The land surface water and energy budgets over the Tibetan Plateau

Tibetan Plateau plays an important role in the Asian Monsoon and global general circulation system. Due to the lack of quantitative observations and complicated cold season processes in high elevation terrain, however, the land surface water and energy budgets are still unexplored over this special region. In this study, the water and energy balances are analyzed in detail based on recently released land surface “reanalysis” data produced by NASA Global Land Data Assimilation System by three different land models, which first ingest all available ground and satellite data into the data assimilation system over the Tibetan Plateau. The major land surface energy and water components in the annual variability are compared. The model and data assimilation skills and deficiencies are also discussed. The total heat fluxes in the transition from heat source to heat sink is observed at the west edge of the TP during winter. But, the area and intensity is far less than the previous hypothesized. The Budyko curve for hydrology indicates that the TP is a typical dry and arid climate where evaporation is mainly controlled by precipitation

Anti-dark and Mexican-hat solitons in the Sasa-Satsuma equation on the continuous wave background

In this letter, via the Darboux transformation method we construct new analytic soliton solutions for the Sasa-Satsuma equation which describes the femtosecond pulses propagation in a monomode fiber. We reveal that two different types of femtosecond solitons, i.e., the anti-dark (AD) and Mexican-hat (MH) solitons, can form on a continuous wave (CW) background, and numerically study their stability under small initial perturbations. Different from the common bright and dark solitons, the AD and MH solitons can exhibit both the resonant and elastic interactions, as well as various partially/completely inelastic interactions which are composed of such two fundamental interactions. In addition, we find that the energy exchange between some interacting soliton and the CW background may lead to one AD soliton changing into an MH one, or one MH soliton into an AD one.Comment: 12 pages, 6 figure

Optimal Dynamic Portfolio with Mean-CVaR Criterion

Value-at-Risk (VaR) and Conditional Value-at-Risk (CVaR) are popular risk measures from academic, industrial and regulatory perspectives. The problem of minimizing CVaR is theoretically known to be of Neyman-Pearson type binary solution. We add a constraint on expected return to investigate the Mean-CVaR portfolio selection problem in a dynamic setting: the investor is faced with a Markowitz type of risk reward problem at final horizon where variance as a measure of risk is replaced by CVaR. Based on the complete market assumption, we give an analytical solution in general. The novelty of our solution is that it is no longer Neyman-Pearson type where the final optimal portfolio takes only two values. Instead, in the case where the portfolio value is required to be bounded from above, the optimal solution takes three values; while in the case where there is no upper bound, the optimal investment portfolio does not exist, though a three-level portfolio still provides a sub-optimal solution