A New Look at Snowpack Trends in the Cascade Mountains

2010 ◽  
Vol 23 (10) ◽  
pp. 2473-2491 ◽  
Author(s):  
Mark T. Stoelinga ◽  
Mark D. Albright ◽  
Clifford F. Mass

Abstract This study examines the changes in Cascade Mountain spring snowpack since 1930. Three new time series facilitate this analysis: a water-balance estimate of Cascade snowpack from 1930 to 2007 that extends the observational record 20 years earlier than standard snowpack measurements; a radiosonde-based time series of lower-tropospheric temperature during onshore flow, to which Cascade snowpack is well correlated; and a new index of the North Pacific sea level pressure pattern that encapsulates modes of variability to which Cascade spring snowpack is particularly sensitive. Cascade spring snowpack declined 23% during 1930–2007. This loss is nearly statistically significant at the 5% level. The snowpack increased 19% during the recent period of most rapid global warming (1976–2007), though this change is not statistically significant because of large annual variability. From 1950 to 1997, a large and statistically significant decline of 48% occurred. However, 80% of this decline is connected to changes in the circulation patterns over the North Pacific Ocean that vary naturally on annual to interdecadal time scales. The residual time series of Cascade snowpack after Pacific variability is removed displays a relatively steady loss rate of 2.0% decade−1, yielding a loss of 16% from 1930 to 2007. This loss is very nearly statistically significant and includes the possible impacts of anthropogenic global warming. The dates of maximum snowpack and 90% melt out have shifted 5 days earlier since 1930. Both shifts are statistically insignificant. A new estimate of the sensitivity of Cascade spring snowpack to temperature of −11% per °C, when combined with climate model projections of 850-hPa temperatures offshore of the Pacific Northwest, yields a projected 9% loss of Cascade spring snowpack due to anthropogenic global warming between 1985 and 2025.

2011 ◽  
Vol 68 (6) ◽  
pp. 986-995 ◽  
Author(s):  
Jeffrey J. Polovina ◽  
John P. Dunne ◽  
Phoebe A. Woodworth ◽  
Evan A. Howell

Abstract Polovina, J. J., Dunne, J. P., Woodworth, P. A., and Howell, E. A. 2011. Projected expansion of the subtropical biome and contraction of the temperate and equatorial upwelling biomes in the North Pacific under global warming. – ICES Journal of Marine Science, 68: 986–995. A climate model that includes a coupled ocean biogeochemistry model is used to define large oceanic biomes in the North Pacific Ocean and describe their changes over the 21st century in response to the IPCC Special Report on Emission Scenario A2 future atmospheric CO2 emissions scenario. Driven by enhanced stratification and a northward shift in the mid-latitude westerlies under climate change, model projections demonstrated that between 2000 and 2100, the area of the subtropical biome expands by ∼30% by 2100, whereas the area of temperate and equatorial upwelling (EU) biomes decreases by ∼34 and 28%, respectively, by 2100. Over the century, the total biome primary production and fish catch is projected to increase by 26% in the subtropical biome and decrease by 38 and 15% in the temperate and the equatorial biomes, respectively. Although the primary production per unit area declines slightly in the subtropical and the temperate biomes, it increases 17% in the EU biome. Two areas where the subtropical biome boundary exhibits the greatest movement is in the northeast Pacific, where it moves northwards by as much as 1000 km per 100 years and at the equator in the central Pacific, where it moves eastwards by 2000 km per 100 years. Lastly, by the end of the century, there are projected to be more than 25 million km2 of water with a mean sea surface temperature of 31°C in the subtropical and EU biomes, representing a new thermal habitat. The projected trends in biome carrying capacity and fish catch suggest resource managers might have to address long-term trends in fishing capacity and quota levels.


2015 ◽  
Vol 28 (23) ◽  
pp. 9451-9458 ◽  
Author(s):  
Changlin Chen ◽  
Guihua Wang

Abstract The annual cycle of sea surface temperature (SST) in the North Pacific Ocean is examined in terms of its response to global warming based on climate model simulations from phase 5 of the Coupled Model Intercomparison Project (CMIP5). As the global ocean warms up, the SST in the North Pacific generally tends to increase and the warming is greater in summer than in winter, leading to a significant intensification of SST annual cycle. The mixed layer temperature equation is used to examine the mechanism of this intensification. Results show that the decrease of mixed layer depth (MLD) in summer is the main reason behind the intensification of SST annual cycle. Because the MLD in summer is much shallower than that in winter, the incoming net heat flux is trapped in a thinner surface layer in summer, causing a warmer summer SST and the amplification of SST annual cycle. The change of the SST annual cycle in the North Pacific may have profound ecological impacts.


2012 ◽  
Vol 25 (19) ◽  
pp. 6554-6566 ◽  
Author(s):  
Bolan Gan ◽  
Lixin Wu

Abstract In this study the modulation of ocean-to-atmosphere feedback over the North Pacific in early winter from global warming is investigated based on both the observations and multiple climate model simulations from a statistical perspective. It is demonstrated that the basin-scale atmospheric circulation displays an equivalent barotropic ridge in response to warm SST anomalies in the Kuroshio–Oyashio Extension (KOE) region. This warm SST–ridge response in early winter can be enhanced significantly by global warming, indicating a strengthening of air–sea coupling over the North Pacific. This enhancement is likely associated with the intensification of storm tracks and, in turn, the amplification of atmospheric transient eddy feedback in a warm climate, although the secular trend of enhanced storm-track activity over the North Pacific is suggested to be biased in reanalysis product.


2014 ◽  
Vol 27 (2) ◽  
pp. 592-606 ◽  
Author(s):  
Dimitry Smirnov ◽  
Matthew Newman ◽  
Michael A. Alexander

Abstract Air–sea interaction over the North Pacific is diagnosed using a simple, local coupled autoregressive model constructed from observed 7-day running-mean sea surface temperature (SST) and 2-m air temperature TA anomalies during the extended winter from the 1° × 1° objectively analyzed air–sea fluxes (OAFlux) dataset. Though the model is constructed from 1-week lag statistics, it successfully reproduces the observed anomaly evolution through lead times of 90 days, allowing an estimation of the relative roles of coupling and internal atmospheric and oceanic forcing upon North Pacific SSTs. It is found that east of the date line, SST variability is maintained by, but has little effect on, TA variability. However, in the Kuroshio–Oyashio confluence and extension region, about half of the SST variability is independent of TA, driven instead by SST noise forcing internal to the ocean. Including surface zonal winds in the analysis does not alter this conclusion, suggesting TA adequately represents the atmosphere. Repeating the analysis with the output of two control simulations from a fully coupled global climate model (GCM) differing only in their ocean resolution yields qualitatively similar results. However, for the simulation employing the coarse-resolution (1°) ocean model, all SST variability depends upon TA, apparently caused by a near absence of ocean-induced noise forcing. Collectively, these results imply that a strong contribution from internal oceanic forcing drives SST variability in the Kuroshio–Oyashio region, which may be used as a justification for atmospheric GCM experiments forced with SST anomalies in that region alone. This conclusion is unaffected by increasing the dimensionality of the model to allow for intrabasin interaction.


2021 ◽  
Author(s):  
Alyse Larkin ◽  
Allison Moreno ◽  
Adam Fagan ◽  
Adam Martiny

<p>From 2014 through 2016, a significant El Niño event and the North Pacific warm anomaly (a.k.a., “the blob”) resulted in a marine heatwave across the Eastern North Pacific Ocean. To develop a deeper understanding of the impacts of El Niño on the Southern California Bight (SCB), we used coastal cyanobacteria populations in order to “bi-directionally” link shifts in microbial diversity and biogeochemical conditions. We sequenced the <em>rpo</em>C1 gene from the ecologically important picocyanobacteria <em>Prochlorococcus</em> and <em>Synechococcus</em> at 434 time points from 2009–2018 in the MICRO time series at Newport Beach, CA. Across the time series, we observed an increase in the abundance of <em>Prochlorococcus</em> relative to <em>Synechococcus</em> as well as elevated frequencies of clades commonly associated with low-nutrient and high-temperature conditions. The relationships between environmental and diversity trends appeared to operate on differing temporal scales. In addition, microdiverse populations from the <em>Prochlorococcous</em> HLI clade as well as <em>Synechococcus</em> Clade II that shifted in response to the 2015 El Niño did not return to their pre-heatwave composition by the end of this study. This research demonstrates that El Niño-driven warming in the SCB can result in persistent changes in key microbial populations.</p>


2005 ◽  
Vol 22 (11) ◽  
pp. 1762-1781 ◽  
Author(s):  
Bruno Buongiorno Nardelli ◽  
Rosalia Santoleri

Abstract Different methods for the extrapolation of vertical profiles from sea surface measurements have been tested on 14 yr of conductivity–temperature–depth (CTD) data collected within the Hawaii Ocean Time-series (HOT) program at A Long-Term Oligotrophic Habitat Assessment (ALOHA) station in the North Pacific Ocean. A new technique, called multivariate EOF reconstruction (mEOF-R), has been proposed. The mEOF-R technique is similar to the previously developed coupled pattern reconstruction (CPR) technique and relies on the availability of surface measurements and historical profiles of salinity, temperature, and steric heights. The method is based on the multivariate EOF analysis of the vertical profiles of the three parameters and on the assumption that only a few modes are needed to explain most of the variance/covariance of the fields. The performances of CPR, single EOF reconstruction (sEOF-R), and mEOF-R have been compared with the results of residual GEM techniques and with ad hoc climatologies, stressing the potential of each method in relation to the length of the time series used to train the models and to the accuracy expected from planned satellite missions for the measurement of surface salinity, sea level, and temperature. The mEOF-R method generally produces the most reliable estimates (in the worst cases comparable to the climatologies) and seems to be slightly less susceptible to errors in the surface input. Multivariate EOF analysis of HOT data also gave by itself interesting results, being able to discriminate the three major signals driving the temporal variability in the area.


2001 ◽  
Vol 75 (4) ◽  
pp. 808-826 ◽  
Author(s):  
Carrie E. Schweitzer

Comprehensive analysis of the Cretaceous and Tertiary decapod crustaceans of the North Pacific Rim, focused primarily on the Brachyura, has resulted in additions to our understanding of the evolution and distribution of these animals, both in that region and globally. Hypotheses about changes in climatological and paleoceanographic conditions have not been extensively tested using decapod crustaceans, although they have been well-documented globally and for the North Pacific Ocean by sedimentological and other faunal evidence. Evidence from the occurrences of decapod crustaceans supports hypotheses obtained through these other means. Because the decapod fauna was studied independent of other faunas, it provides a means by which to compare and test patterns derived from molluscan and other faunal data. The brachyuran decapods show distinctive paleobiogeographic patterns during the Cretaceous and Tertiary, and these patterns are consistent with those documented globally in the molluscan faunas and paleoceanographic modeling. Additionally, the changes in the decapod fauna reflect patterns unique to the North Pacific Ocean. The decapod fauna is primarily comprised of a North Pacific component, a North Polar component, a component of Tethyan derivation, an amphitropical component, and a component derived from the high Southern latitudes. The Cretaceous and Tertiary decapod faunas of the North Pacific Ocean were initially dominated by taxa of North Pacific origin. Decapod diversity was highest in the Pacific Northwest of North America during the Eocene, and diversity has declined steadily since that time. Diversity in Japan was relatively low among the Decapoda until the Miocene, when diversity increased markedly due to the tropical influence of the Tethys and Indo-Pacific region. Diversity has remained high in Japan into the present time. The Cretaceous, Eocene, and Miocene were times of evolutionary bursts within the Brachyura and were separated by periods of evolutionary stasis.


2011 ◽  
Vol 68 (6) ◽  
pp. 996-1007 ◽  
Author(s):  
Chan Joo Jang ◽  
Jisoo Park ◽  
Taewook Park ◽  
Sinjae Yoo

Abstract Jang, C. J., Park, J., Park, T., and Yoo, S. 2011. Response of the ocean mixed layer depth to global warming and its impact on primary production: a case for the North Pacific Ocean. – ICES Journal of Marine Science, 68: 996–1007. This study investigates changes in the mixed layer depth (MLD) in the North Pacific Ocean in response to global warming and their impact on primary production by comparing outputs from 11 models of the coupled model intercomparison projects phase 3. The MLD in the 21st century decreases in most regions of the North Pacific, whereas the spatial pattern of the MLD is nearly unchanged. The overall shoaling results in part from intensified upper-ocean stratification caused by both surface warming and freshening. A significant MLD decrease (>30 m) is found in the Kuroshio extension (KE), which is predominantly driven by reduced surface cooling, caused by weakening of wind. Associated with the mixed layer shoaling in the KE, the primary production component resulting from seasonal vertical mixing will be reduced by 10.7–40.3% (ranges of medians from 11 models) via decreased nitrate fluxes from below it. Spring blooms in most models are projected to initiate earlier in the KE by 0–13 d (ranges of medians from 11 models). Despite the overall trends, the magnitude of changes in primary production and timing of spring blooms are quite different depending on models and latitudes.


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