Modelling the wet deposition of reduced nitrogen over the British Isles using a Lagrangian multi‐layer atmospheric transport model
Modelling the wet deposition of reduced nitrogen over the British Isles using a Lagrangian multi‐layer atmospheric transport model
复制标题
使用拉格朗日多层大气传输模型模拟不列颠群岛上空还原氮的湿沉降
DOI：
10.1256/qj.04.76
复制
发表时间：
2005
影响因子：
8.9
通讯作者：
Mark A. Sutton
中科院分区：
文献类型：
--
作者：
N. Fournier;K. Weston;A. Dore;Mark A. Sutton
利用拉格朗日长期、远距离大气输送模式估算了英国的还原氮湿沉积。这种长距离运输模型被用来制定排放控制战略，以对抗联合王国和欧洲敏感地区的环境酸化。这些模型目前认为湿沉积是使用清扫率和简单的播种器-喂食器效应的损失项。由于不列颠群岛年降雨量的大部分落在锋面事件中，播撒-馈入效应被认为是产生地形降水的主要过程。本文着重分析了湿法沉积去除过程的不同参数化方法。结果表明，播种器-喂食器效应与流动方向密切相关。为此，建立了一个定向地形增雨模式来模拟这一效应。提出了一个修正的湿沉降参数化公式，该公式考虑了该模式产生的定向地形降水。这一新公式还考虑到在山区测量的雨水中溶解的离子浓度较大。此外，通过显式地考虑模型中计算的混合层深度，建立了湿沉积过程的新的描述形式。然后将大气模式的结果与还原氮气湿沉降的实测值进行比较。首先，在新的定向地形降雨下，模拟的英国减少的氮湿沉积收支仍然被低估，但与测量结果的相关性增加。其次，与实测值相比，计算的混合层深度的加入使得模拟的减少的氮湿沉积预算有了很大的改善。版权所有(C)2005皇家气象学会。
Wet deposition of reduced nitrogen is estimated for the United Kingdom using a Lagrangian long‐term, long‐range atmospheric transport model. Such long‐range transport models are used to develop emission‐control strategies to combat environmental acidification in the sensitive regions of the United Kingdom and Europe. These models currently consider the wet deposition as a loss term using scavenging rates and a simple seeder–feeder effect. The seeder–feeder effect is assumed to be the main process producing orographic precipitation since the majority of British Isles annual rainfall falls in frontal events. This paper focuses on the analysis of different parametrizations of the removal process by wet deposition. It is shown that the seeder–feeder effect is very dependent on flow direction. Therefore, a model of directional orographic enhancement of precipitation is developed to simulate this effect. A revised formulation of the wet deposition parametrization is suggested, incorporating the directional orographic precipitation produced with this model. This new formulation also takes into account the larger concentrations of ions dissolved in rain water measured in mountainous areas. Moreover, a new representation of the wet deposition process is developed by considering explicitly the mixing layer's depth calculated in the model. The results from the atmospheric model, with these revised parametrizations of the wet deposition, are then compared with measured wet deposition of reduced nitrogen. Firstly, with the new directional orographic rainfall, the modelled United Kingdom reduced nitrogen wet deposition budget is still underestimated but an increased correlation with measurements is obtained. Secondly, the inclusion of the calculated mixing layer's depth leads to a considerable improvement in the modelled reduced nitrogen wet deposition budget compared with measurements. Copyright © 2005 Royal Meteorological Society.