Impact of African Dust on Clouds and Precipitation in a Caribbean Tropical Montane Cloud Forest

该奖项是根据2009年《美国复苏和再投资法》(公法111-5)资助的。该项目将结合实地调查和模型调查，研究长距离输送的非洲沙尘(LRTAD)气溶胶的物理化学性质如何影响加勒比地区的云特性和波多黎各独特的热带山区云雾森林(TMCF)的降雨量。TMCFs分布在全球的美洲、非洲和亚洲，是饮用水的主要来源。将检验三个主要假设：1)在强LRTAD期间，TMCF中的云特性是否不同；2)LRTAD是否具有影响云特性和过程的独特的化学和物理特性；3)降水模式与LRTAD事件之间的关系是什么？这项研究将在波多黎各(PR)、皮科德尔埃斯特(PE)和圣胡安角(CSJ)车站进行。PE在TMCF中，海拔1051米，处于/高于云凝结高度。这一位置便于研究云，而不需要飞机研究，从而降低了总体复杂性和成本，同时允许在单一云中进行更长期的观测。CSJ是全球大气观测的一个近海平面区域站，位于PE的逆风方向，是PR中信风气团的第一个接触点。该站允许对进入云层的气溶胶(云下气溶胶)的性质进行采样。将通过长期测量和在第二年密集的实地活动期间收集关于气溶胶、云和雨水样本的化学和物理性质的数据。利用这些结果，结合现有的降水、云量、温度和湿度分布以及地面能量收支的数据集，将调查降水分布对LRTAD事件的敏感性，特别是加勒比地区夏季旱季的长度和强度。代表不足的学生群体将与科学家和最先进的仪器进行互动，并接触到独特的研究机会。区域应对AD和气候变化的能力将得到加强。项目成果将用于不同教育水平的学生和社区的教材。在“大气科学强化短期课程方案”中，COPIS/合作者将在波多黎各-里约热内卢大学(UPR-RP)开设短期课程，参与机构之间的学生交流将弥补UPR-RP不存在的大气科学课程。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).The project will combine field and modeling investigations to address how the physico-chemical properties of long range transported African dust (LRTAD) aerosol influence Caribbean cloud properties and precipitation levels in a unique Puerto Rican tropical mountain cloud forest (TMCF). TMCFs occur globally in the Americas, Africa, and Asia and represent a primary source of drinking water. Three major hypotheses will be tested: 1) are cloud properties in the TMCF different during intense LRTAD periods; 2) Does LRTAD have unique chemical and physical properties which influence cloud properties and processes; 3) what is the correlation between precipitation patterns and LRTAD events? The study will be performed in Puerto Rico (PR), at Pico del Este (PE) and Cape San Juan (CSJ) stations. PE is in a TMCF with an elevation of 1051m asl which is at/above the cloud condensation level. This location facilitates the study of clouds without the need for aircraft studies which reduces the overall complexity and costs while allowing longer term observations within a single cloud. CSJ is a near sea level regional station of the Global Atmosphere Watch, upwind from PE, and is the first contact point for the trade wind air masses in PR. This station allows the sampling of the properties of the aerosol that enter the cloud (below-cloud aerosol). Data on the chemical and physical properties of aerosols, clouds, and rainwater samples will be collected via long term measurements and during an intensive field campaign in year 2. Using these results in conjunction with existing data sets of precipitation, cloud cover, temperature and humidity profiles and surface energy budgets, the sensitivity of precipitation distribution to LRTAD events will be investigated, particularly focusing on the length and intensity of the summer dry season in the Caribbean. Underrepresented student groups will interact with scientists and state-of-the-art instrumentation and be exposed to unique research opportunities. The regional capacity to cope with AD and climate change will be strengthened. Project results will be used in educational materials for students and communities over a range of educational levels. The "Program of Intensive Short Courses in Atmospheric Sciences", where CoPIs/collaborators will offer a short course at the University of Puerto Rico-Rio Piedras (UPR-RP), as well as the exchange of students among participating institutions will compensate for the non-existent curricula in atmospheric sciences at the UPR-RP.