Stations North Research Articles

ANALYSIS OF PENGGARON BUS STATION FACILITIES CITY OF SEMARANG

City Of Semarang is a capital city of Central Java Province that have 4 bus station in every corner of direction like Mangkang Bus Station in west,Penggaron Bus Station in east,Teroboyo Bus Station in north,and Banyumanik Bus Station in south.Since 1 September 2018, Teroboyo Bus Station was closed due to poor conditions. Therefore, as a researcher interested in seeing the readiness of the Bus Station to face the removal of passengers from the Teroboyo Bus Station in terms of terminal support facilities. One of research is the management of facilities at the Penggaron Bus Station. This research Result is to know how managing facilities at the Penggaron Bus Station The method used here is a qualitative research method. Data collection techniques are questionnaire, observation and documentation techniques in the form of documents or archives from the Ministry of Transportation of the City of Semarang and statistical data on the Penggaron Terminal. The research results at the Penggaron Terminal will show that the facilities at the Penggaron Bus Station have not been maximized, such as seating in the passenger waiting room don’t have a backrest, poor passenger toilet conditions, location of the mosque is not strategic, BRT (Bus Rapid Transit ) Trans Semarang shelter in quite poor condition, and SPBG (Gas Refueling Stations) that have not yet been opened for public.

Winter storms accelerate the demise of sea ice in the Atlantic sector of the Arctic Ocean

A large retreat of sea-ice in the ‘stormy’ Atlantic Sector of the Arctic Ocean has become evident through a series of record minima for the winter maximum sea-ice extent since 2015. Results from the Norwegian young sea ICE (N-ICE2015) expedition, a five-month-long (Jan-Jun) drifting ice station in first and second year pack-ice north of Svalbard, showcase how sea-ice in this region is frequently affected by passing winter storms. Here we synthesise the interdisciplinary N-ICE2015 dataset, including independent observations of the atmosphere, snow, sea-ice, ocean, and ecosystem. We build upon recent results and illustrate the different mechanisms through which winter storms impact the coupled Arctic sea-ice system. These short-lived and episodic synoptic-scale events transport pulses of heat and moisture into the Arctic, which temporarily reduce radiative cooling and henceforth ice growth. Cumulative snowfall from each sequential storm deepens the snow pack and insulates the sea-ice, further inhibiting ice growth throughout the remaining winter season. Strong winds fracture the ice cover, enhance ocean-ice-atmosphere heat fluxes, and make the ice more susceptible to lateral melt. In conclusion, the legacy of Arctic winter storms for sea-ice and the ice-associated ecosystem in the Atlantic Sector lasts far beyond their short lifespan.

Impact of 2015–2016 El Niño and 2017–2018 La Niña on PM2.5 concentrations across China

Irregular oscillations of Equatorial Pacific sea surface temperatures known as El Niño-Southern Oscillation (ENSO) has been shown to affect air pollution in China by altering atmospheric circulations. In this study, we use hourly PM2.5 data from nearly 1500 monitoring stations across entire China to further explore the connection between ENSO and China's haze pollution by comparing PM2.5 concentrations for the two most recent ENSO events, the 2015–2016 El Niño and the 2017–2018 La Niña. The PM2.5 concentrations show significant differences between the two events and the differences are larger in winter and smaller in summer. In summer, the PM2.5 concentrations are higher across China during El Niño. However in winter, higher concentrations are found at most stations in northern China during El Niño, but at majority of stations in southern China during La Niña. Spring and autumn show a transitional pattern between summer and winter. Dividing the country into nine regions with similar geographical conditions, the relationship between the monthly PM2.5 concentration anomalies and the Niño3.4 indices, as revealed by linear regression, is generally positive at stations in North, Northeast and the northern parts of Central and East China, but generally negative in South, Southwest and the southern parts of Central and East China. No difference is found in the oscillation periods of the PM2.5 concentrations between the two events, except that the seasonal and intra-seasonal oscillatory signals appear to be slightly stronger during El Niño than La Niña. The regional and seasonal differences in PM2.5 concentrations between El Niño and La Niña can be partially explained by the differences in the anomalous atmospheric circulation patterns, particularly the low-level wind and surface precipitation patterns.

Receiver-function imaging of the lithosphere at the Kunlun-Qaidam boundary, Northeast Tibet

We studied the crustal structure and tectonics in the north Tibetan Plateau from the Songpan-Ganzi terrane to the Qaidam Basin using teleseismic receiver-function imaging, across a major lithospheric boundary, the Kunlun-Qaidam boundary, where previous studies suggest a ~15–20-km change in crustal thickness from thicker crust in the Kunlun Mountains to thinner crust in the Qaidam Basin. We report P receiver functions for 70 stations, largely the International Deep Profiling of Tibet and the Himalaya (INDEPTH), phase IV, experiment. Our most dense station coverage is located along the roughly north-south INDEPTH-IV active-source seismic profile at approximately 95° E longitude. Azimuthal and geographical changes in the receiver functions reveal significant changes in crustal structure and Vp/Vs from across the study area. Receiver functions show strong converters that we interpret as the Moho at ~70 km depth beneath the Qiangtang, Songpan-Ganzi terranes and Kunlun Mountains and at ~50 km depth beneath the central Qaidam Basin. This large change in crustal thickness occurs >50 km north of the North Kunlun strike-slip fault, on which the 2001 M8.1 Kunlun earthquake occurred. Receiver functions for some of the stations north of the thickness change at the Kunlun-Qaidam boundary also show a deeper ~70-km bright converter in addition to the 50-km converter. The two converters appear to overlap by up to ~30 km in some locations along the south Qaidam Basin. We combine previous results with these new results to discuss implications for mechanisms for crustal thickening in the north Tibetan Plateau including crustal flow and crustal injection. At depths imaged here, shallower than ~100 km, we see no evidence of southward subduction of Eurasian lithosphere.

Pan coefficient sensitivity to environment variables across China

Data of open water evaporation (Eow), such as evaporation of lake and reservoir, have been widely used in hydraulic and hydrological engineering projects, and water resources planning and management in agriculture, forestry and ecology. Because of the low-cost and maneuverability, measuring the evaporation of a pan has been widely regarded as a reliable approach to estimate Eow through multiplying an appropriate pan coefficient (Kp). Kp is affected by geometry and materials of a pan, and complex surrounding environment variables. However, the relationship between Kp and different environment variables is unknown. Thus, this study chose China D20 pan as an example, used meteorological observations from 767 stations and introduced the latest PenPan model to analyze the sensitivity of Kp to different environment variables. The results show that, the distribution of annual Kp had a strong spatial gradient. For all the stations, annual Kp ranged from 0.31 to 0.89, and decreased gradually from southeast to northwest. The sensitivity analysis shows that for China as a whole, Kp was most sensitive to relative humidity, followed by air temperature, wind speed and sunshine duration. For 767 stations in China, Kp was most sensitive to relative humidity for almost all the stations. For stations north of Yellow River, wind speed and sunshine duration were the next sensitive variables; while for stations south of Yellow River, air temperature was the next sensitive variable. The method introduced in this study could benefit estimating and predicting Kp under future changing environment.

Determination of the Order of a Markov Chain for Daily Rainfall Data of North East India: "Application AIC criterion"

The paper aims at demonstrating the application of the Akaike information criterion to determine the order of two state Markov chain for studying the pattern of occurrence of wet and dry days during the rainy season (April to September) in North-East India. For each station, each day is classified as dry day if the amount of rainfall is less than 3 mm and wet day if the amount of rainfall is greater than or equal to 3 mm. We apply Markov chain of order up to three to the sequences of wet and dry days observed at seven distantly located stations in North East region of India. The Markov chain model of appropriate order for analyzing wet and dry days is determined. This is done using the Akaike Information Criterion (AIC) by checking the minimum of AIC estimate. Markov chain of order one is found to be superior to the majority of the stations in comparison to the other order Markov chains. More precisely, first order Markov chain model is an adequate model for the stations North Bank, Tocklai, Silcoorie, Mohanbari and Guwahati. Further, it is observed that second order and third order Markov chains are competing with first order in the stations Cherrapunji and Imphal, respectively. A fore-knowledge of rainfall pattern is of immense help not only to farmers, but also to the authorities concerned with planning of irrigation schemes. The outcomes are useful for taking decisions well in advance for transplanting of rice as well as for other input management and farm activities during different stages of the crop growing season.

SURFACE DEFORMATION AND EARLY WARNING MAGNITUDE OF 2016 KAIKOURA (NEW ZEALAND) EARTHQUAKE FROM HIGH‐RATE GPS OBSERVATIONS

AbstractOn 13th November 2016, the Kaikoura region of New Zealand was struck by a major Mw7.8 earthquake. In this study, coseismic deformation field is derived from 1 Hz high‐rate GPS observations based on the GAMIT track solution module, combining with PCA spatial filtering method firstly. Then the 5 s peak displacement of P‐wave (Pd) and the peak ground displacement (PGD) are extracted from the real‐time simulated kinematic displacements of the trackRTr module. Finally, the warning magnitude is calculated from the statistical regression model. Our results indicate that the duration time of the kinematic deformation is up to 2 min. The KAIK and HANM stations, which are closest to the epicenter, have secondary severe deformation. And the deformation amplitude of the north stations of the epicenter is larger than that of the south. The static coseismic deformation field from high‐rate GPS observations shows the characteristics of the focal mechanism of strike‐slip after thrust. In addition, the Pd warning magnitudes from different stations have a significant difference, with the maximum magnitude difference of Mw2.5. Considering the timeliness and reliability of the warning magnitude jointly, the warning magnitude from the four‐station PGD joint warning method of reasonable spatial distribution can reach its initial stability (Mw7.56) at 23 s after the event, while final stability (Mw7.78) at 110 s, which is consistent with the USGS moment tensor magnitude (Mw7.8).

Latitudinal features of Total Electron Content over the African and European longitude sector following the St. Patrick’s day storm of 2015

GNSS TEC values have been obtained from 18 stations distributed from the magnetic equator to nearly 80°N magnetic dip in the African and west-European longitude sector corresponding to the March 17–18, 2015 geomagnetic storm. Significantly depleted ionosphere have been observed at stations north of 50°N geographic on March 18, 2015 following the above storm over a longitude swath 11.9°–21°E covering the Eastern Africa and Western European longitude sector. High ROTI values were noted on March 17th at locations around 80°N magnetic dip. Two prominent peaks in PCN were noted around 09:00 UT and 14:00 UT on March 17, 2015 and around 15:00 UT on March 18, 2015. Daytime thermospheric (O/N2) ratio was markedly less on March 18th at latitudes above 60°N geographic which is suggested to be the major driver behind depleted high latitude ionosphere during the recovery phase of the storm on March 18, 2015.

Small‐scale sea ice deformation during N‐ICE2015: From compact pack ice to marginal ice zone

AbstractWe studied small‐scale (50 m to 5 km) sea ice deformation from ship radar images recorded during the N‐ICE2015 campaign. The campaign consisted of four consecutive drifting ice stations (Floes 1–4) north of Svalbard, with a total duration of nearly 5 months. Deformation was calculated using 5 different time intervals from 10 min to 24 h, and the deformation rate was found to depend strongly on the time scale. Floes 1–3 had a mean deformation rate within the range of 0.06–0.07 h−1 with the interval of 10 min, and 0.03–0.04 h−1 with the interval of 1 h. Floe 4 represented marginal ice zone (MIZ) with very high deformation rate, 0.14/0.08 h−1 with the interval of 10 min/1 h. Deep in the ice pack, high deformation rates occurred only with high wind and drift speed, while in MIZ they were found also during calm conditions. The deformation rates were found to follow power law scaling with respect to length and time scale even on this small scale and in small domain (15 km × 15 km). The length scale dependence of deformation rate depends on the time scale: the power law scaling exponent β of the whole study period decreases from 0.82 to 0.52 with the time interval increasing from 10 min to 24 h. Ship radar images reveal the importance of the deformation history of the ice pack, since the deformation events were initialized along the lines of previous damages.

Non-Rayleigh control of upper-ocean Cd isotope fractionation in the western South Atlantic

We present seawater Cd isotopic compositions in five depth profiles and a continuous surface water transect, from 50°S to the Equator, in the western South Atlantic, sampled during GEOTRACES cruise 74JC057 (GA02 section, Leg 3), and investigate the mechanisms governing Cd isotope cycling in the upper and deep ocean.The depth profiles generally display high ε112/110Cd at the surface and decrease with increasing depth toward values typical of Antarctic Bottom Water (AABW). However, at stations north of the Subantarctic Front, the decrease in ε112/110Cd is interrupted by a shift to values intermediate between those of surface and bottom waters, which occurs at depths occupied by North Atlantic Deep Water (NADW). This pattern is associated with variations in Cd concentration from low surface values to a maximum at mid-depths and is attributed to preferential utilization of light Cd by phytoplankton in the surface ocean. Our new results show that in this region Cd-deficient waters do not display the extreme, highly fractionated ε112/110Cd reported in some earlier studies from other oceanic regions. Instead, in the surface and subsurface southwest (SW) Atlantic, when [Cd] drops below 0.1 nmol kg−1, ε112/110Cd are relatively homogeneous and cluster around a value of +3.7, in agreement with the mean value of 3.8±3.3 (2SD, n=164) obtained from a statistical evaluation of the global ocean Cd isotope dataset. We suggest that Cd-deficient surface waters may acquire their Cd isotope signature via sorption of Cd onto organic ligands, colloids or bacterial/picoplankton extracellular functional groups. Alternatively, we show that an open system, steady-state model is in good accord with the observed Cd isotope systematics in the upper ocean north of the Southern Ocean. The distribution of ε112/110Cd in intermediate and deep waters is consistent with the water mass distribution, with the north–south variations reflecting changes in the mixing proportion of NADW and either AABW or AAIW depending on the depth. Overall, the SW Atlantic Cd isotope dataset demonstrates that the large-scale ocean circulation exerts the primary control on ε112/110Cd cycling in the global deep ocean.

South-north dipolar pattern around mid-1990s in Korean summer rainfall variability

From the time series of rainfall in summer (June, July and August) in South and North Koreas for recent 28 years (1981–2008), rainfall has significantly increased in South Korea while it has significantly decreased in North Korea since 1996. In particular, the decreasing trend of summer rainfall in North Korea was more conspicuous during the second Changma (late August – mid-September). This characteristic was also found in the south-north dipolar pattern based on 1996 by empirical orthogonal function analysis using summer rainfall observed in all weather observation stations in South and North Korea.The decreasing rainfall trend in North Korea was found to be associated with the weakening of convection by anomalous northeasterlies from anomalous anticyclone centered on around Baikal Lake during summer. On the other hand, the increasing rainfall trend of South Korea was associated with the strengthened anomalous cyclone in the southern region of China, which in turn strengthened anomalous southwesterlies.

Climate Variability Impact on the Frequency of Occurrence of Mesoscale Convective Systems in Northern Nigeria

Mesoscale Convective Systems (MCSs) form an important component of meteorology in West Africa, and in particular, contribute substantially to precipitation totals. Several authors focused majorly on the contribution of these systems to precipitation and the damages that accompanied it. But in the event of current climate change, it is expected that storm occurrences especially over the tropics will also be impacted due to variability or changing in climate especially in Northern Nigeria which has experienced some extreme weather events over the years. The study was carried out in eight (8) different states within the savannah region of Nigeria. Monthly total rainfall, mean monthly temperature, relative humidity and daily Mesoscale Convective Systems (MCSs) (thunderstorms and line squalls) data of 31 years was used. Man-Kendall and Coefficient of variation (CV) method were used to analyze the data. There were various degrees of variations in some of the data analyzed based on the location of the station. The frequency of occurrence of these systems showed that its number (peals) decreases with an increasing latitude for stations north of 10°N with the north-eastern part of the country recording a decrease of almost one-third between 1981 and 2010. Hence, monsoon type of precipitation can be seen to be contributing more to the total annual rainfall in the northern part of Nigeria in contrast to earlier studies which gave Mesoscale Convective Systems (MCSs) 95% contribution rate.

Latitudinal change in benthic foraminiferal fauna by ITCZ movement along the ~131°W transect in the equatorial Pacific Ocean

Modern and fossil benthic foraminifera were examined from nine surface sediments and two piston cores along the ~131°W transect in the equatorial Pacific Ocean. This study was conducted to clarify the biotic response of abyssal benthic foraminifera during the last 220 ka to changes in the seasonal extent of the Intertropical Convergence Zone (ITCZ). The abundance of modern benthic foraminifera was high at stations between the equator and 6°N, whereas it was low at stations north of 6°N, which is generally consistent with the latitudinal CaCO3 distribution of surface sediments. The northward increase of Epistominella exigua from the equator to ~6°N is similar to the seasonal variations in chlorophyll-a concentrations in the surface water and ITCZ position along ~131°W. This species was more common at core PC5103 (~6°N) than at core PC5101 (~2°N) after ~130 ka, when the Shannon-Wiener diversity (H’) between the two cores started to diverge. Hence, the presentday latitudinal difference in benthic foraminifera (E. exigua and species diversity) between ~2°N and ~6°N along ~131°W has been generally established since ~130 ka. According to the modern relationship between the seasonality of primary production and seasonal ITCZ variations in the northern margin of the ITCZ, the latitudinal divergence of benthic foraminiferal fauna between ~2°N and ~6°N since ~130 ka appear to have been induced by more distinct variations in the seasonal movement of ITCZ.

Vertical profiles of zooplankton community structure in Prydz Bay, Antarctica, during the austral summer of 2012/2013

The abundance and vertical distribution of zooplankton in the mesopelagic zone are important to better understand their role in carbon and energy transfer in the Southern Ocean ecosystem. In the austral summer of 2012/2013, in Prydz Bay, Antarctica, the vertical profiles of zooplankton community structures between 0 and 1500 m were investigated by multivariate analysis of samples collected using a Hydro-Bios MultiNet (200-µm mesh, 0.5 m2 mouth size). Four zooplankton communities belonging to distinct water strata were identified. Group 1 contained samples collected from the surface water strata (<100 m) of four shelf and neritic stations. Group 2 was composed of samples collected from the neritic and shelf regions (<500 m) and the upper layers (0–200 m) of the oceanic region. Group 3 mainly comprised samples collected from the mesopelagic and upper bathypelagic zones (200–1500 m) of shelf and oceanic stations north of the shelf break edge. Group 4 consisted of samples in the 1000–1500 m water stratum of three oceanic stations. The four groups differed more in animal abundance than in species composition. Similarity percentage analysis (SIMPER) showed that zooplankton communities in the upper depth strata (0–200 m) had higher abundance and more pronounced dissimilarity within samples than those below 200 m. A few species (Metridia gerlachei, Rhincalanus gigas, Alacia spp.) showed significant diel vertical migration based on quadratic regression analysis. Sampling depth was the strongest differentiating factor between samples. These results suggest that depth-related differences in environmental characteristics of water masses, such as temperature and salinity, may have the greatest effect upon community structure.

Distribución espacio-temporal de la temperatura, salinidad y oxígeno disuelto alrededor del Domo Térmico de Costa Rica

&lt;p&gt;The Costa Rica Thermal Dome (CRTD) is an oceanographic phenomenon in the Eastern Tropical Pacific (ETP). This is a region of very high biological productivity, resulting in high concentrations of phytoplankton, sea birds, and large pelagics, such as tunas, dolphins and whales. Few publications have looks at the station variability of the water column of the CRTD. Here, horizontal and vertical distribution of some oceanic parameters was analyzed to show the dynamics of ETP, its influence on the CRTD, climatic variations and relationships that justify their distributions. Climatological monthly mean data of Ocean Data View (ODV) from 1900 to 2009 were used to compile profiles of the water column’s temperature, salinity and dissolved oxygen, and their spatial distributions around the Costa Rica Thermal Dome (CRTD). Monthly variations of these parameters depend on the intensity and extent of ocean-meteorological phenomena in the Eastern Tropical Pacific (ETP), which are related to the north-south migration of Intertropical Convergence Zone (ITCZ). The monthly climatic variation of these variables is analyzed down to 200 m depth. Increased climate variability is found in the water column at stations north and east of the CRTD. The two stations north of the CRTD, closer to the coast, are the ones most affected by the wind in front of the Gulf of Papagayo and where the greatest monthly upwelling variation occurs in this region. The distribution and concentration of dissolved oxygen depends on the ocean-atmospheric dynamics. Oxygen is consumed by respiration and organic matter oxidation around CRTD. Moreover, this is one of the regions of the tropical oceans where an Oxygen Minimum Zone (OMZ) exist, which is related also to poor water circulation or lack ocean ventilation. Sources of dissolved oxygen are linked with sub-surface currents coming from the west and from the south of the geographic equator.&lt;/p&gt;&lt;div&gt; &lt;/div&gt;

Post-Accident Sporadic Releases of Airborne Radionuclides from the Fukushima Daiichi Nuclear Power Plant Site.

The Fukushima nuclear accident (March 11, 2011) caused the widespread contamination of Japan by direct deposition of airborne radionuclides. Analysis of weekly air filters has revealed sporadic releases of radionuclides long after the Fukushima Daiichi reactors were stabilized. One major discharge was observed in August 2013 in monitoring stations north of the Fukushima Daiichi nuclear power plant (FDNPP). During this event, an air monitoring station in this previously scarcely contaminated area suddenly reported (137)Cs activity levels that were 30-fold above the background. Together with atmospheric dispersion and deposition simulation, radionuclide analysis in soil indicated that debris removal operations conducted on the FDNPP site on August 19, 2013 are likely to be responsible for this late release of radionuclides. One soil sample in the center of the simulated plume exhibited a high (90)Sr contamination (78 ± 8 Bq kg(-1)) as well as a high (90)Sr/(137)Cs ratio (0.04); both phenomena have usually been observed only in very close vicinity around the FDNPP. We estimate that through the resuspension of highly contaminated particles in the course of these earthmoving operations, gross (137)Cs activity of ca. 2.8 × 10(11) Bq has been released.

Noise behavior in CGPS position time series: the eastern North America case study

Abstract We analyzed the noise characteristics of 112 continuously operating GPS stations in eastern North America using the Spectral Analysis and the Maximum Likelihood Estimation (MLE) methods. Results of both methods show that the combination ofwhite plus flicker noise is the best model for describing the stochastic part of the position time series. We explored this further using the MLE in the time domain by testing noise models of (a) powerlaw, (b)white, (c)white plus flicker, (d)white plus randomwalk, and (e) white plus flicker plus random-walk. The results show that amplitudes of all noise models are smallest in the north direction and largest in the vertical direction. While amplitudes of white noise model in (c–e) are almost equal across the study area, they are prevailed by the flicker and Random-walk noise for all directions. Assuming flicker noise model increases uncertainties of the estimated velocities by a factor of 5–38 compared to the white noise model.

An investigation on generalization ability of artificial neural networks and M5 model tree in modeling reference evapotranspiration

The generalization ability of artificial neural networks (ANNs) and M5 model tree (M5Tree) in modeling reference evapotranspiration (ET 0 ) is investigated in this study. Daily climatic data, average temperature, solar radiation, wind speed, and relative humidity from six different stations operated by California Irrigation Management Information System (CIMIS) located in two different regions of the USA were used in the applications. King-City Oasis Rd., Arroyo Seco, and Salinas North stations are located in San Joaquin region, and San Luis Obispo, Santa Monica, and Santa Barbara stations are located in the Southern region. In the first part of the study, the ANN and M5Tree models were used for estimating ET 0 of six stations and results were compared with the empirical methods. The ANN and M5Tree models were found to be better than the empirical models. In the second part of the study, the ANN and M5Tree models obtained from one station were tested using the data from the other two stations for each region. ANN models performed better than the CIMIS Penman, Hargreaves, Ritchie, and Turc models in two stations while the M5Tree models generally showed better accuracy than the corresponding empirical models in all stations. In the third part of the study, the ANN and M5Tree models were calibrated using three stations located in San Joaquin region and tested using the data from the other three stations located in the Southern region. Four-input ANN and M5Tree models performed better than the CIMIS Penman in only one station while the two-input ANN models were found to be better than the Hargreaves, Ritchie, and Turc models in two stations.

Late summer/early fall phytoplankton biomass (chlorophyll a) in the eastern Bering Sea: Spatial and temporal variations and factors affecting chlorophyll a concentrations

The spatial and temporal variability of late summer/early fall phytoplankton biomass estimated from in situ chlorophyll a (Chla) concentrations was investigated over a 10-year time period from 2003–2012 in the eastern Bering Sea, encompassing both warm (2003–2005) and cold (2007–2012) temperature regimes. Warm temperature regimes were characterized by above average water temperatures and low seasonal sea-ice extent and by below-average temperatures and high seasonal sea-ice extent. The highest phytoplankton Chla was observed near the Pribilof Islands and the southeastern shelf break where nutrient concentrations were high due to onshore flow from Pribilof and Bering Canyons. The lowest Chla was observed on the northeastern middle and inner shelf, north of Nunivak and St. Matthew Islands and south of St. Lawrence Island (~61–63°N). Stations north of St Matthew Island (61°N) did not show significant variations in Chla between temperature regimes. To the south, total phytoplankton Chla was significantly higher in warm compared to cold years on the south-outer shelf and on portions of the middle shelf. Large phytoplankton Chla was higher in warm years over most of the southern middle-shelf. For the entire southeastern Bering Sea shelf (~30–200m bathymetry, south of Nunivak Island), the highest Chla was seen in 2005 and lowest in 2007 and 2008. On the south-middle shelf, wind mixing and temperature below the pycnocline had strong positive associations with Chla (total and large-size fraction) integrated over the top 50m, explaining 85% of the variability in mean Chla. This indicates that Chla in summer and early fall is positively affected by wind-induced upwelling of nutrients to the surface and possibly by other bottom up effects such as temperature-mediated growth. Higher bottom temperature is related to reductions in sea-ice extent, which may elicit ecosystem responses such as reduced biomass of large crustacean zooplankton grazers, potentially due to the removal of ice algae, an important food resource for zooplankton in early spring. This, in turn, could reduce or alter the grazing pressure on phytoplankton later in the growing season. Overall, spatial and temporal variations in phytoplankton Chla are due to a combination of factors, from local inputs of nutrients related to mixing or advection, up to large-scale ecosystem effects.

Development of a Global Fire Weather Database

Abstract. The Canadian Forest Fire Weather Index (FWI) System is the mostly widely used fire danger rating system in the world. We have developed a global database of daily FWI System calculations, beginning in 1980, called the Global Fire WEather Database (GFWED) gridded to a spatial resolution of 0.5° latitude by 2/3° longitude. Input weather data were obtained from the NASA Modern Era Retrospective-Analysis for Research and Applications (MERRA), and two different estimates of daily precipitation from rain gauges over land. FWI System Drought Code calculations from the gridded data sets were compared to calculations from individual weather station data for a representative set of 48 stations in North, Central and South America, Europe, Russia, Southeast Asia and Australia. Agreement between gridded calculations and the station-based calculations tended to be most different at low latitudes for strictly MERRA-based calculations. Strong biases could be seen in either direction: MERRA DC over the Mato Grosso in Brazil reached unrealistically high values exceeding DC = 1500 during the dry season but was too low over Southeast Asia during the dry season. These biases are consistent with those previously identified in MERRA's precipitation, and they reinforce the need to consider alternative sources of precipitation data. GFWED can be used for analyzing historical relationships between fire weather and fire activity at continental and global scales, in identifying large-scale atmosphere–ocean controls on fire weather, and calibration of FWI-based fire prediction models.