scholarly journals A Case Study of Downstream Baroclinic Development over the North Pacific Ocean. Part I: Dynamical Impacts

2006 ◽  
Vol 134 (5) ◽  
pp. 1534-1548 ◽  
Author(s):  
Richard E. Danielson ◽  
John R. Gyakum ◽  
David N. Straub
Keyword(s):  
North Pacific ◽  
Initial Conditions ◽  
North Pacific Ocean ◽  
The North ◽  
Potential Vorticity Inversion ◽  
Surface Cyclone ◽  
Upper Level ◽  
The Impact ◽  
The North Pacific

Abstract The impact of eddy energy growth and radiation from a western North Pacific cyclone on the intensity of an eastern North Pacific cyclone a few days later is examined. Associated with the western cyclone is an upstream ridge and trough couplet, initially over Siberia on 8 March 1977. The amplitude of this couplet is perturbed in 5-day numerical simulations of the two marine cyclones. Balanced initial conditions are created by potential vorticity inversion. The magnitude of the upper-level couplet governs much of the subsequent growth of eddy energy in the western cyclone as well as the propagation of eddy energy between the two cyclones. This culminates in measurable changes in the maximum intensity of the eastern surface cyclone. The broader question of the sensitivity of this cyclone to upstream perturbations is also briefly addressed.

An ensemble analysis to predict future habitats of striped marlin (Kajikia audax) in the North Pacific Ocean

2013 ◽  
Vol 70 (5) ◽  
pp. 1013-1022 ◽  
Author(s):  
Nan-Jay Su ◽  
Chi-Lu Sun ◽  
André E. Punt ◽  
Su-Zan Yeh ◽  
Gerard DiNardo ◽  
...  
Keyword(s):  
Climate Change ◽  
Pacific Ocean ◽  
Water Temperature ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Additive Models ◽  
The North ◽  
The Impact ◽  
The North Pacific ◽  
Ensemble Analysis

Abstract Su, N.-J., Sun, C.-L., Punt, A. E., Yeh, S.-Z., DiNardo, G., and Chang, Y.-J. 2013. An ensemble analysis to predict future habitats of striped marlin (Kajikia audax) in the North Pacific Ocean. – ICES Journal of Marine Science, 70: 1013–1022. Striped marlin is a highly migratory species distributed throughout the North Pacific Ocean, which shows considerable variation in spatial distribution as a consequence of habitat preference. This species may therefore shift its range in response to future changes in the marine environment driven by climate change. It is important to understand the factors determining the distribution of striped marlin and the influence of climate change on these factors, to develop effective fisheries management policies given the economic importance of the species and the impact of fishing. We examined the spatial patterns and habitat preferences of striped marlin using generalized additive models fitted to data from longline fisheries. Future distributions were predicted using an ensemble analysis, which represents the uncertainty due to several global climate models and greenhouse gas emission scenarios. The increase in water temperature driven by climate change is predicted to lead to a northward displacement of striped marlin in the North Pacific Ocean. Use of a simple predictor of water temperature to describe future distribution, as in several previous studies, may not be robust, which emphasizes that variables other than sea surface temperatures from bioclimatic models are needed to understand future changes in the distribution of large pelagic species.

scholarly journals Data Sensitivity of the ECCO State Estimate in a Regional Setting

2009 ◽  
Vol 26 (11) ◽  
pp. 2420-2443 ◽  
Author(s):  
Elizabeth Douglass ◽  
Dean Roemmich ◽  
Detlef Stammer
Keyword(s):  
North Pacific ◽  
General Circulation ◽  
Initial Conditions ◽  
North Pacific Ocean ◽  
Circulation Model ◽  
Data Consistency ◽  
Consistent Estimate ◽  
Regional Setting ◽  
The North ◽  
The North Pacific

Abstract The Estimating the Circulation and Climate of the Ocean (ECCO) consortium provides a framework in which the adjoint method of data assimilation is applied to a general circulation model to provide a dynamically self-consistent estimate of the time-varying ocean state, which is constrained by observations. In this study, the sensitivity of the solution to the constraints provided by various datasets is investigated in a regional setting in the North Pacific. Four assimilation experiments are performed, which vary by the data used as constraints and the relative weights associated with these data. The resulting estimates are compared to two of the assimilated datasets as well as to data from two time series stations not used as constraints. These comparisons demonstrate that increasing the weights of the subsurface data provides overall improvement in the model–data consistency of the estimate of the state of the North Pacific Ocean. However, some elements of the solution are degraded. This could result from incompatibility between datasets, possibly because of hidden biases, or from errors in the model physics made more evident by the increased weight on subsurface data. The adjustments to the control parameters of surface forcing and initial conditions necessary to obtain the more accurate fit to the data are found to be within prior error bars.

scholarly journals Seasonal Prediction of North Pacific SSTs and PDO in the NCEP CFS Hindcasts

2012 ◽  
Vol 25 (17) ◽  
pp. 5689-5710 ◽  
Author(s):  
Caihong Wen ◽  
Yan Xue ◽  
Arun Kumar
Keyword(s):  
North Pacific ◽  
Initial Conditions ◽  
Southern Oscillation ◽  
Signal To Noise Ratio ◽  
Seasonal Prediction ◽  
Prediction Skill ◽  
The North ◽  
The Impact ◽  
The North Pacific ◽  
Central North Pacific

Abstract Seasonal prediction skill of North Pacific sea surface temperature anomalies (SSTAs) and the Pacific decadal oscillation (PDO) in the NCEP Climate Forecast System (CFS) retrospective forecasts is assessed. The SST forecasts exhibit significant skills over much of the North Pacific for two seasons in advance and outperform persistence over much of the North Pacific except near the Kuroshio–Oyashia Extension. Similar to the “spring barrier” feature in the El Niño–Southern Oscillation forecasts, the central North Pacific SST experiences a faster drop in prediction skill for forecasts initialized from November to February than those from May to August. Forecasts for the PDO displayed a constant phase shift from the observation with respect to lead time. The PDO skill has a clear seasonality with highest skill for forecasts initialized in boreal spring. The impact of ENSO on the PDO and North Pacific SST prediction was investigated. The analysis revealed that seasonal prediction skill in the central North Pacific mainly results from the skillful prediction of ENSO. As a result, the PDO is more skillful than persistence at all lead times during ENSO years. On the other hand, persistence is superior to the CFS forecast during ENSO-neutral conditions owing to errors in initial conditions and deficiencies in model physics. Examination of seasonal variance and predictability (signal-to-noise ratio) further articulates the influence of ENSO on the PDO skill. The results suggest that improvement of ENSO prediction as well as reduction in model biases in the western North Pacific will lead to improvements in the PDO and North Pacific SST predictions.

scholarly journals A Case Study of Downstream Baroclinic Development over the North Pacific Ocean. Part II: Diagnoses of Eddy Energy and Wave Activity

2006 ◽  
Vol 134 (5) ◽  
pp. 1549-1567 ◽  
Author(s):  
Richard E. Danielson ◽  
John R. Gyakum ◽  
David N. Straub
Keyword(s):  
Group Velocity ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Wave Activity ◽  
The North ◽  
Initial Evolution ◽  
Activity Center ◽  
The North Pacific ◽  
Made In

Abstract The sequential development of a western, and then an eastern, North Pacific cyclone is examined in terms of eddy energy and a phase-independent wave activity. Based on the propagation of both a contiguous wave activity center and eddy energy, the development of the western cyclone appears to influence its downstream neighbor. A quantitative comparison of these two diagnoses is made in terms of group velocity, and only minor differences are found during much of the initial evolution. It is only once the tropopause undulations lose their wavelike appearance (at which point, application of the group-velocity concept itself becomes quite tenuous) that the downstream propagation of eddy energy seems faster than that of wave activity. Conventional methods of tracking this wave packet are also briefly discussed.

scholarly journals Role of dust alkalinity in acid mobilization of iron

2010 ◽  
Vol 10 (4) ◽  
pp. 10399-10428 ◽  
Author(s):  
A. Ito ◽  
Y. Feng
Keyword(s):  
Pacific Ocean ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Mineral Dissolution ◽  
Dust Particles ◽  
Carbonate Minerals ◽  
Dust Aerosols ◽  
The North ◽  
The Impact ◽  
The North Pacific

Abstract. Atmospheric processing of mineral aerosols by acid gases (e.g., SO2, HNO3, N2O5, and HCl) may play a key role in the transformation of insoluble iron (Fe2O3) to soluble forms (e.g., Fe(II), inorganic soluble species of Fe(III), and organic complexes of iron). However, mineral dust particles also have a potential of neutralizing the acidic species due to the alkaline buffer ability of carbonate minerals (e.g., CaCO3 and MgCO3). Here we demonstrate the impact of dust alkalinity on the acid mobilization of iron in a three-dimensional aerosol chemistry transport model, which is incorporated with a mineral dissolution scheme. In our model simulations, most of the alkaline dust minerals cannot be entirely consumed by inorganic acids during the transport across the North Pacific Ocean. As a result, the inclusion of alkaline compounds in aqueous chemistry substantially limits the iron dissolution in aerosol solution during the long-range transport. Over the North Pacific Ocean, only a small fraction (<0.2%) of iron dissolves from hematite in the coarse-mode dust aerosols, when assuming internally mixed with carbonate minerals. However, if the iron-containing minerals are externally mixed with carbonate minerals, a significant amount (1–2%) of iron would dissolve from the acid mobilization. It implies that the alkaline content in dust aerosols might help to explain the inverse relationship between aerosol iron solubility and particle size.

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