Journal of Geophysical Research, Atmospheres
Supporting Information for
Estimated Errors in Retrievals of Ocean Parameters from SSMIS
Carl A. Mears, Deborah K. Smith and Frank J. Wentz
Remote Sensing Systems, Santa Rosa, CA, USA, 95401
Contents of this file
Text S1
Figure S1
Introduction
The supporting information includes a short discussion of the sources of buoy data used
in the main text, and Figure S1 which provides additional details about the measurement
footprints and resampling.
Text S1.
Sources of Buoy Measurements
We maintain a buoy data set consisting of data from over 200 open-ocean moored
buoys obtained from multiple sources. These buoys make observations in primarily four
regions: the mid-latitude North American coasts and the equatorial Pacific, Atlantic, and
Indian oceans. Buoys located primarily in the coastal and offshore waters of the
continental United States and Canada and the Pacific Ocean around Hawaii are
obtained from the U.S. National Data Buoy Center (NDBC) [Gilhousen and Meindl, 2001]
and the Canadian Marine Environmental Data Service (MEDS) [Gower, 2002]. We only
use buoys located greater than 30 km from shore to avoid land-contamination effects on
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satellite wind estimates. Ocean surface observations from the tropical ocean regions
are made by buoys located in one of four buoy arrays: the Tropical Atmospheric Ocean
(TAO) array [McPhaden et al., 1998], the TRITON array [Kuroda and Amitani, 2001], the
Pilot Research Moored Array in the Tropical Atlantic (PIRATA) [Bourlès et al., 2008;
Servain et al., 1998] and the Research Moored Array for African-Asian-Australian
Monsoon Analysis (RAMA) [McPhaden et al., 2009]. These tropical data sets are
obtained from the Pacific Marine Environmental Laboratory (PMEL).
Most of the moored ocean buoys measure wind speed and direction with additional
atmospheric parameters such as barometric pressure and air/sea surface temperature.
The exact time of data collection and the anemometer height of wind measurement
depend on the type of payload located on the moored buoy. These properties vary for
NDBC and MEDS coastal buoys, but are consistent for the TAO/TRITON, PIRATA and
RAMA equatorial ocean buoys. Buoy measurements were collocated with satellite
retrievals and adjusted to correspond to a 10m reference height using the methods
described in [Mears et al., 2001].
References
Bourlès, B., et al. (2008), The PIRATA program: History, accomplishments, and future
directions, Bulletin of the American Meteorological Society, 89(8), 1111-1125.
Gilhousen, D. B., and E. A. Meindl (2001), An update to data quality control techniques
used by the national data buoy center, Technical Report Rep.
Gower, J. F. R. (2002), Temperature, wind and wave climatologies, and trends from
marine meteorological buoys in the northeast Pacific, Journal of Climate, 15(24),
3709-3718.
Kuroda, Y., and Y. Amitani (2001), TRITON: New ocean and atmosphere observing
buoy network for monitoring ENSO, Umi no Kenkyu, 10, 157-172.
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McPhaden, M. J., G. Meyers, K. Ando, Y. Masumoto, V. S. N. Murty, M. Ravichandran,
F. Syamsudin, J. Vialard, L. Yu, and W. Yu (2009), RAMA: The research moored
array for African-Asian-Australian monsoon analysis and prediction, Bulletin of the
American Meteorological Society, 90(4), 459-480.
McPhaden, M. J., et al. (1998), The Tropical Ocean-Global Atmosphere observing
system: A decade of progress, Journal of Geophysical Research, 103(C7), 1416914240.
Mears, C. A., D. K. Smith, and F. J. Wentz (2001), Comparison of Special Sensor
Microwave Imager and buoy-measured wind speeds from 1987 - 1997, Journal of
Geophysical Research, 106(C6), 11719-11729.
Servain, J., A. J. Busalacchi, M. J. McPhaden, A. D. Moura, G. Reverdin, M. Vianna, and
S. E. Zebiak (1998), A Pilot Research moored Array in the Tropical Atlantic
(PIRATA), Bulletin of the American Meteorological Society, 79(10), 2019-2031.
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Figure S1. Example of SSMIS footprint locations for 19/22 GHz (45x74km) and 37 GHz
(28x45 km) footprints. This example if from near the center of the swath, with the
equator corresponding to 0 km on the y-axis. Two successive scans are shown in color,
with blue and aqua corresponding to 19/22 GHz footprints, and orange and red
corresponding to 37 GHz footprints. The direction of satellite travel is shown by the
black arrow. Note that the measurements are oversampled, particularly in the alongtrack direction. This allows for significant noise reduction via the resampling procedure,
even when resampling the larger 19/22 GHz footprints onto the black target footprint.
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