Elena S. Lobl

Analysis of the Merging Procedure for the MSU Daily Temperature Time Series

Abstract The merging procedure utilized to generate homogeneous time series of three deep-layer atmospheric temperature products from the nine microwave sounding units (MSUs) is described. A critically important aspect in the process is determining and removing the bias each instrument possesses relative to a common base (here being NOAA-6). Special attention is given to the lower-tropospheric layer and the calculation of the bias of the NOAA-9 MSU and its rather considerable impact on the trend of the overall time series. We show that the bias is best calculated by a direct comparison between NOAA-6 and NOAA-9, though there other possible methods available, and is determined to be +0.50°C. Spurious variations of individual MSUs due to orbital drift and/or cyclic variations tied to the annual cycle are also identified and eliminated. In general, intersatellite biases for the three instruments that form the backbone of the time series (MSUs on NOAA-6, -10 and -12) are known to within 0.01°C. After slight m...

High-resolution imaging of rain systems with the advanced microwave precipitation radiometer

Abstract An Advanced Microwave Precipitation Radiometer (AMPR) has been developed and flown in the NASA ER-2 high-altitude aircraft for imaging various atmospheric and surface processes, primarily the internal structure of rain clouds. The AMPR is a scanning four-frequency total power microwave radiometer that is externally calibrated with high-emissivity warm and cold loads. Separate antenna systems allow the sampling of the 10.7- and 19.35-GHz channels at the same spatial resolution, while the 37.1- and 85.5-GHz channels utilize the same multifrequency feedhorn as the 19.35-GHz channel. Spatial resolutions from an aircraft altitude of 20-km range from 0.6 km at 85.5 GHz to 2.8 km at 19.35 and 10.7 GHz. All channels are sampled every 0.6 km in both along-track and cross-track directions, leading to a contiguous sampling pattern ofthe 85.5-GHz 3-dB beamwidth footprints, 2.3 × oversampling of the 37.1-GHz data, and 4.4 × oversampling of the 19.35- and 10.7-GHz data. Radiometer temperature sensitivities ran...

March 2003 EOS Aqua AMSR-E Arctic Sea Ice Field Campaign

An overview of the March 2003 coordinated sea ice field campaign in the Alaskan Arctic is presented with reference to the papers in this special section. This campaign is part of the program to validate the Aqua Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) sea ice products. Standard AMSR-E sea ice products include sea ice concentration, sea ice temperature, and snow depth on sea ice. The validation program consists of three elements, namely: 1) satellite data comparisons; 2) coordinated satellite/aircraft/surface measurements; and 3) modeling and sensitivity analyses. Landsat-7 and RADARSAT observations were used in comparative studies with the retrieved AMSR-E sea ice concentrations. The aircraft sensors provided high-resolution microwave imagery of the surface, atmospheric profiles of temperature and humidity, and digital records of sea ice conditions. When combined with in situ measurements, aircraft data were used to validate the AMSR-E sea ice temperature and snow-depth products. The modeling studies helped interpret the field-data comparisons, provided insight on the limitations of the AMSR-E sea ice algorithms, and suggested potential improvements to the AMSR-E retrieval algorithms

Science data processing for the Advanced Microwave Scanning Radiometer-Earth observing system

The National Aeronautics and Space Administration established the framework for the Science Investigator-led Processing Systems (SIPS) to enable the Earth science data products to be generated by personnel directly associated with the instrument science team and knowledgeable of the science algorithms. One of the first instantiations implemented for NASA was the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) SIPS. The AMSR-E SIPS is a decentralized, geographically distributed ground data processing system composed of two primary components located in California and Alabama. Initial science data processing in the U.S. is conducted at Remote Sensing Systems (RSS) in Santa Rosa, California. RSS ingests antenna temperature orbit data sets from the Japanese Aerospace Exploration Agency and converts them to calibrated, resampled, geolocated brightness temperatures. The brightness temperatures are sent to the Global Hydrology and Climate Center in Huntsville, Alabama, which generates the geophysical science data products (e.g., water vapor, sea surface temperature, sea ice extent, etc.) suitable for climate research and applications usage. These science products are subsequently sent to the National Snow and Ice Data Center Distributed Active Archive Center in Boulder, Colorado for archival and dissemination to the at-large science community. This paper describes the organization, coordination and production techniques employed by the AMSR-E SIPS in implementing, automating and operating the distributed data processing system.

U.S. AMSR-E Products Overview

The Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) continues to operate nominally on NASAs Aqua satellite. This paper provides a sampling of products from AMSR-E that are of use for a variety of global hydrologic investigations.

AMSR-E and unified AMSR (AMSR-U) products

The hydrologic cycle is the process, powered by the suns energy, which moves water between the oceans, the sky, and the land. Atmospheric scientists look for data that would help understand and eventually predict the atmospheric phenomena. The AMSR instruments have obtained atmospheric data since 2002, which are helping in understanding the Earths atmosphere. Long-term atmospheric products sets (15 or more years) like AMSR-U, will further the understanding of the atmospheric hydrologic cycle.

Accomplishments from 9.5 years of AMSR-E observations

The retrieved atmospheric parameters using the observations from AMSR-E on Aqua are used primarily in climate research as well as in atmospheric models used in weather forecasting. This JAXA instrument performed exceptionally well for more than three times its design lifetime. Images of all retrieved atmospheric parameters will be shown, and examples of the science performed with the data will be given. A final algorithm update and data reprocessing will ensure the best quality products are archived at NSIDC for future research.

AMSR-E and its follow-on, AMSR2

The Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) was built in Japan, and it has been flying on the Aqua satellite since May 2002. Aqua has completed its prime mission in September 2008. The observations from AMSR-E are being used by scientists all over the world in conjunction with other ATrain satellite instruments to monitor and understand hydrological processes over land, ocean, and in the cryosphere. The status of AMSR-E will be presented. Images of AMSR-E products will be shown, as well as a summary of the ongoing research with these data. AMSR-Es follow-on instrument, AMSR2, will be launched on JAXAs GCOM-W1 satellite in Japanese fiscal year 2011. The AMSR2 instrument will be similar to AMSR-E with some important enhancements, and will provide a critical bridge of climate observations until the first Microwave Imager Sounder (MIS) flies on the second NPOESS satellite in 2016 or any other radiometer planned, and yet unknown to the international research community. JAXA and NASA are discussing whether to place GCOM-W1 in the same orbit as Aqua, as part of the Atrain constellation. The benefits of the collocation of the two AMSRs will be discussed and examples given of the research possibilities.

Several advanced microwave scanning radiometer for EOS (AMSR-E) environmental results

The Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) is a conically scanning, dual-polarization, total power microwave radiometer flying on NASAs Aqua satellite. It has been taking global observations for more than four years. The instrument was provided by the Japan Aerospace Exploration Agency, JAXA, and it was built by Mitsubishi Electric Company. AMSR-E data provide information on the state of various hydrologic parameters in the atmosphere and on the Earths surface. AMSR-E measures dual linearly polarized radiation (horizontal and vertical polarizations) at frequencies of 6.9, 10.7, 18.7, 36.5, and 89 GHz. These frequencies have diverse amounts of influence from a wide variety of lower atmospheric and surface variables. Examples of environmental results obtained from AMSR-E data are included. One of the most important new capabilities is global SST observations through clouds, including observations of the cold wakes behind hurricanes. The cold wake behind hurricane Katrina will be shown. A monthly, global soil moisture percentage map was developed from the AMSR-E retrievals, and as an additional benefit maps showing large RFI sources have been compiled. Maps of the snow water equivalent (SWE) and detailed maps of the Arctic sea ice will be shown.

Research applications and opportunities using advanced microwave scanning radiometer-Earth observing system (AMSR-E) data

The Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) is a passive microwave radiometer on board the National Aeronautics Space Agency (NASA) Earth Observing System (EOS) Aqua satellite. Aqua, a sun-synchronous polar orbiting platform, is one of a series of spacecraft launched by NASAs Earth Science Enterprise to obtain remotely-sensed data for the advancement of Earth System Science. The AMSR-E measures passive microwave radiation, allowing for derivation of many parameters, including soil moisture, sea surface temperatures, rain rate, snow cover and sea ice extent. The instrument provides improved spatial resolution compared to earlier generations of spacecraft-borne passive microwave instruments (e.g., SMMR and SSM/I) and retrieves information in more frequencies of the microwave spectrum than its predecessors. Data products are archived and distributed by the National Snow and Ice Data Center (NSIDC) Distributed Active Archive Center (DAAC) at the University of Colorado, Boulder (www.nsidc.org/daac/amsr/). This paper summarizes the AMSR-E data sets that will be available at NSIDC and discusses research applications of some of them.