic thermal predictors apprehend more the negative trend than the interannual rainfall variations. Four physically meaningful predictors of June–September Sahel rainfall are first selected through the near-surface April–May information and several experimental hindcasts provided. We then discuss the skills achieved using regression techniques and cross-validated discriminant functions. In that context, 8/11 of the driest seasons and 8/10 of the wettest are correctly predicted. Finally using completely independent training and working periods we show that better and significant hin…
In situ angular measurements of thermal infrared sea surface emissivity—Validation of models
2005
Abstract In this paper, sea surface emissivity (SSE) measurements obtained from thermal infrared radiance data are presented. These measurements were carried out from a fixed oilrig under open sea conditions in the Mediterranean Sea during the WInd and Salinity Experiment 2000 (WISE 2000). The SSE retrieval methodology uses quasi-simultaneous measurements of the radiance coming from the sea surface and the downwelling sky radiance, in addition to the sea surface temperature (SST). The radiometric data were acquired by a CIMEL ELECTRONIQUE CE 312 radiometer, with four channels placed in the 8–14 μm region. The sea temperature was measured with high-precision thermal probes located on oceanog…
Analysis of the atmospheric and emissivity influence on the splitwindow equation for sea surface temperature
1994
Abstract In this paper we have analysed the effects of the different atmospheric species (water vapour, fixed gases and aerosols) and the surface emissivity on the split-window method for determining the sea surface temperature. The widely used split-window method is based on the differential absorption of water vapour in the atmospheric window 10.5ndash;12.5 μm. Other atmospheric species with absorption coefficients different to that of water vapour can then have a large influence on the split-window. The effect of gases, such as C02, N20, CH4, CO and 03, and maritime aerosols is evaluated by comparing the effect of the water vapour alone. To do this we simulated AVHRR measurements in chan…
What Drove Past Teleconnections?
2003
Ice core records from Greenland and Antarctica and sediment records from the world9s oceans have shown that over the past 100,000 years, climate has varied substantially across the globe. In his Perspective, Sirocko asks what drove these--sometimes very rapid--climate oscillations. He highlights the report of Burns et al., whose monsoon record from the Indian Ocean shows strong similarities with ice core records from Greenland. Sirocko argues that the large areas of homogeneous sea surface temperature in the cold circum-Antarctic current and in the warm-water masses of the low latitudes must have played an important role in linking climate forcing between distant parts of the world. The muc…