Пульсации в геомагнитном поле как важный биотропный фактор космической погоды.

Клейменова Н.Г.Институт физики Земли РАН

ИКИ, 2012

• 1. Very many authors presented a lot of evidences that geomagnetic disturbances could be one of the hazard factor for human organisms specially for patients with cardiovascular pathologies. However, not every magnetic storm was bioeffective.

• 2. The magnetite biomineralization and magnetoreception in organisms was found by J.L. Kirschvink.

• The main agent of the space weather influence on the biosphere is still unknown.

• We assume that one of a such agent, probably, could be geomagnetic pulsations.

IMPORTANT NOTES

Magnetic storm classification

│Dst│ 1957-1993 nT

Week 30-50 44%Moderate 50-100 32%Strong 100-200 19%Very strong 200-350 4%Superstorms > 350 1%

The relationship between the solar and geomagnetic cycles activity and the human infarction mortality is absent.

Variations of the infarction mortality (Bulgaria) and solar (Wp and F 10.7) and geomagnetic activity (Kp) for period of 26 years data (1970-1995)

3

The infarction mortality demonstrates the strong season quasi-periodicity with the winter maximum and the summer minimum.

This analysis demonstrated strong season mortality variation with the profound summer minima and winter maxima.

However, it is well known that the maximum of magnetic storm occurrence is attributes to equinox, not to winter.

Thus, we suggest that a biotropic efficacy of the magnetic storms may depend on the season.

Variations of the general infarction mortality in Bulgaria summarised for 16 years

Seasonal variations of MI mortality

(M - men, W – women, T – in towns, C - in the country)

4

Infarction in Moscow and magnetic storms

• We analyzed 129 magnetic storms (1979-1982)• storms infarction (MI) increasing (Moscow)

• Equinox – 75 56 (~75 %)• Summer – 32 1 (~ 5 %)• Winter – 22 21 (~95 %)

• Thus – only less then 5% of the summer magnetic storms and more then 95% of the winter storms showed the MI enhancement.

• As usually, the storm main phase was not accompanied by MI increasing. The most of MI storm increasing was observed during the recovery phase of magnetic storm.

• GEOMAGNETIC PULSATION STUDY HISTORY

• Oscillations in magnetic field have been seen even in the middle of the 18-th century at Uppsala observatory.

• Later on, in 1859 during strong magnetic storm, B. Stewart has seen 30-second oscillation near London.

• The first publication by M. Eschenhagen of one minute rapid periodic changes of the Earth`s magnetism was in J.Terrest. Magn. Vol. 1, April 1896.

• In 1932-1936, L. Harang and E. Sucksdorff published the Scandinavian observations of magnetic pulsations with periods of 1-2 seconds.

• The 1941-1945 World War interrupted the geophysical investigations

In 1952-1953 young scientist of the Institute of the Physics of the Earth Valery Troitskaya discoveredf that the short period oscillations are the typical phenomena in the geomagnetic field of the Earth

Троицкая В.А. Короткопериодные возмущения электромагнитного поля Земли // Докл. АН СССР, новая серия, т.91, №2, с.241, 1953.

In 1956-1957, the similar results have been published by Kato and Watanabe and term these oscillations as geomagnetic pulsations.

Day (Pc) Night (Pi)• Т= 0.2-5.0 s (Рс 1) Т = 1- 40 s (Pi1)• Т= 10 - 45 s (Рс 2-3) Т= 40-120 s (Pi2)• Т= 45 - 150 s (Рс 4) Т > 2-3 min (Pi3)• Т= 3-10 min (Рс 5)

IAGA Classification, 1973V. A. Troitskaya (1917-2010)the

The geomagnetic pulsations are divided into two types: the day-time continues pulsation continues ( Pc) and the night-time irregular pulsations (Pi).

frequency

The amplitude of geomagnetic pulsations strong decreases with decreasing of the pulsation periods

Рс5

Рс4

Рс3

Рс2

100

nT

10

1

Pulsation amplitudes at the middle latitudes

Pc1, Рi1 - tenths of nT

Pc3-4, Pi2 - few nT

Pc5, Pi3 - tens of nT 

The pulsations amplitudes increase with latitude increasing of magnetic activity and latitudes .

Pc3-5 pulsations generation

• The common Pc3-5 generation mechanism is the field line resonance of : Т=2∫dS/Va, there Va is Alfven speed –Va=B/(ρ)0.5. The main energy source is Kelvin-Helmholtz instabillity

• The resonant frequency of a field line is determined by its length, magnetic field strength and the local plasma density.

• The wave resonant frequency decreases with L-shell increasing.

Upstream waves can be another source of Pc3-4 activity, f (mHz) = 6 В (nT).

Pc5 pulsations are typical for high latitudes

Pc4 pulsations are typical for subauroral latitudes

Resonant wave periods

Pc3 pulsations are typical for middle latitudes

Рс3-4 пульсации в магнитосфере

At mid-latitudes, the periods of Pc3-4 pulsations decrease with magnetic activity increasing

Borok obs.

f=20 мГц

f=50 мГц

Рс4

Рс3

The Pc4 pulsations are typical for quiet magnetic conditions and Pc3 – for the disturbed time

Dynamical spectra of Pc3-4 pulsations at middle latitudes

Kp~1-2

Diurnal variations of Pc3 and Pc4 pulsations at subauroral latitudes

Рс3 Рс4

12 MLT

ΣKp>25

ΣKp<25

12 MLT

25-40 мГц 8-20 мГц

Pc1 geomagnetic pulsationsFrequency – 0.5 – 2.0 HzAmplitude – 10 – 100 pTDiurnal occurrence maximum – 00 - 06 MLTDuration – from several minutes to several hours

Pc1 pulsations are typical for the recovery phase of magnetic storm.A number of Pc1 occurrence increases in winter time.

We suggested that one of critical factors which affect a human cardiovascular system could be geomagnetic Pc1 pulsations having the frequency comparable with frequency of heart rate beatings.

1 мин

Рс1 pulsations

Infarctions (Moscow), mortality (Bulgaria), geomagnetic activity and Pc1 pulsations

Very good correlation between Moscow and Bulgaria data (R=0.84) is seen.

There is no real agreement between the medical data and geomagnetic activity (Kp).

However, there is a similarity of the medical data and Pc1 geomagnetic pulsations occurrence.

Mortality from infarctions in Bulgaria (IM) and monthly duration of

geomagnetic pulsations Pc1

The similar season variations of IM and Pc1 are seen.

The number of infarcts increases one day after the Pc1 pulsations occurrence

Ganelina et al., 1982

July 198123 24 25 26 27

Bz

Np

Dst

There was no IM enhancement in summer periods

100

nT

200

-10

-30

Геомагнитные пульсации Рс5

• Частота – 2 – 7 мГц• Период - 3- 8 мин• Амплитуда в средних широтах • – десятки нТл • в высоких – до 200-500 нТл

• Максимум в суточном ходе – 06 – 12 MLT• Скорость изменения магнитного поля

• ~10-100 нТл/мин

SOD

PAF

CZT

Pc5 (1.5 – 7.0 mHz)

1-31.05.1980 1-30.06.1980

000

40

10

2.5

mHz / Hz0.5

Ф=64

Ф=58

Ф=43

Pc5 pulsation MLT occurrence distribution

(Baker et al., J.G.R., 2003)

Рс5 pulsation (T=6-8 min)

Months

Season variations of MI and Pc5 geomagnetic pulsations

Summer minimum is seen

IM

31.10. 200311-12 UT11-12 UT

Contrary to the typical morning Pc5 pulsations in the storm recovery phase there were the unusual strong afternoon Pc5 pulsations

The typical morning Pc5 pulsations in a storm recovery phase are observed at Ф~68-75º

ПОЛДЕНЬ

Восстановительная фаза гигантской бури

Заключение• В средних широтах развитие инфарктов (и других

сердечно-сосудистых заболеваний) имеет четкий сезонный ход с минимумом летом и отсутствием значительных экстремумов в равноденствие, когда имеет место максимум магнитных бурь. Летом биоэффективность магнитных бурь уменьшается, а зимой возрастает.

• Одним из важных биотропных агентов космической погоды могут быть геомагнитные пульсации с периодами от секунды до нескольких минут. Характеристики пульсаций зависят от геомагнитной активности в данный момент и в предшествующее время, от широты точки наблюдения и времени суток.

THANK YOU FOR ATTENTION