High-latitude Routes Research Articles

Организационно-экономические инструменты управления авиационной инфраструктурой Арктической зоны Российской Федерации в обеспечении движения судов по Северному морскому пути

The paper purpose is to substantiate the organizational and economic tools to ensure the ship traffic sustainability along high-latitude routes in the waters of the Northern Sea Route using aviation infrastructure. Based on the systematization of the traffic area restrictions, the author gives the spatial location of Arctic airfields. He proposes using Rosaviation as a management institution that contributes to the prompt resolution of problems in ensuring the ship traffic sustainability along high-latitude routes of the Northern Sea Route.

Impact of flight route changes on cosmic ray exposure: consequences of the conflict between Ukraine and the Russian federation.

This work investigates the impact on cosmic ray exposures to aircrew due to changing flight routes operated in the context of the recent conflict between Ukraine and the Russian Federation. All analyses were done based on Paris-Tokyo and Tokyo-Paris flights taken as examples, and differences in radiation exposures were quantified by comparing the situation before and after the beginning of the conflict. Regarding space weather scenarios, a quiet solar period and an extreme solar event (ground level enhancement (GLE) 5) were considered in the study. Analyses showed that the new Paris-Tokyo flight route established after the beginning of the conflict results in a smaller radiation dose to aircrew than that operated before the conflict, particularly during solar events. In contrast, for Tokyo-Paris flights the new high-latitude route crossing the Atlantic Ocean and North America increases the dose significantly (+ 50% in the worst case). Although this analysis is limited only to flights connecting Paris and Tokyo, it allowed for an evaluation of the consequences of new routes (particularly polar ones) on ambient dose equivalent values.

Changing Arctic Northern Sea Route and Transpolar Sea Route: A Prediction of Route Changes and Navigation Potential before Mid-21st Century

Sea ice concentration and thickness are key parameters for Arctic shipping routes and navigable potential. This study focuses on the changes in shipping routes and the estimation of navigable potential in the Arctic Northern Sea Route and Transpolar Sea Route during 2021–2050 based on the sea ice data predicted by eight CMIP6 models. The Arctic sea ice concentration and thickness vary among the eight models, but all indicate a declining trend. This study indicates that, under the two scenarios, the least-cost route will migrate more rapidly from the low-latitude route to the high-latitude route in the next 30 years, showing that the Transpolar Sea Route will be navigable for Open Water (OW) and Polar Class 6 (PC6) before 2025, which is advanced by nearly 10 years compared to previous studies. The sailing time will decrease to 16 and 13 days for OW and PC6 by 2050, which saves 3 days compared to previous studies. For OW, the navigable season is mainly from August to October, and the Northern Sea Route is still the main route, while for PC6, the navigable season is mainly from July to January of the following year, and the Transpolar Sea Route will become one of the important choices.

The tasks for bathymetric investigations and cartographic support of the northern sea high latitude routes in the East Siberian Sea

The current state and issues of bathymetric investigations of the East Siberian Sea are examined in this study. The main sources of bathymetric data are characterized. The possibilities to solve these issues in order to improve the efficiency of the oncoming bathymetric investigation in the East Siberian Sea for supporting the urgent practical tasks of the Russian Federation concerning the Northern Sea high latitude routes are discussed. The importance of a new hydrographic investigation through the high latitude routes in the East Siberian Sea in order to provide the possibility of year-round navigation of the large-tonnage Arc7‑class icebreaking LNG carriers is especially emphasized. Compiling of the new coastal electronic navigation charts for the new Northern Sea high latitude routes is stated as one of the main priorities. The lack of coastal electronic navigation charts of the high latitude routes in the East Siberian Sea will present a challenge for the establishing of year-round navigation for high ice-capable Arc7‑class LNG carriers during the coming several years. The drafting of high latitude routes must also consider the seafloor gas venting in the East Siberian Sea. The satellite remote sensing data from passive microwave radiometers and optical sensors using «modis & amsr2» technology provided by the University of Bremen ensures the complementary observations of sea ice concentration in the eastern part of the East Siberian Sea. The re-analysis of data from microwave radiometers AMSR‑2 beginning from 2018 provides the conclusion about the autumn degradation of the Aion ice massif. The analysis of the sea-ice concentration of the Aion ice massif during autumn–winter of 2022, the most severe in the last 5 years, allows us to give a recommendation concerning the new high latitude route in the East Siberian Sea. This route passes along the northern coast of Vrangel island into the Chukchi Sea and it is more efficient for large-tonnage Arc7‑class icebreaking LNG carriers ensuring year-round navigation in the East Siberian Sea. It is stated that hydrographic investigations carried out on the sections of the Northern Sea Route must adhere to the requirements of the International Hydrographic Organization. The urgency of developing the state integrated bathymetric database for the Arctic Ocean including the Arctic Seas data along with the necessity of providing all Russian bathymetric data acquired in the Arctic region to the assigned national centre is discussed. The FKU 280 ZKP VMF is proposed as such national centre. The importance of coastal electronic navigation charts for the high latitude routes in the East Siberian Sea created on the basis of modern technology is emphasized.

Cartographic support issues in the Arctic Ocean studying and bathymetric investigation objectives in the Russian Arctic

The current state and issues of the bathymetric investigations of the Arctic Ocean are examined in the study. The main sources of bathymetric data in the Central Arctic region and Arctic seas are characterized. The main possibilities to solve these issues in order to improve the efficiency of oncoming bathymetric investigation in the Russian Arctic sector for solving the urgent practical and scientific tasks of the Russian Federation in the Arctic region are discussed. The problem of hydrographic investigation and marine cartography of the new high latitude routes in the Northern Sea Route and bathymetric investigations of the South-Eastern part of Gakkel Ridge which are important for the Russian extended continental shelf submission is covered as one of the main issues. The importance of a new hydrographic investigation at the high latitude routes in the East Siberian Sea in order to provide the possibility of year-round navigation for the large-tonnage Arc7‑class icebreaking liquefied natural gas carriers is especially emphasized. The questions of geoformation and ice satellite support for efficient navigation along the Northern Sea Route are considered. It is concluded that the poor hydrographic knowledge of the new high latitude route in the East Siberian Sea and the lack of electronic navigation charts will prevent the possibility of establishing the year-round navigation for Arc7‑class icebreaking liquefied natural gas carriers during the coming several years. It is stated that hydrographic investigations carried out on the sections of the Northern Sea Route must adhere to the requirements of the International Hydrographic Organization. The urgency of developing the state integrated bathymetric database for the Arctic Ocean including the arctic seas data along with the necessity of providing all Russian bathymetric data acquired in the Arctic region to the assigned national center is discussed. The FKU 280 ZKP VMF is proposed as such national center. The importance of bathymetric maps of the Arctic Ocean is noted. The main role of creating the electronic bathymetric maps using modern technology and analytical geomorphological mapping on the basis of the system-oriented morphological approach in Earth science is emphasised.

Preferred solar signal and its transfer in the Asian–Pacific subtropical jet region

Solar impact on the tropospheric subtropical jet (SJ) has been identified previously from a zonally averaged perspective. The SJ was observed to be weaker in the high solar activity winters. However, some regional features of solar-induced SJ variations might remain unrecognized. Here it is found that the regional solar signal in wintertime Asian–Pacific zonal wind at 200 hPa, which exhibits a tripolar banded structure, greatly resembles the second internal mode of zonal wind within the same sector. Significant response of the Asian–Pacific SJ (APSJ) to increased solar forcing in boreal winter exclusively marks its center region, showing a deceleration in westerlies. Further exploration suggests two possible top–down routes to interpret this particular manifestation of solar signal in APSJ center, a tropical route and a middle–high latitude route. Regarding the tropical route, during the cold season, driven by the solar-associated reduction in Brewer–Dobson circulation, ozone concentration in tropical lower stratosphere increases notably and merely within the zonal range of APSJ center. This heats the air here and the tropical tropospheric regional upwelling is thereby suppressed. Consequently, a significant weakened APSJ center is produced via local Hadley cell. Regarding the middle–high latitude route, in early winter, solar-related pronounced westerly anomalies in the mid-latitude stratosphere only appear in the longitudinal range of APSJ center. Meanwhile, the upward propagating planetary waves from the troposphere could be reflected back downward by this intensified stratospheric westerlies. As winter progresses, through wave mean flow interactions, a resultant weakened APSJ center markedly presents in the middle of winter.

Fast descent routes from within or near the stratosphere to the surface at Fukuoka, Japan, studied using <sup>7</sup>Be measurements and trajectory calculations

Abstract. By using high concentrations of 7Be as an indicator, we clarify fast descent routes from within or near the stratosphere to Earth's surface, with the study site being in Fukuoka, Japan. Most routes arise from high latitudes through the following processes. First, the descent associated with a tropopause fold occurs, followed by southward movement with slow descent at the rear side of a strong trough. Because this motion occurs along an isentropic surface, the descending air parcels nearly conserve the potential temperature. As an extension, a strong descent associated with a sharp drop in the isentropic-surface height occurs at the southern edge of the trough; this transports air parcels to low altitudes. This process involves irreversible phenomena such as filamentation and cutoff of potential vorticity. Finally, upon meeting appropriate near-surface disturbances, parcels at low altitudes are transported to Earth's surface.In some cases, parcels descend within midlatitudes. In such routes, because the potential temperature is much higher at high altitudes than at low altitudes, descent with conservation of the potential temperature is impossible, and the potential temperature decreases along the trajectories through mixing.The prevalence of the high-latitude route is explained as follows. In the midlatitude route, because parcels at high and relatively low altitudes mix, the high concentrations of 7Be included in high-altitude parcels are difficult to maintain. Therefore, for parcels to arrive at low altitudes in the midlatitude while maintaining high concentrations of 7Be, i.e., conserving the potential temperature, their area of origin should be high altitudes in high latitudes where the potential temperature is almost the same as that in the arrival area.In spring, tropopause folds are frequent in high latitudes, disturbances in the southward transport of parcels are strong, and disturbances occur by which parcels descend to the surface. Therefore, high concentrations of 7Be occur most frequently in spring.

Ozone exposures during trans-continental and trans-Pacific flights.

Ozone concentrations were passively monitored in passenger cabins of commercial airliners flying domestic, Pacific, and south-east Asian routes. One-hundred and six flight segments were monitored for either the full duration and/or approximately 3 h during the middle portion of the flight for a total of 145 time-integrated measurements. Over all samples the mean (+/-SD) concentration was 80 p.p.b. (30.1). Twenty percent of the measurements exceeded 100 p.p.b., the FAA-recommended level. Eleven percent of the measurements exceeded 120 p.p.b., the US EPA's short-term National Ambient Air Quality Standard for ozone. Ozone concentrations measured on Pacific flights were substantially higher during mid-flight than over the full flight (95 p.p.b. vs. 56 p.p.b). Ozone concentrations on the northern Pacific routes were higher than concentrations for other Pacific flights. Season comparison showed that ozone levels were higher during the winter and spring than for the summer and fall. Our study shows that even in aircraft with catalytic ozone converters, passengers and flight crew may be exposed to elevated ozone levels on domestic and international flights. Given the frequency of ozone excess, it is recommended that (1) ozone converters should be required equipment on all commercial passenger aircraft for mid and high latitude routes (2) improved maintenance procedures should be required for catalytic converters (e.g., more frequent servicing/replacement), and (3) ozone should be routinely monitored on all mid and high latitude flights. The authors have demonstrated elevated ozone concentrations in passenger cabins. They give several practical recommendations to help solve the problem.

AIRCRAFT REPORTS OF CIRRIFORM CLOUDS ON CERTAIN HIGH LATITUDE ROUTES AND CALIFORNIA TO HONOLULU

Abstract Special high-level cloud observations from two commercial jet air lines are used to estimate the vertical distribution of cirriform clouds. One year's data are summarized graphically for certain high-latitude routes and the California-Honolulu sector. Tropopauses in very high latitudes are occasionally exceeded in height by cirrus. Tropical tropopause levels are consistently 5 km. or more above the cirrus tops reported between Honolulu and the California coast.