Ice Surfaces, Clouds, Aerosols: Heights, changes and surface roughness in satellite altimetry - Comparison and Integration of Data Analyses from ICESat, CryoSat and ICESat-2
Abstract
Advances in satellite altimetry over the past 20 years have allowed unprecedented detection of height changes throughout the Earth System. During this time, NASA's ICESat mission (2003-2009) and ICESat-2 mission (2018-present) together with ESA's CryoSat-2 mission (2010-present) have provided a continuous survey of glacier and ice sheet height evolution. We have developed algorithms that improve the height detection of these satellite measurements, especially over crevassed regions, to provide integrated time series of elevation, elevation-change, and surface roughness throughout the cryosphere. In this paper, we present results in increasing complexity.
First, we examine the ability of CryoSat-2 to identify surface height over a crevassed glacier. The second topic is the integration of data from the pulse-limited altimetry of ICESat, and the photon-counting altimetry of ICESat-2 necessary to create integrated time series of elevation and elevation change across the different satellite missions. To this end, a new height retrieval algorithm has been developed for ICESat Geoscience Laser Altimeter System (GLAS) data. For analysis of ICESat-2 data, which realize the new micro-pulse photon-counting technology through the Advanced Topographic Laser Altimeter System (ATLAS), we developed Density-Dimension Algorithm for ice surfaces (DDA-ice). The DDA-ice has the ability to detect multiple layers in the return. Results will be illustrated for Jakobshavn Isbræ, Greenland, and other fast-moving outlet glaciers. The next level is calculation of surface-roughness maps of the Greenland Ice Sheet, which have a number of applications in cryospheric research. ICESat-2 ATLAS also collects atmospheric observations, which (a) serve as information on detectability of Earth surfaces and (b) yield data products for applications in atmospheric sciences. The Density-Dimension Algorithm for atmosphere algorithm (DDA-atmos) is applied to derive atmospheric layers and layer boundaries, including those of clouds, aerosols, and blowing snow. A novelty of the ICESat-2 atmospheric data products is the identification of optically thin clouds, which are important in calculation of energy fluxes and resultant constraints for atmospheric components of climate models.- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.C31C1538H
- Keywords:
-
- 3360 Remote sensing;
- ATMOSPHERIC PROCESSES;
- 0726 Ice sheets;
- CRYOSPHERE;
- 0750 Sea ice;
- CRYOSPHERE;
- 4556 Sea level: variations and mean;
- OCEANOGRAPHY: PHYSICAL