Deng, Y., Park, T. - W., & Cai, M. (2013). Radiative and Dynamical Forcing of the Surface and Atmospheric Temperature Anomalies Associated with the Northern Annular Mode. J. Climate, 26(14), 5124–5138.
Abstract: On the basis of the total energy balance within an atmosphere-surface column, an attribution analysis is conducted for the Northern Hemisphere (NH) atmospheric and surface temperature response to the northern annular mode (NAM) in boreal winter. The local temperature anomaly in the European Centre for Medium-Range Weather Forecasts (ECMWF) Interim Re-Analysis (ERA-Interim) is decomposed into partial temperature anomalies because of changes in atmospheric dynamics, water vapor, clouds, ozone, surface albedo, and surface dynamics with the coupled atmosphere-surface climate feedback-response analysis method (CFRAM). Large-scale ascent/descent as part of the NAM-related mean meridional circulation anomaly adiabatically drives the main portion of the observed zonally averaged atmospheric temperature response, particularly the tropospheric cooling/warming over northern extratropics. Contributions from diabatic processes are generally small but could be locally important, especially at lower latitudes where radiatively active substances such as clouds and water vapor are more abundant. For example, in the tropical upper troposphere and stratosphere, both cloud and ozone forcings are critical in leading to the observed NAM-related temperature anomalies. Radiative forcing due to changes in water vapor acts as the main driver of the surface warming of southern North America during a positive phase of NAM, with atmospheric dynamics providing additional warming. In the negative phase of NAM, surface albedo change drives the surface cooling of southern North America, with atmospheric dynamics providing additional cooling. Over the subpolar North Atlantic and northern Eurasia, atmospheric dynamical processes again become the largest contributor to the NAM-related surface temperature anomalies, although changes in water vapor and clouds also contribute positively to the observed surface temperature anomalies while change in surface dynamics contributes negatively to the observed temperature anomalies.
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Silva, J. A., & Matyas, C. J. (2014). Relating Rainfall Patterns to Agricultural Income: Implications for Rural Development in Mozambique. Wea. Climate Soc., 6(2), 218–237.
Abstract: Rural farmers in Mozambique rely on rain-fed agriculture for food and income, yet they experience high rainfall variability ranging from extreme drought to flooding rainfall from tropical cyclone systems. To explore linkages between rainfall and agriculture, the authors regress changes in annual household per capita agricultural income on reliance on staple food crops, agricultural and demographic characteristics, and rainfall patterns using longitudinal data for rural households for 2002 and 2005. They characterize rainfall patterns by defining nine rainfall zones using the percent of normal rainfall received in each month of three agricultural growing seasons and rainfall from two tropical cyclones that occurred during the study period. Results show that in a period where monthly rainfall seldom occurred in normal amounts, most households experienced decreases in agricultural income. Even after controlling for rainfall patterns, they find that greater household dependency on staple crop agriculture is associated with declining annual agricultural income. They also find that areas affected by both wet and dry rainfall extremes in the first year of the study had decreases in the well-being of rural households when measured two years later. Taken together, their findings suggest that antipoverty policies focused on increasing agricultural income seem likely to fail in countries characterized by highly variable rainfall and exposure to extreme events, particularly when coupled with high levels of poverty and widespread dependence on rain-fed agriculture.
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