  It is now becoming widely accepted that photon recoil forces from the
asymmetric reflection and thermal re-radiation of absorbed sunlight are,
together with collisions and gravitational forces, primary mechanisms governing
the dynamical and physical evolution of asteroids. The Yarkovsky effect causes
orbital semi-major axis drift and the YORP effect causes changes in the
rotation rate and pole orientation. We present an adaptation of the Advanced
Thermophysical Model (ATPM) to simultaneously predict the Yarkovsky and YORP
effects in the presence of thermal-infrared beaming caused by surface
roughness, which has been neglected or dismissed in all previous models. Tests
on Gaussian random sphere shaped asteroids, and on the real shapes of asteroids
(1620) Geographos and (6489) Golevka, show that rough surface thermal-infrared
beaming enhances the Yarkovsky orbital drift by typically tens of percent but
it can be as much as a factor of two. The YORP rotational acceleration is on
average dampened by up to a third typically but can be as much as one half. We
find that the Yarkovsky orbital drift is only sensitive to the average degree,
and not to the spatial distribution, of roughness across an asteroid surface.
However, the YORP rotational acceleration is sensitive to the surface roughness
spatial distribution, and can add significant uncertainties to the predictions
for asteroids with relatively weak YORP effects. To accurately predict either
effect the degree and spatial distribution of roughness across an asteroid
surface must be known.
