We study the specific influence of African dust on each one of the categories of Atlantic hurricanes. By applying wavelet analysis, we find a strong decadal modulation of African dust on Category 5 hurricanes and an annual modulation on all other categories of hurricanes. We identify the formation of Category 5 hurricanes occurring mainly around the decadal minimum variation of African dust and in deep water areas of the Atlantic Ocean, where hurricane eyes have the lowest pressure. According to our results, future tropical cyclones will not evolve to Category 5 until the next decadal minimum that is, by the year 2015 +/- 2.
Statistical Modelling of the Relationship Between Main Development Region Sea Surface Temperature and \emph{Landfalling} Atlantic Basin Hurricane Numbers
Five year ahead prediction of Sea Surface Temperature in the Tropical Atlantic: a comparison between IPCC climate models and simple statistical methods
Kilometer-Scale AI Downscaling of Atlantic Hurricanes with Generative Ensembles
Research Applications Laboratory（研究应用实验室）；NSF National Center for Atmospheric Research（美国国家科学基金会国家大气研究中心）；Department of Mathematics, Emory University（埃默里大学数学系）
Tropical cyclones that evolve from a non-tropical origin may pose a special challenge for predictions, as they often emerge at the end of a multi-scale cascade of atmospheric processes. Climatological studies have shown that the 'tropical transition' (TT) pathway plays a prominent role in cyclogenesis, in particular over the North Atlantic Ocean. Here we use operational European Centre for Medium-Range Weather Forecasts ensemble predictions to investigate the TT of North Atlantic Hurricane Chris (2012), whose formation was preceded by the merger of two potential vorticity (PV) maxima, eventual…
African dust exhibits strong variability on a range of time scales. Here we show that the interhemispheric contrast in Atlantic SST (ICAS) drives African dust variability on interannual, multidecadal, and millennial timescales, and a strong anthropogenic decline of African dust in the future can be expected due to the projected increase of the ICAS. During the recent past, the ICAS is found to significantly correlate with various dust observations and proxies that extend as far back as 1851. Physically, positive ICAS anomalies induce large-scale circulation changes that push the Intertropical …
Dynamics of East Atlantic seed vortex populations in global km-scale models
University of Leeds（利兹大学）；University of Oxford（牛津大学）；Met Office（英国气象局）；National Centre for Atmospheric Science (NCAS), University of Reading（雷丁大学国家大气科学中心）；Department of Meteorology, University of Reading（雷丁大学气象系）
National Institute of Standards and Technology（美国国家标准与技术研究院）
The objective of this paper is to employ machine learning (ML) and deep learning (DL) techniques to obtain from input data (storm features) available in or derived from the HURDAT2 database models capable of simulating important hurricane properties such as landfall location and wind speed that are consistent with historical records. In pursuit of this objective, a trajectory model providing the storm center in terms of longitude and latitude, and intensity models providing the central pressure and maximum 1-$min$ wind speed at 10 $m$ elevation were created. The trajectory and intensity models…
Comments by William M. Gray (Colorado State University) on the recently published paper in Science by Webster et al., titled "Changes in tropical cyclone number, duration, and intensity in a warming environment." (September 2005, Vol. 309, pp. 1844-1846, www.sciencemag.org)
Some initial investigations into various atmospheric phenomena and the influence of the solar cycle on weather have been made. Strongly negative North Atlantic Oscillation (NAO) indices, which cause cold and dry winter weather in North West Europe, rarely occur during periods of high solar activity. Coupling between the troposphere and stratosphere is discussed, particularly in the context of Polar-night jet oscillation events (defined by Hitchcock et al., 2013) and the Quasi-Biennial Oscillation. The energy of North Atlantic hurricanes (as indicated by the Accumulated Cyclone Energy Index, AC…
Bayesian statistical models were developed for the number of tropical cyclones and the rate at which these cyclones became hurricanes in the North Atlantic, North and South Indian, and East and West Pacific Oceans. We find that there is small probability that the number of cyclones has increased in the past thirty years. The rate at which these storms become hurricanes appears to be constant. The rate at which hurricanes evolve into category 4 and higher major storms does appear to have increased. We also investigate storm intensity by measuring the distribution of individual storm lifetime in…
Variability of North Atlantic hurricanes: seasonal versus individual-event features
热带气旋受到大量气候因子的影响，这些因素转化为复杂的发生模式。热带气旋活动的年度指标的变化已经被深入研究，特别是自20世纪90年代中期北大西洋突然激活以来。我们首先提供了一个快速的概述不同作者以前的工作，这些年度指标的NAtl盆地，在自然变化的现象，存在的趋势，记录的缺点，以及全球变暖的影响一直是有趣的辩论的主题。接下来，我们提出了一种替代方法，该方法不关注季节特征，而是关注单个事件的特征[Corral et al Nature Phys 6，693，2010]。有人认为，个别风暴功率耗散指数（PDI）构成了一个自然的方式来描述每个事件，并进一步，PDI统计产生一个强大的规律，热带气旋的发生在幂律。在这方面，这些分布的拟合方法进行了讨论。作为这项工作的一个重要扩展，我们引入了一个分布函数，模型的整个范围内的PDI密度（不包括在最小值的不完整性的影响），伽玛分布，包括在一个幂律与指数衰减的尾巴。这种衰减的特征尺度，表示的截止参数，提供了非常有价值的信息的有限大小的盆地，通过最大值的PDIs，盆地可以维持。我们使用伽马拟合来评估海表面温度（SST）对极端PDI值发生的影响，我们发现，对于0.49 degC的SST平均差异，这些全流域事件的值增加了约50%。...
