The habitat, but also the nest hole of a hole-nesting species, will degrade the song during transmission. We investigated how the sounds degrade in a sound transmission experiment with the song of the Pied Flycatcher Ficedula hypoleuca (Muscicapidae). Ten different song elements were transmitted to microphones placed inside and outside a nest box. On average, song degradation was much greater i...

Summertime cloud-to-ground lightning strikes are responsible for the majority of wildfire ignitions across vast sections of the seasonally dry western United States. In this study, a strong connection between active phases of the Madden–Julian oscillation (MJO) and regional summertime lightning activity was found across the interior western United States. This intraseasonal mode of lightning ac...

Carbon dioxide (CO(2)) is the most important anthropogenic greenhouse gas in the present-day climate. Most of the community focuses on its long-term (decadal to centennial) behaviors that are relevant to climate change, but there are relatively few discussions of its higher-frequency forms of variability, and none regarding its subseasonal distribution. In this work, we report a large-scale int...

The Madden-Julian Oscillation (MJO) is the dominant component of tropical intraseasonal variability, and a theory explaining its structure and successful numerical simulation remains a major challenge. A successful model for the MJO should have a propagation speed of 4-7 m/s predicted by theory; a wavenumber-2 or -3 structure for the planetary-scale, low-frequency envelope with distinct active ...

Madden-Julian Oscillation. These oscillations are observed in the tropical stratosphere (and higher) but only above about 20km, i.e. they are absent from the lowest part of the stratosphere. The explanation is that the oscillations excited in the troposphere are refracted into mid-latitudes in the upper troposphere, so are absent in the tropical lower stratosphere, and are then refracted back i...

Lei Zhou 4 Lamont-Doherty Earth Observatory, Columbia University, New York, NY 5 Key Lab of Ocean Dynamic Processes and Satellite Oceanography, SOA, Hangzhou, China 6 7 Adam H. Sobel 8 Department of Applied Physics and Applied Mathematics 9 Department of Earth and Environmental Sciences 10 Lamont-Doherty Earth Observatory 11 Columbia University, New York, NY 12 13 Raghu Murtugudde 14 Earth Syst...