A SIMPLE, INEXPENSIVE, LIGHT WEIGHT, ROBUST AEROSOL OPTICAL SCATTER CELL.

政府间气候变化专门委员会在2007年第四次评估报告中指出，人为气溶胶“仍然是辐射强迫的主要不确定性”。更多的气溶胶应该将更多的阳光反射到太空中，并倾向于冷却气候，或者，如果气溶胶含有黑碳，它们可能会加热空气并导致云蒸发，而较少的云将较少的阳光反射到太空中。更多的气溶胶可能会导致云有更多但更小的水云滴，因此它们会显得“更白”，并将更多的阳光反射回太空，此外，如果较小的水滴不太可能合并并形成降雨和消散，那么云的寿命可能会增加。对于冰云来说，情况甚至更加复杂和不确定。当温度福尔斯到冰点以下时，大部分水滴保持液态并被“过冷”;只有极少数气溶胶粒子具有“冰核”的性质并促进冻结。人为气溶胶对冰核数量的影响基本上是未知的。此外，气溶胶本身可能由对健康有害的污染物组成，因此，如果我们要了解并改进预测污染水平的模型，我们需要更多地了解它们的来源，它们如何在大气中传播以及如何从空气中去除。为了提高我们对大气中气溶胶的认识，我们需要更好地测量它们的分布，以及这种分布如何随着不同天气模式的变化而变化，以及气溶胶如何影响云的特性。特别是，我们需要能够在各种平台和极端条件下进行测量：例如在大风条件下靠近海面。虽然可用的仪器范围很广，但那些具有适合于研究粒子通量（~ 10 Hz）的时间响应的仪器太大且昂贵，而那些具有较小足迹的仪器又太昂贵且时间响应太慢。为了解决这些问题，利兹大学的研究人员开发了一种体积小、重量轻、响应速度快的光谱仪CLASP，它参与了各种各样的项目，这无异于它的成功和普及。然而，必须使用商业上可获得的散射单元，该散射单元已被证明过于复杂，其制造中使用的组件现已过时;此外，要求制造商签署的惩罚性许可协议意味着不能进行进一步的单元开发，并且越来越多的购买CLASP单元的请求被拒绝。最初开发CLASP的团队一直在研究一种新的、大大改进的散射单元，可以通过该单元开发新一代快速响应、小型、重量轻的气溶胶光谱仪，以满足对可用于极端部署场景、个人的仪器的需求采样器，或在尺寸和重量成为问题的平台上。这个新的单元目前处于技术准备水平（TRL）3，并要求提供资金，以使该单元达到TRL 4及更高水平。

The Intergovernmental Panel on Climate Change, in its fourth assessment report in 2007, states that anthropogenic aerosols 'remain the dominant uncertainty in radiative forcing'. More aerosols should reflect more sunlight out to space and tend to cool the climate, or alternatively, if the aerosols contain black carbon they may heat the air and cause clouds to evaporate, and less cloud would reflect less sunlight to space. More aerosols could lead to clouds having more but smaller water cloud droplets so they would appear 'whiter' and reflect more sunshine back to space, in addition, if the smaller droplets are less likely to coalesce and form rain and dissipate, so the cloud lifetime may increase. For ice clouds the situation is even more complex and uncertain. When the temperature falls below freezing most of the water drops remain as liquid and are 'supercooled'; only a very few aerosol particles have the property of being an 'ice nuclei' and promoting freezing. The effect of anthropogenic aerosols on the number of ice nuclei is essentially unknown. In addition aerosols themselves can be composed of pollutants which are deleterious to health, and so we need to know more about their sources, how they are transported around the atmosphere and how they are removed from the air, if we are to understand and consequently improve models forecasting pollution levels. To improve our knowledge of aerosols in the atmosphere we need better measurements of their distribution and how this changes as a function of the different weather patterns and how the aerosols influence the cloud properties. In particular we need to be able to make measurements form a wide range of platforms and in extreme conditions: for example close to sea surface in high wind conditions. Although the range of instrumentation available is wide those with a temporal response suitable for the investigation of particle fluxes (~10Hz) are too large and expensive, while those with a smaller foot print are again expensive and have too slow a temporal response. To address these problems researchers at the University of Leeds developed a small, light weight, fast response optical spectrometer, CLASP, and its participation in a wide variety of projects is tantamount to it success and popularity. Use had to be made, however, of a commercially available scatter cell that has proven overly complex with components used in its fabrication that are now obsolete; in addition the punitive licence agreement required form the manufacturer means that no further cell development can occur and the increasing number of requests to purchase a CLASP unit refused. The team that originally developed CLASP have been working on a new and vastly improved scatter cell from which a new generation of fast response, small, light weight aerosol spectrometers can be developed to address the need for instrumentation that can be used in extreme deployment scenarios, in personal samplers, or on platforms where size and weight is an issue. This new cell is currently at Technology Readiness Level (TRL) 3 and funding is requested to progress this cell to TRL 4 and beyond.