Local Summer Research Articles

A new aspect of ionospheric E region electron density morphology

From global measurements of ionospheric electron density profiles made by the FORMOSAT‐3/COSMIC satellites, the morphology of E region electron density is investigated. Seasonal, latitudinal, and diurnal variations in daytime E region electron density are well described by the Chapman theory, and the E layer peak electron density NmE and its peak height hmE are governed by the solar zenith angle χ in accordance with relations NmE ∝(cosχ)p and hmE ∝ln(secχ), respectively. However, it is revealed that there are three geomagnetic latitude regions where striking enhancements of the E region electron density occur. One of them is located at the geomagnetic equator with relatively narrow latitude extent of about 6°–10°, and the other two with much wider latitude extent of about 10°–20° appear on both sides of the geomagnetic equator in latitude regions ±20°–30°, respectively. The locations of these E region density enhancements are asymmetrical about the geomagnetic equator in solstice seasons, and they have a salient tendency to shift toward (away from) the summer (winter) hemisphere. The off‐equator E region electron density enhancements are closely connected with the bottomside of the F region equatorial anomaly crests, where the component of the electron density parallel to the magnetic field line is maximum. It appears that the off‐equator E region electron density enhancements are very likely the footprints of the F region equatorial anomaly crests. The morphologies of the exponent n and coefficient K in the power law relation between χ and foE (E region critical frequency) are also examined. There is a tendency for the n and K values to be larger in local winter than in local summer seasons in the latitudinal regions the same as the off‐equator electron density enhancements. In addition, it is found that a minor peak in the K values is nearly continuously present in all seasons over the geomagnetic equator. A comparison shows significant discrepancies in the E region electron density morphologies between COSMIC measurement and IRI model prediction. Furthermore, compelling evidence is provided to show the presences of longitudinal wave number 3 and 4 structures of the electron density in the height region 100–200 km, which are in coincident with the longitudinal structures of equatorial electrojet. It is believed that these longitudinal 3‐ and 4‐peak structures are very likely associated with nonmigrating diurnal tides propagating eastward in ionospheric E region.

Yield modelling in a Mediterranean species utilizing cause–effect relationships between temperature forcing and biological processes

Crop yield forecasting has progressed clearly in the past years, mainly due to the growing demand for modelling. In the present research, considering the Mediterranean vocation for the olive cultivation, olive yield forecasting modelling was analysed, to understand the principal relationships between olive tree production and climate features in a large southern Italy area. The simulation of olive yield has practical application in different price formation activities: in management of cropping systems, formation of stocks, commercialization, making of agricultural policies and zoning. Both meteorological and biological variables were considered, pollen indexes were constructed from daily pollen concentrations evaluated by use of aerobiological methodology. The monitored pollen quantities should be considered as a Proxy variable of the olive orchards located around the volumetric pollen traps, even if the final harvest could be highly dependent on local summer meteorological conditions. The model carried out by use of Panel data analysis has demonstrated a great interpretative capacity, considering contemporary meteorological and biological variables (pollen monitored with volumetric traps). The aggregation of historical data (1999–2008) with cross-section data (10 different pollen monitoring stations) permitted to investigate the variability information related to temporal and geographical dimensions. The entire volume of pollen grains emitted during flowering was redundant to investigate the future fruit formation while the specific and concentrated mass of pollen grains during the days before full flowering was related positively with the final production. The statistical technique utilized permitted to obtain interpretative results common to different geographical areas and not limited by local meteorological conditions.

First tomographic observations of the Midlatitude Summer Nighttime Anomaly over Japan

Recently, a chain of digital beacon receivers has been established over Japan, mainly for the tomographic imaging of the ionosphere. These receivers are installed at Shionomisaki (33.45°N, 135.8°E), Shigaraki (34.85°N, 136.1°E), and Fukui (36.06°N,136°E), which continuously track the Low Earth Orbiting Satellites (LEOS), and the simultaneous line‐of‐sight Total Electron Content (TEC) data are used for tomographic reconstruction. In the images obtained during July 2008, it is seen that the nighttime electron densities exceed the daytime values on almost all days over latitudes >33–34°N. On several days, these northern latitudes show enhanced electron densities compared to the low‐latitude region during nighttime. These are the prominent features of the “Midlatitude Summer Nighttime Anomaly (MSNA)” that is recently observed in the northern hemisphere and is considered similar to the nighttime Weddell Sea Anomaly (WSA). This is the first study of the MSNA using tomographic technique and found its significant day‐to‐day variability. The ionosonde data from Wakkanai (45.4°N, 141.7° E), ground‐based GPS TEC observations using the GEONET, CHAMP in situ electron density measurements, and Formosat3/COSMIC (F3/C) occultation measurements are also used to confirm the presence of MSNA over this region and to examine its variability. It is seen that, in general, during the local summer period, electron density over the northern latitudes is highest at ∼2000–2100 LT and the latitudinal enhancement in electron density also begins to appear around the same time, which continues to exist even at later hours.

Seasonal cycles of Stratospheric Aerosol and Gas Experiment II near‐background aerosol in the lower stratosphere

Extinction data from the Stratospheric Aerosol and Gas Experiment (SAGE) II in the lower stratosphere were analyzed for seasonal cycles in the near‐background levels of stratospheric aerosol. The data analyzed were the extinction coefficient at 0.525 μm (β0.525) and the extinction ratio at 0.525 μm (E0.525) on the basis of climatological zonal monthly mean for the years 1998–2004. Distinct seasonal cycles were found for β0.525 at 35–15°S above 28 km (region A) and at 20°S–30°N from 16 to 20.5 km (region B). In the A region, the seasonal cycle of E0.525 was characterized by a maximum in local fall and can be explained by the ascent of mean meridional circulation in local summer and descent in local winter. In the B region, the seasonal cycles of E0.525 were characterized by a maximum in October‐January, which can be interpreted by meridional transport and mixing. The amplitude of the seasonal cycles for E0.525 exhibited asymmetry between the Northern Hemisphere (NH) and the Southern Hemisphere (SH); the amplitudes at latitudes of 20–30° were larger in the SH than in the NH above 29 km, whereas they were larger in the NH than in the SH below 18 km. Comparison of the distribution of E0.525 with that of SAGE II water vapor suggested that the E0.525 distribution is controlled by the stratospheric circulation and troposphere‐originated gases. One difference between E0.525 and water vapor was found in the E0.525 maximum that appears over the winter subtropics. The E0.525 maximum can be attributed to the dominance of temperature and microphysical effects compared to transport effects, whereas the water vapor distribution can be attributed to transport effects. Another difference is that an upward propagation of the seasonal cycle of E0.525 at 5°S–30°N disappeared near 23 km. This difference is explained by the fact that the chemical and microphysical processes of aerosol formation become significant above 23 km.

Auroral electrojet AL index and polar magnetic disturbances in two hemispheres

Earlier we found that the auroral electrojet AL index, indicating substorm activity in the northern hemisphere, in local summer months correlates much better with geomagnetic activity not in the nearby polar cap but in the opposite polar cap; we explained this effect as a result of interhemispheric field‐aligned currents, which suppress substorm field‐aligned currents in the summer hemisphere but increase these currents in the winter hemisphere. In the present paper, we took into account this effect and examined a method for reliably monitoring the substorm auroral electrojet, measured with the auroral electrojet AL index, by using hourly averages of geomagnetic field from two polar observatories (Thule and Vostok) in two hemispheres. We tested this method for 3 years. The correlation between the predicted and actual AL indices for these years was stable and very high, and it showed no significant dependence on season and a relatively weak UT variation. The correlation coefficient between the predicted and actual AL indices for these three years was about 0.89. The proposed method, based on using magnetic field data from two polar geomagnetic observatories in two hemispheres, not only significantly improves the reliability of monitoring the westward auroral electrojet in the northern hemisphere but it may also be used for monitoring the westward auroral electrojet in the southern hemisphere where no AL index is available because a significant portion of the southern auroral zone is located over the oceans. The results of this paper show that measurements of geomagnetic field in two hemispheres are of high importance for reliably monitoring the geomagnetic activity and related events in each hemisphere.

Meteorological study of the first observation of red sprites from Poland

The first red sprite events scientifically observed from Poland on 20/21 July 2007, during the two-week SPARTAN Sprite-Watch 2007 campaign, are analysed in the context of the meteorological conditions over Poland and the Czech Republic at that time. The phenomena were detected and recorded from the IMWM High-Mountain Meteorological Observatory at Mount Śniezka using a low-light television CCD camera. Meteorological conditions over the south-west Poland were monitored on the basis of information from the Polish and Czech meteorological radar and lightning detection systems and also from satellite infra-red difference images, indicating the development of thunderstorm clouds over central Europe. Four sprite events detected in the night-time of 20/21 July indicate that in this region sprites are produced by massive storm cells built on warm fronts which are supplied by warm and humid tropical air masses during local summer thunderstorm season.

Antarctic temperature at orbital timescales controlled by local summer duration

During the late Pleistocene epoch, proxies for Southern Hemisphere climate from the Antarctic ice cores vary nearly in phase with Northern Hemisphere insolation intensity at the precession and obliquity timescales. This coherence has led to the suggestion that Northern Hemisphere insolation controls Antarctic climate. However, it is unclear what physical mechanisms would tie southern climate to northern insolation. Here we call on radiative equilibrium estimates to show that Antarctic climate could instead respond to changes in the duration of local summer. Simple radiative equilibrium dictates that warmer annual average atmospheric temperatures occur as a result of a longer summer, as opposed to a more intense one, because temperature is more sensitive to insolation when the atmosphere is cooler. Furthermore, we show that a single-column atmospheric model reproduces this radiative equilibrium effect when forced exclusively by local Antarctic insolation, generating temperature variations that are coherent and in phase with proxies of Antarctic atmospheric temperature and surface conditions. We conclude that the duration of Southern Hemisphere summer is more likely to control Antarctic climate than the intensity of Northern Hemisphere summer with which it (often misleadingly) covaries. In our view, near interhemispheric climate symmetry at the obliquity and precession timescales arises from a northern response to local summer intensity and a southern response to local summer duration. On orbital timescales, Antarctic climate varies in phase with Northern Hemisphere insolation, but no physical mechanism for such a link is known. A new analysis suggests that at obliquity and precession timescales Antarctic climate may instead be responding to the duration of the local summer, which covaries with Northern insolation.

Advance and prospectus of seasonal prediction: assessment of the APCC/CliPAS 14-model ensemble retrospective seasonal prediction (1980–2004)

We assessed current status of multi-model ensemble (MME) deterministic and probabilistic seasonal prediction based on 25-year (1980–2004) retrospective forecasts performed by 14 climate model systems (7 one-tier and 7 two-tier systems) that participate in the Climate Prediction and its Application to Society (CliPAS) project sponsored by the Asian-Pacific Economic Cooperation Climate Center (APCC). We also evaluated seven DEMETER models’ MME for the period of 1981–2001 for comparison. Based on the assessment, future direction for improvement of seasonal prediction is discussed. We found that two measures of probabilistic forecast skill, the Brier Skill Score (BSS) and Area under the Relative Operating Characteristic curve (AROC), display similar spatial patterns as those represented by temporal correlation coefficient (TCC) score of deterministic MME forecast. A TCC score of 0.6 corresponds approximately to a BSS of 0.1 and an AROC of 0.7 and beyond these critical threshold values, they are almost linearly correlated. The MME method is demonstrated to be a valuable approach for reducing errors and quantifying forecast uncertainty due to model formulation. The MME prediction skill is substantially better than the averaged skill of all individual models. For instance, the TCC score of CliPAS one-tier MME forecast of Niño 3.4 index at a 6-month lead initiated from 1 May is 0.77, which is significantly higher than the corresponding averaged skill of seven individual coupled models (0.63). The MME made by using 14 coupled models from both DEMETER and CliPAS shows an even higher TCC score of 0.87. Effectiveness of MME depends on the averaged skill of individual models and their mutual independency. For probabilistic forecast the CliPAS MME gains considerable skill from increased forecast reliability as the number of model being used increases; the forecast resolution also increases for 2 m temperature but slightly decreases for precipitation. Equatorial Sea Surface Temperature (SST) anomalies are primary sources of atmospheric climate variability worldwide. The MME 1-month lead hindcast can predict, with high fidelity, the spatial–temporal structures of the first two leading empirical orthogonal modes of the equatorial SST anomalies for both boreal summer (JJA) and winter (DJF), which account for about 80–90% of the total variance. The major bias is a westward shift of SST anomaly between the dateline and 120°E, which may potentially degrade global teleconnection associated with it. The TCC score for SST predictions over the equatorial eastern Indian Ocean reaches about 0.68 with a 6-month lead forecast. However, the TCC score for Indian Ocean Dipole (IOD) index drops below 0.40 at a 3-month lead for both the May and November initial conditions due to the prediction barriers across July, and January, respectively. The MME prediction skills are well correlated with the amplitude of Niño 3.4 SST variation. The forecasts for 2 m air temperature are better in El Niño years than in La Niña years. The precipitation and circulation are predicted better in ENSO-decaying JJA than in ENSO-developing JJA. There is virtually no skill in ENSO-neutral years. Continuing improvement of the one-tier climate model’s slow coupled dynamics in reproducing realistic amplitude, spatial patterns, and temporal evolution of ENSO cycle is a key for long-lead seasonal forecast. Forecast of monsoon precipitation remains a major challenge. The seasonal rainfall predictions over land and during local summer have little skill, especially over tropical Africa. The differences in forecast skills over land areas between the CliPAS and DEMETER MMEs indicate potentials for further improvement of prediction over land. There is an urgent need to assess impacts of land surface initialization on the skill of seasonal and monthly forecast using a multi-model framework.

Meridional winds derived from COSMIC radio occultation measurements

Meridional winds at the magnetic meridian in the upper thermosphere are derived from the peak height and density of the ionospheric F2 layer as retrieved by the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) satellites for 4 months from November 2006 to February 2007. These winds (referred to as COSMIC winds) are first validated by comparison at multiple locations with winds obtained from ground‐based incoherent scatter radar (ISR) and Fabry‐Perot interferometer (FPI) measurements. Then longitudinal variations of these winds are investigated and compared with simulations by the National Center for Atmospheric Research Thermosphere‐Ionosphere‐Electrodynamics General Circulation Model (NCAR TIE‐GCM). The results show generally good agreement between COSMIC winds, ground‐based measurements, and the simulations. Significant longitudinal variations are presented in the COSMIC winds. At 40°N (local winter), around midnight the COSMIC winds exhibit stronger and longer‐duration equatorward velocities within 110°W–20°W (large negative magnetic declination sector) than those in other longitudes; during late morning hours the poleward winds show similar longitudinal variations. At 40°S (local summer), during the daytime the poleward winds are stronger within 120°E–110°W (large positive magnetic declination sector) than in 60°W–90°E (large negative magnetic declination sector), while during the nighttime the maximum equatorward winds shifts about 2 h later in 60°W–90°E than in 120°E–110°W. Analysis of the TIE‐GCM simulations suggests that the longitudinal variation of meridional winds is mainly induced by magnetic declination due to the contribution of geographic zonal wind.

Subfossil Chironomidae (Insecta: Diptera) along a latitudinal gradient in Finland: development of a new temperature inference model

AbstractNumerical techniques were used to study chironomid distribution and abundance in lakes from a 1000 km transect in Finland, with special interest on the effect of local summer air temperatures on chironomid assemblages. The final aim of the study was to develop a chironomid‐based palaeotemperature inference model. The dataset consisted of 82 lakes (of which 77 were used in the model after deletion of outliers), with catchments spanning from boreal coniferous forests to mountain birch woodland and tundra vegetation. Numerical analysis showed that the mean July air temperature was the most significant variable explaining the distribution and abundance of chironomids in Finnish lakes. Weighted‐averaging partial least squares techniques were used to develop a palaeotemperature inference model for mean July air temperature reconstructions. The model performance statistics were favourable, with cross‐validated coefficient of determination (r2) of 0.78, root mean squared error of prediction of 0.721°C and maximum bias of 0.794°C. Based on these values, the transfer function is a valid means of performing quantitative palaeotemperature estimates in downcore studies. Copyright © 2008 John Wiley & Sons, Ltd.

O2/N2 ratios of occluded air in the GISP2 ice core

We present and discuss the record of O2/N2 ratios in air occluded in the GISP2 ice core retrieved from Summit, Greenland. In this study, we examine results for 601 samples from 331 depths measured by 1994, and 92 samples from 46 depths newly measured in 2006. Poorly replicated samples, samples with no replicates and samples falling more than three standard deviations from the mean of each δO2/N2 data set are excluded from the analysis. The majority of poorly replicated samples are from the depth zone associated with the transition between gas in bubbles and gas present as clathrate hydrates. We found that the O2/N2 ratio of samples is depleted by an average value of 7.3‰ during 11 years of storage at −35°C O2/N2 ratios measured at various times were corrected for depletion during storage and combined to form a single data set. The stacked GISP2 δO2/N2 record shows strong spectral power at the orbital frequencies, and δO2/N2 is in antiphase with local summer insolation. This observation is consistent with the earlier findings for the Vostok and Dome Fuji ice cores from East Antarctica. It validates previous conclusions that fractionation during bubble close‐off depends on ice grain properties set at the surface by solar insolation. In addition, the GISP2 δO2/N2 record shows millennial duration signals that are in phase with the local temperature record of rapid climate change. The exact mechanisms by which local summer insolation induces orbital variability in δO2/N2, and by which temperature (or related properties) induce high frequency signals in δO2/N2, remain to be identified.

Periodic modulation of Pc3 and Pc4 pulsations in the polar cap by interplanetary and atmospheric processes

The variations in the daily average energy of geomagnetic pulsations and noise in the Pc3 (20–60 mHz) and Pc4 (10–19 mHz) frequency bands in the polar cap have been studied based on the data from P5 Antarctic station (corrected geomagnetic latitude −87°) from November 1998 to November 1999. The daily average pulsation energy has been calculated using the method for detecting the wave packets, the spectral amplitude of which is higher than the threshold level, from the dynamic spectrum. A spectral analysis of the energy of pulsations and noise in the Pc3 and Pc4 bands, performed using the maximal entropy method, has revealed periodicities of 18 days in the local winter and 26, 13, and 7–9 days during the local summer. The simultaneous and coherent variations with periods of 26, 13, and 7–9 days in the solar wind velocity and IMF orientation indicate that the variations in the Pc3–4 wave energy in the polar cap at a sunlit ionosphere are mainly controlled by the parameters of the interplanetary medium. The variations in the Pc3–4 wave energy with a period of 18 days are observed only during the local winter and are supposedly related to the variations in the ionospheric conductivity modulated by planetary waves.

Spatial and temporal characteristics of Outgoing Longwave Radiation (OLR): an update

A study of the Outgoing longwave radiation (OLR) values (Unit, W/m) observed by various satellites during 1979-2002 revealed that the OLR values varied considerably from one geographical region to another ( ~ 100-300 units). The climatology was latitude dependent. At middle and high latitudes, the range (minimum to maximum) was ~ 40-60 units, with maximum in local summer and minimum in local winter, but at lower latitudes, the range reduced considerably and was uncertain near equator. Near equator, the long-term changes (as seen in 12-month moving averages) were: OLR decreases during ENSO events in the eastern Pacific up to the dateline, and OLR increases during ENSO events in the Australasian region. Outside the equatorial region, the OLR changes were small during ENSO events and negligible in other years. In some longitudes at middle and high latitudes, the OLR changes occurred several months after the El Nino events, coinciding with La Nina (cold water events, opposite of warm water El Nino events).

Chronology of the Vostok ice core constrained by O 2/N 2 ratios of occluded air, and its implication for the Vostok climate records

We present a timescale for the Vostok ice core that is derived by orbitally tuning to O 2/N 2 ratios in occluded air for depths deeper than 1550 m (>112 ka), and by gas correlation to the GISP2 chronology for the section shallower than 1422 m (<102 ka). Our chronology of the deeper section rests on the assumption that, during the bubble close off process, local summer insolation indirectly controls the extent of O 2 exclusion and hence the O 2/N 2 ratio in trapped gases. The newly derived O 2/N 2 chronology is consistent with absolutely dated speleothem records. The O 2/N 2 chronology differs from previously published orbital tuning chronologies (CH 4 and δ 18O atm) by up to ∼±6 kyr, and from the original GT4 chronology by up to ∼15 kyr. The difference between the O 2/N 2 chronology and the δ 18O atm chronology varies in time with strong signals centered at 1/100 and 1/41 kyr −1. The ages for the last four glacial terminations in Vostok correspond to high obliquity (>23.7° at terminations’ midpoints). They also correspond with decreasing precession index, corresponding to increasing boreal summer insolation. The Vostok temperature record, boreal summer insolation, and the rate of change of the SPECMAP property (reflecting planktonic foram δ 18O) with respect to time are highly coherent at precession and obliquity periods. These three properties vary almost synchronously, with the possibility that Vostok temperature lags behind the other two. Our new timescale supports the widespread view that boreal summer insolation played an important role in glacial–interglacial cycles.

ACCELERATING CLIMATE CHANGE IMPACTS ON ALPINE GLACIER FOREFIELD ECOSYSTEMS IN THE EUROPEAN ALPS

In the European Alps the increase in air temperature was more than twice the increase in global mean temperature over the last 50 years. The abiotic (glacial) and the biotic components (plants and vegetation) of the mountain environment are showing ample evidence of climate change impacts. In the Alps most small glaciers (80% of total glacial coverage and an important contribution to water resources) could disappear in the next decades. Recently climate change was demonstrated to affect higher levels of ecological systems, with vegetation exhibiting surface area changes, indicating that alpine and nival vegetation may be able to respond in a fast and flexible way in response to 1-2 degrees C warming. We analyzed the glacier evolution (terminus fluctuations, mass balances, surface area variations), local climate, and vegetation succession on the forefield of Sforzellina Glacier (Upper Valtellina, central Italian Alps) over the past three decades. We aimed to quantify the impacts of climate change on coupled biotic and abiotic components of high alpine ecosystems, to verify if an acceleration was occurring on them during the last decade (i.e., 1996-2006) and to assess whether new specific strategies were adopted for plant colonization and development. All the glaciological data indicate that a glacial retreat and shrinkage occurred and was much stronger after 2002 than during the last 35 years. Vegetation started to colonize surfaces deglaciated for only one year, with a rate at least four times greater than that reported in the literature for the establishment of scattered individuals and about two times greater for the well-established discontinuous early-successional community. The colonization strategy changed: the first colonizers are early-successional, scree slopes, and perennial clonal species with high phenotypic plasticity rather than pioneer and snowbed species. This impressive acceleration coincided with only slight local summer warming (approximately -0.5 degree C) and a poorly documented local decrease in the snow cover depth and duration. Are we facing accelerated ecological responses to climatic changes and/or did we go beyond a threshold over which major ecosystem changes may occur in response to even minor climatic variations?

Study on Reflectivity and Wavenumber Occurring Polar Mesosphere Summer Echoes

Polar Mesosphere Summer Echoes (PMSE) are very strong radar echoes near the polar mesopause at local summer. PMSE have been approved to be associated with charged dust or aerosols in the dusty ionosphere. In the paper, the differential scattering cross section based on Born approximation in dusty plasma is derived, and the backscattering cross section per unit volume in published papers are summarized. Comparing the two results between the differential scattering cross section and the backscattering cross section per unit volume, one finds that the statistically experimental conclusion can be verified by the theoretical result. The results show that the reflectivity is inverse proportional to the fourth power of the wavenumber and charged dust grains play an important role in the occurrence of PMSE. The scattering of electromagnetic waves on charged dust particles may be a tool to explore the generation mechanism of PMSE.

Late Quaternary Planktic Foraminifer Fauna andMonsoon Upwelling Records from the Western South China Sea, Near the Vietnam Margin (IMAGESMD012394)

Marine sediment core MD012394 from the Vietnam coastal upwelling area in the western South China Sea was investigated in order to reconstruct the last Quaternary monsoon upwelling based on planktic foraminifer fauna assemblages and fauna-based sea surface temperature (SST) estimates. The age model of core MD012394 was constructed using oxygen isotope stratigraphy of the planktic foraminifer G. sacculifer, with 10 accelerator mass spectrometry (AMS) 14C dating of planktic foraminifers from the sediment samples. Our studies on the relative and absolute abundances of planktic foraminifer assemblages reveal eight dominant species in core MD012394: N. dutertrei+N. pachyderma (right coiling), G. ruber, G. glutinata, G. sacculifer, P. obliquiloculata, G. menardii + G. tumida, G. calida, and G. inflata. In a Q-mode factor analysis of the fauna abundance data, the fauna factors show variations that do not parallel the glacial/interglacial changes throughout the last 135 kyr. The relative abundance patterns of G. inflata and N. dutertrei (including N. pachyderma-R) are interpreted as hydrographic proxies for East Asian summer and winter monsoon, respectively, in the current study. We calculated the fluctuations in the SST using the Revised Analog Method (RAM) in MD012394 and found that the abundance changes of the summer monsoon upwelling indicator G. inflata were similar and nearly synchronous. This suggests that the summer monsoon-driven upwelling signal was strong near the local summer insolation maximum, which induced low SSTs, particular around ~11, 33, 59, and 83 kya. Our studies support the view that the strengths of both summer insolation and the East Asian summer monsoon have determined the relative abundance of planktic foraminifers and the SSTs in the western SCS during the last 135 kyr.

William Thaddeus Coleman, Jr.: Breaking the Color Barrier at the U.S. Supreme Court

William Thaddeus Coleman, Jr.: Breaking the Color Barrier at the U.S. Supreme Court TODD C. PEPPERS Introduction On April 15, 2007, baseball fans celebrated the sixtieth anniversary ofJackie Robinson’s debut with the Brooklyn Dodgers—an event that broke the color barrier and integrated major league baseball. In stadiums across America, professional baseball teams honored the memory and ac­ complishments ofRobinson, as managers and players donned Robinson’s retiredjersey number, Hall of Famers threw out ceremonial first pitches, and tributes boomed from video displays. The tributes to Robinson, however, like his legacy, went far beyond the ballparks, as newspaper and television journalists debated Robinson’s role as a civil-rights pioneer while lamenting the dwindling number ofminorities playing baseball and elementary school children read stories of Robinson’s stirring feats. On September 1, 2008, the U.S. Supreme Court perhaps should celebrate a similar an­ niversary: the sixtiethanniversary ofthe arrival of the first black law clerk at the Court. His name is William Thaddeus Coleman, Jr.,1 and on September 1, 1948, Coleman began clerk­ ing in the Chambers of Associate Supreme Court Justice Felix Frankfurter. A graduate of Harvard Law School, Coleman used his Supreme Court clerkship as a stepping stone to a remarkable legal and political career, highlights of which include working as the first black lawyer in both major Philadelphia and New York law firms, volunteering his time and expertise for the desegregation cases col­ lectively referred to as Brown v. Board ofEd­ ucation, being president and then chairman of the NAACP Legal Defense and Educa­ tional Fund ofthe National Association for the Advancement of Colored People (NAACP), serving as the Secretary of Transportation in the Ford administration, and receiving the Presidential Medal ofFreedom from President Clinton. 354 JOURNAL OF SUPREME COURT HISTORY The purpose of this essay is twofold: It will endeavor to succinctly summarize the im­ portant events of Coleman’s life and profes­ sional career, while making the argument that these achievements were as groundbreaking in the legal community as Robinson’s were to baseball. Admittedly, looking to our na­ tional pastime is hardly an original literary ma­ neuver; The myriad similarities and links be­ tween baseball and the law have offered rich material for many legal writers.2 Moreover, this article does not wish to diminish Cole­ man’s accomplishments by comparing them to a mere “game.” By drawing upon the sixtieth anniversary of Robinson’s debut, my hope is to give Coleman his due and place his laud­ able achievements in the proper perspective. Not only did the two men do much to dispel the pernicious stereotype that they belonged to a race that was doomed to second-class cit­ izenship, but their efforts to integrate their re­ spective professions and to use their talents to effect change reverberatedthroughout society. The Early Life of William T. Coleman, Jr. William Thaddeus Coleman, Jr. was born on July 7, 1920, in Germantown, Pennsylvania to parents William Thaddeus Coleman, Sr. and Laura Beatrice Coleman. One of three chil­ dren, Coleman grewup in a middle-class home where education and hard work were encour­ aged. Social activism and public service were practices engrained into Coleman’s family. His father was a graduate of the Hampton Insti­ tute who balanced his work as the executive director of the Wissahickon Boys Club—an organization originally founded to provided educational and recreational opportunities for minorities and poor whites—with his duties as a field secretary for the Boys Club ofAmerica and as a director of a local summer camp. William Coleman, Sr. was given the mid­ dle name “Thaddeus” in honor of Thaddeus Stevens, a Pennsylvania lawyer and congress­ man who tirelessly worked for the ratification of the Fourteenth Amendmend to the United States Constitution. William Coleman, Jr.’s maternal great-great-grandfather was an Epis­ copal minister who operated the underground railroad in St. Louis, Missouri. Coleman’s mother was a former German teacher who also greatly influenced her son. “My mother always said what would redeem her living in a world where blacks and women were second place [was] that when she got to heaven, God would be a black woman.”3 One pattern of Coleman...

Southern Patagonian glacial chronology for the Last Glacial period and implications for Southern Ocean climate

The Magellan region of southern South America is in a unique setting, at >50°S on the equatorial side of the Antarctic Frontal Zone, to record in detail terrestrial glacial to interglacial events. A 10Be chronology shows growth and millennial fluctuations of a Patagonian Ice Sheet between ∼25 and 17.6–17.0 cal ka. In the Strait of Magellan, the maximum ice margin position is dated to 24.6±0.9 ka, and other moraine ages are 18.5±1.8 and 17.6±0.2 ka (mean±1 standard deviation). In Bahía Inútil, dated moraine ages are 20.4±1.2 and 17.3±0.8 ka. The chronology of the local Last Glacial Maximum (LGM) reveals a record of atmospheric cooling that was broadly in phase with changes in Southern Ocean conditions, such as sea-ice fluctuations and surface water characteristics. Published modeling results indicate that a decline in temperature of ∼6 °C and slight drying over southernmost Patagonia could simulate the growth and sustained presence of an ice sheet to the mapped LGM limit. The terrestrial record in southern Patagonia and marine records in adjacent oceans indicate mean northward movement of the Antarctic Frontal Zone, which caused the last southern South American ice age. The Antarctic Frontal Zone at present lies only 3–5° to the south. Some significant changes in the Magellan region occurred in step with North Atlantic region and the Northern Hemisphere. For example, the overall time span of the last glaciation and the timing of maximum ice extent were similar between the hemispheres, despite maximum local summer insolation intensity in southern South America. Other characteristics of the southern Patagonian glacial history differ from the North Atlantic region, specifically an out-of-phase relationship during deglaciation, which is more similar to that of Southern Ocean and Antarctic records.

Introduction. The boreal forest and global change

The boreal forest is the second largest biome in the world containing 33% of the Earth's forest cover ([FAO 2001][1]) of which approximately 25% is natural. It is circumpolar and shares similar taxa across its range. It has approximately 20 300 identified species. Along with the tropics, the