38 research outputs found
Modulation of chemokine release in cardiac endothelial cells by low doses of ionizing radiation
Insights in the molecular basis of a reduced lymphocyte adhesion to irradiated and stimulated primary endothelial cells
Image segmentation of alveolar macrophages reveals chronic inflammation in carbon ion irradiated rat lungs
Global coastal attenuation of wind-waves observed with radar altimetry
Coastal studies of wave climate and evaluations of wave energy resources are mainly regional
and based on the use of computationally very expensive models or a network of in-situ data.
Considering the significant wave height, satellite radar altimetry provides an established
global and relatively long-term source, whose coastal data are nevertheless typically flagged
as unreliable within 30 km of the coast. This study exploits the reprocessing of the radar
altimetry signals with a dedicated fitting algorithm to retrieve several years of significant
wave height records in the coastal zone. We show significant variations in annual cycle
amplitudes and mean state in the last 30 km from the coastline compared to offshore, in
areas that were up to now not observable with standard radar altimetry. Consequently, a
decrease in the average wave energy flux is observed. Globally, we found that the mean
significant wave height at 3 km off the coast is on average 22% smaller than offshore, the
amplitude of the annual cycle is reduced on average by 14% and the mean energy flux loses
38% of its offshore value
Altimetry for the future: Building on 25 years of progress
In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the “Green” Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments’ development and satellite missions’ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion