Capturing More Than 100 Years of Storms in the Twentieth Century Reanalysis Version 3
Abstract
A 150-year history of the weather can be used not only for studying climate, examining changes in extremes, and providing a long sample of rare events, but also for case studies of weather events, such as strong storms. The NOAA-CIRES Twentieth Century Reanalysis Version 2c (20CRv2c) provides more than a century of estimates of the global atmospheric state at a spatial and temporal resolution fine enough to capture many storms reaching back to 1851. This is achieved by carefully combining a first-guess from a numerical model with surface pressure observations and wind-derived pressure reports from the International Best-Track Archive for Climate Stewardship (IBTrACS), which provides central pressure data from tropical cyclones. However, the resulting analyzed field after assimilating data is not guaranteed to match the observed value; instead, it may exhibit a storm that is too weak. In cases without accompanying IBTrACS reports, the system relies on nearby pressure observations to be able to recreate the storm; otherwise, it may not be present in the reanalysis at all. 20CRv2c suffered from both of these problems: storms that are too weak, and storms that are incorrectly missed. The latest historical reanalysis from CIRES-NOAA-DOE, 20CRv3, represents storms more accurately than 20CRv2c due to its newer and higher-resolution model, algorithmic improvements, and larger set of observations. Several particular cases are studied, including the 1915 Galveston Hurricane, 1992's Hurricane Andrew, and a strong storm that hit Sitka, Alaska in 1880. Results comparing these storms in 20CRv2c, 20CRv3, and other available reanalyses will be shown. Specific updates to the 20CRv3 system that led to its improved performance will also be highlighted.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.A14G..07S
- Keywords:
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- 3305 Climate change and variability;
- ATMOSPHERIC PROCESSESDE: 3309 Climatology;
- ATMOSPHERIC PROCESSESDE: 3315 Data assimilation;
- ATMOSPHERIC PROCESSESDE: 1616 Climate variability;
- GLOBAL CHANGE