STORMS AND WARNINGS FOR APRIL

Prediction of Geomagnetic Storms Associated With Halo CMEs of January and April 1997

The 6 January 1997 and 7 April 1997 halo coronal mass ejections (CMEs) were associated with interplanetary magnetic clouds observed by WIND that led to increased geomagnetic storm activity as indicated by the hourly Dst index. A recently developed storm-prediction method is retrospectively applied to these two solar wind (SW) structures. The results are described in detail. Had the algorithm be...

Warnings for pattern matching

We examine the ML pattern-matching anomalies of useless clauses and non-exhaustive matches. We state the definition of these anomalies, building upon pattern matching semantics, and propose a simple algorithm to detect them. We have integrated the algorithm in the Objective Caml compiler, but we show that the same algorithm is also usable in a non-strict language such as Haskell. Or-patterns ar...

Dust storms and ephemeral lakes

In drylands, both dust storms and ephemeral salt lakes (playas) are common. Observations using remote sensing and ground studies have shown that these playas can be major sources of saline dust storms. Some basins have recently become desiccated as a result of water abstraction by humans, and these have become significant sources of dust. The timing and amounts of dust emissions depends on such...

Of Streams and Storms

Analysis of the 3–7 October 2000 and 15–24 April 2002 geomagnetic storms with an optimized nonlinear dynamical model

[1] A computationally optimized low-dimensional nonlinear dynamical model of the magnetosphere-ionosphere system called WINDMI is used to analyze two large geomagnetic storm events, 3–7 October 2000 and 15–24 April 2002. These two important storms share common features such as the passage of magnetic clouds, shock events from coronal mass ejections, triggered substorms, and intervals of sawtoot...