Antonia Gambacorta

Hyperspectral Earth Observation from IASI: Five Years of Accomplishments

The Infrared Atmospheric Sounding Interferometer (IASI) forms the main infrared sounding component of the European Organisation for the Exploitation of Meteorological Satellitess (EUMETSATs) Meteorological Operation (MetOp)-A satellite (Klaes et al. 2007), which was launched in October 2006. This article presents the results of the first 4 yr of the operational IASI mission. The performance of the instrument is shown to be exceptional in terms of calibration and stability. The quality of the data has allowed the rapid use of the observations in operational numerical weather prediction (NWP) and the development of new products for atmospheric chemistry and climate studies, some of which were unexpected before launch. The assimilation of IASI observations in NWP models provides a significant forecast impact; in most cases the impact has been shown to be at least as large as for any previous instrument. In atmospheric chemistry, global distributions of gases, such as ozone and carbon monoxide, can be produ...

Methodology and Information Content of the NOAA NESDIS Operational Channel Selection for the Cross-Track Infrared Sounder (CrIS)

The Cross-track Infrared Sounder (CrIS) was launched on October 28, 2011 aboard the Suomi National Polar-orbiting Partnership platform and is scheduled to become operational in 2012. The purpose of this paper is to describe the National Oceanic and Atmospheric Administration/National Environmental Satellite and Information Service (NOAA/NESDIS) channel selection methodology applied to the CrIS instrument and to present the main spectral characteristics of the final channel subset that will be operationally distributed to the scientific community for near-real-time data assimilation and retrieval applications. We perform an information content analysis and show that this selection, composed of 399 channels, is capable of fully representing the total atmospheric variability contained in the original 1305-channel spectrum, up to instrumental noise. These results ensure that the replacement of the full 1305-channel list in favor of the proposed 399-channel selection will have no detrimental effects on data assimilation and retrieval performance.

The CrIMSS EDR Algorithm: Characterization, Optimization, and Validation

The Cross-track Infrared Sounder (CrIS) and the Advanced Technology Microwave Sounder (ATMS) instruments aboard the Suomi National Polar-orbiting Partnership satellite provide high-quality hyperspectral infrared and microwave observations to retrieve atmospheric vertical temperature and moisture profiles (AVTP and AVMP) and many other environmental data records (EDRs). The official CrIS and ATMS EDR algorithm, together called the Cross-track Infrared and Microwave Sounding Suite (CrIMSS), produces EDR products on an operational basis through the interface data processing segment. The CrIMSS algorithm group is to assess and ensure that operational EDRs meet beta and provisional maturity requirements and are ready for stages 1–3 validations. This paper presents a summary of algorithm optimization efforts, as well as characterization and validation of the AVTP and AVMP products using the European Centre for Medium-Range Weather Forecasts (ECMWF) analysis, the Atmospheric Infrared Sounder (AIRS) retrievals, and conventional and dedicated radiosonde observations. The global root-mean-square (RMS) differences between the CrIMSS products and the ECMWF show that the AVTP is meeting the requirements for layers 30–300 hPa (1.53 K versus 1.5 K) and 300–700 hPa (1.28 K versus 1.5 K). Slightly higher RMS difference for the 700 hPa-surface layer (1.78 K versus 1.6 K) is attributable to land and polar profiles. The AVMP product is within the requirements for 300–600 hPa (26.8% versus 35%) and is close in meeting the requirements for 600 hPa-surface (25.3% versus 20%). After just one year of maturity, the CrIMSS EDR products are quite comparable to the AIRS heritage algorithm products and show readiness for stages 1–3 validations.

Using MetOp-A AVHRR Clear-Sky Measurements to Cloud-Clear MetOp-A IASI Column Radiances

AbstractHigh spatial resolution measurements from the Advanced Very High Resolution Radiometer (AVHRR) on the Meteorological Operation (MetOp)-A satellite that are collocated to the footprints from the Infrared Atmospheric Sounding Interferometer (IASI) on the satellite are exploited to improve and quality control cloud-cleared radiances obtained from the IASI. For a partial set of mostly ocean MetOp-A orbits collected on 3 October 2010 for latitudes between 70°S and 75°N, these cloud-cleared radiances and clear-sky subpixel AVHRR measurements within the IASI footprint agree to better than 0.25-K root-mean-squared difference for AVHRR window channels with almost zero bias. For the same dataset, surface skin temperatures retrieved using the combined AVHRR, IASI, and Advanced Microwave Sounding Unit (AMSU) cloud-clearing algorithm match well with ECMWF model surface skin temperatures over ocean, yielding total uncertainties ≤1.2 K for scenes with up to 97% cloudiness.

An Experiment Using High Spectral Resolution CrIS Measurements for Atmospheric Trace Gases: Carbon Monoxide Retrieval Impact Study

We perform a demonstration experiment using the National Oceanic Atmospheric Administration Unique Cross-track Infrared Sounder (CrIS)/Advanced Technology Microwave Sounder Processing System to assess the improvement on trace gas retrievals upon switching to high spectral resolution CrIS radiance measurements (0.625 cm-1). The focus of this study is carbon monoxide retrievals. The experimental high spectral resolution CO retrievals show a remarkable improvement, of almost up to one order of magnitude in the degree of freedom of the signal, with respect to the low-resolution mode. Furthermore, high-resolution CO retrievals show similar skill with respect to existing CO operational products from the Atmospheric InfraRed Sounder, Atmospheric Sounder Interferometer, and Measurements of Pollution In The Troposphere instruments, both in terms of spatial variability and degrees of freedom. The results of this research provide evidence to support the need for high spectral resolution CrIS measurements. This is a fundamental prerequisite in guaranteeing continuity to the CO afternoon orbit monitoring as part of a multisatellite uniformly integrated long-term data record of atmospheric trace gases.

Retrieval of nitrous oxide from Atmospheric Infrared Sounder: Characterization and validation

This paper presents the retrieval algorithm of nitrous oxide (N2O) using the Atmospheric Infrared Sounder (AIRS) on EOS/Aqua, its validation using aircraft measurements, and one possible application for monitoring the global N2O annual trend from 2003 to 2013. The results demonstrate that AIRS is sensitive to N2O in the middle to upper troposphere, with the peak vertical sensitivity between 200 and 750 hPa and the sensitivity in the tropics larger than in the high-latitude regions. The degrees of freedom of the N2O retrieval are mostly between 1.0 and 1.5. Validation using the aircraft measurement profiles by the High-Performance Instrumented Airborne Platform for Environmental Research Pole-to-Pole Observations program over the Pacific Ocean indicated that the retrieval RMS error is mostly less than 8 ppb (or ~2.1%). One important feature is that the variability of N2O from AIRS is more than 2 times than that of the aircraft measurements in the lower troposphere. In agreement with surface measurements, a nearly linear trend of N2O can be obtained based on limited AIRS data of 1 day in 15 May in each year from 2003 to 2013, and the increase rate of N2O is about 0.72 ppb yr−1. This algorithm will be implemented in AIRS operational retrieval system, enabling the derivation of the N2O for over 20 years using the AIRS, the Infrared Atmospheric Sounding Interferometer, and the Cross-track Infrared Sounder. Such a unique product will be complementary to currently sparse ground-based observations for monitoring the N2O trend associated with climate change.

Joint Polar Satellite System (JPSS) Cross-track Infrared Microwave Sounding Suite (CrIMSS) environmental data record validation status

This paper reports on the recent status of the validation program for the Suomi National Polar-orbiting Partnership (NPP) Cross-track Infrared Microwave Sounding Suite (CrIMSS), a hyperspectral infrared sounding system designed for providing high resolution atmospheric vertical temperature and moisture profile (AVTP and AVMP) environmental data records (EDRs). CrIMSS EDR validation activities, currently (as of this writing, May 2012) segueing from the Early-Orbit Checkout (EOC) phase to the Intensive Cal/Val (ICV) phase of the program, are briefly highlighted.

Retrieving atmospheric temperature and moisture profiles from SUOMI NPP CrIS/ATMS sensors using CrIMSS EDR algorithm

As a part of the Joint Polar Satellite System (JPSS) and the Suomi National Polar-orbiting Partnership (NPP), the Cross-track Infrared Sounder (CrIS) and Advanced Technology Microwave Sounder (ATMS) instruments make up the Cross-track Infrared and Microwave Sounder Suite (CrIMSS). CrIMSS primarily provides globally-referenced calibrated radiances and vertical profiles of temperature, moisture, and pressure. The CrIMSS operational code has been ported to various LINUX systems and retrievals are performed using both proxy and real ATMS/CrIS data. The high quality proxy data generated from the IASI instrument provided useful testing for the CrIMSS EDR algorithm prior to the launch of the SUOMI NPP satellite. The experience learned from processing the proxy data helped us to handle the SUOMI NPP CrIS/ATMS data as soon as they became available to the CAL/VAL team. In this paper, encouraging preliminary results of applying the ported CrIMSS EDR algorithm to the SUOMI NPP CrIS/ATMS data are presented.

Pre-Launch Evaluation of NPP-CrIMSS EDR Algorithm Products with Matched ECMWF Analysis, RAOB Measurements, and IASI Retrievals

Atmospheric vertical temperature and moisture profiles retrieved by the Cross-track Infrared Sounder and Advanced Technology Microwave Sounder (CrIMSS) algorithm were evaluated with matched radiosonde measurements, model analysis, and retrievals from Infrared Atmospheric Sounder Interferometer (IASI) observations.

Advancing Science and Services during the 2015-16 El Niño: The NOAA El Niño Rapid Response Field Campaign

AbstractForecasts by mid-2015 for a strong El Nino during winter 2015/16 presented an exceptional scientific opportunity to accelerate advances in understanding and predictions of an extreme climat...