STATE OF ANTARCTIC ENVIRONMENT

Transcription

1 FEDERAL SERVICE OF RUSSIA FOR HYDROMETEOROLOGY AND ENVIRONMENTAL MONITORING Russian Federation State Research Center Arctic and Antarctic Research Institute Russian Antarctic Expedition QUARTERLY BULLETIN 2 (27) April - June 24 STATE OF ANTARCTIC ENVIRONMENT Operational data of Russian Antarctic stations St. Petersburg 24

2 FEDERAL SERVICE OF RUSSIA FOR HYDROMETEOROLOGY AND ENVIRONMENTAL MONITORING Russian Federation State Research Center Arctic and Antarctic Research Institute Russian Antarctic Expedition QUARTERLY BULLETIN 2 (27) April - June 24 STATE OF ANTARCTIC ENVIRONMENT Operational data of Russian Antarctic stations Edited by V.V. Lukin St. Petersburg 24

3 Authors and contributors Editor-in-Chief Section 1 Section 2 Section 3 Section 4 Section 5 Section 6 Section 7 Section 8 - M.O. Krichak (Russian Antarctic Expedition (RAE) Department) - M.O. Krichak (RAE), V.Ye. Lagun (Department of Sea-Air Interaction) - Ye.I. Aleksandrov (Department of Meteorology) - L.Yu. Ryzhakov, G.Ye. Ryabkov (Department of Long-Range Weather Forecasting) - A.I. Korotkov (Department of Ice Regime and Forecasting) - Ye.Ye. Sibir (Department of Meteorology) - I.P. Yeditkina, I.V. Moskvin, A.V. Frank-Kamenetsky (Department of Geophysics) - V.V. Lukin (RAE), - V.A. Kuchin (RAE). Translated by I.I. Solovieva Russian Antarctic Expedition, Quarterly Bulletin. Acknowledgements: Russian Antarctic Expedition is grateful to all AARI staff for help and assistance in preparing this Bulletin. For more information about the contents of this publication, please, contact Arctic and Antarctic Research Institute of Roshydromet Russian Antarctic Expedition Bering St., 38, St. Petersburg Russia Phone: (812) Fax: (812) lukin@raexp.spb.su

4 CONTENTS PREFACE DATA OF AEROMETEOROLOGICAL OBSERVATIONS AT THE RUSSIAN ANTARCTIC STATIONS METEOROLOGICAL CONDITIONS IN APRIL JUNE REVIEW OF THE ATMOSPHERIC PROCESSES ABOVE THE ANTARCTIC IN APRIL JUNE BRIEF REVIEW OF ICE PROCESSES IN THE SOUTHERN OCEAN FROM DATA OF SATELLITE AND COASTAL OBSERVATIONS AT THE RUSSIAN ANTARCTIC STATIONS IN APRIL-JUNE RESULTS OF TOTAL OZONE MEASUREMENTS IN THE SECOND QUARTER OF GEOPHYSICAL OBSERVATIONS AT RUSSIAN ANTARCTIC STATIONS IN APRIL JUNE XXVII ANTARCTIC TREATY CONSULTATIVE MEETING MAIN RAE EVENTS IN APRIL, MAY AND JUNE 24 7

5 1 PREFACE The Bulletin is prepared on the basis of data reported from the Russian Antarctic stations in real time via the communication channels. The Bulletin is published from 1998 on a quarterly basis. Section I in this issue presents monthly averages of standard meteorological and solar radiation observations and upper-air sounding for the second quarter of 24. Standard meteorological observations are carried out at present at Mirny, Novolazarevskaya, Bellingshausen, Progress (from February this year) and Vostok stations (at Vostok station after its reactivation, a complete set of meteorological observations was resumed from March 24). The upper-air sounding is undertaken once a day at. UT at two stations - Mirny Observatory and Novolazarevskaya. More frequent sounding is conducted during the periods of the International Geophysical Interval (in accordance with the International Geophysical Calendar in 24 from 8 to 21 March, 14 to 27 June, 13 to 26 September and 13 to 26 December) at both stations at h and 12 h UT. In the meteorological tables, the atmospheric pressure values for the coastal stations are referenced to sea level. Along with the monthly averages of meteorological parameters, the tables in Section 1 present their deviations from multiyear averages (anomalies), deviations in σ f fractions (normalized anomalies - (f-f avg )/ σ f ) and relative anomalies (f/f avg ) of the monthly sums of precipitation and total radiation. The statistical characteristics necessary for the calculation of anomalies were derived at the AARI Department of Meteorology for the period recommended by the World Meteorological Organization. Section 1 also presents the diagrams of temporal variations of mean daily values of meteorological parameters at the stations for specific months allowing an assessment of fluctuations of these parameters during a month. The section also presents the upper-air-temporal temperature and wind speed sections in the free atmosphere obtained from the results of regular upper-air sounding at Mirny and Novolazarevskaya stations. The Bulletin contains brief overviews of the state of the Antarctic environment based on actual data. Sections 2 and 3 are devoted to the meteorological and synoptic conditions. The reviews of synoptic conditions (section 3) are prepared on the basis of the analysis of current aerological and synoptic information, which is performed by the weather forecaster at Novolazarevskaya station and also on the basis of more complete data of the Southern Hemisphere collected at the AARI. The analysis of ice conditions in the Southern Ocean (Section 4) is based on satellite data received at Bellingshausen, Novolazarevskaya and Mirny stations and on the observations conducted at the coastal Bellingshausen and Mirny stations. The anomalous character of ice conditions is evaluated against the multiyear averages of the drifting ice edge location and the onset of different ice phases in the coastal areas of the Southern Ocean adjoining the Antarctic stations. The multiyear averages were obtained at the AARI Department of Ice Regime and Forecasting over the period Section 5 presents an overview of total ozone (TO) on the basis of measurements at the Russian stations. Data of geophysical observations published in Section 6 present the results of measurements under the geomagnetic and ionospheric programs (magnetic and riometer observations; vertical sounding of the ionosphere) in Mirny Observatory, at Novolazarevskaya and Vostok stations. At the beginning of 24, practically the entire complex of geophysical observations was resumed at Vostok station, however the vertical sounding of the ionosphere was temporally stopped due to technical causes. This type of observations is carried out now only in Mirny Observatory. The geophysical information also includes the PC-index indicator of magnetic activity, which is calculated from data of geomagnetic observations of Vostok station. Section 7 presents information about the XXVII Antarctic Treaty Consultative Meeting held in late May-early June in Cape Town (South Africa). The last Section (8) is traditionally devoted to the main directions of the logistics activities of RAE during the period under consideration.

6 2 Russian Antarctic stations in operation in April - June 24 MIRNY OBSERVATORY STATION SYNOPTIC INDEX METEOROLOGICAL SITE HEIGHT ABOVE SEA LEVEL 39.9 m GEOGRAPHICAL COORDINATES ϕ = S; λ = 93 1 E GEOMAGNETIC COORDINATES Φ = ; = BEGINNING AND END OF POLAR DAY 7 December 5 January BEGINNING AND END OF POLAR NIGHT No NOVOLAZAREVSKAYA STATION STATION SYNOPTIC INDEX METEOROLOGICAL SITE HEIGHT ABOVE SEA LEVEL 119 m GEOGRAPHICAL COORDINATES ϕ = 7 46 S; λ = 11 5 E BEGINNING AND END OF POLAR DAY 15 November - 28 January BEGINNING AND END OF POLAR NIGHT 21 May - 23 July BELLINGSHAUSEN STATION STATION SYNOPTIC INDEX 895 METEOROLOGICAL SITE HEIGHT ABOVE SEA LEVEL 14.3 m GEOGRAPHICAL COORDINATES ϕ = S; λ = W BEGINNING AND END OF POLAR DAY BEGINNING AND END OF POLAR NIGHT No PROGRESS STATION STATION SYNOPTIC INDEX METEOROLOGICAL SITE HEIGHT ABOVE SEA LEVEL 64 m GEOGRAPHICAL COORDINATES ϕ = S; λ = E BEGINNING AND END OF POLAR DAY 21 November 22 January BEGINNING AND END OF POLAR NIGHT 28 May 16 July VOSTOK STATION STATION SYNOPTIC INDEX 8966 METEOROLOGICAL SITE HEIGHT ABOVE SEA LEVEL 3488 m GEOGRAPHICAL COORDINATES ϕ = S; λ = 6 52 E GEOMAGNETIC COORDINATES Φ = ; = BEGINNING AND END OF POLAR DAY 21 October - 21 February BEGINNING AND END OF POLAR NIGHT 23 April - 21 August

7 3 1. DATA OF AEROMETEOROLOGICAL OBSERVATIONS AT THE RUSSIAN ANTARCTIC STATIONS APRIL 24 MIRNY OBSERVATORY Table 1.1 Monthly averages of meteorological parameters (f) and their deviations from multiyear averages (f avg ) Parameter f mon.avg f max f min Anomaly f-f avg Normalized anomaly (f-f avg )/σ f Mirny, April 24 Relative anomaly f/f avg Sea level pressure, hpa Air temperature, C Relative humidity, % Total cloudiness (sky coverage), tenths Lower cloudiness(sky coverage),tenths Precipitation, mm Mean wind speed, m/s Prevailing wind direction, deg 158 Total radiation, MJ/m Total ozone content (TO), DU

8 4 SURFACE AIR TEMPERATURE, С A SEA LEVEL PRESSURE, hpa B -24 APRIL 24 C 95 4 APRIL 24 D RELATIVE HUMIDITY, % APRIL 24 E SURFACE WIND SPEED MODULUS, m/s APRIL 24 F DAILY PRECIPITATION SUM, mm 4 2 APRIL 24 SNOW COVER THICKNESS, sm APRIL 24 Fig Intra-monthly variation of daily mean values of surface temperature (A, bold line), maximal (А, thin line), minimal (A, dotted line) air temperature, sea level pressure (B), relative humidity (C), mean (D, black circles), maximal (D, crosses) values of surface wind speed, maximal gust of the wind (D, white circles), precipitation (E), snow cover thickness (F) in Mirny Observatory, April 24.

9 5 Isobaric surface, P, hpa Results of aerological atmospheric sounding (from CLIMAT-TEMP messages) Isobaric surface height, H m Temperature, T C Dew point deficit, D C Resulting wind direction, deg Resulting wind speed, m/s Wind stability parameter,% Mirny, April 24 Number of days without temperature data Table 1.2 Number of days without wind data Anomalies of standard isobaric surface heights and temperature Mirny, April 24 Table 1.3 P, hpa Н-Н avg, m (Н-H avg )/σ Н Т-Т avg, С (Т-Т avg )/σ Т

10 6 A 2 3 PRESSURE, hpa APRIL, 24 B 2 PRESSURE, hpa APRIL 24 Fig.1.2. Intra-monthly variations of temperature (A, С) and wind speed (B, m/s) in the free atmosphere in Mirny Observatory, April 24 ( GMT.)

11 7 NOVOLAZAREVSKAYA STATION Table 1.4 Monthly averages of meteorological parameters (f) and their deviations from multiyear averages (f avg ) Parameter f mon.avg f max f min Anomaly f-f avg Novolazarevskaya, April 24 Normalized anomaly (f-f avg )/σ f Relative anomaly f/f avg Sea level pressure, hpa Air temperature, C Relative humidity, % Total cloudiness (sky coverage), tenths Lower cloudiness(sky coverage),tenths Precipitation, mm Mean wind speed, m/s Prevailing wind direction, deg 18 Total radiation, MJ/m Total ozone content (TO), DU

12 8-4 A B SURFACE AIR TEMPERATURE, С APRIL 24 C SEA LEVEL PRESSURE, hpa APRIL 24 D RELATIVE HUMIDITY, % APRIL24 E SURFACE WIND SPEED MODULUS, m/s APRIL 24 F DAILY PRECIPITATION SUM, mm 1 APRIL 24 PLACE SNOW COVERAGE, balls APRIL 24 Fig.1.3. Intra-monthly variation of daily mean values of surface temperature (A, bold line), maximal (А, thin line), minimal (A, dotted line) air temperature, sea level pressure (B), relative humidity (C), mean (D, black circles), maximal (D, crosses) values of surface wind speed, maximal gust of the wind (D, white circles), precipitation (E), place snow coverage (F) at Novolazarevskaya station, April 24.

13 9 Isobaric surface, P, hpa Results of aerological atmospheric sounding (from CLIMAT-TEMP messages) Isobaric surface height, H m Temperature, T C Dew point deficit, D C Resulting wind direction, deg Resulting wind speed, m/s Novolazarevskaya, April 24 Number of Wind days stability without parameter,% temperature data Table 1.5 Number of days without wind data Anomalies of standard isobaric surface heights and temperature Novolazarevskaya, April 24 Table 1.6 P, hpa Н-Н avg, m (Н-H avg )/σ Н Т-Т avg, С (Т-Т avg )/σ Т

14 A 2 3 PRESSURE, hpa APRIL 24 B 2 3 PRESSURE, hpa APRIL 24 Fig.1.4. Intra-monthly variations of air temperature (A, С) and wind speed (B, m/s) in the free atmosphere at Novolazarevskaya station, April 24 ( GMT).

15 11 BELLINGSHAUSEN STATION Table 1.7 Monthly averages of meteorological parameters (f) and their deviations from multiyear averages (f avg ) Parameter f mon.avg f max f min Anomaly f-f avg Bellingshausen, April 24 Normalized Relative anomaly anomaly f/f (f-f avg )/σ avg f Sea level pressure, hpa Air temperature, C Relative humidity, % Total cloudiness (sky coverage), tenths Lower cloudiness (sky coverage),tenths Precipitation, mm Mean wind speed, m/s Prevailing wind direction, deg 158 Total radiation, MJ/m

16 12 6 A 2 B SURFACE AIR TEMPERATURE, С RELATIVE HUMIDITY, % APRIL 24 C APRIL 24 E SURFACE WIND SPEED MODULUS, m/s SEA LEVEL PRESSURE, hpa APRIL 24 D APRIL 24 F DAILY PRECIPITATION SUM, mm APRIL 24 SNOW COVER THICKNESS, sm APRIL 24 Fig.1.5. Intra-monthly variation of daily mean values of surface temperature (A, bold line), maximal (А, thin line), minimal (A, dotted line) air temperature, sea level pressure (B), relative humidity (C), mean (D, black circles), maximal (D, crosses) values of surface wind speed, maximal gust of the wind (D, white circles), precipitation (E), snow cover thickness (F) at Bellingshausen station, April 24.

17 13 PROGRESS STATION Table 1.8 Monthly averages of meteorological parameters (f) Progress, April 24 Parameter f mon.avg f max f min Sea level pressure, hpa Air temperature, C Relative humidity, % 64 Total cloudiness (sky coverage), tenths 6.6 Lower cloudiness(sky coverage),tenths 3.5 Precipitation, mm 22 Mean wind speed, m/s Prevailing wind direction, deg 9 Total radiation, MJ/m

18 14-2 A B SURFACE AIR TEMPERATURE, С SEA LEVEL PRESSURE, hpa APRIL 24 C APRIL 24 3 D RELATIVE HUMIDITY, % APRIL 24 E SURFACE WIND SPEED MODULUS, m/s 2 4 APRIL 24 F DAILY PRECIPITATION SUM, mm 4 2 APRIL 24 APRIL 24 Fig.1.6. Intra-monthly variation of daily mean values of surface temperature (A, bold line), maximal (А, thin line), minimal (A, dotted line) air temperature, sea level pressure (B), relative humidity (C), mean (D, black circles), maximal (D, crosses) values of surface wind speed, maximal gust of the wind (D, white circles), precipitation (E) and snow cover thickness (F) at Progress station, April 24. SNOW COVER THICKNESS, sm 3 2

19 Parameter f mon.avg f max f min Anomaly f-f avg 15 VOSTOK STATION Table 1.9 Monthly averages of meteorological parameters (f) and their deviations from multiyear averages (f avg ) Vostok, April 24 Normalized Relative anomaly anomaly f/f (f-f avg )/σ avg f Station surface level pressure, hpa Air temperature, C Relative humidity, % Total cloudiness (sky coverage), tenths Lower cloudiness(sky coverage),tenths. Precipitation, mm Mean wind speed, m/s Prevailing wind direction, deg 225 Total radiation, MJ/m Total ozone content (TO), DU - the observations were interrupted due to the low Sun s height

20 16 SURFACE AIR TEMPERATURE, С APRIL 24 A C SURFACE PRESSURE, hpa APRIL 24 B D RELATIVE HUMIDITY, % APRIL 24 E SURFACE WIND SPEED MODULUS, m/s APRIL 24 F DAILY PRECIPITATION SUM, mm APRIL 24 SNOW COVER THICKNESS, sm 3 25 APRIL 24 Fig.1.7. Intra-monthly variation of daily mean values of surface temperature (A, bold line), maximal (А, thin line), minimal (A, dotted line) air temperature, sea level pressure (B), relative humidity (C), mean (D, black circles), maximal (D, crosses) values of surface wind speed, maximal gust of the wind (D, white circles), precipitation (E), snow cover thickness (F) at Vostok station, April 24.

21 17 A P R I L Atmospheric Mean sea pressure level pressure, at at sea hpa level, hpa hpa (Vostok st.data pressure at station 992.6surface level) Mirny Novolaz Bellings Bellings Progress Progress Vostok Mirny Novolaz Bellings Progress (f-f avg )/σf Air temperature, C C Mirny Novolaz Bellings Progress Vostok Mirny Novolaz Bellings BellingsProgress Progress Vostok (f-f avg )/σf Relative humidity, %% Mirny Novolaz Bellings Bellings Progress Progress Vostok (f-f avg )/σf Total cloudiness, tenths Mirny Novolaz Bellings Bellings Progress Progress Vostok (f-f avg )/σf Precipitation, mm Mirny Novolaz Bellings Bellings Progress Progress Vostok f/f avg Mean wind speed, m/s m/s Mirny Novolaz Bellings Bellings Progress Progress Vostok (f-f avg )/σf Fig.1.8. Comparison of monthly averages of meteorological parameters at the stations. April 24. (Atmospheric pressure at Vostok staition is the surface pressure).

22 18 MAY 24 MIRNY OBSERVATORY Table 1. Monthly averages of meteorological parameters (f) and their deviations from multiyear averages (f avg ) Parameter f mon.avg f max f min Anomaly f-f avg Normalized anomaly (f-f avg )/σ f Mirny, May 24 Relative anomaly f/f avg Sea level pressure, hpa Air temperature, C Relative humidity, % Total cloudiness (sky coverage), tenths Lower cloudiness(sky coverage),tenths Precipitation, mm Mean wind speed, m/s Prevailing wind direction, deg 112 Total radiation, MJ/m Total ozone content (TO), DU

23 19-2 A B SURFACE AIR TEMPERATURE, С SEA LEVEL PRESSURE, hpa MAY 24 C 96 4 MAY 24 D RELATIVE HUMIDITY, % MAY 24 E SURFACE WIND SPEED MODULUS, m/s MAY 24 F DAILY PRECIPITATION SUM, mm MAY 24 SNOWCOVER THICKNESS, sm MAY 24 Fig.1.9. Intra-monthly variation of daily mean values of surface temperature (A, bold line), maximal (А, thin line), minimal (A, dotted line) air temperature, sea level pressure (B), relative humidity (C), mean (D, black circles), maximal (D, crosses) values of surface wind speed, maximal gust of the wind (D, white circles), precipitation (E), snow cover thickness (F) in Mirny Observatory, May 24.

24 2 Isobaric surface, P, hpa Table 1.11 Results of aerological atmospheric sounding (from CLIMAT-TEMP messages) Mirny, May 24 Isobaric surface height, H m Temperature, T C Dew point deficit, D C Resulting wind direction, deg Resulting wind speed, m/s Wind stability parameter,% Number of days without temperature data Number of days without wind data Table 1.12 Anomalies of standard isobaric surface heights and temperature Mirny, May 24 P, hpa Н-Н avg, m (Н-H avg )/σ Н Т-Т avg, С (Т-Т avg )/σ Т

25 21 A 2 PRESSURE, hpa MAY 24 B 2 PRESSURE, hpa MAY 24 Fig.1.. Intra-monthly variations of air temperature (A, С) and wind speed modulus (B, m/s) in the free atmosphere in Mirny Observatory, May 24 ( GMT).

26 22 NOVOLAZAREVSKAYA STATION Table 1.13 Monthly averages of meteorological parameters (f) and their deviations from multiyear averages (f avg ) Parameter f mon.avg f max f min Anomaly f-f avg Novolazarevskaya, May 24 Normalized Relative anomaly anomaly f/f (f-f avg )/σ avg f Sea level pressure, hpa Air temperature, C Relative humidity, % Total cloudiness (sky coverage), tenths Lower cloudiness(sky coverage),tenths Precipitation, mm Mean wind speed, m/s Prevailing wind direction, deg 135 Total radiation, MJ/m Total ozone content (TO), DU - the observations were interrupted due to the low Sun s height

27 23-6 A 2 B SURFACE AIR TEMPERATURE, С MAY 24 C SEA LEVEL PRESSURE, hpa MAY 24 D RELATIVE HUMIDITY, % MAY24 E SURFACE WIND SPEED MODULUS, m/s MAY 24 F DAILY PRECIPITATION SUM, mm MAY 24 PLACE SNOW COVERAGE, balls MAY 24 Fig Intra-annual variation of daily mean values of surface temperature (A, bold line), maximal (А, thin line), minimal (A, dotted line) air temperature, sea level pressure (B), relative humidity (C), mean (D, black circles), maximal (D, crosses) values of surface wind speed, maximal gust of the wind (D, white circles), precipitation (E), place snow coverage (F) at Novolazarevskaya station, May 24.

28 24 Isobaric surface, P, hpa Table 1.14 Results of aerological atmospheric sounding (from CLIMAT-TEMP messages) Novolazarevskaya, May 24 Isobaric surface height, H m Temperature, T C Dew point deficit, D C Resulting wind direction, deg Resulting wind speed, m/s Wind stability parameter,% Number of days without temperature data Number of days without wind data Table 1.15 Anomalies of standard isobaric surface heights and temperature Novolazarevskaya, May 24 P, hpa Н-Н avg, m (Н-H avg )/σ Н Т-Т avg, С (Т-Т avg )/σ Т

29 25 A 2 PRESSURE, hpa MAY 24 B - -2 PRESSURE, hpa MAY 24 Fig Intra-monthly variations of air temperature (A, С) and wind speed modulus (B, m/s) in the free atmosphere at Novolazarevskaya station, May 24 ( GMT).

30 26 BELLINGSHAUSEN STATION Table 1.16 Monthly averages of meteorological parameters (f) and their deviations from multiyear averages (f avg ) Parameter f mon.avg f max f min Anomaly f-f avg Bellingshausen, May 24 Normalized anomaly (f-f avg )/σ f Relative anomaly f/f avg Sea level pressure, hpa Air temperature, C Relative humidity, % Total cloudiness (sky coverage), tenths Lower cloudiness(sky coverage),tenths Precipitation, mm Mean wind speed, m/s Prevailing wind direction, deg 338 Total radiation, MJ/m

31 27 4 A 4 B SURFACE AIR TEMPERATURE, С SEA LEVEL PRESSURE, hpa MAY 24 C 94 4 MAY 24 D RELATIVE HUMIDITY, % MAY 24 E SURFACE WIND SPEED MODULUS, m/s 3 2 MAY 24 F DAILY PRECIPITATION SUM, mm MAY 24 SNOW COVER THICKNESS, sm 5 MAY 24 Fig Intra-monthly variation of daily mean values of surface temperature (A, bold line), maximal (А, thin line), minimal (A, dotted line) air temperature (А), sea level pressure (B), relative humidity (C), mean (D, black circles), maximal (D, crosses) values of surface wind speed, maximal gust of the wind (D, white circles), precipitation (E), snow cover thickness (F) at Bellingshausen station, May 24.

32 28 PROGRESS STATION Table 1.17 Monthly averages of meteorological parameters (f) Progress, May 24 Parameter f mon.avg f max f min Sea level pressure, hpa Air temperature, C Relative humidity, % 59 Total cloudiness (sky coverage), tenths 6.8 Lower cloudiness(sky coverage),tenths 3.2 Precipitation, mm 17.5 Mean wind speed, m/s Prevailing wind direction, deg 9 Total radiation, MJ/m 2 7.7

33 29 SURFACE AIR TEMPERATURE, С MAY 24 A C SEA LEVEL PRESSURE, hpa MAY 24 B D RELATIVE HUMIDITY, % MAY 24 E SURFACE WIND SPEED MODULUS, m/s MAY 24 3 F DAILY PRECIPITATION SUM, mm MAY 24 SNOW COVER THICKNESS, sm MAY 24 Fig Intra-monthly variation of daily mean values of surface temperature (A, bold line), maximal (А, thin line), minimal (A, dotted line) air temperature, sea level pressure (B), relative humidity (C), mean (D, black circles), maximal (D, crosses) values of surface wind speed, maximal gust of the wind (D, white circles), precipitation (E), snow cover thickness (F) at Progress station, May 24.

34 3 VOSTOK STATION Table 1.18 Monthly averages of meteorological parameters (f) and their deviations from multiyear averages (f avg ) Parameter f mon.avg f max f min Anomaly f-f avg Normalized anomaly (f-f avg )/σ f Vostok, May 24 Relative anomaly f/f avg Station surface level pressure, hpa Air temperature, C Relative humidity, % Total cloudiness (sky coverage), tenths Lower cloudiness(sky coverage),tenths. Precipitation, mm Mean wind speed, m/s Prevailing wind direction, deg 27 Total radiation, MJ/m 2 Total ozone content (TO), DU Polar night - the observations were interrupted due to the low Sun s height

35 31 SURFACE AIR TEMPERATURE, С RELATIVE HUMIDITY, % MAY 24 MAY 24 A C E SURFACE WIND SPEED MODULUS, m/s SURFACE PRESSURE, hpa MAY 24 MAY 24 B D F DAILY PRECIPITATION SUM, mm 2 1 MAY 24 SNOW COVER THICKNESS, sm 3 25 MAY 24 Fig Intra-monthly variation of daily mean values of surface temperature (A, bold line), maximal (А, thin line), minimal (A, dotted line) air temperature, sea level pressure (B), relative humidity (C), mean (D, black circles), maximal (D, crosses) values of surface wind speed, maximal gust of the wind (D, white circles), precipitation (E), snow cover thickness (F) at Vostok station, May 24.

36 32 M a y Atmospheric Mean sea pressure level pressure,hpa at sea level, hpa hpa (Vostok st.data pressure at station 994.4surface level) Mirny Novolaz Bellings Bellings Progress Progress Vostok Mirny Novolaz Bellings Progress (f-f avg )/σf Air temperature, C C Mirny Novolaz Bellings Bellings Progress Progress Vostok (f-f avg )/σf Relative humidity, % Mirny Novolaz Bellings Bellings Progress Progress Vostok (f-f avg )/σf Total cloudiness, tenths Mirny Novolaz Novolaz Bellings Bellings Progress Progress Vostok (f-f avg )/σf Precipitation, mm Mirny Novolaz Bellings Bellings Progress Progress Vostok f/f avg Mean wind speed, m/s Mirny Novolaz Bellings Bellings Progress Progress Vostok (f-f avg )/σf Fig Comparison of monthly averages of meteorological parameters at the stations. May 24. (Atmospheric pressure at Vostok staition is the surface pressure).

37 33 JUNE 24 MIRNY OBSERVATORY Table 1.19 Monthly averages of meteorological parameters (f) and their deviations from multiyear averages (f avg ) Parameter f mon.avg f max f min Anomaly f-f avg Normalized anomaly (f-f avg )/σ f Mirny, June 24 Relative anomaly f/f avg Sea level pressure, hpa Air temperature, C Relative humidity, % Total cloudiness (sky coverage), tenths Lower cloudiness(sky coverage),tenths Precipitation, mm Mean wind speed, m/s Prevailing wind direction, deg 112 Total radiation, MJ/m Total ozone content (TO), DU - the observations were interrupted due to the low Sun s height

38 34-6 A B SURFACE AIR TEMPERATURE, С JUNE 24 C SEA LEVEL PRESSURE, hpa JUNE 24 D RELATIVE HUMIDITY, % JUNE 24 E SURFACE WIND SPEED MODULUS, m/s JUNE 24 F DAILY PRECIPITATION SUM, mm 4 2 JUNE 24 SNOW COVER THICKNESS, sm JUNE 24 Fig Intra-monthly variation of daily mean values of surface temperature (A, bold line), maximal (А, thin line), minimal (A, dotted line) air temperature, sea level pressure (B), relative humidity (C), mean (D, black circles), maximal (D, crosses) values of surface wind speed, maximal gust of the wind (D, white circles), precipitation (E), snow cover thickness (F) in Mirny Observatory, June 24.

39 35 Table 1.2 Results of aerological atmospheric sounding (from CLIMAT-TEMP messages) Mirny, June 24 Isobaric surface, P, hpa Isobaric surface height, H m Temperature, T C Dew point deficit, D C Resulting wind direction, deg Resulting wind speed, m/s Wind stability parameter,% Number of days without temperature data Number of days without wind data Anomalies of standard isobaric surface heights and temperature Table 1.21 Mirny, June 24 P, hpa Н-Н avg, m (Н-H avg )/σ Н Т-Т avg, С (Т-Т avg )/σ Т

40 36 A 2 PRESSURE, hpa JUNE 24 B PRESSURE, hpa JUNE 24 Fig Intra-monthly variations of air temperature (A, С) and wind speed modulus (B, m/s) in the free atmosphere in Mirny Observatory, June 24 ( GMT).

41 37 NOVOLAZAREVSKAYA STATION Table 1.22 Monthly averages of meteorological parameters (f) and their deviations from multiyear averages (f avg ) Parameter f mon.avg f max f min Anomaly f-f avg Novolazarevskaya, June 24 Normalized anomaly (f-f avg )/σ f Relative anomaly f/f avg Sea level pressure, hpa Air temperature, C Relative humidity, % Total cloudiness (sky coverage), tenths Lower cloudiness(sky coverage),tenths Precipitation, mm Mean wind speed, m/s Prevailing wind direction, deg 135 Total radiation, MJ/m 2 Polar night Total ozone content (TO), DU - the observations were interrupted due to the low Sun s height

42 SURFACE AIR TEMPERATURE, С RELATIVE HUMIDITY, % DAILY PRECIPITATION SUM, mm JUNE 24 JUNE 24 JUNE 24 A C E SEA LEVEL PRESSURE, hpa SURFACE WIND SPEED MODULUS, m/s JUNE 24 JUNE 24 MAY 24 Fig Intra-annual variation of daily mean values of surface temperature (A, bold line), maximal (А, thin line), minimal (A, dotted line) air temperature, sea level pressure (B), relative humidity (C), mean (D, black circles), maximal (D, crosses) values of surface wind speed, maximal gust of the wind (D, white circles), precipitation (E), snow cover thickness (F) at Novolazarevskaya station, June 24. PLACE SNOW COVERAGE, balls B D F

43 39 Table 1.23 Results of aerological atmospheric sounding (from CLIMAT-TEMP messages) Novolazarevskaya, June 24 Isobaric surface, P, hpa Isobaric surface height, H m Temperature, T C Dew point deficit, D C Resulting wind direction, deg Resulting wind speed, m/s Wind stability parameter,% Number of days without temperature data Number of days without wind data Anomalies of standard isobaric surface heights and temperature Table 1.24 Novolazarevskaya, June 24 P, hpa Н-Н avg, m (Н-H avg )/σ Н Т-Т avg, С (Т-Т avg )/σ Т

44 4 A 2 PRESSURE, hpa JUNE 24 B 2 PRESSURE, hpa JUNE 24 Fig.1.2. Intra-monthly variations of air temperature (A, С) and wind speed modulus (B, m/s) in the free atmosphere at Novolazarevskaya station, June 24 ( GMT).

45 41 BELLINGSHAUSEN STATION Table 1.25 Monthly averages of meteorological parameters (f) and their deviations from multiyear averages (f avg ) Parameter f mon.avg f max f min Anomaly f-f avg Bellingshausen, June 24 Normalized anomaly (f-f avg )/σ f Relative anomaly f/f avg Sea level pressure, hpa Air temperature, C Relative humidity, % Total cloudiness (sky coverage), tenths Lower cloudiness(sky coverage),tenths Precipitation, mm Mean wind speed, m/s Prevailing wind direction, deg 158 Total radiation, MJ/m

46 42 6 A 2 B SURFACE AIR TEMPERATURE, С SEA LEVEL PRESSURE, hpa JUNE 24 C JUNE 24 D RELATIVE HUMIDITY, % JUNE 24 E SURFACE WIND SPEED MODULUS, m/s JUNE 24 F DAILY PRECIPITATION SUM, mm JUNE 24 SNOWCOVER THICKNESS, sm JUNE 24 Fig Intra-monthly variation of daily mean values of surface temperature (A, bold line), maximal (А, thin line), minimal (A, dotted line) air temperature, sea level pressure (B), relative humidity (C), mean (D, black circles), maximal (D, crosses) values of surface wind speed, maximal gust of the wind (D, white circles), precipitation (E), snow cover thickness (F) at Bellingshausen station, June 24.

47 43 PROGRESS STATION Table 1.26 Monthly averages of meteorological parameters (f) Progress, June 24 Parameter f mon.avg f max f min Sea level pressure, hpa Air temperature, C Relative humidity, % 63 Total cloudiness (sky coverage), tenths 6.3 Lower cloudiness(sky coverage),tenths 3.6 Precipitation, mm 23.7 Mean wind speed, m/s Prevailing wind direction, deg 9 Total radiation, MJ/m 2.6

48 44-4 A B SURFACE AIR TEMPERATURE, С JUNE 24 C SEA LEVEL PRESSURE, hpa JUNE 24 D RELATIVE HUMIDITY, % JUNE 24 E SURFACE WIND SPEED MODULUS, m/s JUNE 24 F DAILY PRECIPITATION SUM, mm JUNE 24 JUNE 24 Fig Intra-monthly variation of daily mean values of surface temperature (A, bold line), maximal (А, thin line), minimal (A, dotted line) air temperature, sea level pressure (B), relative humidity (C), mean (D, black circles), maximal (D, crosses) values of surface wind speed, maximal gust of the wind (D, white circles), precipitation (E), snow cover thickness (F) at Progress station, June 24. SNOW COVER THICKNESS, sm

49 45 VOSTOK STATION Table 1.27 Monthly averages of meteorological parameters (f) and their deviations from multiyear averages (f avg ) Parameter f mon.avg f max f min Anomaly f-f avg Normalized anomaly (f-f avg )/σ f Vostok, June 24 Relative anomaly f/f avg Station surface level pressure, hpa Air temperature, C Relative humidity, % Total cloudiness (sky coverage), tenths Lower cloudiness(sky coverage),tenths. Precipitation, mm Mean wind speed, m/s Prevailing wind direction, deg 315 Total radiation, MJ/m 2 Polar night Total ozone content (TO), DU - the observations were interrupted due to the low Sun s height RELATIVE HUMIDITY, % SURFACE AIR TEMPERATURE, С JUNE 24 A C SURFACE PRESSURE, hpa JUNE 24 JUNE 24 JUNE 24 Fig Intra-monthly variation of daily mean values of surface temperature (A, bold line), maximal (А, thin line), minimal (A, dotted line) air temperature, sea level pressure (B), relative humidity (C), mean (D, black circles), maximal (D, crosses) values of surface wind speed, maximal gust of the wind (D, white circles) at Vostok station, June 24. SURFACE WIND SPEED MODULUS, m/s B D

50 46 J u n e Atmospheric Mean sea pressure level pressure, at sea hpa level, hpa hpa (Vostok st.data pressure at station 989surface level) Mirny Novolaz Bellings Bellings Progress Progress Vostok Mirny Novolaz Bellings Progress (f-f avg )/σf Air temperature, C C Mirny Novolaz Novolaz Bellings Bellings Progress Progress Vostok (f-f avg )/σf Relative humidity, % Mirny Novolaz Bellings Bellings Progress Progress Vostok (f-f avg )/σf Total cloudiness, tenths Mirny Novolaz Bellings Bellings Progress Progress Vostok (f-f avg )/σf Precipitation, mm Mirny Novolaz Bellings Bellings Progress Progress Vostok f/f avg Mean wind speed, m/s Mirny Novolaz Bellings Bellings Progress Progress Vostok f/f avg Fig Comparison of monthly averages of meteorological parameters at the stations. June 24. (Atmospheric pressure at Vostok staition is the surface pressure).

51 47 2. METEOROLOGICAL CONDITIONS IN APRIL-JUNE 24 The air temperature conditions at the Antarctic continent in April-June 24 are characterized in Fig. 2.1, which presents monthly averages and surface air temperature anomalies at the Russian and foreign meteorological stations. The actual data of the Russian Antarctic stations contained in /1/ were used for the Russian Antarctic stations and data contained in /2, 3/ were used for the foreign stations. The multiyear averages for the period were adopted from /4/. In April-June, predominantly weak (up to 1σ) and moderate (up to 1.5σ) anomalies of mean monthly air temperature were observed. In April, the main cold center was located at the Atlantic coast in the western area of the Queen Maud Land. At Halley-Bay and Novolazarevskaya stations, the anomalies of mean monthly air temperature were equal to -6.1 о С (-2.3 σ) and -2.9 о С (-1.6 σ), respectively. The mean monthly air temperature at these stations was о С and о С, respectively. The April 24 was the second coldest April at Halley station, and the third coldest April at Novolazarevskaya station over the entire operation period of the stations. The lowest mean monthly temperatures for April at these stations were observed in 1997 at Halley station (-28.7 о С, -3. σ), and in 1963 at Novolazarevskaya station (-17.3 о С, -3.σ). The heat center was located in the vicinity of the Polar Plateau and the Antarctic Peninsula. At Vostok, Amundsen-Scott and Rothera stations, the anomalies of mean monthly air temperature comprised 2.4 о С (1.1 σ), 3. о С (1.2 σ) and 2.3 о С (1. σ), respectively. In May, the anomalies of mean monthly air temperature at the Antarctic stations were predominantly less than 1 σ. The cold center was situated at the Indian Ocean coast in the Adelie Land area. Here at Dumont-d Urville station, the anomaly of mean monthly air temperature was equal -2.7 С (-1.4σ). In the vicinity of the Antarctic Peninsula, small positive (around 1σ) anomalies were preserved. In June, small negative air temperature anomalies were recorded almost over the entire continent. In the cold centre core near the Amundsen-Scott station, the temperature anomaly was -3.4 о С (-1.1σ). Small by area heat centers were detected in the areas of the Adelie Land, in the eastern part of the Queen Maud Land coast and at the Antarctic Peninsula. Here at Dumont-d Urville, Syowa and Bellingshausen stations, the temperature anomalies were 3.3 о С (1.3 σ), 3.1 о С (1.5 σ) and 3. о С (1.5 σ), respectively. An assessment of long-period changes in mean monthly air temperature at the Russian stations in these months reveals a statistically significant trend only at Bellingshausen station in May (Figs ). The temperature increase for May amounted here to 2.5 С/37 years (Table 2.1). During the last decade, the most significant linear temperature trend was recorded at Mirny and Vostok stations for May the temperature increase was about 6 and 8 С/ years, respectively. The atmospheric pressure at the Russian stations in April-June was characterized predominantly by negative anomalies. The largest negative anomalies were observed at Mirny and Novolazarevskaya stations. In Mirny in April and June, the air pressure anomalies were -6.2 hpa (-2. σ) and -7.8 hpa (-1.4 σ), respectively. At Novolazarevskaya station in June the pressure anomaly was hpa (-2.6 σ). The atmospheric pressure at these stations in June was the lowest over the entire period of their operation. The precipitation amount in April and June at Mirny, Novolazarevskaya and Bellingshausen stations was less than the multiyear average. At the same time at inland Vostok station, a significant precipitation fallout was noted in April and May. In April, precipitation exceeded the monthly multiyear average 4.6-fold and in May 3.-fold, which is probably connected with penetration of cyclones to the inland areas of the continent. For Vostok station, this is the first case of such abundant precipitation in these months over the entire observation period beginning from 1957.

52 48 Linear trend parameters of mean monthly surface air temperature Table 2.1 Stations, Parameter IV V VI IV V VI Operation period Entire observation period Novolazarevsk о С/ years aya % Р Mirny о С/ years % Р 95 Vostok о С/ years % Р 9 Bellingshausen о С/ years % Р 95 Note: First line is the linear trend coefficient; Second line is the dispersion accounted for the linear trend; Third line P=1- α, where α is the level of significance (given if P exceeds 9%). References: Atlas of the Oceans. The Southern Ocean. RF MD (in press)

53 49 Fig.2.1. Mean monthly surface air temperatures (1), their anomalies (2) and normalized anomalies (3) in April (IV), May (V) and June (VI) 24 from data of stationary meteorological stations in the South polar area.

54 5 Fig Interannual variations of temperature and atmospheric pressure anomalies at the Russian Antarctic stations. April.

55 51 Fig Interannual variations of temperature and atmospheric pressure anomalies at the Russian Antarctic stations. May.

56 52 Fig Interannual variations of temperature and atmospheric pressure anomalies at the Russian Antarctic stations. June.

57 53 3. REVIEW OF THE ATMOSPHERIC PROCESSES IN THE ANTARCTIC IN APRIL-JUNE 24 Beginning from April 24, there was a change in the character of the atmospheric processes above the Antarctic from the increased activity of meridional circulation that took place at the beginning of the year to zonal processes observed throughout the entire second quarter. The typical macro-processes of the Southern Hemisphere and their manifestations at the synoptic charts of the Antarctic were described in a number of publications /1, 2/. As can be seen from Table 3.1, there was constantly a significant frequency of occurrence of zonal circulation (Z form) in April- June with spreading of the circumpolar centre of negative atmospheric pressure anomalies over the entire South Polar Area. Table 3.1 Frequency of occurrence of the atmospheric circulation forms of the Southern Hemisphere and its anomalies in April-June 24 Month Frequency of occurrence (days) Anomalies (days) Z M a M b Z M a M b April May June At the same time, one should note intensification of the South American high pressure core in April May. In April, the New Zealand ridge of the subtropical High was also intensified. This contributed to increased meridional character at the general background of dominating high zonality. In April and May, the major cyclonic activity was observed at the Falkland and Central Atlantic and also South African and Kerguelen branches of cyclonic trajectories. Cyclones reached sometimes a significant depth and penetrated far to the Antarctic dome leading in some periods to increased cloudiness, humidity, air temperature and wind speed. The meteorological conditions at Vostok station testify to this (Figs.1.7, 1.15, Tables 1.9, 1.18). However, the cyclones frequently attained a zonal motion component and moved along the coast. In May, the general character of tropospheric processes allowed us to speak about transition to the winter regime of atmospheric circulation. This was manifested in the general decrease of the tropospheric temperature and the decrease of the temperature at the tropopause level. In June, the cases of deep cyclones persisting near the shores of Antarctica were more frequent being accompanied with storm weather conditions. This was mainly observed above the areas of the Weddell, Lazarev, Cosmonauts and Davis Seas. An extensive belt of negative pressure anomalies was formed that covered the Antarctic Seas. In some regions, the anomalies of mean monthly pressure comprised - hpa to -13 hpa. At the slope of the Antarctic dome, the dominance of the High was noted as usual. At Vostok station in June, the pressure was equal to a multiyear average while the air temperature was slightly lower than the multiyear average. The general analysis of macro-processes above the Antarctic Seas and the coast of East Antarctica indicates an anomalous beginning of winter, which is characterized by the decreased atmospheric pressure background and low temperature over considerable expanses of East Antarctica. References: 1. Dydina L.A., Rabtsevich S.V., Ryzhakov L.Yu., Savitsky G.B. Atmospheric circulation forms in the Southern Hemisphere. AARI Proceedings, 1976, V. 33, p Ryzhakov L.Yu. Multiyear tendencies of the frequency of occurrence of the atmospheric circulation forms of the Southern Hemisphere and their manifestations in the synoptic processes of the Antarctic. Bulletin State of Antarctic Environment, 22, No. 4(21), p

58 54 4. BRIEF REVIEW OF ICE PROCESSES IN THE SOUTHERN OCEAN FROM DATA OF SATELLITE AND COASTAL OBSERVATIONS AT THE RUSSIAN ANTARCTIC STATIONS IN APRIL-JUNE 24 In April, intensive expansion of the ice belt that began from the second half of March continued in the Antarctic in general (see review 4 in /1/). The Atlantic massif that was distinguished by increased sizes for the last two years especially advanced northward. The massif fully blocked as early as the end of the month the South Orkneys Islands reaching the 6 th parallel in the Scotia Sea. There was also of interest an unusual expansion of the ice belt in the vicinity of Novolazarevskaya station opposite the Lazarev Ice shelf, where at 15 E the ice edge spread up to parallel 65 S. A similar situation was also created in most of the marginal seas of the Indian Ocean sector. At the same time in the Amundsen Sea in the Pacific Ocean sector, the ice belt edge reached only 7 S. Moreover, in the neighboring Bellingshausen Sea, the ice formation had still an inert character being absent at all near the west coast of the Antarctic Peninsula. During May, on the one hand the tendency for an anomalous development of the Atlantic massif and displacement of the ice belt northward in the area of 15 E (Fig.4.1) was preserved. The formed deep edge bend ( embayment in ice) at 8-9 W penetrated far to the south up to S. On the other hand, the ice belt expansion in the Indian sector sharply slowed, which determined here a decreased background ice extent (Table 4.1). Simultaneously, there was intensification of the ice formation process in the Pacific Ocean sector except for Bransfield Strait near the northwest tip of the Antarctic Peninsula. According to data of Bellingshausen station (Table 4.2), slush occurred here only episodically on 9 and May. In June, a sharp increase in the ice cover extent so typical of the Antarctic zone of the Southern Ocean was observed. Already in the first -day period, the aforementioned edge bend corresponding to the area of the so-called Weddell polynya (area between S and W- E) was completely covered by young ice. Moreover the ice edge in the Atlantic sector everywhere reached 58 S by the end of the month. In the western half of the Indian sector, the ice edge moved to S, and in its eastern part to 64 S. A significant ice belt increment was also noted in the Pacific Ocean sector. In the Amundsen and Bellingshausen Seas, the ice belt boundary spread on average up to 66 and 68 S, respectively. Only the Bransfield Strait area where no stable ice formation began remained ice-free. The character of the development of ice processes during the period under consideration was probably determined in many respects by continuation of the increased summer background cyclonic activity in the Antarctic. The related relatively high air temperature and the dominance of strong wind considerably delayed the landfast ice formation and influenced its thickness in the coastal zone (Tables 4.2 and 4.3). References: 1. Quarterly Bulletin State of Antarctic Environment. Operational data of Russian Antarctic stations. January March 24, No. 1 (26), Review 4.

59 55 Table 4.1 Latitudinal location of the external northern drifting ice belt edge in the Southern Ocean based on satellite data received at Bellingshausen, Novolazarevskaya and Mirny stations in May 24 Meridians Actual Multiyear average 13 W W E E Note: 1 Clear, ice is absent, and instead of the ice edge position, the latitude of the Antarctic coast point at the place of its intersection by the corresponding meridian is presented

60 56 Table 4.2 Dates of the main ice phases near the Russian Antarctic stations in the first half of 24 Station Ice formation Landfast ice formation Freeze-up (water body) First Stable First Stable First Stable Mirny Actual (roadstead) Multiyear average Progress Actual (Vostochnaya Multiyear Bay) average Bellingshausen Actual 9.5 no 1 no no no no (Ardley Bay) Multiyear average Note: 1 - Phenomenon not observed (not yet occurred) 2 - Actual dates are of preliminary character and can be further specified Table 4.3 Landfast ice thickness and snow depth (cm) near the Russian Antarctic stations from profile measurement data in April-June 24 Station Characteristics Months IV V VI Ice Actual Mirny Multiyear average Snow Progress Ice Snow 4 1 1

61 57 Fig Actual (solid line) and mean multiyear (dash line) location of the external northern drifting ice edge in the Southern Ocean in May 24.