Weather Cycles

Solar cycle changes in coronal holes and space weather cycles

[1] Potential field source surface models of the coronal magnetic field, based on Mt. Wilson Observatory synoptic magnetograms, are used to infer the coronal hole sources of low-heliolatitude solar wind over approximately the last three solar cycles. Related key parameters like interplanetary magnetic field and bulk velocity are also calculated. The results illustrate how the evolving contribut...

Weather Conditions, Weather Information and Car Crashes

Road traffic safety is the result of a complex interaction of factors, and causes behind road vehicle crashes require different measures to reduce their impacts. This study assesses how strongly the variation in daily winter crash rates associates with weather conditions in Finland. This is done by illustrating trends and spatiotemporal variation in the crash rates, by showing how a GIS applica...

Weather Videos

Tropical weather

There are two reasons why tropical weather is different from that at higher latitudes. The sun shines more directly on the tropics than on higher latitudes (at least in the average over a year). This makes the tropics warm. And, the vertical direction (up, as one stands on the earth’s surface) is perpendicular to the earth’s axis of rotation at the equator, while the two are the same at the pol...

The Weather-Huffman Method of Data Compression of Weather Images

This document is disseminated under the sponsorship of the Department of Transportation in the interest of information exchange. The United States Government assumes no liability for its contents or use thereof. Providing an accurate picture of the weather conditions in the pilot's area ofinterest is a highly useful application for ground-ta-air datalinks. The problem with using data links to t...