Long-term ice forecasts

Long-term forecast of terms of fast ice breaking and clearance of water area around

Dickson Island in summer 2016

Present forecast is a first experience of preliminary forecasting of formation of sea ice conditions in the area of Dickson Island near the north-western Taymyr coast during the current season. Peculiarities of formation of meteorological conditions and conditions of growth of fast ice thickness during cold season 2015/16 were analyzed; long-term forecasts of meteorological and ice conditions were managed. Base station of natural observations is Dickson Island. Stations of ice observations used for the forecast are following: polar station Dickson Island, Sopochnaya Karga, Sterlegova Cape.

1. Monitoring of atmosphere processes and meteorological conditions near the north-western Taymyr coast during the cold period from October 2015 till May 2016

Cold period around Dickson Island started in 28 September, when stable transition of average daily air temperature from positive to negative values was fixed. Cold period started 3 days later than average. Monthly averaged meteorological parameters for Dickson Island during the cold period from October 2015 till 12 May 2016 are presented in Table 1.

Table 1 – Prevailed atmosphere processes and average monthly directions of air fluxes, air temperature and its extreme values in the area around Dickson Island in October 2015 – May 2016

Advection of warm air masses prevailed during all months of cold period of winter 2015/16, excepting October, when background temperature was near the multiyear average. Changes of monthly averaged anomalies of air temperature during October 2015 – April 2016 is shown in Figure 1.

Fig. 1 – Changes of monthly averaged anomalies of air temperature (°C) during October 2015 – April 2016 in the area around Dickson Island

February was the warmest month, and October - coldest. Average monthly positive anomaly of air temperature fixed in February was 9.6°C, in October it was 0.6°C. Generalizing results of monitoring of atmosphere processes and meteorological conditions around Dikson Island, it was concluded that: air temperature background in this area of the Kara Sea during the current hydrological year in average for October – April saved higher than normal; therewith tendency to its dramatic increase was noted. Figure 2 presents interannual variability of average values of air temperature anomalies during the cold period from October till April.

Fig. 2 - Interannual variability of average values of air temperature anomalies during the cold period from October till April in the area around Dickson Island

Average air temperature anomaly was +5,7°С in the current hydrological year, that is very close to its value in cold period of October 2011 – April 2012.

All peculiarities mentioned above had an impact on growth of ice thickness and formation of ice cover.

2. Monitoring of formation of ice cover and thickness of fast ice near the north-western Taymyr coast during cold season 2015/16

Terms of autumn ice phases were close to average multiyear norm in the area of Dickson Island and in water area adjacent to it. Terms of ice phases on polar stations of Dickson region of the Kara Sea in autumn 2015 (within brackets – deviance from a norm, days) are shown in Table 2.

Table 2 - Terms of ice phases on polar stations of Dickson region of the Kara Sea in autumn 2015 (within brackets – deviance from a norm, days).

Therefore, appearance and onset of fast ice in October – November in the Arctic shallow waters happened approximately in average terms, corresponding to average temperature conditions. Positive air temperature anomalies were accompanied by slow ice formation and negative thickness anomalies. Fast ice area in the Kara Sea was firmly lower than average multiyear norm. Fast ice, as observable spatial formation, appeared in October inshore the river Pyasina. In November fast ice dominated in the Ob’-Yenisey area; in December fast ice covered entire area of the Nordensheld archipelago. In January fast ice formed continuous band along the entire north-western Taymyr coast, and at the end of February, first time for the hydrological season, fast ice totally covered the Vilkitskiy Strait.

In accordance with predominance of warm winter in December – February, fast ice thickness in Dickson area was significantly less than average (Figure 4).

Fig. 4 – Fast ice thickness in the polar station Dickson Island (continuous line – norm, dashed line – cold season 2015/16)

Thickness of fast ice near Dickson Island was steadily lower than normal during the cold season: thickness anomaly at the end of November was 9 cm, at the end of December – 23 cm, at the end of January and February – 22 cm, at the end of March – 17 cm, at the end of April – 24 cm. In the first ten-day period of May ice thickness was 131 cm (multiyear norm is 156 cm).

3. Long-term meteorological forecast.

Forecasted temperature and wind parameters in the area of Dickson Island in May, June and July 2016 are presented in Table 3.

Table 3 - Forecasted temperature and wind parameters in the area of Dickson Island in May, June and July 2016

Consequently, air fluxes of alternate directions and air temperature about (in May)/above (in June and July) a norm are expected during the forecasted period.

4. Long-term forecast of terms of fast ice breaking and clearance of water area around Dickson Island in summer 2016

Main peculiarities of development of natural processes during cold season 2015/16 for the water area near the north-western Taymyr were established as a result of analysis:

- prevalence of zonal and eastern forms of atmosphere circulation with, predominantly, south-western directions;

- air temperature during the cold season was above the average multiyear values, particularly in January – April;

- in consequence of soft winter the ice thickness was significantly below normal, and as for the first ten-day period of May it was 131 cm near Dickson Island (norm is 156 cm) and anomaly was -25 cm;

- first-year thick ice prevailed on the water area in the first half of May; as well as significant amount of first-year medium ice was fixed;

- development of fast ice in the Kara Sea is below normal; sea edge of fast ice is in a southern position; flaw polynyas are covered by young ice.

Initial data allow to manage a long-term forecast of summer ice phases (terms of fast ice breaking and clearance of ice) on the water area of the Kara Sea, adjacent to Dickson Island.

1. Thickness of fast ice in the area around polar station Dickson Island at the end of cold season (May) is expected to be about 130-135 cm, which is approximately 25 cm below normal.

2. Intensive processes of melting and breaking of ice cover near the north-western Taymyr coast are expected. Particularly, fast ice breaking near the polar station Dickson Island is forecasted at 8 July, i.e. about 10 days earlier than average multiyear norm (norm is 18 July).

3. Thin ice, intensive beginning of melting and early breaking of fast ice will be accompanied by early terms of sea clearance of ice. Complete water area clearance of ice near polar station Dickson Island is forecasted about 15 July, i.e. approximately 12 days earlier than normal (norm is 27 July).

Therefore, according to the forecast, development of ice conditions in summer 2016 in the area of Dickson Island near the north-western Taymyr coast will be have favorable, easy character.

Present forecast can be specified and corrected depending on peculiarities of natural processes during the second half of May and in June.

Forecast by:

Leader scientific researcher of the Long-term ice forecasts laboratory – A.G. Egorov

Head of the Meteorological forecasts laboratory – V.V. Ivanov

12 May 2016

Head of the Center Sever

Arctic and Antarctic Research Institute

S.V. Brestkin


The long-term forecast of breaking and clearing of the Yenisei River in the area around the port Dudinka in spring 2016

1. The long-term meteorological forecast

The analysis of atmosphere processes by complex of hydrometeorological parameters for the cold period from September 2015 till April 2016 allowed to define a variety of special features. These features contributed to select the years with analogous development of the processes from the archive and to establish the most probable tendencies of development of processes in future. Basing on the years-homologues, the long-term particularized meteorological forecast for the area around the port Dudinka for the period from 20 May till 20 June 2016 was developed.

Anticyclonic weather regime will prevail during the period 20-31 May. Background air pressure is expected to be higher than normal. Directions of air fluxes will be south-eastern and eastern (with deviations to the south-west). Prevailed air temperature will be +1 … -3 °C. Short-term increases of air temperature will be up to +3…+7 °C and decreases to -4…-8 °C, during the clearings in the beginning of the period decreases will be intermittently to -10 °C.

Cyclonic weather regime will prevail during the period 1-10 June. Background air pressure is expected to be about normal. Forecasted directions of air fluxes are southern with short-term deviations to the north-east and north-west. Prevailed air temperature will be +1…+5 °C. Short-term increases of air temperature will be up to +8…+12 °C and decreases to 0…-3 °C, during the clearings in the beginning of the period decreases will be intermittently to -5…-6 °C.

During the period 11-20 June the area will be influenced by North Atlantic cyclones. Background air pressure is expected to be lower than normal. Air fluxes will have south-western directions with short-term deviations to the north-west in the rear of passing cyclones. Prevailed air temperature will be +4…+9 °C with short-term increases up to +12…+16 °C and at the end of the period intermittently up to +18…+20 °C. Decreases of air temperature during the clearings will be to -1…+2 °C.

The table shows forecasted background meteorological parameters in the area around the port Dudinka from 20 May to 20 June 2016. Pass of air temperatures through 0 degree to positive values is expected at the end of the third ten-day period of May.

2. The long-term forecast of breaking and clearing terms

This forecast of breaking and clearing terms is based on analysis of the observational information of ice processes development since 1934 till present. Autumn stable formation of floating ice in the area of the port Dudinka was fixed at 18 October 2015 that is close to normal. Freeze-up was fixed at 19 October (15 days earlier than normal). Port Dudinka is year-round operating port and ice cover on the water area around it is partly artificially destroying in winter, this is daily fixing by observators. Anthropogenic influence on terms of breaking of the Yenisei river stream way is not considered because of no artificial ice destroying happens upstream.

On 20 April 2016 according to operative information, the ice on the river was 101 cm thick (27 cm less than normal).

In spring 2016 terms of breaking and clearing in the area around the port Dudinka are expected to be slightly earlier than normal. Breaking of ice cover is expected on 31 May (±4 days), clearing – on 6 June (±5 days)

In a case of significant difference of factual meteorological conditions from the forecasted, terms of breaking and clearing of ice will be corrected in the middle of May 2016.

Date of the long-term forecast management – April 22, 2016. The long-term forecasts were managed:

Meteorologicalby head of the Laboratory of long-term meteorological forecasts AARI V.V.Ivanov

Iceby head of section of the Department of hydrological information and calculations of the Center “Sever”, AARI Yu.V.Nalimov and Leading engineer A.A.Stepanova

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B YU L OF L E T E N
"Long-term ice forecasts for the Arctic seas
on the first half of navigation (June-August), 2016"


The predictive bulletin includes general information about the expected ice conditions in the Russian Arctic seas in the first half of navigation (June-August), 2016. For an assessment of intensity of the expected development of ice conditions, the forecast is compared to mean annual values (the norm calculated from 1970 for 2010).
Kara Sea
The area of the Novozemelsky ice massif in June-August is expected 10-14% less than average long-term values (fig. 1): the third decade of June – 65%, norm of 75%; the third decade of July – 20%, norm of 34%; the first decade of August – 5%, norm of 18%.
In the first half of navigation in southwest part of the Kara Sea the easy type of ice conditions (fig. 2) is expected.
The area of the Severozemelsky ice massif in July-August is expected 14-18% less than average long-term values (fig. 1): July – 50%, norm of 68%; August – 25%, norm of 39%.
In the first half of navigation in northeast part of the Kara Sea the average type of ice conditions (fig. 2) is expected.
Breaking of
fast ice near Vilkitsky Strait is expected for 10 days before mean annual term – on July 20, norm on July 30.
Laptev Sea
The area of the Taimyr ice massif in July-August is expected 11% less than average long-term values (fig. 1): July – 60%, norm of 71%; August – 32%, norm of 43%.
In the first half of navigation in the western part of the sea the average type of ice conditions (fig. 2) is expected.
The area of the Yansky ice massif in July-August is expected 11-17% less than average long-term values (fig. 1): July – 60%, norm of 77%; August – 5%, norm of 16%.
In the first half of navigation in east part of the sea the easy type of ice conditions (fig. 2) is expected.
Breaking of
fast ice along the coast in the western part of the sea is expected for 10 days before average long-term terms – on July 10, norm on July 17, in east part of the sea for 10 days before average long-term terms – on July 5, norm – on July 15.
East Siberian Sea
The area of the Novosibirsk ice massif in July-August is expected 0-10% less than average long-term values (fig. 1): July – 81%, norm of 81%, August – 23%, norm of 33%.
In the first half of navigation in the western part of the sea the average type of ice conditions (fig. 2) is expected.
The area of the Ayonsky ice massif in July-August is expected 0-10% less than average long-term values (fig. 1): July – 87%, norm of 87%, August – 56%, norm of 66%.
In the first half of navigation in east part of the sea the average type of ice conditions (fig. 2) is expected.
Breaking of
fast ice in a throat of Chaun Bay (on a site Aion-Valkarkay) is expected for 5 days before average long-term value – on June 27, norm on July 2.
Chukchi Sea
The area of the Vrangelevsky ice massif in July-August is expected 7-15% less than average long-term values: July – 21% norm of 36%; August – 5%, norm of 12% (fig. 1).
Breaking of fast ice
on a coastal site the cape Yakan – the cape Vankar is expected for 10 days of earlier average long-term terms – on July 1, norm on July 10.

In the first half of navigation in southwest part of the sea the easy type of ice conditions (fig. 2) is expected.

Thus, in the first half of navigation in the Arctic seas the following type of ice conditions (fig. 2) is expected:
- easy – in southwest part of Karsky, east part of Laptev and Chukchi the seas;
- average – in northeast part of Karsky, the western part of Laptev and East Siberian the seas;
- realization of heavy type on water areas of the Arctic seas in the first half of navigation isn't expected.

March 21, 2016.

Director AARI

I. FROLOV

Fig. of 1 Anomaly of the areas of ice massifs in the Arctic seas in the first half of navigation (July-August) (deviations from mean annual values, %)

Fig. 2 the General assessment of the expected ice conditions in the Arctic seas in the first half of navigation (June-August)

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Federal Service for Hydrometeorology and Environmental Monitoring

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AARI

HYDROLOGICAL BULLETIN
No. 1

THE EXPECTED ICE THICKNESS
FOR THE END OF APRIL AND TERMS OF OPENING OF THE SIBERIAN RIVERS

St. Petersburg

2016

1. The short review of ice conditions in estuarial areas of the rivers of the Arctic zone of Siberia from October, 2015 to March, 2016.
Process of freezing took place in mouths of the rivers of the Arctic zone of Siberia within October. Floating ice has been noted in mouths of the rivers of the Kara Sea from October 6 to October 18, the Laptev Sea from October 4 to October 12, the East Siberian Sea from October 6 to October 8.
Estuarial areas of the rivers of the basin of the Kara Sea.
Steady emergence of floating ice has been noted: before norm for 4-9 days in points Salekhard, Tazovskoye and Igarka, it is close to norm in points Dudinka, Guard, Sopochnaya the Hag and New Port. Terms of a freeze-up are noted: after norm in points Salekhard (5 days), New Port (3 days), Igarka (4 days); before norm in Tazovskoye's points, Dudinka and Guard (5-6 days). In the item of Sopochnaya the Hag the term of a freeze-up met standard. Period duration with floating ice has made of 0 days in the item. Guard till 19 days in the item Salekhard.
Thickness of ice were observed at the end of March less norm on 6-57 cm.
Estuarial areas of the rivers of the basin of the Laptev Sea.
Freezing took place in estuarial areas of the rivers of the basin of the Laptev Sea in later terms in comparison with norm: steady emergence of floating ice – for 3-6 days (except the item of Habarovo (Lena River) where the ice has appeared in time close to norm), the freeze-up is noted for 4-5 days after norm in estuarial part of the Olenyok River, for 1-4 days after norm in estuarial part of the Lena River and for 1 day before norm in estuarial part of the Yana River.
Period duration with floating ice is various: of 1 day on the Yana River till 12 days on the Lena River (the item Kyusyur).
Ice thickness at the end of March were observed significantly less norm: on 31-55 cm in estuarial part of the Olenyok River, on 29-32 cm in the mouth of the Lena River and on 16 cm in the mouth of the Yana River.
Estuarial areas of the rivers of the basin of the East Siberian Sea.
On an estuarial site of the Indigirka River emergence of floating ice and a freeze-up have been noted after norm for 3-6 days. The period with floating ice is equal to 7 days. On an estuarial site of the Kolyma River floating ice has appeared for 1 day before norm, the freeze-up is noted for 4 days after norm. Period duration with floating ice – 8 days.
Ice thickness at the end of March were observed less norm on 22-25 cm.

2. The long-term forecast of thickness of ice for the end of April and terms of opening of lower reaches and mouths of the rivers of Siberia for spring of 2016.

Opening of estuarial part of the large rivers will take place in May – June. Terms of opening of ice are expected before norm in estuarial part of the rivers of pools Karsky and East Siberian the seas and the Laptev Sea.
Ice thickness for the end of April are at all points predicted less average values.
Estuarial area of the rivers of the basin of the Kara Sea.
In estuarial areas of the large rivers of the basin of the Kara Sea of ice thickness at the end of April up to 50 cm less mean annual values are expected. The beginning of an ice drift is expected before norm: in estuarial part of the Ob River for 3-7 days, in estuarial part of the Taz River for 3 days, in estuarial part of the Yenisei River for 4-7 days.
Estuarial area of the rivers of the basin of the Laptev Sea.
In estuarial areas of the large rivers of the basin of the Laptev Sea at the end of April ice thickness less norm to 52 cm are expected. The beginning of an ice drift is expected before norm: in estuarial part of the Olenyok River for 4-6 days, in estuarial part of the Lena River for 3-4 days, in estuarial part of the Yana River for 6 days.
Estuarial area of the rivers of the basin of the East Siberian Sea. In estuarial sites of the Indigirka and Kolyma Rivers of thickness of ice up to 32 cm less norms are expected. The beginning of an ice drift is expected before norm: in estuarial part of the Indigirka and Kolyma Rivers for 1-2 days.

The expected ice thickness for the end of April, 2016 on lower reaches and estuarial areas of the rivers of Siberia

The expected terms of opening of lower reaches and mouths of the rivers of Siberia in the spring of 2016.