Arctic Floats: A Pilot Effort for Arctic Argo

北冰洋在调节世界海洋的热量、淡水及其营养循环方面发挥着重要作用。因此，了解、监测和预测北冰洋如何随着气候变化而变化是势在必行的，但只有通过全面的观测网络才能实现。极为成功的全球ARGO方案由分布在世界各地的大约3000台自主仪器组成，它测量水柱上部2000米的物理性质，证明了如何使用低成本的自主剖面浮标来维持这样的监测系统。技术进步使在北极深水盆地部署ARGO类型的浮标成为可能，但海冰减少了浮标？能够定期浮出水面以确定它们的位置并向卫星传输数据。利用模拟，我们将调查与延长的“沉默时间”相关的不确定性，在此期间，浮标无法浮出水面。我们将确定温度和盐度测量的降低精度作为浮标S初始位置和静默时间长度的函数。还将探索使用辅助信息来估计花车在静默时间的移动。这些模拟将有助于确定浮标在冰下停留1-5年后报告其位置的可能性，以及减少测量水团性质的不确定性所需的浮标数量，帮助我们设计在不久的将来使用北极浮标的计划。拟议的工作利用了大量的高纬度卫星和现场观测，并使用北极亚极地涡旋状态估计(ASTE)来提取尽可能多的信息：(A)与操作近期浮标技术相关的不确定性，以及(B)新观测将对更好地了解北极发生的水文变化产生最大影响的地区的地理分布。我们将量化几个指标，这些指标与浮标的可能性有关--S的浮出水面时间是时间平均和时变海冰状态的函数，浮标相关的位置不确定性，以及隐含的水文不确定性。观测和状态估计的使用是相辅相成的，因为ASE可以为浮动部署的初始设计提供信息，而未来的浮动数据将被用来进一步约束和改进ASE

The Arctic Ocean plays an important role in regulating the world ocean's heat, and freshwater, and its nutrient cycles. Understanding, monitoring, and predicting how the Arctic Ocean changes as climate changes are thus imperative, but can only be achieved with a comprehensive observation network. The exceedingly successful global Argo program, which consists of roughly 3000 autonomous instruments distributed throughout the world ocean measuring physical properties of the upper 2000 m of the water column, has demonstrated how such a monitoring system can be maintained using low-cost autonomous profiling floats. Technological advancement has made it possible to deploy Argo-type floats in the deep Arctic basin, but sea ice reduces the floats? ability to surface at regular intervals to determine their position and to transmit data to satellites. Using simulations, we will investigate uncertainties associated with extended "silent times" during which floats are unable to surface. We will determine the reduced accuracies in temperature and salinity measurements as a function of a float?s initial position and length of silent times. Use of auxiliary information to estimate the float's movements during silent times will also be explored. These simulations will help establish the likelihood that floats will report their positions after residing 1-5 years under ice and the number of floats that are needed to reduce the uncertainty in the measurement of water mass properties, helping us design a plan for using Arctic floats in the near future.The proposed work leverages much of the high latitude satellite and in situ observations and the use of the Arctic Sub-polar gyre state estimate (ASTE) to extract as much information as possible on: (a) the uncertainty associated with operating near-future float technology, and (b) the geographic distribution of where new observations would have the most impact on better understanding the hydrographic changes occuring in the Arctic. We will quantify several metrics, related to the likelihood of a float?s' surfacing-time as a function of time-mean and time-varying sea ice state, the float's associated position uncertainties, and the implied hydrographic uncertainties. The use of the observations and the state estimate are complementary in that ASTE can inform the initial design of the float deployment, and in turn future float data will be used to further constrain and improve ASTE