Quantifying the impact of atmospheric aerosol on diffuse radiation and the Amazon biosphere

量化大气气溶胶对漫射辐射和亚马逊生物圈的影响

基本信息

批准号：
NE/J004723/1
负责人：
Dominick Spracklen
金额：
$ 10.19万
依托单位：
University of Leeds
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2012
资助国家：
英国
起止时间：
2012 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FJ004723%2F1
关键词：
Quantifying impact atmospheric aerosol diffuse

项目摘要

Trees in the Amazon are getting bigger absorbing large amounts of carbon dioxide from the atmosphere; equivalent to almost 10% of anthropogenic greenhouse gas emissions. This "carbon sink" slows the buildup of atmospheric carbon dioxide and therefore plays an important role in regulating climate change. At the moment we do not understand why the Amazon forest is behaving in this way. One potential reason is changes to the amount of tiny particles in the atmosphere called aerosols. We know that human activity has significantly changed the amount of aerosol over the Amazon: each dry season, humans start forest fires across southern parts of the Amazon basin (the so called "Arc of deforestation"). These fires emit large quantities of smoke aerosol into the atmosphere, scattering and absorbing radiation from the sun. This scattering of the sun's rays decreases the amount of direct radiation reaching the surface but increases the amount of diffuse radiation. It has been known for a long time that increases in diffuse radiation can increase plant productivity. For example, gardeners place "diffuser sheets" inside greenhouses that increase diffuse radiation in the similar way to atmospheric particles. The reason why diffuse radiation increases plant productivity is that it penetrates deeper into the canopy and illuminates leaves that would otherwise be in the shade. These previously shaded leaves can do more photosynthesis. A recent study showed that this effect can be very important, increasing the amount of carbon taken up by forests globally by 25%. It is therefore likely that deforestation fires (a major source of carbon dioxide emissions) are at least partly contributing to the sink of carbon dioxide in undisturbed forests in the Amazon basin. So far this effect has not been carefully studied for forests in the Amazon. Firstly, it is not well known exactly how much the amount of aerosol particles over the Amazon has changed. Second, no one has quantified how this change in aerosol particles has altered the amount of diffuse radiation. And finally we do not know whether these changes in diffuse radiation are sufficient to explain any of the observed changes in forest biomass across the Amazon. In this project we will use a suite of atmospheric aerosol, radiation and land-surface models to explore the problem. We will use a global model of atmospheric aerosol to simulate how aerosol distributions have changed over the Amazon over the last few decades. We will input these changes in aerosol into an atmospheric radiation model to quantify how amounts of diffuse radiation have changed. Finally, we will use these changes in diffuse radiation as input to a land-surface model to quantify how it impacts Amazon forests. At each step in the process we will use observations from ground-sites and satellite sensors to test how well the models explain observed changes. The project will lead to a much better understanding of how Amazon aerosol has changed and how this impacts diffuse radiation and the biosphere.

亚马逊的树木从大气中吸收了更大的吸收二氧化碳。相当于近10％的人为温室气体排放。这种“碳汇”减慢了大气二氧化碳的积累，因此在调节气候变化中起着重要作用。目前，我们不明白为什么亚马逊森林以这种方式行事。一个潜在的原因是，大气中的小颗粒数量变化称为气溶胶。我们知道，人类活动已大大改变了亚马逊上的气溶胶数量：每个旱季，人类在亚马逊盆地南部的南部启动森林大火（所谓的“森林砍伐弧”）。这些火灾将大量烟雾气雾剂散发到大气中，从太阳散射和吸收辐射。太阳射线的散射减少了到达表面的直接辐射量，但增加了弥散辐射的量。很长一段时间以来，弥漫性辐射的增加可以提高植物的生产率。例如，园丁在温室内放置“扩散片”，以与大气颗粒相似的方式增加散射辐射。弥漫性辐射提高植物生产率的原因是，它更深地渗入树冠并照亮叶子，否则将在阴影中。这些先前阴影的叶子可以进行更多的光合作用。最近的一项研究表明，这种影响可能非常重要，将全球森林占用的碳量增加了25％。因此，森林砍伐火灾（二氧化碳排放的主要来源）可能至少部分促成亚马逊盆地未受干扰的森林中二氧化碳的水槽。到目前为止，尚未对亚马逊森林进行仔细研究。首先，目前尚不清楚亚马逊上的气溶胶颗粒数量发生了多少变化。其次，没有人量化这种气溶胶颗粒的变化如何改变了扩散辐射的量。最后，我们不知道这些扩散辐射中的这些变化是否足以解释整个亚马逊森林生物量的任何观察到的变化。在这个项目中，我们将使用一套大气气溶胶，辐射和土地表面模型来探索问题。我们将使用全球大气气溶胶模型来模拟过去几十年来气溶胶分布在亚马逊上的变化。我们将在气溶胶中将这些变化输入到大气辐射模型中，以量化弥散辐射的量如何变化。最后，我们将使用这些变化在弥漫性辐射中作为土地表面模型的输入，以量化它如何影响亚马逊森林。在此过程中的每个步骤中，我们将使用地面位点和卫星传感器的观测值来测试模型如何解释观察到的变化。该项目将使人们更好地了解亚马逊气溶胶的变化以及这如何影响弥漫性辐射和生物圈。

项目成果

期刊论文数量（10）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Extending water vapor trend observations over Boulder into the tropopause region: Trend uncertainties and resulting radiative forcing.

将博尔德上空的水汽趋势观测扩展到对流层顶区域：趋势不确定性和由此产生的辐射强迫。

DOI：
10.1002/jgrd.50831
发表时间：
2013
期刊：
JGR
影响因子：
0
作者：
Kunz A
通讯作者：
Kunz A

Impact of gas-to-particle partitioning approaches on the simulated radiative effects of biogenic secondary organic aerosol

DOI：
10.5194/acp-15-12989-2015
发表时间：
2015-01-01
期刊：
ATMOSPHERIC CHEMISTRY AND PHYSICS
影响因子：
6.3
作者：
Scott, C. E.;Spracklen, D. V.;Pringle, K. J.
通讯作者：
Pringle, K. J.

Impact on short-lived climate forcers increases projected warming due to deforestation.

DOI：
10.1038/s41467-017-02412-4
发表时间：
2018-01-11
期刊：
Nature communications
影响因子：
16.6
作者：
Scott CE;Monks SA;Spracklen DV;Arnold SR;Forster PM;Rap A;Äijälä M;Artaxo P;Carslaw KS;Chipperfield MP;Ehn M;Gilardoni S;Heikkinen L;Kulmala M;Petäjä T;Reddington CLS;Rizzo LV;Swietlicki E;Vignati E;Wilson C
通讯作者：
Wilson C

Small global effect on terrestrial net primary production due to increased fossil fuel aerosol emissions from East Asia since the turn of the century.

DOI：
10.1002/2016gl068965
发表时间：
2016-08-16
期刊：
GEOPHYSICAL RESEARCH LETTERS
影响因子：
5.2
作者：
O'Sullivan, M.;Rap, A.;Reddington, C. L.;Spracklen, D. V.;Gloor, M.;Buermann, W.
通讯作者：
Buermann, W.

Enhanced global primary production by biogenic aerosol via diffuse radiation fertilization