Arctic Floats: A Pilot Effort for Arctic Argo

北冰洋在调节世界海洋的热量、淡水和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必要的，但只有通过一个全面的观测网络才能实现。全球Argo项目非常成功，该项目由分布在全球海洋的大约3000台自主仪器组成，测量2000米以上水柱的物理特性，它展示了如何使用低成本的自主剖面浮标来维护这样一个监测系统。技术的进步使得在北极盆地深处部署argo型浮标成为可能，但海冰会减少浮标的数量。定期浮出水面以确定其位置并向卫星传送数据的能力。通过模拟，我们将研究与浮子无法浮出水面的“静默时间”延长相关的不确定性。我们将确定温度和盐度测量的降低精度作为浮子的函数。S初始位置和沉默时间长度。使用辅助信息来估计浮动在静默时间的运动也将被探索。这些模拟将有助于确定浮标在冰下居住1-5年后报告其位置的可能性，以及减少测量水质量特性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部分高纬度卫星和现场观测以及北极亚极地环流状态估计（ASTE）的使用，以获取尽可能多的信息：(a)与近期浮动技术操作相关的不确定性，以及(b)新观测对更好地理解北极发生的水文变化影响最大的地理分布。我们将量化与浮动可能性相关的几个指标。S的表面时间作为时间平均和时变海冰状态的函数，浮子的相关位置不确定性，以及隐含的水文不确定性。观测结果和状态估计的使用是互补的，因为ASTE可以为浮子部署的初始设计提供信息，反过来，未来的浮子数据将用于进一步约束和改进ASTE

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