Earth Observing System (EOS) Aqua Advanced Microwave Scanning
Advanced Microwave Scanning Radiometer (AMSR-E) on NASA's Earth
Observing System Aqua
spacecraft is scheduled for launch sometime in 2002. The AMSR-E
will be used to study the Earth's hydrological cycle and will retrieve
precipitation, soil moisture, snow cover, sea surface temperature, oceanic
water vapor, cloud water, near surface wind speed, and sea ice parameters.
AMSR-E Sea Ice Animations
AMSR-E Sea Ice Algorithms
The sea ice parameters to be retrieved from AMSR-E include sea
ice concentration, sea ice temperature, and snow depth on sea
ice. The sea ice concentration products will be generated using
two algorithms: the enhanced NASA Team (NT2) algorithm (Markus
and Cavalieri, 2000) and the AMSR Bootstrap algorithm (ABA). In
the Arctic, the NT2 algorithm will be used to obtain the standard
sea ice concentration, whereas in the Antarctic, the ABA algorithm
will provide the standard product. In addition, the (ABA-NT2)
and the (NT2-ABA) ice concentration differences will be provided
for the Arctic and Antarctic, respectively. Sea ice temperature
is a by-product of the ABA algorithm and the sea ice snow depth
will be obtained from an algorithm described by Markus and Cavalieri
(1998). The theoretical basis of these algorithms are described
in the Algorithm
Theoretical Basis Document (Cavalieri and Comiso, 2000).(top)
AMSR-E Sea Ice Validation
The accuracy of these products will be determined through the
implementation of the AMSR-E
Validation Plan . The plan consists of both Arctic
(Cavalieri et al., 2002) and Antarctic post-launch field
campaign components (Comiso et al., 2002). A pre-launch Arctic
campaign called Meltpond2000 (Cavalieri, 2000) took place from
June 25 through July 6, 2000 with the objective of quantifying
the errors incurred by the AMSR-E sea ice algorithms resulting
from the presence of melt ponds. Melt ponds are currently the
largest single source of error in the determination of Arctic
sea ice concentrations with satellite passive microwave sensors.
Arctic Field Campaigns
Sea Ice Extent and Area Time Series from Satellite Microwave
This project is a collaborative effort with Claire Parkinson to continue
to develop and analyze sea ice data records derived from satellite passive
microwave radiometers and is an extension of work undertaken by Goddard
scientists including Cavalieri, Comiso, Gloersen, Parkinson, and Zwally.
The aim of this work is to understand the role of the polar sea ice
covers in the global climate system. In particular, we will study the
long-term variability of the polar sea ice covers, quantify long-term
trends, and seek to understand these changes in the context of changes
in the ocean-atmosphere system.
Current Data Sets Derived from Satellite
Arctic and Antarctic daily and monthly sea ice extents and areas were
derived using Nimbus 7 SMMR and DMSP SSM/I data sets with the NASA Team
sea ice algorithm which is summarized in Gloersen et al., 1992. The
method of matching the time series of extents and areas from the different
sensors is described in Cavalieri et al. (1999). Early and more recent
results from combining these sensors have been reported by Cavalieri
et al. (1997), Parkinson et al. (1999), Gloersen et al. (1999), Parkinson
and Cavalieri (2002), and Zwally et al. (2002). Through 1998, these
data sets were developed in a collaborative effort involving Cavalieri,
Comiso, Gloersen, Parkinson, and Zwally. The extension beyond 1998 is
being done by Cavalieri and Parkinson. Any use of these data should
make reference to all five participants.
Sea Ice Time Series Publications:
1. Cavalieri, D. J., P. Gloersen, C. L. Parkinson, J. C. Comiso, and
H. J. Zwally, Observed
Hemispheric Asymmetry in Global Sea Ice Changes, SCIENCE, 272, 1104-1106,
2. Cavalieri, D. J., C. L. Parkinson, P. Gloersen, J. C. Comiso, and
H. J. Zwally, Deriving Long-Term Time Series of Sea Ice Cover from Satellite
Passive-Microwave Multisensor Data Sets, J. Geophys. Res., 104, 15,803-15,814,
3. Gloersen, P., C. L. Parkinson, D. J. Cavalieri, J. C. Comiso, and
H. J. Zwally, Spatial Distribution of Trends and Seasonality in the
Hemispheric Sea Ice Covers: 1978-1996, J. Geophys. Res., 104, 20,827-20,836,
4. Gloersen, P., W. J. Campbell, D. J. Cavalieri, J. C. Comiso, C.
L. Parkinson, H. J. Zwally, Arctic and Antarctic Sea Ice, 1978-1987:
Satellite Passive Microwave Observations and Analysis , National Aeronautics
and Space Administration, Special Publication 511, Washington, D.C.,
5. Parkinson, C. L., and D. J. Cavalieri, A 21-year record of Arctic
sea ice extents and their regional, seasonal, and monthly variability
and trends, Annals of Glaciol., in press, 2002.
6. Parkinson, C. L., D. J. Cavalieri, P. Gloersen, H. J. Zwally, and
J. C. Comiso, Variability of the Arctic Sea Ice Cover 1978-1996, J.
Geophys. Res., 104, 20,837-20,856, 1999.
7. Zwally, H. J., J. C. Comiso, C. L. Parkinson, D. J. Cavalieri, and
P. Gloersen, Variability of Antarctic Sea Ice 1979-1998, J. Geophys.
Res., in press, 2002.
Arctic Climate and Atmospheric Planetary Waves
The goal of this work is to study the variability of sea
level pressure (SLP) planetary waves and relate these planetary-scale
variations to some of the climatic changes observed in the Arctic over
the last fifty years. This work is in contrast to many recent Arctic
climate studies that use EOF-defined indices such as the North Atlantic
Oscillation, the Pacific North American, and Arctic Oscillation. Results
suggest that the variations in phase of the two longest planetary SLP
waves drive low frequency Arctic Ocean and sea ice variability (Cavalieri,
2002; Cavalieri and Häkkinen, 2001).
Cavalieri, D. J., A
link between Fram Strait sea ice export and atmospheric planetary wave
phase, Geophys. Res. Lett., 20 (12), 10.1029/2002GL014684, 2002.
Cavalieri, D. J. and S. Häkkinen, Arctic
climate and atmospheric planetary waves, Geophys. Res. Lett., 28(5),