Storm Of August Research Articles

Sediment budget monitoring of a debris-flow torrent (French Prealps)

ABSTRACT The Manival near Grenoble (French Prealps) is a very active debris-flow torrent equipped with a large sediment trap (25 000 m 3 ) protecting an urbanized al-luvial fan from debris-flows. We began monitoring the sediment budget of the catchment controlled by the trap in Spring 2009. Terrestrial laser scanner is used for monitoring topographic changes in a small gully, the main channel, and the sediment trap. In the main channel, 39 cross-sections are surveyed after every event. Three periods of intense geomorphic activ-ity are documented here. The first was induced by a convective storm in August 2009 which triggered a debris-flow that deposited ~1,800 m of sediment in the trap. The debris-flow originated in the upper reach of the main channel and our observations showed that sediment outputs were entirely supplied by channel scouring. Hillslope debris-flows were initiated on talus slopes, as revealed by terrestrial LiDAR resur-veys; however they were disconnected to the main channel. The second and third periods of geomorphic activity were induced by long duration and low inten-sity rainfall events in September and October 2009 which generate small flow events with intense bed-load transport. These events contribute to recharge the debris-flow channel with sediments by depositing important gravel dunes propagating from headwaters. The total recharge in the torrent subsequent to bedload transport events was estimated at 34% of the sediment erosion induced by the August debris-flow.

Influence of the Amazon/Orinoco Plume on the summertime Atlantic climate

A plume of fresh water forms in the Atlantic due to discharge from the Amazon and Orinoco rivers and creates a stable barrier layer near the surface that is associated with warm sea surface temperature anomalies (SSTAs). The boreal summer atmospheric response to this sea surface temperature (SST) forcing is investigated using a regional atmospheric model. Results from two ensembles, one with the plume SSTA removed, and the other with an idealized plume SSTA imposed, reveal that the scale of the SSTA forcing is large enough to influence the summer climate over the tropical western Atlantic and Central America. Rainfall increases over the SSTAs and downstream over the Caribbean Sea and Central America, as sensible and latent heating associated with the plume SSTAs force a Rossby/Kelvin wave dynamical response. The result is westward shift by 12° of longitude of the North Atlantic subtropical anticyclone, a northward repositioning of the summertime subtropical anticyclone extension over the Gulf of Mexico, and increased moisture convergence into Central America. Warm SSTAs associated with the plume also influence simulated summer tropical Atlantic storms. The presence of the plume increases the number of Atlantic basin storms by 60% (i.e., 4.66 more storms). An increase in storm intensity also occurs, with a 61% increase of the number of storms that reach tropical storm and hurricane strength. However, these storms tend to be shorter lived and are associated with a 12% decrease in the number of tropical storm days. Storm trajectories also shift westward over the western Atlantic associated with the presence of the plume, bringing them closer to the U.S. coast as both the steering winds and vertical wind shear over the Atlantic are modified. These results suggest that the August storm systems may be more likely to track closer to the U.S. coast and/or over the Gulf of Mexico. Since the Amazon and Orinoco rivers are fed primarily by rainfall in the Amazon Basin during austral summer, the influence of the plume SSTs on Atlantic climate is an example of interhemispheric forcing of climate variability across seasons.

Simultaneous Observations and Analysis of Severe Storms Using Polarimetric X-Band SAR and Ground-Based Weather Radar

Recent advances in synthetic aperture radar (SAR) technology have revived meteorological applications with this type of radar. SARs are designed for surface imaging, but now that several X-band multipolarization SAR satellites are in orbit, the attenuation and backscatter caused by precipitation can be better studied. The results presented here demonstrate some of the possibilities by analyzing observations from dual-polarization (HH, VV) TerraSAR-X (TSX) acquisitions over central Florida surrounding severe storms in August 2008. Simultaneous to the SAR acquisitions, WSR-88D ground weather radars in Melbourne and Tampa Bay, FL, collected reflectivity and radial velocity data; the observed strong precipitation cells from convective storms are colocated with severe attenuation in the corresponding SAR images. The observations from SAR measurements are explained quantitatively by converting ground radar reflectivity into spaceborne radar attenuation via a theoretical model. In addition, polarization analysis comparing the SAR image to two additional TSX acquisitions 11 days apart and without rain provides an indication of storm-induced propagation effects on X-band SAR. Specifically, the copolar ratio Z_dr and the copolar correlation differences exhibit behavior that is better explained by the precipitation impact versus surface changes. Multiple regions with varying ground cover, including urban, and storm characteristics are analyzed to highlight the complexity of meteorological research using SAR while revealing a potential use of the technology to investigate the storm structure.

Extreme geomagnetic storms, recent Gleissberg cycles and space era-superintense storms

Extreme historical and space era geomagnetic storms ( Δ H or Dst ≤ − 400 nT ) are studied in terms of their sunspot and Gleissberg solar cycle distributions. Interplanetary and magnetospheric processes associated with the Carrington storm are summarized and the intense storm of August 4, 1972 is discussed in the context of the possibility of having occurred as an extreme storm instead, if the polarity of the related magnetic cloud would have been opposite. We also discuss about superintense geomagnetic storms ( Dst ≤ − 250 nT ) that occurred in the space era, showing their solar cycle and seasonal distributions and also providing averages for the peak values of their main associated interplanetary parameters. A discussion about the possible occurrence of more Carrington type storms is also addressed.

Sulfate and strontium water source identification by O, S and Sr isotopes and their temporal changes (1997–2008) in the region of Freiberg, central-eastern Germany

Abstract Various waters (bulk atmospheric precipitation, groundwater, river water, flowing mine water, mine drainage galleries and flooding mine water) were studied in the region of Freiberg to achieve an improved understanding of sources and mixing processes in the hydrological cycle and to specify the main sources that determine the isotope composition of dissolved sulfate and strontium (δ18OSO4, δ34SSO4 and 87Sr/86Sr) in river water. The combined use of isotope and chemical data led to identification of three major sulfate sources: i) sulfate from groundwater, ii) sulfate from the oxidation of local ore sulfides that remained in unflooded und flooded parts after mine decommissioning, and iii) “industrial” sulfate released from abundant waste, slag and tailing deposits left behind after a long mining and industrial history of the region. The same three components (groundwater, pore water from oxidation of residual ores and industry source) were identified by analyzing Sr isotope ratios. However, the Sr isotopes pointed out a fourth, yet unrecognized source that contributed to water of the flooded mine section. The data show that the isotope composition of water of the river Freiberger Mulde was mainly determined by uncontaminated groundwater diluted with atmospheric precipitation, whereas the other two end-members played only a minor role for this river water. However, for the river Triebisch the isotope compositions of dissolved sulfate and strontium record a strong impact of end-members II and III after recharging the flooding water into the river. A twelve year monitoring (1997–2008) revealed a strong decrease of δ18OSO4 values of water from bulk atmospheric precipitation as of 2006–2008 (7‰) compared to 1997 (14‰), while δ34SSO4 values remained constant (5‰). This isotope shift was probably caused by a lower contribution of “primary” sulfates to atmospheric precipitation in recent years. Groundwater and river water (Freiberger Mulde) also showed decreasing δ18OSO4 values albeit to a lower degree (by 4–5‰). A decrease of δ18OSO4 values was again found in flowing mine water (by 5–6‰) mainly affected by end-member I (uncontaminated groundwater). The flood event in August 2002 likely washed out large parts of “older” groundwater and thus enabled the relatively large oxygen isotope decrease (δ18OSO4) of groundwater and river water within a few years. The previously high input from the “industrial” source (waste and slag deposits) decreased from 1997 to 2002 in some drainage galleries and flooding water that discharge their water into local rivers. This led to lower δ18O and δ34S values of dissolved sulfates in these waters accompanied by a concentration decrease of several elements (Cl, Na and Mg). However, no further decrease of the impact of this source could be detected after the storm and flood event in August 2002.

O- AND H-ISOTOPE RECORD OF CAPE TOWN RAINFALL FROM 1996 TO 2008, AND ITS APPLICATION TO RECHARGE STUDIES OF TABLE MOUNTAIN GROUNDWATER, SOUTH AFRICA

The O- and H-isotope composition of rainfall collected over a variety of time periods at the University of Cape Town (UCT) between 1996 and 2008 has been determined. A continuous record of monthly rainfall from 1996 to 2008 has a range in δD and δ 18 O values from −57 to +18‰ and −8.1 to +3.5‰, respectively. These data show limited but discernable temperature and amount effects. Daily rainfall between June 2000 to September 2001 ranges in δD and δ 18 O from −57 to + 27‰, and, −9.0 to +6.4‰ respectively, showing only a marginally greater temperature and amount effect than the monthly data. Rainfall collected at 18 O value of 26 and 3.3‰, respectively in as little as 30 minutes during the passage of a cold front. Unusual events such as snow and hail in the area have much lower δD and δ 18 O values (−60 and −10.9‰). The deuterium excess values were significantly higher in the storm samples (average 20.0) and the hail and snow samples (average 30.1) than in the monthly rain samples (average 12.4). The UCT monthly samples define a meteoric water line whose equation is δ= 6.41*δ 18 O + 8.66 (r = 0.88). The daily and hail/snow samples show a better correlation (r = 0.93) due to the greater spread of values, with an equations of the line of best fit of δD = 6.64δ 18 O + 11.89. Rain water collected during two storms in July and August show an excellent correlation between δD and δ 18 O (r = 0.97) with an equation of best fit of δD = 7.89 δ 18 O + 19.35. There has been no systematic change in annual amount, mean temperature or weighted mean isotope composition from 1996 to 2008, but 1996 (16.1°C) was, on average, 1.3°C colder than 1997 to 2008 (ave. 17.3°C). Annual rainfall at UCT has varied from ~1000 mm (1997) to 1700 mm (2001), and the weighted mean annual δD and δ 18 O values calculated from the monthly samples varies from −16 to −7‰ and −3.8 to −2.6‰, respectively. The years 2005 and 2006 showed a significantly lower deuterium excess (~6) compared to typical values of about 16, which suggests that these years experienced less frontal rain. This difference in isotope composition of rainfall is detectable in the isotope composition of water collected from springs on the lower slopes of Table Mountain and suggests that the Table Mountain aquifer(s) are recharged by approximately 50% within three years.

The geomagnetic storm of August 2010 as a lesson of the space weather modeling

A model of the magnetic storm of August 4, 2010, is presented in the paper.Simulated Dst index series is obtained from an empirical model of the solar wind magnetosphereinteraction and is compared with real data. In broader context, the underlyingstudy can be conceived as an example of the space weather modeling. A brief survey ofthe approaches to this topic is provided in the paper. In particular, the link is made tothe previous studies based on artificial neural networks which could be beneficial for themagnetic storm modeling as well.

Magnitude–frequency relationships of debris flows — A case study based on field surveys and tree-ring records

Debris-flow activity in a watershed is usually defined in terms of magnitude and frequency. While magnitude–frequency (M–F) relations have long formed the basis for risk assessment and engineering design in hydrology and fluvial hydraulics, only fragmentary and insufficiently specified data for debris flows exists. This paper reconstructs M–F relationships of 62 debris flows for an aggradational cone of a small (< 5 km 2), high elevation watershed in the Swiss Alps since A.D. 1863. The frequency of debris flows is obtained from tree-ring records. The magnitude of individual events is given as S, M, L, XL, and derived from volumetric data of deposits, grain size distributions of boulders, and a series of surrogates (snout elevations, tree survival, lateral spread of surges). Class S and M debris flows (< 5 × 10 3 m 3) encompass a typical size of events and have mean recurrence intervals of 5.4 (SD: 3.2) and 7.4 years (SD: 6.7), respectively. Class XL events (10 4–5 ×10 4 m 3) are, in contrast, only identified three times over the past 150 years, and major erosional activity on the cone was restricted to two of these events in 1948 and 1993. A comparison of results with hydrometeorological records shows that class L and XL events are typically triggered by advective storms (rainfall > 50 mm) in August and September, when the active layer of the rock glacier in the source area of debris flows is largest. Over the past ∼ 150 years, climate has exerted control on material released from the source area and prevented triggering of class XL events before 1922. With the projected climatic change, permafrost degradation and the potential increase in storm intensity are likely to produce “ class XXL” events in the future with volumes surpassing 5 × 10 4 m 3 at the level of the debris-flow cone.

Variations in the total electron content during the powerful typhoon of August 5–11, 2006, near the southeastern coast of China

The variations in the total electron content (TEC), obtained from the data of 11 ground-based GPS stations in the region (5°S–80°N; 110–160°E) in the period August 2–15, 2006, have been analyzed in order to search for possible ionospheric manifestations of the SAOMAI powerful typhoon (August 5–11, 2006) near the south-eastern coast of China. The global TEC maps (GIM) have also been used. In the region of the typhoon action during the magnetic storm of August 7, 2006, an intensification of the TEC variations in the evening local time within the 32–128 min periods range was detected. However, this effect was most probably caused by the dynamics of the irregular structure of the equatorial anomaly and by the disturbed geomagnetic situation (Kp ∼ 3–6, Dst varied from −74 to −153 nT). The analysis of the diurnal variations in the absolute values of TEC and TEC variations with periods of 2–25 min did not reveal a substantial increase in the intensity and changes in the spectrum of the TEC variations in the period of typhoon action as compared to the adjacent days. Thus, we failed to detect ionospheric disturbances unambiguously related to the SAOMAI typhoon.

Relationship between FAC at plasma sheet boundary layers and AE index during storms from August to October, 2001

Unlike the previous single (dual) satellite observation, the four Clusterll satellites make it possible to directly compute the continuous field-aligned current (FAC) density according to the magnetic data from them and to enable the investigation of the relationship between the FAC and geomagnetic activity. This paper analyzes the observation data when the Cluster satellites crossed the plasma sheet boundary layer (PSBL) in the magnetotail during the two magnetic storms in August to October 2001. According to the data, during the magnetic storms the relationship between the variations of FAC and AE index turned out to be: 1) FAC was obviously increasing during the storms; 2) FAC density was approximately negatively correlated with AE index from the sudden commencement to the early main phase of the storm; 3) they were approximately positively correlated during the late main phase and early recovery phase; 4) they were no apparent correlation during the late recovery phase.

Severe storms and their effects in sub-Mediterranean Slovenia from the 14th to the mid-19th century

The paper presents an overview of severe storms and a reconstruction of periods with their reiterative occurrence in sub-Mediterranean Slovenia in the warm half of the year during the so-called pre-instrumental period. The data were gathered in secondary and tertiary historical sources, chronicles first and foremost. The presented chronology does not provide a complete reconstruction because of insufficient data, yet it offers a basic insight into the periods of frequenter occurrence of these phenomena. Outstanding are the 17th and the 18th centuries, especially their first halves whose weather conditions rank among the most unfavourable in the last millennium. In addition to severe winters with damages done by frosts, dry or too wet summers, 12 violent storms in the 17th century and 16 in the 18th century caused great damage and considerably aggravated the conditions of living. The occurrence of storms in the first halves of the 17th and the 18th centuries was equal to that at the end of the 20th century, when frequenter occurrence of such weather extremes is mainly believed to be caused by the general warming of the atmosphere. It is evident from the chronicle that the characteristics of severe storms and the kinds of resulting damage have not significantly changed until today. The only phenomenon that has not been recorded in the recent history of climate is such a sharp drop in temperature in the lower parts of the Primorska (Littoral) region during an August storm as to cause that snow fell, which, supposedly, happened in August 1710.

Effect of summer storms on early life stages of Uca minax, U. pugnax and U. pugilator in North Inlet Estuary, South Carolina, USA

Estuarine fiddler crabs have a complex life cycle that spans vastly different salinity regimes. Larvae are spawned in estuaries and travel to the coastal ocean where development takes place; after metamorphosing to the megalopal stage, fiddler crabs reinvade estuaries where they set- tle and metamorphose. In the coastal ocean, larvae experience relatively stable physical conditions; however, upon reinvading estuaries, they are exposed to great fluxes in salinity and temperature. In this study, we measured shifts in the salinity regime caused by storm events, and determined the impact of these changes on species frequencies of megalopae from 3 Uca species in the water column and of their recently settled juvenile crabs on the benthos along a salt marsh creek in South Carolina. Adults of the 3 species examined are found in different salinity regimes: adult Uca pugnax generally occupy areas with relatively high salinity and plant cover, while U. minax are found in low salinity or freshwater areas; U. pugilator are found in open sandy areas over a broad range of salinities, but gen- erally occupy higher salinity environments than U. minax. For megalopal stages in the water column, we found that the relative proportions of the 3 species changed significantly along salinity gradients and in response to storm events. When the salinity regime normalized, species frequencies for mega- lopae returned to pre-storm proportions. Only U. minax megalopae were present in the water column during a storm event in July, whereas U. pugnax had been the most abundant species in the water column prior to the storm. Although all 3 species were able to survive storm events as juveniles, U. pugnax juveniles survived low salinity conditions significantly better than the other 2 species during the July storm. During a less severe storm in August, which lasted 5 d and altered the existing profile for a week, the benthic juvenile stages did not exhibit significant changes in species frequencies. Our results show that the duration and severity of salinity change are important variables that impact on the presence of these Uca species in the water column, and suggest that the physiology and behav- ior of the megalopal stage strongly influence where populations occur within estuaries.

Characteristics of re-suspended road dust and its impact on the atmospheric environment in Beijing

A sampling campaign of re-suspended road dust samples from 53 sites that could cover basically the entire Beijing, soil samples from the source regions of dust storm in August 2003, and aerosol samples from three representative sites in Beijing from December 2001 to September 2003, was carried out to investigate the characteristics of re-suspended road dust and its impact on the atmospheric environment. Ca, S, Cu, Zn, Ni, Pb, and Cd were far higher than its crustal abundances and Ca 2+, SO 4 2−, Cl −, K +, Na +, NO 3 − were major ions in re-suspended road dust. Al, Ti, Sc, Co, and Mg in re-suspended road dust were mainly originated from crustal source, while Cu, Zn, Ni, and Pb were mainly derived from traffic emissions and coal burning, and Fe, Mn, and Cd were mainly from industrial emissions, coal combustion and oil burning. Ca 2+ and SO 4 2− mainly came from construction activities, construction materials and secondary gas-particle conversions, Cl − and Na + were derived from industrial wastewater disposal and chemical industrial emissions, and NO 3 − and K + were from vehicle emissions, photochemical reactions of NO X , biomass and vegetable burning. The contribution of mineral aerosol from inside Beijing to the total mineral aerosols was ∼30% in spring of 2002, ∼70% in summer of 2002, ∼80% in autumn of 2003, ∼20% in PM 10 and ∼50% in PM 2.5, in winter of 2002. The pollution levels of the major pollution species, Ca, S, Cu, Zn, Ni, Pb, Fe, Mn, and Cd in re-suspended road dust reached ∼76%, ∼87%, ∼75%, ∼80%, ∼82%, ∼90%, ∼45%, ∼51%, and ∼94%, respectively. Re-suspended road dust from the traffic and construction activities was one of the major sources of pollution aerosols in Beijing.

Solar-terrestrial extrastorm of August 22–25, 2005. I. Solar sources

The solar-terrestrial extrastorm of August 22–25, 2005, has been considered in the context of the cyclic dynamics and structure of the large-scale open solar magnetic field and has been rated among the other extrastorms of cycle 23. It has been established that the storm under discussion was one of the last six extrastorms in the cycle that occurred during the specific third interval of the declining phase—the period of quasirigidly corotating four-sector structure. Inside this structure, we have revealed convergent motions of the photospheric sources of open fields, the active sector boundary, and the formation of a narrow longitudinal sector with the activity complex responsible for the set of four extrastorms of January–September 2005. It is shown that all extrastorms were accompanied by significant variations (up to 1021 μs) of the open field flux Φ. The storm of August 22–25 was accompanied by an increase in the magnetic flux Φ in the corresponding sector (with a doublet of solar flares) and a fast expansion of the sector to the dimensions at the beginning of this interval (September 2004).

Response of nighttime equatorial and low latitude F-region to the geomagnetic storm of August 18, 2003, in the Brazilian sector

This paper presents an investigation of geomagnetic storm effects in the equatorial and low latitude F-region in the Brazilian sector during the intense geomagnetic storm on 18 August, 2003 (SSC 14:21 UT on 17/08; ΣKp = 52+; Ap = 108; ∣Dst∣ max = 168 at 1600 UT on 18/08). Simultaneous ionospheric sounding measurements from two stations, viz., Palmas (10.2°S, 48.2°W; dip latitude 5.7°S) and Sao Jose dos Campos (23.2°S, 45.9°W; dip latitude 17.6°S), Brazil, are presented for the nights of 16–17, 17–18 and 18–19 August, 2003 (quiet, disturbed and recovery phases). Both stations are equipped with the Canadian Advanced Digital Ionosonde (CADI). Quiet and disturbed conditions of the F-region ionosphere are compared using data collected from the two stations. The relationship between magnetospheric disturbance and low-latitude ionospheric dynamics, and generation of ionospheric irregularities are discussed. On the disturbed nights (17–18 and 18–19 August), the low latitude station S. J. Campos showed strong enhancements in the F-region critical frequency (foF2), whereas the near equatorial station Palmas showed strong uplifting of the F-layer about 1 h earlier. Normally during the June solstice months (May–August) in the Brazilian sector, large-scale ionospheric irregularities in form of plasma bubbles are rarely observed. On the night of 17–18 August, ionsospheric sounding observations at Palmas showed the presence of bottomside spread-F, whereas on the night of 18–19 August, the observations at Palmas and S. J. Campos showed the presence of plasma bubbles when the storm recovery phase had just started. The complementary GPS data available from several stations in the “Rede Brasileira de Monitoramento Continuo de GPS (Brazilian Network for Continuous GPS Monitoring)” are used to obtain the vertical total electron content (VTEC) and the rate of change of TEC per minute on UT days 18 and 19 August, 2003 and presented. Also, several global ionospheric TEC maps from the worldwide network of GPS receivers are presented, showing widespread latitudinal and longitudinal TEC changes during the different phases of the storm. All the observations (local ionospheric sounding and GPS network measurements, and global GPS measurements) presented in this investigation related to the geomagnetic storm on 18 August indicate that the equatorial and low latitude region in the Brazilian sector had much stronger effect during the recovery phase compared with the main phase. A comparison of the observed disturbance drifts with the Fejer–Scherliess storm-time model drifts indicate that the modeled drifts are not consistent with the present observations.

Geomagnetic cutoff rigidities and geomagnetic coordinates appropriate for the Carrington flare Epoch

Using the trajectory-tracing technique for cosmic rays in the geomagnetic field, vertical cutoff rigidity values for a world grid have been determined for Epoch 1850. These values have been used to derive a world map of iso-rigidity contours that would have been appropriate for the era of the Carrington flare in September 1859. When comparing these iso-rigidity contours with those determined for Epoch 2000, large differences are found, particularly in the Atlantic Ocean region. Geomagnetic cutoff rigidity values and geomagnetic coordinates have been determined for selected mid and low latitude geographic locations for which aurora were sighted during the geomagnetic storms of late August and early September 1859 and compared with the values for those locations calculated for the year 2000. While the geomagnetic latitude differences are relatively small, there are major changes in the vertical cutoff rigidity values for these same locations over this 150-year period. The cutoff differences are attributed to a combination of: (1) the decreasing internal geomagnetic field over the last 150 years and (2) the westward drift of the major features of the geomagnetic field. The relatively small changes in geomagnetic latitude are attributed to the small change in the latitude of the north magnetic pole over this 150-year period. This study emphasizes that while geomagnetic cutoff values are essential for the analysis of high-energy solar proton events, they are not an appropriate parameter for evaluation of the equatorward extent of an auroral display.

The super storms of August/September 1859 and their effects on the telegraph system

The space weather event of August/September 1859 is now famous because of the observation by Carrington and Hodgson of a solar flare. However, at the time, the associated magnetic disturbances produced widespread auroral displays and disruption to telegraph transmissions which attracted much public attention and were widely reported in the newspapers and scientific articles. In this paper, I review all the available literature to assess the characteristics of the magnetic disturbances and the locations and times of the telegraph effects. This information is used to construct a timeline for the whole of the disturbed interval comprising the magnetic storms of August 28/29 and September 2/3. The first magnetic disturbance started in the evening of August 28 and telegraph operations were disrupted in North America and Europe through till the next morning. The second disturbance started with a sudden commencement at 04.40 UT on September 2 and a major disturbance followed immediately. Between 06.00 and 06.30 UT reports of a negative H variation of ∼3000 nT at Rome and a large swing in Z at Greenwich indicate the expansion of the auroral oval to mid latitudes. This coincides with the time of the large disturbance at Bombay but there is no evidence that the auroral currents contributed to the Bombay disturbance. This initial disturbance subsided but magnetic activity increased again in the latter half of September 2 with lesser activity occurring on subsequent days. Telegraph operation in Europe was severely affected by the initial magnetic disturbance. In North America, 5 or 6 hours behind in local time, this initial disturbance occurred during local night time and the telegraph was not operating. Instead, the North American telegraph were affected by the second phase of the disturbance. During this time a notable event occurred when the operators of the telegraph in the Boston area disconnected their batteries and were able to send messages using only the “celestial power” induced in the telegraph lines by the magnetic disturbances.

Duration and extent of the great auroral storm of 1859

The great geomagnetic storm of August 28 through September 3, 1859 is, arguably, the greatest and most famous space weather event in the last two hundred years. For the first time observations showed that the sun and aurora were connected and that auroras generated strong ionospheric currents. A significant portion of the world’s 200,000 km of telegraph lines were adversely affected, many of which were unusable for 8 h or more which had a real economic impact. In addition to published scientific measurements, newspapers, ship logs, and other records of that era provide an untapped wealth of first hand observations giving time and location along with reports of the auroral forms and colors. At its height, the aurora was described as a blood or deep crimson red that was so bright that one “could read a newspaper by.” At its peak, the Type A red aurora lasted for several hours and was observed to reach extremely low geomagnetic latitudes on August 28–29 (∼25°) and on September 2–3 (∼18°). Auroral forms of all types and colors were observed below 50° latitude for ∼24 h on August 28–29 and ∼42 h on September 2–3. From a large database of ground-based observations the extent of the aurora in corrected geomagnetic coordinates is presented over the duration of the storm event.

Comparison of the aurora of September 1/2, 1859 with other great auroras

The maximum equatorward boundary of a number of visual auroral events for the period subsequent to that of the great storms of August and September 1859 are examined. These boundaries, in terms of dipole magnetic latitude, are related to the half-daily aa index. A least squares regression line, magnetic latitude = 55.86 − 0.056 aa, with a correlation coefficient of 0.84, adequately represents the data. The September 1859 event, in the context of these other storms, fits into the totality of the events examined as one of the two largest events of the sample, but is otherwise not unique. The discussion includes indications for further work in this area.

Soviet Operational and Tactical Combat in Manchuria, 1945 'August Storm', and: The Soviet Strategic Offensive in Manchuria, 1945 (review)

Reviewed by: Soviet Operational and Tactical Combat in Manchuria, 1945 ‘August Storm’, and: The Soviet Strategic Offensive in Manchuria, 1945 Curtis S. King Soviet Operational and Tactical Combat in Manchuria, 1945 ‘August Storm’. By David M. Glantz. Portland, Oreg.: Frank Cass, 2003. ISBN 0-7146-5300-4. Maps. Photographs. Tables. Figures. Appendixes. Notes. Bibliography. Index. Pp. xvi, 368. $59.50. The Soviet Strategic Offensive in Manchuria, 1945. By David M. Glantz. Portland, Oreg.: Frank Cass, 2003. ISBN 0-7146-5279-2. Maps. Photographs. Illustrations. Tables. Appendixes. Bibliography. Index. Pp. xxviii, 451. $59.50. This reviewer has had the pleasure of reading many of David Glantz's works on the Eastern Front in World War Two and the privilege of reviewing several of those efforts. In so doing, I had noticed a pattern: Glantz's research and grasp of detail has always been extensive, but his writing in earlier works was often dry. In later works, Glantz has shown a more deft writing touch, particularly in books such as Zhukov's Greatest Defeat, Stumbling Colossus, and When Titans Clash (co-authored by Jonathan House). Unfortunately, Glantz's two volume history of the Soviet offensive in Manchuria, while maintaining a high standard of research and detail, is so mechanistically written as to be useful mostly as a source book, not as a readable narrative of the campaign. Glantz's theme in both volumes is straightforward, to show that the Soviets executed their offensive in Manchuria with tremendous skill. The first, Strategic, book states that the "Manchurian campaign represented and still represents the highest stage of military art the Red Army reached during its operations during the Second World War" (p. xxvi). Similarly, the Operational and Tactical volume posits that "the massive scale of the Soviet [End Page 1299] attack was matched by the audaciousness, skill, and relentlessness with which it was conducted" (p. xvii). This reviewer is sympathetic to efforts that dispel the myth that Soviet victories depended solely on a massive advantage in numbers, and Glantz makes a good general case for the skill of Soviet commanders and the efficacy of their doctrine. However, Glantz occasionally seems to overstate his case. Both volumes are replete with descriptions of Soviet advances against negligible opposition, Japanese disarray and lack of resources, and spectacular offensives after the dropping of the American atomic bomb and the initiation of surrender discussions between Soviet and Japanese officials. In short, the overall shortage of Japanese troops and equipment, as well as the hopelessness of their situation—despite the Japanese soldiers' fighting prowess—make it hard to measure Soviet skill on the battlefield. Given this caveat, Glantz has a strong case for Soviet skill at achieving surprise and overcoming difficult terrain, but a less firm claim concerning the Red Army's skill with echelons, maneuver, and formations. The structure of the two volumes follows an interesting approach that has much merit. The Strategic book gives an overview of the campaign and sets the "big picture" for the reader. The Operational and Tactical volume contains a selection of case studies, which provide greater detail on the operations of the Soviet forces. The two part structure allows the author to make his overall case before looking at specific operational and tactical fights. While this method could lead to a selective use of case studies, Glantz has chosen his samples well. There are examples of major mechanized offensives, advances over tremendously difficult terrain, battles for fortified regions, amphibious operations, and many other varieties of tactical combat. A more traditional, strictly chronological, approach would not have allowed for the detail found in the individual case studies, and Glantz should be applauded for this fresh approach. Unfortunately, the strengths of Glantz's work are marred by a writing style that makes both volumes a difficult read. These writing weaknesses are revealed early in the first, Strategic, volume. Of 346 pages of 'text' (more on Glantz's text below) in this volume, 181 pages are devoted to planning for the offensive. More than half of the book discusses preparations, unit structures, terrain, the whole accompanied by overwhelming statistical data. Often tables of statistical information are repeated in the narrative and the reader is left in...