Superconducting gravimeters (SG) measure temporal changes of the Earth's gravity field with high accuracy and long-term stability. Variations in local water storage components (snow, soil moisture, groundwater, surface water, and water stored by vegetation) can have a significant influence on SG measurements and — from a geodetic perspective — add noise to the SG records. At the same time, this hydrological gravity signal can provide substantial information about the quantification of water balances. A 4D forward model with a spatially nested discretization domain was developed to investigate the local hydrological gravity effect on the SG records of the Geodetic Observatory Wettzell, Germany. The possible maximum gravity effect was investigated using hypothetical water storage changes based on physical boundary conditions. Generally, on flat terrain, a water mass change of1 m in the model domain causes a gravity change of 42 µGal. Simulation results show that topography increases this value to 52 µGal. Errors in the Digital Elevation Model can influence the results significantly. The radius of influence of local water storage variations is limited to 1000 m. Detailed hydrological measurements should be carried out in a radius of 50 to 100 m around the SG station. Groundwater, soil moisture, and snow storage changes dominate the hydrological gravity effect at the SG Wettzell. Using observed time series for these variables in the 4D model and comparing the results to the measured gravity residuals show similarities in both seasonal and shorter-term dynamics. However, differences exist, e.g., the range comparison of the mean modeled (10 µGal) gravity signal and the measured (19 µGal) gravity signal, making additional hydrological measurements necessary to describe the full spatiotemporal variability of local water masses

We present a coupled hydrology and entomology model for the mechanistic simulation of local-scale response of malaria transmission to hydrological and climatological determinants in semiarid, desert fringe environments. The model is applied to the Sahel village of Banizoumbou, Niger, to predict interannual variability in malaria vector mosquito populations that lead to variations in malaria transmission. Using a high-resolution, small-scale distributed hydrology model that incorporates remotely sensed data for land cover and topography, we simulate the formation and persistence of the pools constituting the primary breeding habitat of Anopheles gambiae s.l. mosquitoes, the principal regional malaria vector mosquitoes. An agent-based mosquito population model is coupled to the distributed hydrology model, with aquatic-stage and adult-stage components. Through a dependence of aquatic-stage mosquito development and adult emergence on pool persistence, we model small-scale hydrology as a dominant control of mosquito abundance. For each individual adult mosquito, the model tracks attributes relevant to population dynamics and malaria transmission, which are updated as mosquitoes interact with their environment, humans, and animals. Weekly field observations were made in 2005 and 2006. A 16% increase in rainfall between the two years was accompanied by a 132% increase in mosquito abundance between 2005 and 2006. The model reproduces mosquito population variability at seasonal and interannual timescales and highlights individual pool persistence as a dominant control. Future developments of the presented model can be used in the evaluation of impacts of climate change on malaria, as well as the a priori evaluation of environmental management-based interventions.

"Isotope ratios of precipitation and water vapor were observed during the passage of Typhoon Shanshan at Ishigaki Island, southwestern Japan, on 15–16 September 2006. Such high-resolution isotopic observations allow for qualitative understanding of atmospheric moisture cycling; they revealed that isotope ratios of both the precipitation and water vapor decreased radially inward in the cyclone's outer region; anomalously high isotope ratios appeared in the cyclone's inner region; and d-excess tended to decrease in the cyclone's inner region. In the cyclone's outer region, the water vapor was isotopically depleted due to the rainout effect which involves both condensation efficiency as reflected in inwardly increasing cloud thickness and isotopic exchange between falling droplets and the ambient water vapor. In contrast, water vapor in the cyclone's inner region was isotopically enriched due to weak rainout effect in conjunction with intensive isotopic recharge from the sea spray and sea surface with heavy isotope ratios. Since water vapor mainly acts as a source of precipitation, the isotope ratios of precipitation also had systematic variation. A unique circumstance is the intensity of isotopic exchange with almost saturated surface air and high winds, causing anomalously high isotope ratios and low d-excess values in the cyclone's inner region. "

"This paper presents a hypothesis that soil moisture (SM) and precipitation (P) interactions over the Southwest depend on sea surface temperature anomalies (SSTAs). On the basis of moisture transport and geography, the Southwest can be separated into two regions. The western region (32°–36°N, 107.5°–113°W) includes Arizona and western New Mexico and the eastern region (32°–36°N, 103°–107°W) includes eastern New Mexico. For both regions, years from 1900 to 2004 are classified based on the winter to summer P evolution. When winter and the following summer P anomalies have an inverse relationship, SSTAs do not persist. The summer SSTAs have strong influence on P. Soil moisture does not play a major role in modulating P anomalies. For cases that wetness (dryness) occurs in both winter and the following summer, the SSTA forcing associated with the P regime tends to persist. Positive SM-P feedbacks enhance P anomalies. For eastern New Mexico, there is a linear relationship between SM anomalies in spring and P anomalies in summer when SSTAs persist. "

..."These results indicate that the MJO and its associated cloudiness, rainfall, and circulation variability systematically influence the variability in remote sensing aerosol retrieval results. Several physical and retrieval algorithmic factors that may contribute to the observed aerosol-rainfall relationships are discussed. Preliminary analysis indicates that cloud contamination in the aerosol retrievals is likely to be a major contributor to the observed relationships, although we cannot exclude possible contributions from other physical mechanisms. Future research is needed to fully understand these complex aerosol-rainfall relationships. "