Baseline Instruments for the GOES-R Series: Providing Major Improvements to Hurricane Observations
James J. Gurka, Timothy J. Schmit, Thomas M. Renkevens, Mark DeMaria James.Gurka@noaa.gov
In order to meet the requirements, documented by the Geostationary Operational Environmental Satellite (GOES) user communities, the instruments designated for the GOES-R notional baseline include an Advanced Baseline Imager (ABI), a Geostationary Lightning Mapper (GLM), space weather and solar instruments. This paper will focus on the instruments of primary interest to hurricane forecasters: the ABI and GLM.
The Advanced Baseline Imager (ABI) is a state of the art, 16-band imager covering 6 visible (VIS) to near-infrared (NIR) bands (0.47 um to 2.25 um), and 10 infrared (IR) bands (3.9 um to 13.3 um). Spatial resolutions are band dependent, 0.5 km at nadir for broadband VIS, 1.0 km for NIR and 2.0 km for IR. The ABI will be capable of scanning the Full Disk (FD) in approximately 5 minutes, although routine full disk scans every 15 minutes are likely. ABI will improve every product from the current GOES Imager and will introduce a host of new products.
The Geostationary Lightning Mapper (GLM) will complement today’s operational ground based lightning detection systems, which only provide information on cloud to ground strikes over land, with information on total lightning flash rate (including both cloud to cloud and cloud to ground), over both land and adjacent oceans. The GLM will provide nearly continuous information on lightning flash rates, leading to improved: severe thunderstorm forecasts and warnings, aviation weather services, and lightning climatology.
The additional channels on ABI together with vastly improved radiometrics, spatial and temporal resolutions will provide significantly improved satellite derived winds in the storms environment and resultant improvements in model forecasts. It will also mean more frequent and accurate estimates of hurricane intensity based on pattern recognition, such as the Dvorak technique. The capability of observing the convective towers within the storm as often as every 30 seconds holds the potential for better understanding the mechanism for rapid intensification. The three water vapour channels, the 8.5 µm band, along with the restoration of the split window channel to better detect the Saharan dust layer, will promote a better understanding of the conditions leading to intensification or weakening. The new ozone channel (9.6 µm) will reveal information about troposphere/stratosphere exchanges, which may also be important for intensity changes. Likewise the capability to nearly continuously monitor the trends of total lightning flash rate will lead to a better understanding of the role of lightning in the hurricane life cycle.