主辦單位：北航中法數學中心

主講人：Olivier Pironneau

講座時間：10月27日（周日）15:00-17:00

講座地點：杭州國際校園會議中心2003&2004

參與方式：本次講座為公開學術活動，可算做杭州校區一次德育類博雅課程。學院路校區、沙河校區數學專業想參加的同學請在10月26日中午12:00前發送【講座報名+學號+學院+聯系方式】至“北航數韻”微信公眾號報名。

講座提要

Convective Trails may have a large effect on climate. They form rapidly propagating high altitude cirrus and the burned gases absorb infrared light resulting in a change of temperature in the atmosphere. To study the temperature in the earth atmosphere subjected to electromagnetic radiations, one may use the Radiative Transfer equations coupled with the Navier-Stokes equations. The problem has 7 dimensions; however with minimal simplifications it is equivalent to a small number of integro-differential equations in 3 dimensions. A numerical implementation using an H-matrix compression scheme allows us to measure the effect of clouds and airplane contrails on the temperature in the atmosphere. The result is very fast and the method is capable of handling variable absorption and scattering functions of spatial positions and frequencies.

The talk will not deal with the mathematical technicality of the method but will put these developments in perspective within the general problem of climate modeling.

對流尾跡可能對氣候產生顯著影響。它們形成快速傳播的高空卷云，燃燒的氣體吸收紅外光后導致大氣溫度發生變化。可以使用輻射傳輸方程和納維-斯托克斯方程來研究受電磁輻射影響的地球大氣溫度。該問題有 7 個維度，但經過最小限度的簡化后，它等價于少量的3 維積分微分方程。使用 H 矩陣壓縮方案的數值實現使我們能夠測量云和飛機尾跡對大氣溫度的影響。該方法不僅效率很高，還可以處理空間位置和頻率的可變吸收和散射函數。

本次報告不會涉及上述方法的具體數學技術細節，只會從氣候建模的一般問題的角度來看待這些進展。

專家簡介

Olivier Pironneau is a French mathematician who is a professor at the Université Pierre et Marie Curie and member of the French Academy of Sciences. Pironneau is a worldwide recognized expert in computational fluid dynamics, scientific computing, computational engineering, optimal design, numerical analysis and partial differential equations. He is a member of French Academy of Sciences since 2002 and associate member of the Russian Academy of Sciences since 2004. He was awarded the Ordre National du Mérite and he is also the recipient of the Marcel Dassault Prize and Blaise Pascal Prize by the French Academy of Sciences.

French Academy of Sciences (Académie des Sciences in French) was established in 1666.

奧利維爾·皮羅諾（Olivier Pironneau）是法國數學家，法國索邦大學（原皮埃爾和瑪麗居里大學）教授，法國科學院院士。皮羅諾院士是國際公認的計算流體力學、科學計算、計算工程、優化設計、數值分析和偏微分方程等領域的專家。他分別于2002年和2004年當選法國科學院院士和俄羅斯科學院外籍院士，曾獲法國國家功績勛章和法國科學院馬塞爾·達索獎（Marcel Dassault Prize）和布萊斯·帕斯卡獎（Blaise Pascal Prize）等重要獎項。

法國科學院始建于1666年，是法國最高的學術權威機構。

編輯：張嘉鑫