干旱区生态环境知识资源中心

The Mediterranean Israeli dust experiment (MEIDEX) flew on-board the space shuttle in winter 2003, in a 39degrees-inclination orbit for 16 days, passing over the major thunderstorm regions on Earth. The primary science instrument of the MEIDEX payload is a Xybion IMC-201 image-intensified radiometric camera with six narrow band filters, boresighted with a wide-FOV color video camera. During the nightside of the orbit there will be dedicated observations toward the Earth's limb above areas of active thunderstorms, in an effort to image transient luminous events (TLEs) from space. Optical observations from space will be conducted with the 665 nm filter that matches the observed wide peak centered at 670 nm that typifies red sprites, and also with the 380 and 470 rim filters for recording blue jets. Observations will consist of a continuous recording of the Earth's limb, from the direction of the dusk terminator towards the nightside. Areas of high convective activity will be forecasted and uplinked to the crew before the observation. The astronaut will direct the camera toward areas with lightning activity, observed visually through the windows and on monitors in the crew cabin. Simultaneously with the optical observations from space, dedicated ground measurements will be conducted on a global scale. Two field sites in the Negev Desert in Israel will be used to collect electromagnetic data in the ELF and VLF frequency range. Additional ground stations in Germany, Hungary, USA, Antarctica, Chile, South Africa, Australia, Taiwan and Japan will also record Schumann resonance and VLF signals. The coordinated measurements from various locations on Earth and from space will enable us to triangulate the location and determine the polarity and charge moment of the parent lightning of the optically observed TLEs. The success of the campaign will further clarify the geographical distribution of Sprites, Elves and Jets. (C) 2003 Elsevier Science Ltd. All rights reserved.