Previous studies have shown that when the MJO main convective envelope is over the Indian Ocean, rainfall and its diurnal cycle over the land in the Maritime Continent reach their maxima due to an increase in the atmospheric instability caused by strong solar insolation in the clearer skies and moistening environment (e.g., Fujita et al. 2011; Peatman et al. 2014; Birch et al. 2016).
The enhanced Asian summer monsoon during the MWP, as compared to the LIA, is associated with larger land sea temperature contrasts (e.g., Man et al. 2012; Shi et al., 2016a, b) induced by strong summertime insolation (Fig. 1; detailed in the Methods section).
Some consider heath and thus shallow soils as favouring west-facing slopes, which are expected to experience drier microclimates due to insolation, strong and desiccating winds, and severe summer fires.
However, why is the insolation stronger in the rainy and cloudy season?
The Atlantic Forest represents an excellent opportunity to test phylogeographic hypotheses, because it has a wide range of vegetation types, including unforested habitats covered predominantly by herbaceous and shrubby plants, which are strongly influenced by the harsh environment with strong wind and high insolation.
This discrepancy between the strong variation of terrestrial insolation reported in [ 1] and the energy budget at Earth's surface suggests that the data analysis in [ 1] is biased by systematic effects not related to solar activity changes, a hypothesis which will be explored in the next section.
The ideal characteristics for dust devil breeding grounds are (1) intense surface heating through insolation and a strong near-surface superadiabatic temperature lapse rate; (2) smooth arid terrain with some rock cover but few trees, buildings, or grassy areas; and (3) relatively level to gently sloping topography [ Balme and Greeley, 2006; Kurgansky et al., 2011].
When compared to the results of regression analyses using annual mean values, a stronger association between latitude and insolation (r2 = 0.80; p<0.001) is observed for winter months, which is in agreement with the findings of Kimlin and colleagues [11].
Since the corresponding variations in total solar irradiance on top of the atmosphere are accurately determined from satellite observations to be of the order of 0.1% only [ 2], the one order of magnitude stronger effect in the terrestrial insolation data was interpreted as evidence for cosmic-ray induced aerosol formation in the atmosphere.
We also show that, consistent with paleoclimate model simulations, Southeast Asia experienced dry conditions during the early Holocene summer insolation maxima, despite the strong Asian Monsoon at that time, thus highlighting that Asian monsoon strength and regional precipitation do not always co-vary.
