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Deep Convective Clouds (DCC) and clusters of DCC constitute classes of extreme precipitation events related to storms. DCC in the tropical zone are identified with the Atmospheric Infrared Sounder (AIRS) as spectra where the cloud top temperatures are less than 225K and the water lines are inverted. Between 2002-2012 the frequency of DCC has increased by 2% /year for the tropical lands, but has decreased by 1% /year for the tropical oceans, such that the tropical land/ocean combined trend in the frequency of DCC has changed by less than 0.2%/year. A similar pattern of land/ocean opposite trends is seen for the size and the frequency of DCC clusters. With the assumption that the count of DCC clusters and the mean size of DCC clusters are proxies for the severity of storms, severe storms have weakened for the oceans, but strengthened for land. Since a large fraction of the annual regional precipitation is associated with severe storms, the observed globally zero, but land/ocean opposite trends in DCC frequency may be interpreted as a shift in precipitation from ocean to land. The correlation of DCC and DCC cluster frequency with the Nino34 index for ocean and the anti-correlation for land suggests that the observed changes are part of a decadal variability.

A 90-100 year cycle in the sunspot number, geomagnetic activity, occurrence of midlatitude auroras and large fluence Solar Energetic Particle events has been widely reported. However the importance of this cycle, which we call the Centennial Gleissberg Cycle (CGC), for Space Weather had not received proper attention until the recent occurrence of the deep minimum during the transition from the 23rd to 24th 11-year solar cycle. This deep minimum validated the earlier CGC minima that occurred in the beginning of the 20th century and 19th century (the Dalton minimum). In this note we will describe the CGC patterns of variation in sunspot numbers, geomagnetic activity and auroras and the observed effects on the frequency and intensity of Space Weather events. We will also comment on what this implies for Space Weather during the next 30 years.

We discuss a source for high-frequency Alfven waves, associated with twisted magnetic loops emerging on the solar surface and reconnecting with the open field. We identify the loops with the ephemeral regions (small-scale bipoles) observed by ground-based instruments and by SOHO. To characterize the loops we employ the concept of a minimum energy state for topologically complex fields. Our estimates of the power that can be released and the range of wave frequencies marginally agree with models of coronal heating and acceleration of the solar wind by high-frequency Alfven waves. We suggest that severe requirements on the upper-bound frequency, used in these models, can be relaxed by taking into account the energy released due to reconnections within magnetic loops whose footpoints are twisted by surface convective motions. This presentation updates our more extended discussion of the source of coronal heating (1).

The fluctuations in solar-wind velocity measured by the Ulysses spacecraft above the polar regions of the Sun are organized into structures called microstreams. The application of wavelet transformations to the Ulysses data reveals the scales and positions of the microstreams and their association with variations in the helium content of the solar wind. It is concluded that the microstreams must have their origin in solar structures associated with the acceleration of the solar wind with little modification resulting from interplanetary phenomena.

The origin of the 1/f low-frequency spectrum of fluctuations observed in the solar wind is discussed. It is suggested that this spectrum arises due to sampling random perturbations produced at the Sun. The perturbation process is characterized by a power-law distribution. It is pointed out that, due to solar rotation, the sampling is equivalent to scanning across different size scales on the Sun. The limits of the spectrum found from the observations are used to estimate the characteristic scales on the Sun, the scales related to the origin of the solar wind.