عنوان
پدید آورنده
موضوع
رده
کتابخانه
محل استقرار
شماره کتابشناسی ملی
شماره
TLpq304292979
زبان اثر
زبان متن نوشتاري يا گفتاري و مانند آن
انگلیسی
عنوان و نام پديدآور
عنوان اصلي
Precipitation simulation in global climate models:
نام عام مواد
[Thesis]
نام نخستين پديدآور
M. J. Shaikh
عنوان اصلي به قلم نويسنده ديگر
Impact of horizontal resolution and improved land surface scheme
نام ساير پديدآوران
R. E. Dickinson
وضعیت نشر و پخش و غیره
نام ناشر، پخش کننده و غيره
The University of Arizona
تاریخ نشرو بخش و غیره
1996
مشخصات ظاهری
نام خاص و کميت اثر
246
یادداشتهای مربوط به پایان نامه ها
جزئيات پايان نامه و نوع درجه آن
Ph.D.
کسي که مدرک را اعطا کرده
The University of Arizona
امتياز متن
1996
یادداشتهای مربوط به خلاصه یا چکیده
متن يادداشت
This dissertation examines the improvement in the simulation of precipitation by using a high resolution model and a highly physically-based land surface scheme. To investigate the impact of the horizontal resolution on the simulated fields, six versions of NCAR's latest Community Climate Model (CCM2) are analyzed. The simulations were conducted for periods of 4-20 years. To study the effects of the improved land surface scheme in the model, the coupling of BATS to the standard model and a revised version of CCM2 with modified optical properties for clouds are compared. It is evident that the refinement of the model resolution adds further accuracy to the simulation. The increased resolution of the model improves the definition of the major mountain ranges and the average surface topography of lands and oceans. The taller mountains in a high resolution model play an important role in modifying the vapor flux over the land surface. They obstruct more water flow and reduce the specific humidity and the total precipitable water over land. The vapor transport to the land surface is also partly influenced by the changes in the large scale circulation. The adjusted surface pressures over the sea surface levels simulate more closely the position and magnitude of the observed pressure systems. A major problem in CCM2 is the excessive surface radiation, which is up to 50-100 Wm higher than the Surface Radiation Budget (SRB) dataset over vast areas in the summer hemisphere. At a high resolution, the lower land clouds reduce the planetary albedo and allow more solar radiation to reach the surface. But in spite of this, the high resolution model improves the amount and distribution of the land precipitation. The RCCM2-BATS model, which increases the optical thickness of the summer clouds, substantially reduces the overestimate of the surface radiation. This helps reduce the large discrepancies obtained in summer precipitation. The land surface scheme predicts the regional climate more accurately than the standard model, but its performance is restricted by the inputs and does not show any major improvement in precipitation predictions which are mainly controlled by various processes in the atmospheric model.
موضوع (اسم عام یاعبارت اسمی عام)
موضوع مستند نشده
Atmosphere
موضوع مستند نشده
climate
موضوع مستند نشده
Earth sciences
موضوع مستند نشده
Hydrology
موضوع مستند نشده
Hydrology
موضوع مستند نشده
Pure sciences
نام شخص به منزله سر شناسه - (مسئولیت معنوی درجه اول )
مستند نام اشخاص تاييد نشده
M. J. Shaikh
مستند نام اشخاص تاييد نشده
R. E. Dickinson
دسترسی و محل الکترونیکی
نام الکترونيکي
مطالعه متن کتاب وضعیت انتشار
فرمت انتشار
p
اطلاعات رکورد کتابشناسی
نوع ماده
[Thesis]
کد کاربرگه
276903
اطلاعات دسترسی رکورد
سطح دسترسي
a
تكميل شده
Y
