{'fraction_non_alphanumeric': 0.030727106784301794, 'fraction_numerical': 0.02099178582293885, 'mean_word_length': 4.971843778383288, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Upper Ocean Heat Observation using UpTempO buoys during RV Mirai Arctic cruise MR14-05

This report describes surface water temperature measurements obtained by an autonomous observing instrument “UpTempO” as a part of RV Mirai Arctic cruise in 2014, MR14-05. The UpTempO is a drifting buoy consisting of an underwater thermistor chain, carrying 16 thermistors and 3 pressure sensors, and a surface floating unit for Iridium satellite communication with sensors of sea surface temperature and sea level pressure. Three UpTempOs have been deployed from RV Mirai in the ice-free Chuckhi Plateau. UpTempOs have successfully collected the near-surface temperature data to reveal seasonal change of surface layer heat content during a transition from late summer to mid-winter. The past Mirai expeditions, aiming to reveal the yearlong air-sea heat exchange in the Arctic, has faced difficulties to continue the observation after the surface freezing onsets since RV Mirai is not designed to sufficiently resist pressures from surrounding ice floes. Then, deploying the autonomous instrument such as UpTempO from the ship could make it possible to carry out the prolonged observation even the freezing onset onward.


Introduction
The Arctic ice cover has experienced an extreme reduction over the last few decades (Comiso, 2008;Parkinson and Cavalieri, 2002). The Arctic sea-ice extent reached a record minimum in September 2012 displacing the same month in 2007. This diminished ice condition in the Arctic Ocean could massively influence the global climate system by causing the enhanced atmospheric disturbances (Honda et al., 2009;Inoue and Hori, 2011), propagating towards the lower latitudes as planetary waves, since the airwater heat exchanges can be promoted.
In the polar seas, there has been common difficulties in executing scientific observations, especially collecting under-ice hydrographical data because it requires many research staff, technical facilities and operational platforms such as ships with ice-breaking ability, submarines and sea-floor moorings (e.g. Surface Heat Budget of the Arctic (SHEBA)). Currently, non-manned hydrographical observation using autonomous observing systems, which are mostly installed on perennial ice floes and communicate via an Iridium satellite, are partly replacing the ship-based in situ observation in the Arctic (e.g. Krishfield et al., 2005;Richter-Menge et al., 2006).  (Kikuchi et al., 2007;Kawaguchi et al., 2012) (Fig. 3a).
As of the late February in 2015, UpT13 has been only buoy that is reporting the seamless data. Meanwhile, other two UpTempOs (UpT14 and 15) terminated its data sending following the surface freezing onset, at which almost simultaneously all of the instruments entered the marginal ice zone (Fig. 3b). This probably means that the spherical-shaped surface floats have either underlain the ice floes or been breached by lateral pressure from surrounding ice floes. To prevent this fault, we will attempt to replace the spherical full into conical-shaped one in the future opportunity because the lateral ice pressure may less affect it.

Preliminary Results
This section describes the preliminarily upper water temperature recorded by the UpTempOs between early September and mid-November when the seasonal change in surface heat content is the most dramatic.
Initially, from early September to mid-September, the sea water is the warmest at depths shallower than 20-30 m, underneath which it is colder with the lowest temperatures of −1.3 -−1.2°C at 30-40 m depth (Fig. 3b).
In the near-surface warm layer, UpT13 and 14 show the maximum temperature being about 1.3-1.5°C, while UpT15 shows temperatures no warmer than 0.2°C, implying there is a horizontal surface front structure between the deployment positions of UpT14 and UpT15 (Fig. 3b). In the surface layer within 20 m depth, temperature continues to decrease until the mid-October when it gets to almost the freezing point of −1.6°C (Fig. 3b). Prior to the late September, the thermistor chain of UpT13 and 14 shows that there is a vertical temperature inversion -the colder water (~10 m depth) overlies the warmer water in the deeper SML. In this period, we guess the surface heat flux due to the atmospheric cooling deprives the oceanic heat mostly from the thin boundary layer, and there is surely insignificant heat supply from the layer underneath the SML (i.e. no catastrophic mixing eroding the SML base). In fact, the ship-based microstructure measurement at the FPO station depicts that the deeper SML is relatively quiet from the midto late September, where the buoyant Reynolds number is generally less than 20 (Yamazaki, 1990). After the freezing temperature achieved, temperature profile becomes nearly homogeneous and gradually deepened down to~35-40 m depth by 25 th October. This suggests that the buoyancydriven convective motion, accompanying sea-ice formation in the surface water, actively eroded the SML base (e.g., Y. Kawaguchi et al. Kikuchi et al. 2004;Peralta-Ferriz and Woodgate, 2015).
After that, it persists at the nearly freezing temperature.
The all buoys travelled towards northwest along the local bathymetry (Fig. 3a). The traveling speed was approximately between 10 to 30 cm s −1 . This can be considered that the travelling of the UpTempOs was

Conclusion and Future Works
Upper water temperature observation was performed using the UpTempO buoys during MR14-05 in collaboration with Polar Science Center of U. Washington.
During the cruise, three UpTempOs were deployed in the east part of ice-free Chukchi Plateau. The UpTempOs have successfully collected the data to show how upper water temperature is changing during a transition between late summer to mid-winter including the surface freezing event.
In the past Mirai expeditions we have had difficulties retrieving the hydrographic data in the icecovered Arctic Ocean especially once the surface water starts to freeze. Hence, it is rather rare to obtain the year-round temperature data in the seasonally open water region near the central Arctic, which describes the surface water being cooled by the air and frozen. In this sense, utilizing the autonomous observing instrument would be a very effective means to gain a better understanding about the yearlong airice-ocean coupling system in terms of heat in the western Arctic Ocean. Thus, in future on-site examinations, the combination of the ship-based manned observation and the use of autonomous instrument would give a particular advantage and progress in this scientific field.