کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1778384 | 1021802 | 2006 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
On the response of the exospheric temperature to the auroral heating impulse during geomagnetic disturbances
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
فیزیک زمین (ژئو فیزیک)
پیش نمایش صفحه اول مقاله

چکیده انگلیسی
On the basis of an assumed impulse-type energy input at auroral oval due to the particle precipitation, the response of the exospheric temperature Tâ has been investigated in terms of changes in input energy, geomagnetic indices and latitude under simplified assumptions It is shown that the resulting Tâ is proportional to the peak heating rate and inversely proportional to the gradient of the atmospheric density. Even during low solar activity and quiet geomagnetic conditions, the precipitated electron energy density in the thermosphere is found in the range of about 1-1.5Ã10â6Â erg/cm3Â s, reaching to about 3Ã10â6Â erg/cm3Â s at 2000Â K and is easily supported by the solar wind-magnetospheric interaction. The auroral energy inputs lasting less than 2Â h or so hardly generate geomagnetic storms. The inhomogeneous energy equation has been solved in horizontal two dimensions in presence of horizontal heat conduction, to study the Tâ at other latitudes and its time delay with respect to the peak impulse heating time. This time delay is independent of the storm intensity, i.e., proxy geomagnetic indices and is about 6-7Â h at low and mid latitudes and about 3Â h or less at high latitudes in agreement with recent coupled magnetospheric-ionospheric-thermospheric models and with the available observed values. The diffusion coefficient of horizontal heat conduction deduced is about 7Ã104Â m2/s. The role of the horizontal heat conduction in the energy budget needs further investigation.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Atmospheric and Solar-Terrestrial Physics - Volume 68, Issue 11, July 2006, Pages 1237-1244
Journal: Journal of Atmospheric and Solar-Terrestrial Physics - Volume 68, Issue 11, July 2006, Pages 1237-1244
نویسندگان
V.P. Bhatnagar, A. Tan, R. Ramachandaran,