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Papers by Charles Jones

Novel ways of monitoring the large-scale variability of the southwest monsoon in the Indian Ocean... more Novel ways of monitoring the large-scale variability of the southwest monsoon in the Indian Ocean are presented using multispectral satellite datasets. The fields of sea surface temperature (SST), surface latent heat flux (LHF), net surface solar radiation (SW), precipitation (P), and SW Ϫ LHF over the Indian Ocean are analyzed to characterize the seasonal and interannual variability with special emphasis on the period 1988-90. It is shown that satellite data are able to make a significant contribution to the multiplatform strategy necessary to describe the large-scale spatial and temporal variability of air-sea interactions associated with the Indian Ocean Monsoon. The satellite data analyzed here has shown for the first time characteristics of the interannual variability of air-sea interactions over the entire Indian Ocean. Using monthly means of SST, LHF, SW, P, and the difference SW Ϫ LHF, the main features of the seasonal and interannual variability of air-sea interactions over the Indian Ocean are characterized. It is shown that the southwest monsoon strongly affects these interactions, inducing dramatic exchanges of heat between air and sea and large temporal variations of these exchanges over relatively small timescale (with regards to typical oceanic timescales). The analyses indicate an overall good agreement between satellite and in situ (ship) estimates, except in the southern Indian Ocean, where ship sampling is minimal, the disagreement can be large. In the latitudinal band of 10ЊN-15ЊS, differences in climatological in situ estimates of surface sensible heat flux and net longwave radiation has a larger influence on the net surface heat flux than the difference between satellite and in situ estimates of SW and LHF.

The Quarterly Journal of Economics, Nov 1, 1998

The electrically exploded 0.05 to 0.25 mm diameter metal wires and film thicknesses from 0.1 to 1... more The electrically exploded 0.05 to 0.25 mm diameter metal wires and film thicknesses from 0.1 to 10 (SIGMA) m were studied for lengths from 3.0 to 100 cm. These exploded metal conductor initiated discharges proved to be sources for intense radiation in the near ultraviolet range, 200 to 300 nm, with brightness temperatures measured over 40,000 K. The impedance matching characteristics and scaling laws developed through these studies are presented and compared with more recent results on surface spark discharges. These latter discharges do not appear to be as nearly blackbody as the conductor initiated discharges, but through selected insulator surfaces, intense emission in the spectral range of interest can be obtained.

Nber Working Papers, Jul 6, 1999

Research and development is a key determinant of long-run productivity and welfare. A central iss... more Research and development is a key determinant of long-run productivity and welfare. A central issue is whether a decentralized economy undertakes too little or too much R&D. We develop an endogenous growth model that incorporates parametrically four important distortions to R&D: the surplus appropriability problem, knowledge spillovers, creative destruction, and duplication externalities. Calibrating the model, we find that the decentralized economy typically underinvests in R&D relative to what is socially optimal. The only exceptions to this conclusion occur when the duplication externality is strong and the equilibrium real interest rate is simultaneously high.

The Journal of Portfolio Management, 1985

Supplement to Thomas Deborah J Bralower Timothy J Jones Charles E Neodymium Isotopic Reconstruction of Late Paleocene Early Eocene Thermohaline Circulation Earth and Planetary Science Letters 209 309 322 Doi 10 1016 S0012 821x00096 7, Dec 2, 2003

The endosomal sorting complex required for transport (ESCRT)-I protein complex functions in recog... more The endosomal sorting complex required for transport (ESCRT)-I protein complex functions in recognition and sorting of ubiquitinated transmembrane proteins into multivesicular body (MVB) vesicles. It has been shown that ESCRT-I contains the vacuolar protein sorting (Vps) proteins Vps23, Vps28, and Vps37. We identified an additional subunit of yeast ESCRT-I called Mvb12, which seems to associate with ESCRT-I by binding to Vps37. Transient recruitment of ESCRT-I to MVBs results in the rapid degradation of Mvb12. In contrast to mutations in other ESCRT-I subunits, which result in strong defects in MVB cargo sorting, deletion of MVB12 resulted in only a partial sorting phenotype. This trafficking defect was fully suppressed by overexpression of the ESCRT-II complex. Mutations in MVB12 did not affect recruitment of ESCRT-I to MVBs, but they did result in delivery of ESCRT-I to the vacuolar lumen via the MVB pathway. Together, these observations suggest that Mvb12 may function in regulating the interactions of ESCRT-I with cargo and other proteins of the ESCRT machinery to efficiently coordinate cargo sorting and release of ESCRT-I from the MVB.

Journal of Geophysical Research Atmospheres

Two extreme snowfall events associated with extratropical cyclones, one interacting with the west... more Two extreme snowfall events associated with extratropical cyclones, one interacting with the western and one with the central Himalaya are simulated with the Weather Research and Forecasting (WRF) model over eight days. One event in January 1999 was driven by a longwave trough over west Asia, with the cyclone becoming terrain-locked in the western-Himalayan notch. Another event in March 2006 was driven by a trough further south and east, facilitating the passage of two successive cyclones along the entire Himalayan ridge, drawing moisture from warm tropical waters. These flow patterns are typical for extreme winter precipitation in the western and central Himalaya, respectively, but were amplified in these two cases. In the WRF simulations, snowfall is confined to the western Himalaya in the January simulation, while a near-continuous band of accumulated snowfall along the Himalayan ridge forms in the March simulation. Precipitation rate throughout both simulations is largely determ...

Theoretical and Applied Climatology, 2015

Extratropical cyclones, including winter westerly disturbances (WWD) over central Asia, are funda... more Extratropical cyclones, including winter westerly disturbances (WWD) over central Asia, are fundamental features of the atmosphere that maintain energy, momentum, and moisture at global scales while intimately linking large-scale circulation to regional-scale meteorology. Within high mountain Asia, WWD are the primary contributor to regional precipitation during winter. In this work, we present a novel WWD tracking methodology, which provides an inventory of location, timing, intensity, and duration of events, allowing for a comprehensive study of the factors that relate WWD to orographic precipitation, on an individual event basis and in the aggregate. We identify the relationship between the strength of disturbances, the state of the background environment during their propagation, and precipitation totals in the Karakoram/western Himalaya. We observe significant differences in convective and mechanical instability contributions to orographic precipitation as a function of the relationship between the intensity of WWD and the background temperature and moisture fields, which exhibit strong intraseasonal variability. Precipitation is primarily orographically forced during intense WWD with strong cross-barrier winds, while weaker WWD with similar precipitation totals are observed to benefit from enhanced instability due to high moisture content and temperature at low levels, occurring primarily in the late winter/premonsoon. The contribution of these factors is observed to fluctuate on a per-case basis, indicating important influences of intraseasonal oscillations and tropical-extratropical interactions on regional precipitation.

Eos, Transactions American Geophysical Union, 2010

The exchange of moisture and heat fluxes across the ocean-atmosphere interface exerts a strong in... more The exchange of moisture and heat fluxes across the ocean-atmosphere interface exerts a strong influence on the oceanic and atmospheric circulations, and therefore on the maintenance of the climate system equilibrium. Observational measurements of these fluxes over large areas of the ocean`s surface are limited by the lack of in-situ data. This paper reports research efforts to estimate the freshwater budget and freshwater oceanic transport using remotely sensed data. Six years (1988--1993) of surface evaporation estimated with satellite and in-situ data re combined with satellite-derived precipitation to compute the freshwater budget and freshwater oceanic transport. The interannual variability of the freshwater budget and oceanic transport eliminates are examined for two contrasting events: the La Nina of 1988--89 and the El Nino condition during 1991--92, one of the longest El Nino episodes on record. Possible implications for future climate change are discussed.

Traffic, 2012

The multivesicular body (MVB) pathway delivers membrane proteins to the lumen of the vacuole/lyso... more The multivesicular body (MVB) pathway delivers membrane proteins to the lumen of the vacuole/lysosome for degradation. The resulting amino acids are transported to the cytoplasm for reuse in protein synthesis. Our study shows that this amino acid recycling system plays an essential role in the adaptation of cells to starvation conditions. Cells respond to amino acid starvation by upregulating both endocytosis and the MVB pathway, thereby providing amino acids through increased protein turnover. Our data suggest that increased Rsp5-dependent ubiquitination of membrane proteins and a drop in Ist1 levels, a negative regulator of endosomal sorting complex required for transport (ESCRT) activity, cause this response. Furthermore, we found that target of rapamycin complex 1 (TORC1) and a second, unknown nutrient-sensing system are responsible for the starvation-induced protein turnover. Together, the data indicate that protein synthesis and turnover are linked by a common regulatory system that ensures adaptation and survival under nutrient-stress conditions.

SSRN Electronic Journal, 2000

Climate Dynamics, 2014

spatiotemporal variations are crucial to improve our knowledge of the hydrologic cycle within Hig... more spatiotemporal variations are crucial to improve our knowledge of the hydrologic cycle within High Mountain Asia as well as our ability to project the future status of Asia's water resources.

The Quarterly Journal of Economics, 1998

A large empirical literature reports estimates of the rate of return to R&D ranging from 30% to o... more A large empirical literature reports estimates of the rate of return to R&D ranging from 30% to over 100%, supporting the notion that there is too little private investment in research. This conclusion is challenged by the new growth theory. We derive analytically the relationship between the social rate of return to R&D and the coefficient estimates of the empirical literature. We show that these estimates represent a lower bound on the true social rate of return. Using a conservative estimate of the rate of return to R&D of about 30%, optimal R&D investment is at least four times larger than actual investment.

The Journal of Portfolio Management, 1984